Would you believe that we owe our present day continuous flow cell separators (apheresis machines) to an IBM engineer whose son was diagnosed with Leukemia? Well, its true, and this powerpoint presentation takes you through how it all happened
https://drive.google.com/file/d/0B14BC5DZjXDHZGd3d0MtT3h0Mlk/view?usp=sharing
copy and paste the link onto a new tab and press enter.
I've used the IBM 2991/2997 during my very early days in blood component separation and let me tell you, they are (were) engineering marvels! It'll also give you a hint as to how old I must be!
Monday, January 12, 2015
Tuesday, September 3, 2013
Contaminated Platelets - A Major Risk at +22~
Since the advent of blood component therapy in the 1960s and its popularization in the 1970s, one of the gravest problems facing blood transfusion has been the transmission of bacterial and viral diseases through the use of blood.
The viral illnesses that are transmitted via blood transfusion seem to not be much affected by storage conditions, however, the same cannot be said for bacterial and protozoal pathogens. Dangerous bacteria in particular, can thrive and multiply in blood.
We do screen each donated unit to try to detect and then eliminate any disease carrying blood from the supply. The TTI testing has grown in sophistication, sensitivity and specificity to such an extent that very few TTIs actually take place. The concentration in TTI testing is to detect anything commonly pathogenic that is already present in a detectable quantity at the time of donation.
However, what happens to pathogens that are present in the blood and for which we do not routinely do TTI testing, and what happens to the few pathogens that may have entered the blood at the point of donation and then multiply on storage to dangerous levels? The different blood components are stored in different ways. For example, RBCs store well at +4C and this temperature does not encourage most bacterial pathogens to proliferate and so the storage temperature itself does lessen the risk quite a bit for this component. The same is true of FFP as it is commonly stored at -30C or below.
While at first PLT too were stored at +4C, at that temperature they had a shelf life of only 24 hours. The numbers of PLT that we had to discard daily because of this short expiry was mind boggling, and there were also frequent shortages of PLT. However, from the late 1970s onwards, it was recognized that PLT do better when kept at room temperature (20 to 24C). At first, due to limitations of the plastics available, these room temp platelets were discarded after 3 days. However, as our storage technology improved, it was found that PLT could well survive and be useful in transfusion for up to 7 days.
Soon, though, we had to pull back from this 7 day storage as quite a number of PLT units were then found with heavy bacterial contamination. The risks of transfusing such contaminated PLT units should be very obvious, and many deaths and serious illnesses were associated with PLT transfusions. The storage period was therefore limited to 5 days as this somewhat mitigates the ability of bacterial contaminants to proliferate to the very dangerous levels seen in 7 day-old PLT.
Since it was soon recognized that many of the contaminated units were growing skin comensals, we knew that the point of donation, when the phlebotomy needle pierces the skin, was a very probable source for these contaminants. Therefore, most blood banks now take extra care to completely clean the site and surroundings of the venipuncture before starting the bleed (see our earlier blog post on donor prep and see the LinkedIn Blood Components Group discussion here). Another useful practice is to sequester the first few milliliters of blood drawn as that probably contains the 'skin plug' that enters the bore of the phlebotomy needle. This practice is also very useful at reducing the amount of contaminated PLT. In spite of these measures, unfortunately, PLT bacterial contamination continues to be a very major source of transfusion related morbidity and even mortality.
One would think that spotting a unit of PLT that has been heavily contaminated would be easy, but it is not so. There are mostly few, if any, signs that there could be something wrong with the PLT unit.
Furthermore, we have to be able to do any testing with the blood samples drawn at the time of donation or within the closed system itself and this limitation has made practical testing difficult. Very recently we have seen a few tests that can be done at the time of issue or even POC before starting the PLT transfusion. There's a beautiful and detailed PPT on "Enhancement of Bacterial Testing in Platelets" by Mark Edmunds, MD, (Blood Centers of the Pacific) that clearly summarizes the current scene.
Of course, further testing does add to the cost, but compared to the very serious risks involved, we should certainly encourage the development of better and quicker tests for contamination. It's very good to see that some companies have introduced workable tests and that they have also started getting approval in the US (FDA) and in Europe for these tests.
One factor that will help mitigate the additional costs will be the savings of being able to store and issue PLT for the full 7 day period. One would hope that safer PLT can also be made available in developing countries with special pricing and with the encouragement of local entrepreneurs/scientists to help bring the costs down.
Another promising technique that is being explored is to neutralize any pathogens inside the blood unit, and some of these techniques have been introduced and are proving promising, see our LI Group Discussion on this started by Dr. Rashmi Sood.
One would also hope that all PLT units are well enough tested before release from the blood bank that we stop seeing cases of contaminated PLT altogether!
Here are a few online references:
http://www.cdc.gov/bloodsafety/bbp/bacterial-contamination-of-platelets.html
http://www.veraxbiomedical.com/products/platelet-pgd-test.asp https://www.lstream.org/Files/Edmunds.pdf http://www.psbc.org/news/pdf/2012_September_Platelet_Bacterial_Safety.pdf
http://www.youtube.com/watch?v=4uOhFXb4KOk http://www.aabb.org/events/misc/Pages/public-conference.aspx
http://www.cap.org/apps/cap.portal?_nfpb=true&cntvwrPtlt_actionOverride=%2Fportlets%2FcontentViewer%2Fshow&_windowLabel=cntvwrPtlt&cntvwrPtlt{actionForm.contentReference}=cap_today%2Ffeature_stories%2F0905Platelet.html&_state=maximized&_pageLabel=cntvwr
http://www.cap.org/apps/docs/committees/0412_are_those_platelets_safe.pdf
http://www.fenwalinc.com/PressReleases/Pages/News/Verax-Platelet-PGD-Test-Cited-As-Important-Safety-Measure.aspx
Abbreviations:
FFP - Fresh Frozen Plasma
PLT - Platelet Concentrate
POC - Point of Care
RBC - Red Blood Cells (packed red blood cells, packed cells)
TTI - Transfusion Transmitted Diseases, testing
The viral illnesses that are transmitted via blood transfusion seem to not be much affected by storage conditions, however, the same cannot be said for bacterial and protozoal pathogens. Dangerous bacteria in particular, can thrive and multiply in blood.
We do screen each donated unit to try to detect and then eliminate any disease carrying blood from the supply. The TTI testing has grown in sophistication, sensitivity and specificity to such an extent that very few TTIs actually take place. The concentration in TTI testing is to detect anything commonly pathogenic that is already present in a detectable quantity at the time of donation.
However, what happens to pathogens that are present in the blood and for which we do not routinely do TTI testing, and what happens to the few pathogens that may have entered the blood at the point of donation and then multiply on storage to dangerous levels? The different blood components are stored in different ways. For example, RBCs store well at +4C and this temperature does not encourage most bacterial pathogens to proliferate and so the storage temperature itself does lessen the risk quite a bit for this component. The same is true of FFP as it is commonly stored at -30C or below.
While at first PLT too were stored at +4C, at that temperature they had a shelf life of only 24 hours. The numbers of PLT that we had to discard daily because of this short expiry was mind boggling, and there were also frequent shortages of PLT. However, from the late 1970s onwards, it was recognized that PLT do better when kept at room temperature (20 to 24C). At first, due to limitations of the plastics available, these room temp platelets were discarded after 3 days. However, as our storage technology improved, it was found that PLT could well survive and be useful in transfusion for up to 7 days.
Soon, though, we had to pull back from this 7 day storage as quite a number of PLT units were then found with heavy bacterial contamination. The risks of transfusing such contaminated PLT units should be very obvious, and many deaths and serious illnesses were associated with PLT transfusions. The storage period was therefore limited to 5 days as this somewhat mitigates the ability of bacterial contaminants to proliferate to the very dangerous levels seen in 7 day-old PLT.
Since it was soon recognized that many of the contaminated units were growing skin comensals, we knew that the point of donation, when the phlebotomy needle pierces the skin, was a very probable source for these contaminants. Therefore, most blood banks now take extra care to completely clean the site and surroundings of the venipuncture before starting the bleed (see our earlier blog post on donor prep and see the LinkedIn Blood Components Group discussion here). Another useful practice is to sequester the first few milliliters of blood drawn as that probably contains the 'skin plug' that enters the bore of the phlebotomy needle. This practice is also very useful at reducing the amount of contaminated PLT. In spite of these measures, unfortunately, PLT bacterial contamination continues to be a very major source of transfusion related morbidity and even mortality.
One would think that spotting a unit of PLT that has been heavily contaminated would be easy, but it is not so. There are mostly few, if any, signs that there could be something wrong with the PLT unit.
Furthermore, we have to be able to do any testing with the blood samples drawn at the time of donation or within the closed system itself and this limitation has made practical testing difficult. Very recently we have seen a few tests that can be done at the time of issue or even POC before starting the PLT transfusion. There's a beautiful and detailed PPT on "Enhancement of Bacterial Testing in Platelets" by Mark Edmunds, MD, (Blood Centers of the Pacific) that clearly summarizes the current scene.
Of course, further testing does add to the cost, but compared to the very serious risks involved, we should certainly encourage the development of better and quicker tests for contamination. It's very good to see that some companies have introduced workable tests and that they have also started getting approval in the US (FDA) and in Europe for these tests.
One factor that will help mitigate the additional costs will be the savings of being able to store and issue PLT for the full 7 day period. One would hope that safer PLT can also be made available in developing countries with special pricing and with the encouragement of local entrepreneurs/scientists to help bring the costs down.
Another promising technique that is being explored is to neutralize any pathogens inside the blood unit, and some of these techniques have been introduced and are proving promising, see our LI Group Discussion on this started by Dr. Rashmi Sood.
One would also hope that all PLT units are well enough tested before release from the blood bank that we stop seeing cases of contaminated PLT altogether!
Here are a few online references:
http://www.cdc.gov/bloodsafety/bbp/bacterial-contamination-of-platelets.html
http://www.veraxbiomedical.com/products/platelet-pgd-test.asp https://www.lstream.org/Files/Edmunds.pdf http://www.psbc.org/news/pdf/2012_September_Platelet_Bacterial_Safety.pdf
http://www.youtube.com/watch?v=4uOhFXb4KOk http://www.aabb.org/events/misc/Pages/public-conference.aspx
http://www.cap.org/apps/cap.portal?_nfpb=true&cntvwrPtlt_actionOverride=%2Fportlets%2FcontentViewer%2Fshow&_windowLabel=cntvwrPtlt&cntvwrPtlt{actionForm.contentReference}=cap_today%2Ffeature_stories%2F0905Platelet.html&_state=maximized&_pageLabel=cntvwr
http://www.cap.org/apps/docs/committees/0412_are_those_platelets_safe.pdf
http://www.fenwalinc.com/PressReleases/Pages/News/Verax-Platelet-PGD-Test-Cited-As-Important-Safety-Measure.aspx
Abbreviations:
FFP - Fresh Frozen Plasma
PLT - Platelet Concentrate
POC - Point of Care
RBC - Red Blood Cells (packed red blood cells, packed cells)
TTI - Transfusion Transmitted Diseases, testing
Tuesday, February 12, 2013
Donor Prep is Important in Reducing Contaminated Blood Components
The discussion can be followed at the LinkedIn http://linkd.in/V27Da0 group Blood Components on the importance of correctly prepping the phlebotomy site before drawing blood.
A better prestick prep will help reduce contaminated blood components.
Platelet concentrates (PLT) are particularly susceptible as they are stored at 22C which is a temperature favorable for bacterial multiplication.
Some important web resources for this discussion:
Skin antiseptics in venous puncture-site disinfection for prevention of blood culture contamination: systematic review with meta-analysis.
Caldeira, D., et. al., 2011. Journal of Hospital Infection 77(3):223-32.
doi: 10.1016/j.jhin.2010.10.015
Interventions Implemented to Reduce the Risk of Transmission of Bacteria by Transfusion in the English National Blood Service.
McDonald, C.P., 2011. Transfusion Medicine and Hemotherapy 38(4): 255–258.
doi: 10.1159/000330474
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3190222/
Skin disinfection methods: prospective evaluation and postimplementation results.
Ramirez-Arcos, S., Goldman M., 2010. Transfusion 50(1):59-64.
doi: 10.1111/j.1537-2995.2009.02434.x. (abstract)
Reducing the Risk of Transfusion-Transmitted Bacterial Infections in Platelet Concentrates: Current Status and Developments.
Rood, I.G.H., et. al., 2008. LABMEDICINE 39 Number 9
doi: 10.1309/bdnbmdcn7tt2r9f5
http://labmed.ascpjournals.org/content/39/9/553.full.pdf (CE Update)
Bacterial persistence on blood donors' arms after phlebotomy site preparation: analysis of risk factors.
Cid, J., et. al., 2003. Haematologica 88:839-840
http://www.haematologica.it/content/88/7/839.full.pdf (Letters to the editor)
Evaluation of donor arm disinfection techniques.
Mcdonald, C.P., et.al. 2001, Vox Sanguinis 80, 135-141
http://basiswebnet.chu-lyon.fr/cons/doc01/0009617.pdf
Evaluation of donor skin disinfection methods.
Goldman, M., et. al., 1997. Transfusion 37(3):309-12
http://www.ncbi.nlm.nih.gov/pubmed/9122905 (abstract)
I'm including in full the latest guidance issued by AABB:
Early strategy focused on moving the membership away from the use of
green soap to prepare venipuncture sites and toward the use of pouches
that divert the first milliliters of blood withdrawn from the donor,
potentially containing a contaminated skin plug, into tubes used for
testing rather than flowing into a collection bag.
BB/TS Standard 5.1.5.1 was published in 2003 in the 22nd ed. with an effective date of March 1, of 2004. Practically, the result of implementation of Standard 5.1.5.1. was detection of bacterial contamination in apheresis platelets by culture-based methods. Eventually this included pre-storage pooled whole blood-derived platelets. Remaining whole blood-derived platelets were evaluated using a variety of methods including the use of pH and glucose readings, as well as observation of swirling.
Association Bulletin #03-12 issued October 1, 2003 – Further Guidance on Methods to Detect Bacterial Contamination of Platelet Components – was a comprehensive document that provided the membership with 1) background information on the risk to recipient safety posed by bacterial contamination of platelets and the underpinnings of the approaches that had been considered to limit and detect contamination, 2) practical guidance on the implementation of some of the techniques, and 3) sample plans and algorithms.
Association Bulletin #04-07 issued October 14, 2004 – Actions Following an Initial Positive Test for Possible Bacterial Contamination of a Platelet Unit – is still an active bulletin.
Association Bulletin #09-04 issued July 20, 2009 – Developments in Bacterial Testing and BBTS Standard 5.1.5.1. – reviewed what was then the current status of technology available to meet the intent of Standard 5.1.5.1 and provided an update on new technologies in development that would offer an alternate method for meeting the standard. It also informed members that once studies demonstrated the efficacy of an alternate method in detecting bacteria in whole blood-derived platelets (similar to the studies required for FDA approval), AABB would likely adopt a more prescriptive interim standard.
BB/TS Interim Standard 5.1.5.1.1 was announced in Association Bulletin #10-02 issued May 3, 2010 and became effective January 31, 2011. The Standard was subsequently published in the 27th edition.
Association Bulletin #10-05 issued August 19, 2010 – Suggested Options For Transfusion Services and Blood Collectors to Facilitate Implementation of BB/TS Interim Standard 5.1.5.1.1 – was published to assist transfusion services with making a complete transition away from surrogate testing (pH and glucose) to culture-based or rapid immunoassay (point-of-issue) bacterial screening. Another option provided was use of approaches or methods that were not FDA-cleared but that had been validated to be of equivalent clinical sensitivity to an approved assay.
In July of this year AABB provided the opportunity for public discussion of issues surrounding the remaining residual risk of bacterial contamination of platelet components. While a variety of experiences and data were presented and discussed, the focus of the workshop was apheresis platelets and the impact secondary screening for bacterial contamination has had and might have if more broadly applied. FDA did not co-sponsor the workshop but was represented on the planning committee. As follow-up to the public conference AABB is reviewing its current policy and will issue further recommendations in an Association Bulletin.
Because AABB recognizes the remaining residual risk of bacterial contamination in apheresis platelets, the association welcomes guidance from FDA on ways to reduce this risk. Multiple approaches, in addition to those proposed by FDA today, require careful consideration. Any further actions, however, must be validated as to their efficacy and impact on patients who depend on platelets for treatment. Specifically, no change should be advocated in the absence of a careful evaluation of the impact on platelet availability.
http://www.aabb.org/pressroom/statements/Pages/statement092112.aspx as viewed Feb 12, 2013.
As I understand the current status of India's SOPs governing phlebotomy procedures for blood banks, each blood bank has to develop and have approved their own SOPs. The guidelines do refer to phlebotomy as follows:
D. MAINTENANCE ;
The premises shall be maintained in a clean and proper manner to ensure adequate cleaning and maintenance of proper operations. The facilities shall include –
( 1) Privacy and thorough examination of individuals to determine their suitability as donors.
(2) Collection of blood from donors with minimal risk of contamination or exposure to activities and equipment unrelated to blood collection.
G. GOOD MANUFACTURING PRACTICES (GMPs)/STANDARD OPERATING PROCEDURES (SOPs):
Written Standard Operating Procedures shall be maintained and shall include all steps to be followed in the collection, processing, compatibility testing, storage and sale or distribution of blood and/or preparation of blood components for homologous transfusion, autologous transfusion and further manufacturing purposes. Such procedures shall be available to the personnel for use in the concerned areas. The Standard Operating Procedures shall inter alia include :
1. (a) criteria used to determine donor suitability.
(b) methods of performing donor qualifying tests and measurements Including minimum and maximum values for a test or procedure, when a factor in determining acceptability;
(c) solutions and methods used to prepare the site of phlebotomy so as to give maximum assurance of a sterile container of blood;
(d) method of accurately relating the product(s) to the donor;
(e) blood collection procedure, including in-process precautions taken to measure accurately the quantity of blood drawn from the donor;
H. CRITERIA FOR BLOOD DONATION :
Conditions for donation of blood :
( 1) General -No person shall donate blood and no blood bank shall draw blood from a person, more than once in three months. The donor shall be in good health, mentally alert and physically fit and shall not be inmates of jail, persons having multiple sex partners and drug-addicts. The donors shall fulfill the following requirements, namely :-
(a) the donor shall be in the age group of 18 to 60 years.
(b) the donor shall not be less than 45 kilograms;
(c) temperature and Pulse of the donor shall be normal;
(d) the systolic and diastolic blood pressures are within normal limits without medication;
(e) haemoglobin which shall not be less than 12.5 grams;
(f) the donor shall be free from acute respiratory diseases;
(g) the donor shall be free from any skin diseases at the site of phlebotomy ;
(h) the donor shall be free from any disease transmissible by blood transfusion, insofar as can be determined by history and examination indicated above;
(i) the arms and forearms of the donor shall be free from skin punctures or scars indicative of professional blood donors or addiction of self injected narcotics
http://cdsco.nic.in/html/guideline.htm as viewed on Feb 12, 2013.
I welcome suggestions for inclusion of other articles or copies of SOPs that may be helpful to this discussion.
A better prestick prep will help reduce contaminated blood components.Platelet concentrates (PLT) are particularly susceptible as they are stored at 22C which is a temperature favorable for bacterial multiplication.
Some important web resources for this discussion:
Skin antiseptics in venous puncture-site disinfection for prevention of blood culture contamination: systematic review with meta-analysis.
Caldeira, D., et. al., 2011. Journal of Hospital Infection 77(3):223-32.
doi: 10.1016/j.jhin.2010.10.015
Interventions Implemented to Reduce the Risk of Transmission of Bacteria by Transfusion in the English National Blood Service.
McDonald, C.P., 2011. Transfusion Medicine and Hemotherapy 38(4): 255–258.
doi: 10.1159/000330474
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3190222/
Skin disinfection methods: prospective evaluation and postimplementation results.
Ramirez-Arcos, S., Goldman M., 2010. Transfusion 50(1):59-64.
doi: 10.1111/j.1537-2995.2009.02434.x. (abstract)
Reducing the Risk of Transfusion-Transmitted Bacterial Infections in Platelet Concentrates: Current Status and Developments.
Rood, I.G.H., et. al., 2008. LABMEDICINE 39 Number 9
doi: 10.1309/bdnbmdcn7tt2r9f5
http://labmed.ascpjournals.org/content/39/9/553.full.pdf (CE Update)
Bacterial Contamination of Blood Components.
Brecher, M.E., Hay, S.N., 2005. Clinical Microbiology Rev. 18(1): 195–204.
doi: 10.1128/CMR.18.1.195-204.2005
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC544173/Bacterial persistence on blood donors' arms after phlebotomy site preparation: analysis of risk factors.
Cid, J., et. al., 2003. Haematologica 88:839-840
http://www.haematologica.it/content/88/7/839.full.pdf (Letters to the editor)
Evaluation of donor arm disinfection techniques.
Mcdonald, C.P., et.al. 2001, Vox Sanguinis 80, 135-141
http://basiswebnet.chu-lyon.fr/cons/doc01/0009617.pdf
Evaluation of donor skin disinfection methods.
Goldman, M., et. al., 1997. Transfusion 37(3):309-12
http://www.ncbi.nlm.nih.gov/pubmed/9122905 (abstract)
I'm including in full the latest guidance issued by AABB:
Statement Before BPAC on Considerations for Options to Further Reduce the Risk of Bacterial Contamination in Platelets
21 September 2012 Considerations for Options to Further Reduce the Risk of Bacterial Contamination in Platelet. M. Allene Carr-Greer, Director, Regulatory Affairs
AABB
is an international, not-for-profit association representing
individuals and institutions involved in the field of transfusion
medicine and cellular therapies. The association is committed to
improving health by developing and delivering standards, accreditation
and educational programs that focus on optimizing patient and donor care
and safety. AABB membership consists of nearly 2,000 institutions and
8,000 individuals, including physicians, nurses, scientists,
researchers, administrators, medical technologists and other health care
providers. AABB members are located in more than 80 countries. AABB thanks you for the opportunity to speak today. We also wish to
thank the Food and Drug Administration for addressing the issue of
bacterial contamination of platelet components in a public venue. AABB
has addressed this issue on several fronts during the past decade and we
appreciate the opportunity to provide a record for this meeting of the
actions AABB has required member facilities to take to limit and detect
bacterial contamination in platelet components and of education provided
to the membership to support implementation of the various requirements
and recommendations.AABB strategies have been developed using the expertise of members of
its Bacterial Contamination Task Force, Transfusion Transmitted
Diseases Committee, and Blood Bank and Transfusion Service Standards
Program Unit. The method for AABB policy and requirements to be
communicated to accredited members is through publication of Association
Bulletins and development of Standards. The current requirements of an
accredited AABB member, applicable to today's discussion, as published
in Standards for Blood Banks and Transfusion Services (28th edition) are listed here. The standards were also applicable in the 27th edition.
| 5.1.5 | Sterility | |||
| Aseptic methods shall be employed to minimize the risk of microbial contamination of blood and blood components. Equipment and solutions that come into direct contact with blood or blood components shall be sterile and pyrogen-free. Single-use equipment shall be used whenever possible. | ||||
| 5.1.5.1 | The blood bank or transfusion service shall have methods to limit and to detect or inactivate bacteria in all platelet components. Standard 5.6.2 applies. | |||
| 5.1.5.1.1 | Detection methods shall either be approved by the FDA or be validated to provide sensitivity equivalent to FDA-approved methods. | |||
| 5.1.5.2 | When a true-culture positive result is obtained and an appropriate specimen is available, additional testing to identify the organism shall be performed. Additional testing and followup shall be defined. Standards 5.2.4 and 7.1 to 7.1.4 apply. | |||
| 5.6 | Blood Collection | |||
| 5.6.1 | Methods | |||
| Blood shall be collected into a sterile closed system. | ||||
| 5.6.2 | Protection Against Contamination | |||
| The venipuncture site shall be prepared so as to minimize risk of bacterial contamination. Green soap (USP) shall not be used. | ||||
| 5.6.2.1 | Blood collection containers with draw line (inlet) diversion pouches shall be used for any collection of platelets, including whole blood from which platelets are made. | |||
BB/TS Standard 5.1.5.1 was published in 2003 in the 22nd ed. with an effective date of March 1, of 2004. Practically, the result of implementation of Standard 5.1.5.1. was detection of bacterial contamination in apheresis platelets by culture-based methods. Eventually this included pre-storage pooled whole blood-derived platelets. Remaining whole blood-derived platelets were evaluated using a variety of methods including the use of pH and glucose readings, as well as observation of swirling.
Association Bulletin #03-12 issued October 1, 2003 – Further Guidance on Methods to Detect Bacterial Contamination of Platelet Components – was a comprehensive document that provided the membership with 1) background information on the risk to recipient safety posed by bacterial contamination of platelets and the underpinnings of the approaches that had been considered to limit and detect contamination, 2) practical guidance on the implementation of some of the techniques, and 3) sample plans and algorithms.
Association Bulletin #04-07 issued October 14, 2004 – Actions Following an Initial Positive Test for Possible Bacterial Contamination of a Platelet Unit – is still an active bulletin.
Association Bulletin #09-04 issued July 20, 2009 – Developments in Bacterial Testing and BBTS Standard 5.1.5.1. – reviewed what was then the current status of technology available to meet the intent of Standard 5.1.5.1 and provided an update on new technologies in development that would offer an alternate method for meeting the standard. It also informed members that once studies demonstrated the efficacy of an alternate method in detecting bacteria in whole blood-derived platelets (similar to the studies required for FDA approval), AABB would likely adopt a more prescriptive interim standard.
BB/TS Interim Standard 5.1.5.1.1 was announced in Association Bulletin #10-02 issued May 3, 2010 and became effective January 31, 2011. The Standard was subsequently published in the 27th edition.
Association Bulletin #10-05 issued August 19, 2010 – Suggested Options For Transfusion Services and Blood Collectors to Facilitate Implementation of BB/TS Interim Standard 5.1.5.1.1 – was published to assist transfusion services with making a complete transition away from surrogate testing (pH and glucose) to culture-based or rapid immunoassay (point-of-issue) bacterial screening. Another option provided was use of approaches or methods that were not FDA-cleared but that had been validated to be of equivalent clinical sensitivity to an approved assay.
In July of this year AABB provided the opportunity for public discussion of issues surrounding the remaining residual risk of bacterial contamination of platelet components. While a variety of experiences and data were presented and discussed, the focus of the workshop was apheresis platelets and the impact secondary screening for bacterial contamination has had and might have if more broadly applied. FDA did not co-sponsor the workshop but was represented on the planning committee. As follow-up to the public conference AABB is reviewing its current policy and will issue further recommendations in an Association Bulletin.
Because AABB recognizes the remaining residual risk of bacterial contamination in apheresis platelets, the association welcomes guidance from FDA on ways to reduce this risk. Multiple approaches, in addition to those proposed by FDA today, require careful consideration. Any further actions, however, must be validated as to their efficacy and impact on patients who depend on platelets for treatment. Specifically, no change should be advocated in the absence of a careful evaluation of the impact on platelet availability.
http://www.aabb.org/pressroom/statements/Pages/statement092112.aspx as viewed Feb 12, 2013.
As I understand the current status of India's SOPs governing phlebotomy procedures for blood banks, each blood bank has to develop and have approved their own SOPs. The guidelines do refer to phlebotomy as follows:
D. MAINTENANCE ;
The premises shall be maintained in a clean and proper manner to ensure adequate cleaning and maintenance of proper operations. The facilities shall include –
( 1) Privacy and thorough examination of individuals to determine their suitability as donors.
(2) Collection of blood from donors with minimal risk of contamination or exposure to activities and equipment unrelated to blood collection.
G. GOOD MANUFACTURING PRACTICES (GMPs)/STANDARD OPERATING PROCEDURES (SOPs):
Written Standard Operating Procedures shall be maintained and shall include all steps to be followed in the collection, processing, compatibility testing, storage and sale or distribution of blood and/or preparation of blood components for homologous transfusion, autologous transfusion and further manufacturing purposes. Such procedures shall be available to the personnel for use in the concerned areas. The Standard Operating Procedures shall inter alia include :
1. (a) criteria used to determine donor suitability.
(b) methods of performing donor qualifying tests and measurements Including minimum and maximum values for a test or procedure, when a factor in determining acceptability;
(c) solutions and methods used to prepare the site of phlebotomy so as to give maximum assurance of a sterile container of blood;
(d) method of accurately relating the product(s) to the donor;
(e) blood collection procedure, including in-process precautions taken to measure accurately the quantity of blood drawn from the donor;
H. CRITERIA FOR BLOOD DONATION :
Conditions for donation of blood :
( 1) General -No person shall donate blood and no blood bank shall draw blood from a person, more than once in three months. The donor shall be in good health, mentally alert and physically fit and shall not be inmates of jail, persons having multiple sex partners and drug-addicts. The donors shall fulfill the following requirements, namely :-
(a) the donor shall be in the age group of 18 to 60 years.
(b) the donor shall not be less than 45 kilograms;
(c) temperature and Pulse of the donor shall be normal;
(d) the systolic and diastolic blood pressures are within normal limits without medication;
(e) haemoglobin which shall not be less than 12.5 grams;
(f) the donor shall be free from acute respiratory diseases;
(g) the donor shall be free from any skin diseases at the site of phlebotomy ;
(h) the donor shall be free from any disease transmissible by blood transfusion, insofar as can be determined by history and examination indicated above;
(i) the arms and forearms of the donor shall be free from skin punctures or scars indicative of professional blood donors or addiction of self injected narcotics
http://cdsco.nic.in/html/guideline.htm as viewed on Feb 12, 2013.
I welcome suggestions for inclusion of other articles or copies of SOPs that may be helpful to this discussion.
Thursday, September 13, 2012
Platelet Concentrate, How to Maintain Quality
The new discussion on the Blood Components group at LinkedIn on producing good quality platelet concentrates (PLT) is of very great importance. PLT is considered something of a mystery to many blood bankers and with good reason. I thought of sharing a few tips here in support of this discussion.
In the first place, there are so many methods of making PLT (see the previous post). But, that's only the beginning of the confusion. Many manufacturers the world over make blood bank centrifuges. Each manufacturer offers a number of different rotors - 4, 6, 8, and 12 place rotors are all fairly common. In each case, the way the individual centrifuge spins its rotor (the g profile) is different. So, making random donor platelets (the commonest procedure) varies widely from blood bank to blood bank. In general, though, for the first spin (platelet rich plasma or PRP method) we need to keep the g under 1000 to ensure that the g force itself does the least damage to the PLT. In each case, for a given g force, the spin time will vary. Some centrifuges have advanced braking systems, so the time to a complete stop after the spin is lessened. In other cases one has to wait patiently for the rotor to come to a complete halt.
Removing the blood bags from the centrifuge smoothly and without shake is of very great importance. Be sure to give your techs plenty of hands on training before allowing them to work with 'real' blood components. Contamination of the PLT with RBCs and with buffy-coat elements has to be minimized. Then, the technicians have to be very careful when expressing the PRP into the satelite bags not to attempt to take too much buffy-coat so as to avoid RBC contamination. Ideally a PLT of 50 to 70 mL should have less than 0.5 mL of RBC in it. The second spin yields the platelet concentrate (PLT) and platelet poor plasma. In this spin, again the g force needs to be kept as low as possible but should yield a good button of platelets which then have to be left for a short time to rest before resuspension. It's best to use a weighing device to precisely leave 50 mL (sometimes 70 mL) of plasma behind in the3 PLT bag.
For storage over 2 days, special plastic must be used which breathes and allows a high enough O2 concentration to maintain the pH in an ideal range. In situations like dengue hemorrhagic fever, or with directed donations (say for patients on chemo) where the platelets will be used within 48 hours, a lot of money can be saved for the patients by using 'ordinary' plastic double or triple bags.
At this stage, once the rest period is over, the PLT should SWIRL. this is of critical importance. Hold the PLT bag up to the light and look for the swirl. If it's not there after 2-4 hours of rest, that PLT unit should be discarded!
Some blood banks use the buffy-coat method, and here a short very hard spin is first used to produce RBC with platelets and leaving the majority of the white cells in the platelet poor plasma layer. Then a soft spin of the RBC yields the platelets in the buffy coat. This procedure, using a top and bottom bag, is common in the US. These bags are costlier and the pooling of buffy-coats that is usually required involves the use of SCDs, but when a leukocyte filter is included you do end up with an excellent product and still less costly than when using an apheresis (cell separator) technique.
These are some basic points that I have found useful. It is a deep and fascinating subject, and I am sure that many of you may have some points to add. Comment below, or even better, submit a separate write up for publication here.
ClinLab Navigator has a short recent (2012) summary: http://www.clinlabnavigator.com/platelet-concentrates.html?letter=P
Towards targeting platelet storage lesion-related signaling pathways Blood Transfusion 2010 June; 8(Suppl 3): s69–s72. Peter Schubert and Dana V. Devine
Evidence-Based Platelet Transfusion Guidelines HEMATOLOGY: January 1, 2007 vol. 2007 no. 1 172-178 Sherrill J. Slichter, MD, Director, Platelet Transfusion Research, Puget Sound Blood Center, 921 Terry Avenue, Seattle, WA 98104-1256; phone (206) 292-6541; fax (206) 292-8030; sjslichter@psbc.org
In vitro assessment of platelet storage lesion in leucoreduced random donor platelet concentrates Blood Transfusion 2010 January; 8(1): 28–35. Amal S. Ahmed, Ola Leheta, and Soha Younes
2 videos that demo the platelet swirl:
In the first place, there are so many methods of making PLT (see the previous post). But, that's only the beginning of the confusion. Many manufacturers the world over make blood bank centrifuges. Each manufacturer offers a number of different rotors - 4, 6, 8, and 12 place rotors are all fairly common. In each case, the way the individual centrifuge spins its rotor (the g profile) is different. So, making random donor platelets (the commonest procedure) varies widely from blood bank to blood bank. In general, though, for the first spin (platelet rich plasma or PRP method) we need to keep the g under 1000 to ensure that the g force itself does the least damage to the PLT. In each case, for a given g force, the spin time will vary. Some centrifuges have advanced braking systems, so the time to a complete stop after the spin is lessened. In other cases one has to wait patiently for the rotor to come to a complete halt.
Removing the blood bags from the centrifuge smoothly and without shake is of very great importance. Be sure to give your techs plenty of hands on training before allowing them to work with 'real' blood components. Contamination of the PLT with RBCs and with buffy-coat elements has to be minimized. Then, the technicians have to be very careful when expressing the PRP into the satelite bags not to attempt to take too much buffy-coat so as to avoid RBC contamination. Ideally a PLT of 50 to 70 mL should have less than 0.5 mL of RBC in it. The second spin yields the platelet concentrate (PLT) and platelet poor plasma. In this spin, again the g force needs to be kept as low as possible but should yield a good button of platelets which then have to be left for a short time to rest before resuspension. It's best to use a weighing device to precisely leave 50 mL (sometimes 70 mL) of plasma behind in the3 PLT bag.
For storage over 2 days, special plastic must be used which breathes and allows a high enough O2 concentration to maintain the pH in an ideal range. In situations like dengue hemorrhagic fever, or with directed donations (say for patients on chemo) where the platelets will be used within 48 hours, a lot of money can be saved for the patients by using 'ordinary' plastic double or triple bags.
At this stage, once the rest period is over, the PLT should SWIRL. this is of critical importance. Hold the PLT bag up to the light and look for the swirl. If it's not there after 2-4 hours of rest, that PLT unit should be discarded!
Some blood banks use the buffy-coat method, and here a short very hard spin is first used to produce RBC with platelets and leaving the majority of the white cells in the platelet poor plasma layer. Then a soft spin of the RBC yields the platelets in the buffy coat. This procedure, using a top and bottom bag, is common in the US. These bags are costlier and the pooling of buffy-coats that is usually required involves the use of SCDs, but when a leukocyte filter is included you do end up with an excellent product and still less costly than when using an apheresis (cell separator) technique.
These are some basic points that I have found useful. It is a deep and fascinating subject, and I am sure that many of you may have some points to add. Comment below, or even better, submit a separate write up for publication here.
ClinLab Navigator has a short recent (2012) summary: http://www.clinlabnavigator.com/platelet-concentrates.html?letter=P
Towards targeting platelet storage lesion-related signaling pathways Blood Transfusion 2010 June; 8(Suppl 3): s69–s72. Peter Schubert and Dana V. Devine
Evidence-Based Platelet Transfusion Guidelines HEMATOLOGY: January 1, 2007 vol. 2007 no. 1 172-178 Sherrill J. Slichter, MD, Director, Platelet Transfusion Research, Puget Sound Blood Center, 921 Terry Avenue, Seattle, WA 98104-1256; phone (206) 292-6541; fax (206) 292-8030; sjslichter@psbc.org
In vitro assessment of platelet storage lesion in leucoreduced random donor platelet concentrates Blood Transfusion 2010 January; 8(1): 28–35. Amal S. Ahmed, Ola Leheta, and Soha Younes
2 videos that demo the platelet swirl:
Abstracts:
Past and future approaches to assess the quality of platelets for transfusion.
Transfusion Medicine Review. 2007 Oct;21(4):295-306.
Maurer-Spurej E, Chipperfield K. emaurer@interchange.ubc.ca
Transfusion Medicine Review. 2007 Oct;21(4):295-306.
Maurer-Spurej E, Chipperfield K. emaurer@interchange.ubc.ca
Suitability of measurement of swirling as a marker of platelet shape change in concentrates
stored for transfusion.
Platelets. 2006 Sep;17(6):393-6.
Mathai J, Resmi KR, Sulochana PV, Sathyabhama S, Baby Saritha G, Krishnan LK. jaisym@sctimst.ker.nic.in
stored for transfusion.
Platelets. 2006 Sep;17(6):393-6.
Mathai J, Resmi KR, Sulochana PV, Sathyabhama S, Baby Saritha G, Krishnan LK. jaisym@sctimst.ker.nic.in
Monday, September 3, 2012
Platelet Concentrate Preparations, Brief Comparison
When platelets are in demand, the options are:
- Random Donor Platelets RDPc.
- Single Donor Platelets SDPc-A (automated apheresis or cell separator processed)
- Single Donor Platelets SDPc-M (manual apheresis)
- Pooled Buffy Coat Platelets (PBCPc)
There is little doubt that quality-wise the Single Donor Platelet concentrates win hands down over the other options both for quality of product and safety. However, in the automated process (using cell separators) cost can be a major inhibiting factor, especially in developing countries. Now, with the US dollar on the rise against most currencies, this becomes an even bigger problem as both the equipment and the single use disposables costs have jumped upwards between 15% to 20% just over the last 6 months. In Pakistan a kit can cost 15,000, while in India it's typically 12,000, for one popular brand.
Manually processed single donor platelets are now a good option to explore. Of course, it is as time consuming (and labor intensive) as the automated process, and the most platelets one can hope to harvest will be equivalent to 2 RDPc at one donor sitting. Still, the safety of the single donor approach is maintained, and costs can come down to INR 500 to 1,000 for these 2 units together (depending on the pricing structure for platelets) as it only requires the use of 2 double bags per session, and double bags are relatively inexpensive. [Of course, as the platelets are collected in 'ordinary' double bags, there is no question of storing for longer than a day. It is a major factor in significantly reducing the cost. A note added after the initial posting]
For diseases like dengue where pediatric cases are more common, SDPc-M (harvesting 2 RDPc units worth of platelets a day) can be more than sufficient to maintain minimum platelet counts, while harvesting a lot of platelets SDPc-A (using a cell separator) may lead to a lot of wastage and may compromise the donors' abilities to maintain healthy platelet counts over the period of 1-2 weeks when the disease is at its most critical.
Platelet Concentrate Product
|
Total Plt Counts
|
Typical Volume
|
Plt/mL
|
Typical Process
|
|
1
|
Random Donor Platelets
RDPc
|
4.5x10(10) or 45x10(9)
|
50 mL to 70 mL
|
6.5x10(8)
|
Manual, triple bags
|
2
|
Single Donor Platelets
SDPc-A
|
3x10(11) or 300x10(9)
|
300 ml
|
1x10(9)
|
Automated apheresis/cell
separator
|
3
|
Single Donor Platelets
SDPc-M
2 units
|
9x10(10) or 90x10(9)
|
100 mL
|
9x10(8)
|
Manual, double bags
|
4
|
Pooled Buffy Coat
Platelets PBCPc
Plt from 4 units + 1 unit
plasma
|
1.8x10(11) or 180x10(9)
|
250 mL
|
8.8x10(8)
|
Manual, 'top and bottom'
bags
|
Comments please!
Some References:
1. Buffy-coat-derived pooled platelet concentrates and apheresis platelet concentrates: which product type should be preferred?
H. Schrezenmeier,
E. Seifried
Vox Sanguinis
Volume 99, Issue 1, pages 1–15, July 2010
2. Storage of Apheresis and Pooled Buffy-Coat Platelet Concentrates Treated
with Pathogen Inactivation Using the INTERCEPT Blood System Peter Schlenke, Valentine Franck, Lily Lin, Holger Kirchner Presented at the XXIX International Congress of the
International Society of Blood Transfusion (ISBT) September 2-7, 2006 http://www.interceptbloodsystem.com/poster_pdfs_2006/ISBT-2006_Schlenke.pdf
3. Canadian Blood Services Transfusionmedicine.ca Vein to Vein: Preparation of Platelets (online)
Sunday, September 2, 2012
The Blood Components Group Blog
Welcome to the Blood Components Group! The group aims to promote blood component use particularly in developing nations - where far too much whole blood is being prescribed. This battle has been fought and won in the developed nations, but has to be again fought and won in the developing world! Welcome to the battle and we look forward to your contributions.
We're going to start out at LinkedIn with a discussion on platelet concentrates and the possibilities of using a manual 'apheresis' method instead of the much more expensive automated apheresis that has been touted by some as a solution. Visit the LinkedIn group for the main discussion, and do join the group if you haven't already.
I hope to see many other discussions started by group members as we collectively try to make blood component therapy the norm rather than the exception in the developing world.
Blood Component Group members Please submit any potential articles or documents that you want to share/display here in this blog (in Word) to my personal email samlcarr@gmail.com and I will screen and post them to the blog. I'm right now working alone on this, but promise to get it done as soon as possible.
We're going to start out at LinkedIn with a discussion on platelet concentrates and the possibilities of using a manual 'apheresis' method instead of the much more expensive automated apheresis that has been touted by some as a solution. Visit the LinkedIn group for the main discussion, and do join the group if you haven't already.
I hope to see many other discussions started by group members as we collectively try to make blood component therapy the norm rather than the exception in the developing world.
Blood Component Group members Please submit any potential articles or documents that you want to share/display here in this blog (in Word) to my personal email samlcarr@gmail.com and I will screen and post them to the blog. I'm right now working alone on this, but promise to get it done as soon as possible.
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