Bacterial contamination and septic transfusion reaction rates associated with platelet components before and after introduction of primary culture: experience at a US Academic Medical Center 1991 through 2017.

BACKGROUND: The high incidence of septic transfusion reactions (STRs) led to testing being mandated by AABB from 2004. This was implemented by primary culture of single-donor apheresis platelets (APs) from 2004 and prestorage pooled platelets (PSPPs) from 2007. STUDY DESIGN/METHODS: Platelet (PLT) aliquots were cultured at issue and transfusion reactions evaluated at our hospital. Bacterial contamination and STR rates (shown as rates per million transfusions in Results) were evaluated before and after introduction of primary culture by blood centers that used a microbial detection system (BacT/ALERT, bioMerieux) or enhanced bacterial detection system (eBDS, Haemonetics). RESULTS: A total of 28,457 PLTs were cultured during pre-primary culture periods (44.7% APs; 55.3% at-issue pooled PLTs [AIPPs]) and 97,595 during post-primary culture periods (79.3% APs; 20.7% PSPPs). Forty-three contaminated units were identified in preculture and 34 in postculture periods (rates, 1511 vs. 348; p < 0.0001). Contamination rates of APs were significantly lower than AIPPs in the preculture (393 vs. 2415; p < 0.0001) but not postculture period compared to PSPPs (387 vs. 198; p = 0.9). STR rates (79 vs. 90; p = 0.98) were unchanged with APs but decreased considerably with pooled PLTs (826 vs. 50; p = 0.0006). Contamination (299 vs. 324; p = 0.84) and STR rates (25 vs. 116; p = 0.22) were similar for PLTs tested by BacT/ALERT and eBDS primary culture methods. A change in donor skin preparation method in 2012 was associated with decreased contamination and STR rates. CONCLUSION: Primary culture significantly reduced bacterial contamination and STR associated with pooled but not AP PLTs. Measures such as secondary testing near time of use or pathogen reduction are needed to further reduce STRs.

Blood platelet kinetics and platelet transfusion.

The discovery of citrate anticoagulant in the 1920s and the development of plastic packs for blood collection in the 1960s laid the groundwork for platelet transfusion therapy on a scale not previously possible. A major limitation, however, was the finding that platelet concentrates prepared from blood anticoagulated with citrate were unsuitable for transfusion because of platelet clumping. We found that this could be prevented by simply reducing the pH of platelet-rich plasma to about 6.5 prior to centrifugation. We used this approach to characterize platelet kinetics and sites of platelet sequestration in normal and pathologic states and to define the influence of variables such as anticoagulant and ABO incompatibility on post-transfusion platelet recovery. The "acidification" approach enabled much wider use of platelet transfusion therapy until alternative means of producing concentrates suitable for transfusion became available.

History of patient blood management.

This article traces the development of modern patient blood management (PBM) from its origins in 17th-century transfusion to the present day.

Origins of platelet transfusion therapy.

In 1955, animal studies suggested that thrombocytopenia was not the initiating cause of hemorrhage. Coagulation studies in vitro revealed the correction of coagulation by fresh platelets. Platelets, freshly collected with use of nonwettable surfaces, corrected thrombocytopenia, controlled associated hemorrhage, and prevented death from bleeding. Thus, in vitro and animal studies can be misleading (bench to bedside). Careful clinical observations, elaborated by in vitro studies, which create hypotheses testable in the clinic, lead to therapeutic advances (bedside to bench and back). Platelet replacement for thrombocytopenia prevents the hemorrhagic diathesis and has been universally practiced for over 50 years.

Jon Van Rood: pioneer at the crossroad of human leukocyte antigens and transplantation.

Jon Van Rood (born in 1926) has made major contributions to the fields of transfusion medicine as well as organ and stem cell transplantation. His group was the first to start unraveling the complexity of the human leukocyte antigen (HLA) system through collaborative studies that used panels of sera and leukocyte samples. Furthermore, using HLA typing, he introduced the first HLA-matched platelet transfusions and developed routine leukocyte depletion as a means to prevent HLA alloimmunization. Van Rood has also been active in the fields of kidney transplantation (Eurotransplant) and stem cell transplantation (Europdonor). He combined scientific laboratory research with application to clinical medicine. He retired from his university position in 1991 but remains active in the field.

Platelet transfusion therapy: from 1973 to 2005.

Platelet transfusions are indispensable for supportive care of patients with hematological diseases. We describe the developments in platelet products for transfusion since the 1970s, when, in particular, support for patients with allo-antibodies against human leukocyte antigens was a laborious exercise with a high failure rate. Currently, due to many stepwise innovations, platelet transfusions are of low immunogenicity and sufficiently available, they have a shelf life up to 7 days, and even matched platelets can often be routinely delivered, provided that there is good communication between all partners in the chain. Future improvements can be expected from uniform type and screen approaches for immunized patients and cross-matching by computer. For efficient use of health care resources, blood banks and stem cell donor banks could share their typed donor files.

Four decades of therapy for AML.

A review of the last four decades of leukemia research and treatment provides a view toward the next four decades. What is learned in leukemia research may apply to the treatment of other cancers. The biology of cancer, the importance of chromosomes, and the suppressor genes may hold the answers to future treatments.

Trigger factors for prophylactic platelet transfusion.

The level of 20x10(9)/L for prophylactic platelet transfusion has rightly been challenged over the last few years, with some units recommending a level as low as 5x10(9)/L. The higher levels are usually based on retrospective data from the 1950s. We examined the more recent data and came to the conclusion that a threshold of 10x10(9)/L is safe in the stable patient; higher levels are recommended for specific clinical circumstances. This threshold will reduce donor exposure, costs and possibly donor alloimmunization. The dearth of prospective controlled clinical trials in the literature also presents an opportunity for both in-house and national audit.