A comparison of adverse reaction rates for PAS C versus plasma platelet units.

BACKGROUND: Plasma constituents have been implicated in some types of platelet (PLT) transfusion reactions. Leukoreduced apheresis PLTs stored in InterSol have 65% less plasma than apheresis PLTs stored in 100% plasma (PPs). This study compared transfusion reaction rates in InterSol PLTs (PLT additive solution [PAS] C) versus PPs. STUDY DESIGN AND METHODS: The study design was an open-label, nonrandomized retrospective review. Statistical methods were applied to substantiate noninferiority and superiority of PAS C compared to PP in terms of transfusion reaction rates. Adverse reactions (ARs) were categorized using the Biovigilance Component of the National Healthcare Safety Network. Active surveillance was used to monitor all transfusions, both with ARs and without ARs. RESULTS: A total of 14,005 transfusions from six study sites were included, with 9845 PP transfusions given to 2202 patients and 4160 PAS C to 1444 patients. A total of 165 ARs were reported. Percentages of transfusions with ARs were 1.37% for PPs, 0.55% for PAS C, and 1.13% overall. The relative risk (RR) for PAS C versus PPs was calculated as 0.403 with an upper confidence limit (UCL) of 0.663. Overall, ARs with the highest incidence were allergic transfusion reactions (ATRs) and febrile nonhemolytic transfusion reactions (FNHTRs), at 0.66 and 0.40% of total transfusions reported, respectively. The relative risks (UCLs) for ATRs and FNHTRs, respectively, were 0.350 (0.686) and 0.336 (0.827). CONCLUSIONS: PAS C PLTs were statistically superior and noninferior to PPs with respect to the transfusion-related AR rate. PAS C noninferiority and superiority were also demonstrated for ATRs and FNHTRs, separately.

Evaluation of a rapid colorimetric assay for detection of bacterial contamination in apheresis and pooled random-donor platelet units.

BACKGROUND: Despite existing strategies, bacterial contamination of platelets (PLTs) remains a problem, and reliable testing near the time of use is needed. We evaluated the BacTx assay (Immunetics, Inc.), a rapid colorimetric assay for detection of bacterial peptidoglycan, for this purpose. STUDY DESIGN AND METHODS: Apheresis- and whole blood-derived PLT units, the latter tested in 6-unit pools, inoculated with 10 representative bacterial species (eight aerobic, two anaerobic), were tested with the BacTx assay at two sites to determine analytic sensitivity and time to detection. Specificity on sterile PLTs and reproducibility across different PLT units and assay kit lots was also determined. RESULTS: Analytical sensitivity for the 10 bacterial species ranged from 6.3 × 10(2) to 7.6 × 10(4) colony-forming units (CFUs)/mL. In time-to-detection studies after inoculation of PLTs with 0.7 to 5.3 CFUs/mL, 10 replicates of all eight aerobic species were positive when bacterial titers were above the analytic sensitivity detection limit, which occurred at 48 hours for 60 PLT units and at 72 hours for the remaining 4 units, as well as at 7 days for all units. Specificity was 99.8% and reproducibility was 100%. CONCLUSIONS: The BacTx assay had an analytical sensitivity below the 10(5) CFUs/mL threshold of clinical significance, detected all eight aerobic bacterial species 48 to 72 hours after inoculation as well as at 7 days, and had high specificity and reproducibility. These findings suggest that the BacTx assay will be a valuable test for detection of clinically relevant levels of bacterial contaminants in PLT units and pools near time of use.

Detection of bacterial contamination in prestorage culture-negative apheresis platelets on day of issue with the Pan Genera Detection test.

BACKGROUND: Bacterial contamination is currently the most important infectious risk associated with transfusion of platelet (PLT) products. Prestorage culture has reduced but not eliminated this problem. STUDY DESIGN AND METHODS: Eighteen hospitals studied the Pan Genera Detection (PGD) test, a rapid, lateral-flow immunoassay for the detection of Gram-positive and Gram-negative bacteria. The PGD test was performed on day of issue on apheresis PLTs released by collection centers as culture negative. Confirmatory bacterial culture was performed when PGD tests were repeatedly reactive, with three sites performing culture on all doses studied. RESULTS: PGD tests on nine of 27,620 (1:3069, 95% confidence interval [CI] 1:6711 to 1:1617; or 326 per million, 95% CI 149-618 per million) apheresis PLT doses were repeatedly reactive and verified as bacterially contaminated by confirmatory culture. Bacterial species isolated included coagulase-negative staphylococci (n = 6), Bacillus sp. (n = 2), and Enterococcus faecalis (n = 1). The ages of these contaminated doses were Day 3 (n = 4), Day 4 (n = 2), and Day 5 (n = 3). Two contaminated doses with nonreactive PGD tests were detected among 10,424 doses at hospitals where concurrent culture was performed, and one other was identified via a transfusion reaction investigation. There were 142 PGD false positives (0.51%). CONCLUSIONS: The PGD test detected bacterial contamination in 1:3069 (9 of 27,620) doses released as negative by prestorage culture in PLTs as young as 3 days old. Three contaminated doses, two clinically insignificant, had nonreactive PGD tests, while 0.51% of tests were false positives. Application of this test on day of issue can interdict contaminated units and prevent transfusion reactions.

Evaluation of the properties of components prepared and stored after holding of whole blood units for 8 and 24 hours at ambient temperature.

BACKGROUND: The capability of holding whole blood (WB) units at ambient temperature, overnight, should help in platelet (PLT) concentrate preparation logistics. We summarize the results of a study conducted in the early 1990s that compared, in particular, PLT and red blood cell (RBC) in vivo viability properties following storage after preparation after 8- and 24-hour WB hold periods. STUDY DESIGN AND METHODS: Individuals donated units of WB on two occasions. Centrifugation at 20 to 24°C to separate PLTs and additive system RBC placement at 1 to 6°C was completed 8 hours after phlebotomy or after 24 hours in randomized order. Components were not leukoreduced. Studies including in vitro biochemical and hematologic analyses and autologous in vivo RBC and PLT evaluations were conducted at two sites. RESULTS: RBC 24-hour in vivo (mean ± SD) recoveries (single-label approach), after 35 days of storage, were 79.2 ± 4.3 and 79.4 ± 3.9% (n = 9; p > 0.05), with WB holding periods of 8 and 24 hours, respectively. With 42 days of storage, recovery after a 24-hour hold was slightly less than with an 8-hour hold (72.9 ± 6.5% vs. 76.0 ± 5.4%; n = 17; p < 0.05). RBC 2,3-diphosphoglycerate acid levels were substantially less after the 24-hour hold compared to after the 8-hour hold (n = 18; p < 0.05). PLT recovery after 5 days of storage with 8- and 24-hour hold periods were similar, 51.1 ± 14.9 and 50.6 ± 17.7%, respectively (n = 18; p > 0.05). The PLT survival variable and in vitro properties reflecting storage quality also showed no significant difference. CONCLUSION: RBC and PLT in vivo variables, and most in vitro variables, were not significantly different after storage with WB holding times of 8 and 24 hours except for a slight diminution of RBC recovery with the 24-hour hold after 42 days of storage.