Kamel Hany, Townsend Mary, Bravo Marjorie, Vassallo Ralph R
Blood Systems, Inc, Scottsdale, Arizona.
Transfusion. 2017 Oct;57(10):2413-2419. doi: 10.1111/trf.14198. Epub 2017 Jun 22.
Reports of septic transfusion reactions (STRs) after transfusion of culture-negative platelets (PLTs) justify more effective prevention strategies. Pathogen reduction technologies or performance of additional point-of-issue testing are proposed strategies to enhance safety through Day 5 of storage.
Trima leukoreduced apheresis PLTs (APs) were collected during two study periods (45 and 31 months) using standard procedures, with target settings adjusted during the second period to maintain split rate after increased culture volume. Primary testing for bacterial contamination was performed using BacT/ALERT 3D with sampling from the mother bag 24 to 36 hours after collection. Two culture approaches were compared: in Period A, an 8-mL sample in one aerobic culture bottle (CB), and in Period B a minimal proportional sample volume (PSV) of at least 3.8% of mother bag volume into one to three aerobic CBs (7-10 mL per bottle).
In Periods A and B, 188,389 and 159,098 AP collections were tested, respectively. The true-positive (TP) rate in Period A was 0.90 per 10,000 collections and in Period B was 1.83 per 10,000 (p < 0.05). In Period B, 12 of 29 (41%) TP results had discrepant CB results (DCBRs; at least one of multiple bottles without growth). The false-positive rate in Period B, 15.05 per 10,000 collections, was significantly higher than that of Period A, 3.66 per 10,000. One contaminated collection resulting in STR(s) was reported in each study period. Implementation of PSV was operationally successful and did not impact the AP split rate.
Proportional sample volume improved the sensitivity of primary testing and identified collections that could have escaped detection had only a single bottle with 8- to 10-mL volume been used. PSV may represent another approach to enhanced PLT safety for 5-day storage without a requirement for secondary testing.
关于输注培养阴性血小板（PLT）后发生败血症性输血反应（STR）的报告证明需要更有效的预防策略。病原体灭活技术或在发放时进行额外检测是为提高储存第5天安全性而提出的策略。
在两个研究阶段（分别为45个月和31个月）采用标准程序采集Trima白细胞滤除单采血小板（AP），在第二阶段调整目标设置以在培养体积增加后维持分离率。采集后24至36小时从母袋取样，使用BacT/ALERT 3D进行细菌污染的初步检测。比较了两种培养方法：在A阶段，将8 mL样本接种于一个需氧培养瓶（CB）中；在B阶段，将至少占母袋体积3.8%的最小比例样本量（PSV）接种于一至三个需氧CB中（每个瓶子7 - 10 mL）。
在A阶段和B阶段，分别检测了188,389次和159,098次AP采集。A阶段的真阳性（TP）率为每10,000次采集0.90例，B阶段为每10,000次采集1.83例（p < 0.05）。在B阶段，29例TP结果中有12例（41%）出现培养瓶结果不一致（DCBR；多个瓶子中至少有一个无生长）。B阶段的假阳性率为每10,000次采集15.05例，显著高于A阶段的每10,000次采集3.66例。每个研究阶段均报告了1例因污染采集导致的STR。PSV的实施在操作上是成功的，且未影响AP的分离率。
比例样本量提高了初步检测的灵敏度，并识别出若仅使用一个8至10 mL体积的瓶子可能漏检的数据。PSV可能代表了另一种无需二次检测即可提高PLT储存5天安全性的方法。
