Platelet concentrates intended for transfusion to immunosuppressed patients are irradiated to minimize transfusion-induced graft-versus-host disease. Because few reports describe how irradiation influences stored platelets, the authors studied whether 5000 rad of gamma irradiation, the maximum dose currently used clinically, altered platelets in vitro. Platelet concentrates were stored for either 1 day or 5 days in plastic (PL 732) containers before gamma irradiation. One unit of a pair of identical platelet concentrates was irradiated; the second unit served as a control. Irradiation did not alter platelet morphology, mean platelet volume, expression of platelet-factor-3 activity, response to hypotonic stress, extent of discharge of lactate dehydrogenase, release of beta-thromboglobulin, formation of thromboxane B2, nor the ability to undergo synergistic aggregation. The lack of any substantial change was observed whether the platelet concentrates were stored initially for either 1 day or 5 days. These results suggest that stored platelets are not altered deleteriously by irradiation with 5000 rad.

Platelet concentrates are routinely stored with continuous agitation but may need to be maintained without agitation for substantial time periods. Studies were conducted in vitro to assess the retention of platelet properties after the discontinuation of agitation. Platelets were maintained without agitation in an insulated cardboard container. In one study, platelet concentrates were kept at 20 to 24 degrees C for the entire 24-hour period. In another study, they were kept at 37 degrees C for 6 hours with subsequent storage at ambient room temperature for the remainder of the 24-hour holding period. Under the simulated shipping conditions, discontinuation of agitation for 24 hours between Days 2 and 3 of a 7-day storage period minimally influenced the maintenance of a series of in vitro platelet properties. The maintenance of platelet concentrates at 20 to 24 degrees C, sitting undisturbed on a bench top for 9 hours, after storage for 6 days with continuous agitation, also had no damaging influence.

The BD FACSVia™ System features novel designs in hardware, software, and instrument QC. We compared the performance of the BD FACSVia System using the BD Leucocount™ kit with the BD FACSCalibur™ flow cytometer. Leucoreduced platelet (PLT, n = 252) and red blood cell (RBC, n = 278) specimens were enrolled at four sites. Each specimen was stained in four tubes using the BD Leucocount kit reagents and acquired on the two systems. BD Leucocount Control cells (high and low) were used to evaluate the inter‐site reproducibility on the BD FACSVia System at three sites over 20 days. Deming regression and Bland–Altman analysis were performed to determine the WBC absolute counts on the BD FACSVia System vs. the BD FACSCalibur system. Assay accuracy for the range of 0–350 WBCs/µl was adequate. For samples with <25 WBCs/µl, the bias with 95% limits of agreement was 0.136 (–1.897 to 2.169) WBC/µl for PLTs (n = 184) and 0.170 (–2.025 to 2.365) WBC/µl for RBCs (n = 193). For inter‐site reproducibility, the CV% was 6.46% (upper 95% CI 7.16%) for the PLT high control and 9.49% (10.52%) for the PLT low control. The CV% was 7.51% (8.32%) for the RBC high control and 10.76% (11.92%) for the RBC low control. The BD FACSVia System reported equivalent results of WBC absolute counts for leucoreduced PLT and RBC samples compared to the BD FACSCalibur system. The inter‐laboratory reproducibility of the BD FACSVia System met study specifications. © 2018 The Authors. Cytometry Part A Published by Wiley Periodicals, Inc. on behalf of ISAC.

The Platelet Monitoring System (PMS) and the Non-invasive Assessment of Platelet Shape and Concentration (NAPSAC) instruments which relate light scattering characteristics of platelet concentrates (PC) to platelet concentration and shape, were evaluated to determine their accuracy in assessing platelet quality during storage from 1 to 7 days. The results were correlated with platelet concentration, % discs and pH on 121 PC stored in PL732 containers. NAPSAC output is in the form of platelet concentration and % discs. When NAPSAC and standard method values were compared, correlation coefficients (r) did not exceed 0.76 for counts and 0.62 for % discs. PMS output is in the form of lights with red indicating poor quality and green or amber indicating acceptable quality. Sensitivity of the PMS instrument did not exceed 83% and specificity did not exceed 63%. Mean platelet number, % discs and pH were comparable for units triggering red versus green or amber lights. In a separate study, 13 PL732 PC stored 5 days and transfused autologously were evaluated on the PMS. Three red light units exhibited recovery and survival times similar to those observed with PC triggering green/amber lights. These data indicate that neither instrument adequately assesses the quality of PL732 PC.

The container and packing methods described moderate the rate of change in the temperature of platelet components during their exposure to challenging ambient conditions. The use of TSPs substantially improves the performance of the system. In addition, the system meets freight carrier requirements and is easy to use, environmentally friendly, and durable.