Assessing Changes in Platelet and White Blood Cell Counts and the Risk of Bacterial Contamination during Storage of Single Donor Platelets: A Cross-sectional Study

Introduction: Single Donor Platelets (SDP) is crucial in managing thrombocytopenia and other platelet-related disorders. Compared with random donor platelets, SDPs minimise donor exposure and reduce the risk of alloimmunisation. Although SDPs are preferred over random donor platelets, their quality deteriorates during storage due to metabolic, biochemical, and morphological changes. These changes can influence post-transfusion platelet recovery and clinical efficacy. Moreover, the risk of bacterial contamination increases with longer storage duration despite leucoreduction and improved storage conditions. Therefore, continuous evaluation of in-vitro quality parameters and post-transfusion outcomes is essential to ensure that stored SDP units remain effective and safe for patient use. Aim: To assess changes in platelet and White Blood Cell (WBC) counts and the risk of bacterial contamination during storage of SDP, and to evaluate post-transfusion platelet count increment in recipients. Materials and Methods: The present prospective observational cross-sectional study was conducted in the Department of Immunohematology and Blood Transfusion (IHBT), Nizam’s Institute of Medical Sciences, Hyderabad, Telangana State, India, from April 2023 to March 2024. One hundred SDP donors and 100 transfusion recipients were included (patients). The collected platelets were stored in sterile, oxygen permeable polyvinyl chloride bags. A 5 mL sample was drawn on day 0 (day of collection) for WBC and platelet count estimation and for bacterial culture using BACT/ALERT PF+ culture bottles. Comparisons of WBC and platelet counts between day 0 and subsequent storage days (days 1-5) were performed using the paired t-test. Bacterial contamination was assessed by sterility testing (culture reports) from samples collected on each storage day. For evaluating platelet count increments in patients, mean pretransfusion and post-transfusion platelet counts were calculated and compared using the paired t-test. Microsoft Excel was used for data entry, and statistical analysis was performed with IBM Statistical Package for Social Sciences (SPSS) software, version 2022. Results: The mean donor age was 29.7 years, with an average height of 168.9 cm and weight of 75.5 kg. The most common patient diagnoses were AML (18 cases), followed by CML (14 cases) and lymphoma (15 cases); refractory ITP and cholangitis with severe anaemia were least common (1 case each). Platelet counts showed no significant change on days 0 and 3, but significant reductions were observed on days 1, 2, 4, and 5. Bacterial contamination was detected in some units by day 3 and day 5. There was a significant increase in the patient platelet count (p<0.05). Conclusion: Platelet counts in SDP units decline with longer storage, and patients transfused earlier experience better count recovery. Bacterial contamination risk increases after day 3.