Extracellular accumulation of bioactive substances; interleukin-1beta (IL-1beta) and plasminogen activator inhibitor-1 (PAI-1) in stored blood units and relation to bacterial contamination.

Bacterial contamination of blood and its cellular components remains an unresolved problem in transfusion medicine and is considered to be the most common microbiological cause of transfusion associated morbidity and mortality. The present work was designed to explore the levels of two bioactive compounds interleukin-1 beta (IL-1beta) and plasminogen activator inhibitor-1 (PAI-1) in stored blood units and their relation to bacterial contamination of these units. This study was conducted on 112 blood units obtained from blood bank of Mansoura University Children Hospital. Sequential blood samples were obtained both immediately at donation and after 10 days for measurement of IL-1beta and PAI-1 and for bacterial culture by BACTEC 9050 system. There was statistically significant increase in both IL-1 beta and PAI-1 (P = 0.0001) after 10 days of blood units storage. Bacteriological culture revealed no growth in 68% and positive growth in 32% of blood units. The commonest isolated organism was Staphylococcus aureus (15%) followed by Staphylococcus epidermedis (13%) then Yersinia sp. and Enterobacter sp. (2%) for each. From the present study we could conclude that stored blood units contain platelets and WBCs derived bioactive substances PAI-1 and IL-1beta which increase with the duration of blood storage. Furthermore, the extended duration of storage carries the danger of blood contamination by bacteria. Automated blood culture system seems to be helpful in identification of bacterial contamination of blood units. We recommend fresh blood transfusion as early as possible and the practice of Leucofiltration to avoid blood transfusion complications.