Background: Due to the contemporary red blood cell (RBC) storage methods e.g. appropriate preservative solutions and adequate temperature, the storage duration for so-called erythrocyte concentrate (EC) has been extended to 42 days. Depending on the method of EC preparation, they are non- or leucoreduced. The clinical retrospective studies appearing over the past decade have pointed out the potential risk of adverse transfusion outcomes, especially in the case of long stored and non-leucoreduced RBCs. The increased haemolysis as well as the appearing immunomodulatory processes can depend on the antigen-antibody reaction. After 120 days in human bloodstream, senescent RBCs are removed by the spleen macrophages in autoimmunological process recalling the warm IgG-RBC interaction, characteristic for the autoimmune haemolytic anaemia (AIHA).
Aim of this study was to evaluate the mode of interaction of fresh vs stored RBCs with autoantibodies of AIHA suffering patients.
Material and methods: Autoantibodies from 10 blood samples of AIHA patients were eluted and combined. The autoantibody titre was assessed against 24 fresh, leucoreduced RBC samples and 24 stored for six weeks, non- and leucoreduced RBCs. Results of titration study by the indirect antiglobulin test (IAT) were presented as score values. Morphological parameters of 60 blood samples from leukoreduced ECs were estimated at the beginning and at the end of RBC storage period. For statistical analysis, the t-student test was applied for groups of related (morphology) as well as for groups of unrelated (autoantibody reactivity). Results: Autoantibody reactivity against fresh RBCs was statistically lower than against 6 weeks stored leucoreduced or not RBCs (p < 0.001). MCV of fresh RBCs was significantly lower than of those stored (p < 0.001).
Conclusion: Six weeks stored RBCs, irrespectively on the leucocyte presence in the ECs, reveal stronger activity with autoantibodies when compared with fresh RBCs. This observation can be explained by the direct changes in the antigenic structure or their increased accessibility related with the enlarging RBC volume during the storage period.