Evaluation of IgG and Complement Component C4 Levels in Low-Income Countries, Yemen Republic in Light of Their Proposed Role in the Hemolysis of Stored CPDA-1 Whole Blood.

Objective: Hemolysis is the most severe change that occurs in stored blood and can cause severe consequences in patients after transfusion. This study examines the potential role of IgG and complement, exampled by C4, in the hemolysis of stored CPDA-1 blood under poor storage conditions in low-income countries.

Methods: The study was performed on 30 whole blood units (250 mL) drawn from convenience healthy volunteer donors with CPDA-1 anticoagulant and stored at 2-6 °C for 35 days. Each well-mixed blood bag was sampled at 0, 7, 21 and 35 days and examined for CBC, plasma hemoglobin, hemolysis percent and determination of IgG and C4.

Results: The plasma hemoglobin level and hemolysis percent increased continuously to reach 1.56 g/dl and 7.05% at the end of storage time. Hemolysis increased alongside the mean IgG concentration that was increased significantly from day 0 of storage (7.68±1.75 g/L) and peaked on day 7 (11.55±1.57 g/L), then declined to reach 8.33±2.09 g/L on day 35. Also, the mean concentration of C4 increased from day 0 of storage (0.15±0.06 g/L) to a peaked on day 21 (0.18±0.04) then declined on day 35 (0.17±0.06 g/L). The coordinated action of IgG and C4 is reflected by the positive correlation of their delta changes (r=0.616, p<0.0001).

Conclusion: Elevated hemolysis percent in whole CPDA-1 stored blood in Yemen was accompanied by initial increase of IgG and C4 followed by final decline, which indicate their activation and consumption during hemolysis. Further studies for other hemolysis markers and analyses will give a full idea about that.