BACKGROUND
A patient with B+ sickle cell disease received 3 units of red blood cells (RBCs) from two O+ donors and developed fever and hypotension after the first unit, consistent with an acute transfusion reaction (ATR). Anti‐B titers in plasma from each O+ donor were markedly elevated and nondiscriminatory. In order to evaluate the potential for the transfused units to produce complement‐mediated hemolysis of B+ RBCs, hemolytic complement testing was performed.
STUDY DESIGN AND METHODS
Plasma from each donor was diluted in veronal buffer and incubated with B+ RBCs, and free hemoglobin was measured by spectrophotometer in the complement hemolysis using human erythrocytes (CHUHE) assay. Peptide inhibitor of complement C1 (PIC1) was used to confirm antibody‐initiated complement pathway activation.
RESULTS
A 96‐fold difference (p = 0.014) in hemolysis was measured between plasma samples from the two O+ donors using the CHUHE assay. The extremely high degree of hemolysis produced by the one plasma was inhibited by PIC1 in a dose‐dependent manner.
CONCLUSION
These results indicate that hemolytic complement testing with the CHUHE assay can be used to assess the risk of antibody‐initiated, complement‐mediated hemolysis from a transfusion beyond what can be achieved with antibody titers alone.