SCREENING FOR DEFICIENCIES IN THE CLASSICAL AND ALTERNATIVE PATHWAYS OF COMPLEMENT BY HEMOLYSIS IN GEL

Abstract

Two assays based on hemolysis in gel were assessed for screening complement (C) component deficiencies. In one assay sensitized sheep erythrocytes (EA) were incorporated in agarose gel containing Ca²⁺ and Mg²⁺, in the other guinea pig erythrocytes (GpE) were used in the presence of Mg²⁺ and EGTA. With few exceptions, fresh samples from healthy individuals produced homogenous areas of complete hemolysis in both assays. Clearly aberrant patterns were observed in approximately 4% of healthy blood donors. Sera from patients having complete deficiencies of Clq, C2 or C4 produced clear lysis of GpE only, whereas in sera lacking C3 or C8 lysis was grossly impaired in both assays. Properdin deficient serum produced very slight lysis of GpE but normal lysis of EA. Reconstitution of these C-deficient sera gave normal lysis. Together, the two assays supplement immunochemical C3 and C4 determinations for screening out C disorders.