Circulating immune complexes in normal blood donors of three races

Circulating immune complexes were measured by means of a modified Raji cell assay in 50 blood donors from each of three race groups - Indian, Black and White. The results ranged widely and were, on average, higher in Blacks than in others. The difference is probably related to the hypergammaglobulinaemia commonly found in Blacks. For maximum clinical usefulness, results should be expressed so as to indicate the degree of variation from the appropriate normal mean.