Characteristics of anti-A and anti-B in black Zimbabweans.

Sera from young, black, group 0 Zimbabwean blood donors were screened for anti-A and anti-B haemolysins. Nearly one fifth of the sera were found to be strongly haemolytic for either A or B cells or both. Some of the sera were titrated for agglutination in saline before and after treatment with dithiothreitol. Serum dilutions beyond the endpoint of agglutination were further tested by the indirect antiglobulin technique using specific anti-IgM and anti-IgG sera. More than 60% of the strongly lytic sera had high titres of IgG (> or = 64). The IgM and IgG concentrations both of anti-A and anti-B were correlated and these levels were in turn correlated with haemolytic activity.