[Relation of the effect of human complement in the cytotoxic test to the origin of the HLA serum].

The use of human complement in HLA typing produced strongly positive results only in examinations with polyspecific sera from pregnant women, while with mono- or bispecific sera positive results were obtained only in some instances and the results were usually weaker. With polyspecific sera from patients after multiple transfusions negative results were obtained. The action of complement did not depend on the titre of HLA cytotoxins. The results confirm the hitherto held view that it is not suitable to use human complement for HLA typing.