[Persistence of antibodies of the IgG class against cytomegaloviruses in blood donors].
High titre plasmas gained from blood donors are the initial material used for producing human immunoglobulin containing cytomegalovirus antibodies (CMV-HIG). For this purpose the sera gained from 467 permanent donors at the District Institute for Blood and Transfusion Service in Berlin were investigated on their CMV antibody content of IgG class by means of an indirect immunofluorescence test (IFT). The infection rate of blood donors amounted to 62% (291/467). CMV-IgG titre greater than or equal to 1:40 was determined in 88 sera (18.8%) and greater than or equal to 1:160 in 14 sera (3%). Two CMV-HIG laboratory samples (charges 3113 and 3117) were produced from these plasmas. Particularly immunoglobulin fraction of charge 3117 (No. 3117 N II) revealed excellent antibody titres (IFT 1:640 [CMV-IgG] or 1:40 [CMV-IgM] respectively, neutralisation test 1:32). Checks made with the donors' CMV-IgG titres after repeated application of plasmapheresis resulted in maximal titres changes of two dilution stages in a period of 15 months. Thus, in producing CMV-HIG a sure, tested pool of donors can be resorted to.