Anti-HTLV-III screening of blood donors

In a survey on 82,383 blood donor specimens from Hessen, West Germany, the observed percentage of repeatedly positive HTLV-III/LAV antibody ELISA results was 0.2%, but only 0.018% were confirmed by Western blot, immunofluorescence assay or radioimmunoprecipitation assay. These data are consistent with larger epidemiological data compiled from other German blood banks and suggest a high degree of nonspecific false-positive results; one of the causes for false-positives are HLA-DR4 antibodies, which react in the HTLV-III/LAV test. Epidemiological data on 127 dialysis patients and 1,153 prison inmates are presented.