DETECTION AND IDENTIFICATION OF ANTINUCLEAR AUTOANTIBODIES IN THE SERUM OF NORMAL BLOOD-DONORS

The occurrence of antinuclear antibodies (ANA) in the serum of 485 hea lthy volunteer blood donors was assessed. Sixty two sera displayed nuc lear immunofluorescence staining on Hep-2 cells using a polyvalent ant i-Ig conjugate. In general, the titer of these antibodies was low (421 62 sera displaying a titer lower than or equal to 1:80). In only 23 se ra were the ANA of the IgG isotype, which is the more disease-related immunoglobulin class of autoantibodies. In order to define the frequen cy of antibodies to extractable nuclear antigens and dsDNA within this population, sera were further analyzed by counterimmunoelectrophoresi s, Western blot and the Crithidia luciliae assay. One serum displayed weak anti-ds DNA reactivity; another serum had anti-SSA/Ro activity. O n Western blot several patterns were found. They could not be identifi ed with any of the available reference antisera.