BK virus specific IgM responses in cord sera, young children and healthy adults detected by RIA

Abstract
An IgM capture solid-phase radioimmunoassay (MACRIA) for BK virus (BKV) specific IgM is described. This test was found to be more sensitive in detecting BKV specific IgM than both haemagglutination inhibition and immune electron microscopy with serum fractions from sucrose density gradients. The use of this specific assay allowed large numbers of sera to be examined with ease so that the distribution of BKV specific IgM in different populations could be studied more fully. BKV specific IgM was detected in 11/300 sera from London blood donors, in 24/114 sera from children aged between 2 and 11 years admitted to a paediatric unit and 14/79 sera taken from children aged between 2 and 5 years for the investigation of anti-streptolysin 0 titres. BKV specific IgM was not detected in 404 cord sera examined to investigate the transplacental transfmission of BK virus.