A recombinant immunoblot and ELISA for detection of acute parvovirus B19 infection

Laboratory diagnosis of parvovirus B19 (B19) infection has been hampered by the limited availability of B19 virus. Recombinant viral proteins are now available for use as antigen in serological assays. We compared detection of anti-B19 IgM by "mu-capture assay" using viral B19 particles to a recombinant (rec.) immunoblot and a rec. enzyme-immunoassay (ELISA) using viral structural proteins as antigens expressed in E. coli. The rec. immunoblot was 94.3% sensitive and 96.4% specific for anti-B19 IgM, and the sensitivity of the rec. ELISA was 94.3% and the specificity, only 72.7%. There was an agreement between the "mu-capture assay" and the rec. immunoblot in 87.8% and the rec. ELISA in only 74.4%. For detection of anti-B19 IgG in patients with acute B19 infection, the rec. immunoblot was 94.3% and the rec. ELISA 85.7% sensitive. The rec. immunoblot is more reliable for detection of acute B19 infection than the rec. ELISA.