Development of an IgM antibody capture test using labelled fusion protein as antigen for diagnosis of B19 human parvovirus infections.

ABSTRACT

A new anti-B19 IgM ELISA was developed using the antibody-capture principle. Biotinylated fusion protein was used as antigen. The specificity of the test was analysed using sera IgM positive to rubella, hepatitis B core antigen, cytomegalovirus and Epstein Barr virus as well with sera positive for rheumatoid factors, antinuclear antibodies and with sera from normal blood donors. The specificity of the test was 96.18%. One hundred serum samples were tested by the new ELISA and the standard MACRIA tests for the presence of B19 IgM. Eighty-eight sera gave the same results with both tests. Fifty-three were negative and 35 were positive. Six sera were ELISA negative MACRIA positive and six MACRIA negative ELISA positive. In a clinical study with 725 sera from suspected B19 infections, 161 (22%) were recorded as positive by the ELISA test. The positive sera were from patients suffering from arthritis (35%), rash (35%), acute or chronic erythroblastopenia (21%), pancytopenia (5%), vascular purpura (2%) and lymphadenopathy (2%).