ANTIBODY-CAPTURE HAEMADHERENCE TESTS FOR PARVOVIRUS B19-SPECIFIC IGM AND IGG

In the absence of serum inhibitor human parvovirus B19 agglutinates pr imate red cells. Agglutination of baboon erythrocytes by inhibitor fre e baculovirus expressed VP1/VP2 proteins of B19 virus was enhanced by low pH. To avoid interference from inhibitor(s) present in serum speci mens microtitre tests with an antibody capture configuration were desi gned and optimised. Antigen binding was demonstrated by the adherence of baboon erythrocytes. These tests (MACHAT, GACHAT) detected IgM or I gG anti-B19 in 1032 serum specimens with an overall sensitivity of 99% , specificity of 98.2% and positive predictive value of 96.8% with ref erence to the radioimmunoassays currently in diagnostic use. MACHAT an d GACHAT are straightforward, and well suited to large scale research and seroepidemiological investigations. They are without the risks fro m infectious antigen and radiation associated with existing radioimmun oassays and allow the phenomenon of B19 virus haemagglutination to be put to practical advantage.