The specific reactivity of immunoglobulin M antibodies, as measured by a commonly used immunodiagnostic technique for schistosomiasis mansoni, the immunofluorescence assay (IFA) on Rossman-fixed sections of adult worms, was analyzed with monoclonal antibodies. Using monoclonal antibodies directed against 3 major gut-associated antigens, circulating anodic antigen (CAA), circulating cathodic antigen (CCA) and the 32 kDa antigen in blocking experiments, it was demonstrated that the measured IFA reaction was primarily due to reactivity with CCA. After blocking with anti-CCA monoclonal antibody, a mean decrease of fluorescent antibody titres of 95.8%, 92.9% and 83.8% was observed for sera from groups of patients with a recent infection (0-6 months), a static infection (6 months - 5 years), and a chronic infection (over 5 years), respectively. Titres of the group of recently infected patients were, after blocking, significantly lower (P less than 0.05) than those of the group of chronically infected patients.

Animals↗

PubMedDate not supplied

Serological diagnosis of Oesophagostomum infections.

A sensitive and specific enzyme-linked immunosorbent assay (ELISA) is described to diagnose human infection with Oesophagostomum bifurcum. In an ELISA using crude soluble antigen, prepared from adult O. bifurcum, many cross reactions occurred when measuring IgG titres in patients with other helminth infections. An ELISA based on the detection of specific IgG4, however, had a specificity of over 95%. The sensitivity of the IgG4 ELISA was difficult to assess because a reliable parasitological diagnosis is not available. The IgG4-ELISA described seems to be a powerful new tool to study the distribution of this little known but locally very common nematode parasite.

Adolescent↗