Reactivity of fractionated egg antigens of schistosoma mansoni with sera of patients infected with schistosoma haematobium
Ogunba, E.O.; Maddison, S.E.; Tsang, V.C.W.; Slemenda, S.B.
African Journal of Medicine and Medical Sciences 11(2): 67-74
ISSN/ISBN: 1116-4077 Accession: 006267354
Serologically reactive antigens, extracted from eggs of S. mansoni in the liver of infected mice, were tested for cross-reactivity using the microtiter enzyme-linked immunosorbent assay (ELISA). Four reactive antigens, namely SEA(M) SEA(P)M, MSA-M and SEA-M-8U, were isolated from S. mansoni ova subjected to the various extraction procedures used. The test sera were obtained from Egyptian patients and Nigerian school children with S. haematobium and S. mansoni infections, and American controls with or without parasitic infections other than schistosomiasis. Attempts to extract antigens from eggs of S. haematobium in urine were unsuccessful. The sera from all the Egyptian patients with severe chronic S. mansoni infection were positive with all the antigens. All the Egyptian severe chronic cases of S. haematobium infections reacted with MSA-M. Only 68% of the sera from Nigerians with S. haematobium infection reacted with MSA-M. The other antigenic fractions (SEA-M; SEA(P)M;) were less reactive with not only the sera of the Nigerian children but also to a lesser degree with Egyptian sera from patients with S. haematobium infections. Cross-reactivity was lowest in the urea soluble antigen (SEA-M-8U) with sera from patients with echinococcosis, amoebiasis and trichinosis. There does not appear to be any correlation between the levels of reactivity in ELISA and the eggg load of the Nigerian children infected with S. haematobium but further studies with homologous antigens and larger groups of test sera may be useful in determining the factors responsible for decreased reactivities of sera from patients with S. haematobium infections.