Human resistance to reinfection with schistosomes. II. Specific IgA titres before & 3 months after praziquantel treatment.
Specific IgA assays by ELISA technique for schistosomal cases of school age children (12-14 years), were performed before and 3 months after praziquantel treatment. Sera of the resistant cases (non-reinfected after chemotherapeutic cure) showed a significant higher titres of anti-soluble egg antigen (anti-SEA) and anti-soluble worm antigen preparation (anti-SWAP) IgA antibodies than that of reinfected schistosomal cases before and 3 months after treatment. Praziquantel therapy insignificantly (P > 0.05) increased anti-SEA and anti-SWAP IgA antibodies in the sera of schistosomal cases and 3 months after treatment. Anti-SEA IgA & IgE anti-SWAP IgA & IgE were correlated positively with each other among schistosomal cases either resistant or reinfected while anti-SEA and anti-SWAP IgA antibody levels of schistosomal cases with eosinophilia were significantly higher than that with normal eosinophilic counts. Anti-SEA IgA antibody titres of schistosomal cases were correlated negatively, before treatment, with intensity of infection but anti-SWAP IgA titres were not, which might indicates that anti-SEA IgA antibodies inhibit schistosomes for egg laying and subsequently pathological complications due to granuloma formation. The higher titres of specific IgA antibody of resistant cases, its positive correlation with IgE and its negative correlation with intensity of infection might support the role of IgA as an essential component of acquired (resistance) immunity to share with IgE in protection of cured schistosomal cases against reinfection.
Ali
A E
AE
Department of Parasitology, Banha Faculty of Medicine, Zagazig University, Cairo, Egypt.
Shaheen
H I
HI
D000293:Adolescent; D004797:Enzyme-Linked Immunosorbent Assay; D004802:Eosinophilia / Q000188:drug therapy / Q000276:immunology; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D011223:Praziquantel / Q000627:therapeutic use*; D012008:Recurrence; D012552:Schistosomiasis / Q000188:drug therapy / Q000276:immunology*
D007070:Immunoglobulin A; D007073:Immunoglobulin E; D011223:Praziquantel