Quantitative Changes In Antibodies Against Onchocercal Native Antigens Two Months Postivermectin Treatment Of Onchocerciasis Patients

HO Osue, M Galadima, F Engelbrecht, L Odama, HI Edeghere



Serum antibodies to Onchocerca volvulus native sodium duodecylsulphate slat extracted antigens and epitopes recognized by three monoclonal antibodies designated Cam8, Cam22, and Cam28 were measured using indirect (sandwich) and competitive enzyme-linked immunosorbent assay (ELISA). Paired serum samples (n=32) were obtained before and two months post-ivermectin treatment. Those with increases of ten percent and above (≥10%) were 16 (50%) for IgG, 13 (40.7%) for both IgG1 and IgG4. Nine (28.2%) for IgM, eight (25%) for IgG3, IgA with four (12.5%) was the least, while IgG2 was not assayed due to cross-reaction. The higher increases in IgG, IgG1 and IgG4 antibodies in
females (n=16) than males (n=16) were significant by T-test of unpaired data (P<0.05). Those without onchocercal skin disease, OSD (n=18) had a significant increase of 20.5±29.6%, with pre- and posttreatment values of 0.59±0.15 versus 0.68±0.13 for IgG antibody (P<0.05). Both IgG1 and IgG4 antibodies for those with OSD (n=14) increased by 16.0±24.8%. Only IgG4 antibody increased with the presence of palpable nodule and higher skin microfilarial density. Trend exhibited by Cam 22 and Cam 8 were similar to that of IgG and IgG4, respectively. In conclusion, while IgG1 and IgG4 were both associated with skin diseases, IgG4 assay proved more suitable for onchocerciasis drug screening.

African Journal of Clinical and Experimental Microbiology Vol. 10 (1) 2009: pp. 26-37