STRONG IGG ISOTYPIC ANTIBODY-RESPONSE IN SOWDAH TYPE ONCHOCERCIASIS

Persons exposed to Onchocerca volvulus express differences in manifest ations of onchocerciasis ranging from hyporeactive (generalized) to hy perreactive (sowdah) forms; absence of disease is seen in endemic norm al persons. Analysis of the IgG isotypic antibody response to O. volvu lus extracts and nonparasite ubiquitous antigens in 92 West Africans r evealed highest anti-O. volvulus IgG1 and IgG2 responses in sowdah, hi gh levels in the generalized form, and low antibody levels in endemic normal persons. Nonexposed persons had no antibodies. A significant Ig G3 antibody response was detected only in sowdah, while high IgG4 leve ls occurred in both polar groups but were absent in both control group s. Isotypic responses to antigens unrelated to O. volvulus were simila r in all groups but showed higher IgG1 and IgG2 levels in sowdah. Sowd ah patients had high levels of Ro/SS-A antibodies, circulating immune complexes, and eosinophil cationic protein. These results document a s trong B cell response in African sowdah and indicate variations in imm une responsiveness.