Heterogeneity in filarial-specific immune responsiveness among patients with lymphatic obstruction

The relationship between chronic obstructive disease and antifilarial immune responsiveness was studied in the Haitian community of Leogane, where Wuchereria bancrofti is endemic. Differences in sex ratios and in the prevalence of microfilaremia were observed between patients with hydrocele and those with lymphedema or elephantiasis of the lower limb. Only 2 of 84 patients with limb involvement (74 women, 10 men) were microfilaremic compared with 25 of 42 men with hydrocele. Microfilaria-positive men with hydrocele had significantly lower IgG2 and proliferative responses to filarial antigen than did amicrofilaremic men with hydrocele or individuals with lymphedema or elephantiasis. Parasite-specific cellular responses of amicrofilaremic individuals with obstructive disease were greater, although not significantly so, than those of amicrofilaremic asymptomatic members of the community. These results are compatible with the hypothesis that development of obstructive disease of the lymphatics has an immune component in amicrofilaremic persons.