CLEARANCE OF WUCHERERIA-BANCROFTI ANTIGEN AFTER TREATMENT WITH DIETHYLCARBAMAZINE OR IVERMECTIN

The present study was undertaken to assess the relationship between mi crofilarial clearance and clearance of circulating filarial antigen fr om the blood of Wuchereria bancrofti-infected persons following chemot herapy with either diethylcarbamazine or ivermectin. Patients received either 12 weekly doses of 6 mg/kg of diethylcarbamazine (DEC), a sing le dose of 6 mg/kg of DEC, a single dose of 420 mu g/kg of ivermectin, or 20 mu g/kg of ivermectin, followed by 6 mg/kg of DEC five days lat er. Microfilarial clearance was marked in all groups, but was signific antly less in the single-dose DEC. In contrast, as monitored by the Og 4C3 monoclonal antibody assay, clearance of circulating filarial antig en was highly variable, not only between groups but within each group. As a result, there were few statistically significant differences in antigen clearance between groups. In no instance did the antigen level fall to zero, even in individuals that remained microfilaria negative during two or three years of follow-up. These results suggest that li ving adult worms persist in almost all persons treated with DEC and/or ivermectin.