Abstract
The effect of concurrent HTLV-I infection on the efficacy of anti-Strongyloides chemotherapy has been tested in a prognostic study on 96 patients with uncomplicated strongyloidiasis. The efficacy of treatment with pyrvinium pamoate and thiabendazole was found to be significantly low in the HTLV-I seropositive patients, as compared to that in the seronegative group. The cure rates in the HTLV-I seropositive patients, when assessed by both faecal examination and serological testing, were only 8.6% for pyrvinium pamoate treatment and 35.0% for thiabendazole treatment. On the other hand, the cure rates were 31.3% for pyrvinium pamoate treatment and 57.1% for thiabendazole treatment in the seronegative group.
Although antibody response against Strongyloides did not decrease among the HTLVI seropositive patients, the total serum IgE levels, as well as eosinophil counts in peripheral blood, were relatively low in the seropositive group. Abnormal lymphocytes were demonstrated in 38.5% of the patients with concurrent HTLV-I infection. The presence of abnormal lymphocytes, however, appeared not to correlate with the therapeutic efficacy. A possible connection between the poor efficacy and depressed immune responses provided by the concurrent HTLV-I infection is discussed. The low efficacy in the HTLV-I seropositive patients also provides a causal explanation for the significant accumulation of patients with concurrent HTLV-I infection in Okinawa.
