T cell subpopulations in amoebic liver abscess.

BACKGROUND. Cellular immunity may play a major role in the pathogenesis of amoebic liver abscess but there is little data on the effect of treatment on T cell subpopulations in such patients. METHODS. We performed a prospective, controlled study of the T lymphocyte subpopulations in 17 patients with amoebic liver abscess before, and at 4 and 8 weeks after treatment with metronidazole (30 mg/kg/day). T4 and T8 cells were studied using monoclonal antibodies by the alkaline phosphatase anti-alkaline phosphatase staining technique. RESULTS. The mean T4 cell percentages in the acute stage of illness and at 4 and 8 weeks after treatment were 27, 26 and 27 respectively and the mean T8 cell percentages were 19, 24 and 29. The T4:T8 ratio at the acute stage was 1.7, and 1.1 and 1.2 at 4 and 8 weeks of therapy. The T4:T8 ratio at the acute stage did not differ significantly (p > 0.05) from that in the control group. However, at 4 and 8 weeks after therapy there was a significant increase (p < 0.05) in the T8 cells with no significant change in the T4 cells. CONCLUSION. We suggest that sensitization of the T8 cells occurs in patients with amoebic liver abscess in the later phase of the disease. This may be responsible for the elimination of the parasite from the human host.