Thalidomide induces imbalances in T-lymphocyte sub-populations in the circulating blood of healthy males

Abstract

Lepromatous leprosy patients experiencing erythema nodosum leprosum (ENL) have been reported to have an increase in the ratio of circulating T-helper to T-suppressor cells (H:S ratio). Thalidomide is an effective drug in the management of ENL. To determine if thalidomide affected cells of the immunoregulatory system, B cells, T cells, T-suppressor cells, T-helper and natural killer cells in the blood of the healthy males were enumerated. Thalidomide induced a decrease in the T-helper to T-suppressor cell ratio. The decrease was due to a significant reduction in the percentage and absolute number of T-helper cells and an apparent increase in the percentage and absolute number of T-suppressor cells. B cells and natural killer cells were not affected. Thalidomide's ability to decrease the H:S ratio in healthy individuals suggests that it may act in ENL by reducing an elevation of that ratio.