Epidemiologic characteristics of leprosy reactions.

An 8-year prospective study of a cohort of 176 newly diagnosed leprosy patients was conducted to examine the possible influence of age, sex, multidrug therapy (MDT), and duration of illness on the risk of either type 1 or type 2 reactions. Patients were enrolled over a 5-year period (1984-1989) and followed for a minimum of 3 years. All reactions studied were severe enough to warrant hospital admission. Overall, 45% of this cohort developed a reaction; 32% of patients considered at risk developed type 1 reactions, and 37% of patients considered at risk developed type 2 reactions. Despite the predominance of men among the leprosy patients, type 1 reactions occurred with significantly greater frequency in women, and did not appear to be influenced by age of onset of leprosy. Individuals experiencing one type 1 reaction were not likely to experience a recurrence, suggesting that the immunologic mechanisms of this reaction may be limited or regulated by genetic or immunologic factors. Type 2 reactions, on the other hand, occurred with equal frequency in both males and females, but were highly associated with onset of leprosy in the second decade of life. Individuals who experienced type 2 reactions often had one or more recurrence of the reaction. No increased risk was seen for either reaction with longer duration of leprosy or longer duration of treatment. The mechanisms by which these differences relate to the pathogenesis of leprosy reactions remains unclear, but future studies of clinical and immunological parameters of leprosy reactions may benefit from stratification of data by gender and age of onset of leprosy in addition to the routine grouping of results by leprosy classification.

Studies of human leprosy lesions in situ using suction-induced blisters. 1. Cellular components of new, uncomplicated lesions.

The cellular contents of blisters induced by suction over new, uncomplicated leprosy lesions, and in the skin of cured, control patients, have been examined with enzyme- and immuno-histochemical staining over a period of 4 days. The total cellularity of the blisters varied over a wide range, not correlated with the type of leprosy. Mononuclear cells predominated at all times studied, with nearly equal percentages of monocytes and T lymphocytes. The T-helper: suppressor ratio was significantly greater in BT than in BL and LL lesions at 48 hr. Suction blisters offer a painless, quantitative, reproducible, multiple-sampling method for obtaining cells from the cutaneous infiltrates of leprosy for phenotyping or functional analysis.