Cell-mediated immunologic status of healthy members of families with a history of leprosy.

The cell-mediated immune status of 20 apparently healthy children from families with a history of leprosy has been studied. They have been compared with 20 age- and sex-matched controls from families with no history of leprosy. Lymphocyte transformation tests using PHA, PPD and lepromin and skin tests to lepromin, PPD and candida were carried out. No evidence of a depression of cell-mediated immunity in the children from families with leprosy was obtained. The only two children giving a negative Mitsuda lepromin skin test both subsequently developed leprosy in the succeeding 16 months. One was classified histologically as indefinite lepromatous and the other as borderline lepromatous. This emphasizes the practical significance of a negative lepromin skin test in an endemic leprosy area as a prognosis of clinical lepromatous leprosy.