Mycobacterium leprae-induced alterations in macrophage Fc receptor expression and monocyte-lymphocyte interaction in familial contacts of leprosy patients

Abstract

Macrophage Fc receptor expression and monocyte-lymphocyte interaction in the presence of Mycobacterium leprae were examined in familial contacts of leprosy patients. Defective Mf functions similar to those of borderline and lepromatous patients could he observed in approximately 71% of consanguineous contacts and 43% of of spouses of index patients. Although the values in the latter group were markedly lower than those of the consanguineous contacts, they tended to be higher than those of normal individuals (20%). These in vitro Mf functions were independent of age, sex, and age at onset of exposure and were only weakly associated with duration of exposure. The outcome of the monocyte-lymphocyte interaction lest paralleled to a large extent the in vivo Mitsuda lepromin response. Four contacts with defective Mf functions also showed signs of leprosy. The value of these in vitro tests as markers of 'susceptibility' could therefore prove significant.