Isolation and characterization of infiltrates in the nerves of patients with neuritic leprosy.

A study was done on the characteristics of infiltrating cells in the nerves of 9 patients with pure neuritic leprosy, by preparing a single cell suspension. The patients had no skin lesion. Histopathological examination revealed that 2 of the 9 nerves showed granulomas characteristics of tuberculoid leprosy, while the remaining 7 had features of lepromatous granulomas. In the nerves showing tuberculoid granulomas, a high proportion of lymphocytes were T cells as they formed rosettes with sheep erythrocytes and only a few percent were EAC rosette forming cells. On the other hand, the nerves showing lepromatous granulomas contained only occasional lymphocytes which formed E and EAC rosettes. Macrophages from the granulomas of all the nerves were esterase positive, peroxidase negative, contained M. leprae and did not exhibit C3 surface receptors.