An attempt to improve pure neural leprosy diagnosis using immunohistochemistry tests in peripheral nerve biopsy specimens.

The diagnosis of pure neural leprosy (PNL) is based on clinical and laboratory data, including the histopathology of nerve biopsy specimens and detection of Mycobacterium leprae DNA by polymerase chain reaction (PCR). Given that histopathologic examination and PCR methods may not be sufficient to confirm the diagnosis, immunolabeling of lipoarabinomanan (LAM) and/or phenolic glycolipid 1 (PGL-1) M. leprae wall components was utilized in the present investigation in an attempt to detect any vestigial presence of M.

Schwann cells producing matrix metalloproteinases under Mycobacterium leprae stimulation may play a role in the outcome of leprous neuropathy.

Matrix metalloproteinases (MMPs) mediate demyelination and breakdown of the blood-nerve barrier in peripheral neuropathies. Matrix metalloproteinases and tissue inhibitor of metalloproteinase 1 gene expression and secretion were studied in cells of the human Schwann cell line ST88-14 stimulated with Mycobacterium leprae and tumor necrosis factor (TNF) and in nerve biopsies from patients with neural leprosy (n = 21) and nonleprous controls (n = 3). Mycobacterium leprae and TNF induced upregulation of MMP-2 and MMP-9 and increased secretion of these enzymes in cultured ST88-14 cells.