An immunohistochemical, clinical and electroneuromyographic correlative study of the neural markers in the neuritic form of leprosy

Abstract

The nerve biopsies of 11 patients with pure neuritic leprosy were submitted to routine diagnostic procedures and immunoperoxidase staining with antibodies against axonal (neurofilament, nerve growth factor receptor (NGFr), and protein gene product (PGP) 9.5) and Schwann cell (myelin basic protein, S-100 protein, and NGFr) markers. Two pairs of non-adjacent histological cross-sections of the peripheral nerve were removed for quantification. All the fascicles of the nerve were examined with a 10X-ocular and 40X-objective lens. The immunohistochemistry results were compared to the results of semithin section analysis and clinical and electroneuromyographic data. Neurofilament staining was reduced in 100% of the neuritic biopsies. NGFr positivity was also reduced in 81.8%, PGP staining in 100% of the affected nerves, S100 positivity in 90.9%, and myelin basic protein immunoreactivity in 90.9%. Hypoesthesia was associated with decreased NGFr (81.8%) and PGP staining (90.9%). Reduced potential amplitudes (electroneuromyographic data) were found to be associated with reduced PGP 9.5 (63.6%) and nerve fiber neurofilament staining (45.4%) by immunohistochemistry and with loss of myelinated fibers (100%) by semithin section analysis. On the other hand, the small fibers (immunoreactive dots) seen amid inflammatory cells continued to be present even after 40% of the larger myelinated fibers had disappeared. The present study shows an indepth view of the destructive effects of leprosy upon the expression of neural markers and the integrity of nerve fiber. The association of these structural changes with the clinical and electroneuromyographic manifestations of leprosy peripheral neuropathy was also discussed. Correspondence

Leprosy patients: neurotrophic factors and axonal markers in skin lesions

“…Moreover, the authors reported lack of neuropeptides in most of leprosy lesions. Reduction of neurofilament and PGP 9.5 immunostaining in nerve biopsies from pure neuritic leprosy was also demonstrated by Antunes et al 30 , as well as its correlation with reduced potential amplitudes in electroneuromyographic evaluation. Our results have shown positive correlation between p75 NTR and PGP 9.5 (r=0.40; p=0.01), indicating the association between Schwann cells and axons in Remak bundles.…”

Molecular mimicry between Mycobacterium leprae proteins (50S ribosomal protein L2 and Lysyl-tRNA synthetase) and myelin basic protein: a possible mechanism of nerve damage in leprosy

“…Earlier, it was reported that M. leprae has a strong demyelinating effect on infected Schwann cells (Sc) neuron culture [23]. Further, it was also showed by Antunes et al (2006) [24] that M. leprae has direct destructive effect on the integrity of nerve fibers in leprosy patients. However, our findings suggest that anti-MBP antibodies are associated with extent of nerve involvement in leprosy patients.…”

Ulnar neuropathy as a first sign of HIV infection: a diagnostic challenge for leprosy endemic countries

“…In this regard, PCR has proven to be a very useful tool in confirming PNL diagnoses (Antunes et al, 2006). In previous studies, mononeuritis and mononeuritis multiplex have been the most common PNL presentations (de Freitas, 2007).…”