Hanseníase neural, aspectos diagnósticos da forma neural pura e mecanismos imunopatogênicos da lesão do nervo na doença. Participação de quimiocinas CCL2 e CXCL10 e metaloproteinases 2 e 9

O diagnostico da hanseniase neural pura baseia-se em dados clinicos e laboratoriais do paciente, incluindo a histopatologia de especimes de biopsia de nervo e deteccao de DNA de Mycobacterium leprae (M. leprae) pelo PCR. Como o exame histopatologico e a tecnica PCR podem nao ser suficientes para confirmar o diagnostico, a imunomarcacao de lipoarabinomanana (LAM) e/ou Glicolipidio fenolico 1 (PGL1) - componentes de parede celular de M. leprae foi utilizada na primeira etapa deste estudo, na tentativa de detectar qualquer presenca vestigial do M. leprae em amostras de nervo sem bacilos. Alem disso, sabe-se que a lesao do nervo na hanseniase pode diretamente ser induzida pelo M. leprae nos estagios iniciais da infeccao, no entanto, os mecanismos imunomediados adicionam severidade ao comprometimento da funcao neural em periodos sintomaticos da doenca. Este estudo investigou tambem a expressao imuno-histoquimica de marcadores envolvidos nos mecanismos de patogenicidade do dano ao nervo na hanseniase. Os imunomarcadores selecionados foram: quimiocinas CXCL10, CCL2, CD3, CD4, CD8, CD45RA, CD45RO, CD68, HLA-DR, e metaloproteinases 2 e 9. O estudo foi desenvolvido em especimes de biopsias congeladas de nervo coletados de pacientes com HNP (n=23 / 6 BAAR+ e 17 BAAR - PCR +) e pacientes diagnosticados com outras neuropatias (n=5) utilizados como controle. Todas as amostras foram criosseccionadas e submetidas a imunoperoxidase. Os resultados iniciais demonstraram que as 6 amostras de nervos BAAR+ sao LAM+/PGL1+. Ja entre as 17 amostras de nervos BAAR-, 8 sao LAM+ e/ou PGL1+. Nas 17 amostras de nervos BAAR-PCR+, apenas 7 tiveram resultados LAM+ e/ou PGL1+. A deteccao de imunorreatividade para LAM e PGL1 nas amostras de nervo do grupo HNP contribuiu para a maior eficiencia diagnostica na ausencia recursos a diagnosticos moleculares... The diagnosis of pure neural leprosy (PNL) is based on clinical and laboratory data, including the histopathology of nerve biopsy specimens and detection of M. leprae DNA by polymerase chain reaction (PCR). Given that histopathological examination and PCR methods may not be sufficient to confirm diagnosis, immunolabeling of lipoarabinomanan (LAM) and/or phenolic glycolipid 1 (PGL1) M. leprae wall components were utilized in the first step of this investigation in an attempt to detect any vestigial presence of M. leprae in AFB- nerve samples. Furthermore, it´s well known that nerve damage in leprosy can be directly induced by Mycobacterium leprae in the early stages of infection; however, immunomediated mechanisms add gravity to the impairment of neural function in symptomatic periods of the disease. Therefore, this study also investigated the immunohistochemical expression of immunomarkers involved in the pathogenic mechanisms of leprosy nerve damage. These markers selected were CXCL10, CCL2 chemokines and CD3, CD4, CD8, CD45RA, CD45RO, CD68, HLA-DR, metalloproteinases 2 and 9 in nerve biopsy specimens collected from leprosy (23) and nonleprosy patients (5) suffering peripheral neuropathy. Twenty-three PNL nerve samples (6 AFB+ and 17 AFB-PCR+) were cryosectioned and submitted to LAM and PGL1 immunohistochemical staining by immunoperoxidase; 5 nonleprosy nerve samples were used as controls. The 6 AFB-positive samples showed LAM/PGL1 immunoreactivity. Among the 17 AFB- samples, only 8 revealed LAM and/or PGL1 immunoreactivity. In 17 AFB-PCR+ patients, just 7 had LAM and/or PGL1-positive nerve results. In the PNL cases, the detection of immunolabeled LAM and PGL1 in the nerve samples would have contributed to enhanced diagnostic efficiency in the absence of molecular diagnostic facilities...