Leprosy neuropathy is considered the most common peripheral neuropathy of infectious etiology worldwide, representing a public health problem. Clinical diagnosis of primary neural leprosy (PNL) is challenging, since no skin lesions are found and the slit skin smear bacilloscopy is negative. However, there are still controversial concepts regarding the primary-neural versus pure-neural leprosy definition, which will be explored by using multiple clinical-laboratory analyses in this study. Seventy patients diagnosed with primary neural leprosy from 2014 to 2016 underwent clinical, laboratorial and neurophysiological evaluation. All patients presented an asymmetric neural impairment, with nerve thickening in 58.6%. Electroneuromyography showed a pattern of mononeuropathy in 51.4%. Positivity for ELISA anti-PGL1 was 52.9%, while the qPCR of slit skin smear was 78.6%. The qPCR of nerve biopsies was positive in 60.8%. Patients with multiple mononeuropathy patterns showed lower levels of anti-PGL-1 (p = 0.0006), and higher frequency of neural thickening (p = 0.0008) and sensory symptoms (p = 0.01) than those with mononeuropathy. PNL is not a synonym of pure neural leprosy, as this condition may include a generalized immune response and also a skin involvement, documented by molecular findings. Immunological, molecular, and neurophysiological tools must be implemented for diagnosing primary neural leprosy to achieve effective treatment and reduction of its resultant disabilities that still represent a public health problem in several developing nations. Finally, we propose a algorithm and recommendations for the diagnosis of primary neural leprosy based on the combination of the three clinical-laboratorial tools. The long incubation period, insidious symptoms and signs of leprosy produce difficulties in its diagnosis and correct clinical classification, especially in its primary neural form characterized by negative bacilloscopy and lack of cutaneous lesions. Despite significant progress in leprosy control in recent years, early identification of cases remains one of the primary goals of leprosy control programs. In addition, the failure of current therapeutic schemes on the incidence of leprosy shows that elimination of this disease, a public health problem, depends on incisive action to interrupt its transmission chain. Therefore, efforts must be focused on improving the leprosy diagnosis. However, because it is a primarily neural disease, the use of neurophysiological, serological and molecular methods in this group of patients may contribute not only to early diagnosis, but also to a correct classification and treatment, preventing sequelae and controlling outbreaks of infection. Therefore, in order to improve the leprosy elimination program in many countries, we propose the implementation of a combination of specific tools for detecting M. leprae and its neural impairment, which may further break down the transmission chain, enabling a more effective control of the disease.

A hanseníase, cujo agente etiológico Mycobacterium Ieprae, é doença de amplo espectro clínico e imunopatológico. Suas apresentações clínicas estão correlacionadas com padrões imunológicos distintos, variando de uma vigorosa resposta imune mediada por células ao M. Ieprae, com padrão Th1 no pólo tuberculóide, a uma ausência de resposta celular específica aos antígenos do M. Ieprae no pólo lepromatoso, com predomínio da resposta Th2 e exacerbação da resposta humoral. É provável que a suscetibilidade ao M. Ieprae é determinada por diferentes genes polimórficos. Estudos adicionais são necessários para esclarecer os mecanismos das interações complexas entre as citocinas e a participação da diversidade fenotípica da rede de células que contribuem para a defesa do hospedeiro. O entendimento de tais mecanismos poderá oferecer novas abordagens para identificar agonistas e/ou antagonistas para os efeitos pró- ou anti-inflamatórios e em quais circunstâncias sua utilização seria apropriada para intervenções imunológicas e/ou imunoterapeuticas.

Early diagnosis of leprosy is challenging, particularly its inflammatory reactions, the major cause of irreversible neuropathy in leprosy. Current diagnostics cannot identify which patients are at risk of developing reactions. This study assessed blood RNA expression levels as potential biomarkers for leprosy. Prospective cohorts of newly diagnosed leprosy patients, including reactions, and healthy controls were recruited in Bangladesh, Brazil, Ethiopia and Nepal. RNA expression in 1,090 whole blood samples was determined for 103 target genes for innate and adaptive immune profiling by dual color Reverse-Transcription Multiplex Ligation-dependent Probe Amplification (dcRT-MLPA) followed by cluster analysis. We identified transcriptomic biomarkers associated with leprosy disease, different leprosy phenotypes as well as high exposure toMycobacterium lepraewhich respectively allow improved diagnosis and classification of leprosy patients and detection of infection. Importantly, a transcriptomic signature of risk for reversal reactions consisting of five genes (CCL2, CD8A, IL2, IL15andMARCO) was identified based on cross-sectional comparison of RNA expression. In addition, intra-individual longitudinal analyses of leprosy patients before, during and after treatment of reversal reactions, indicated that several IFN-induced genes increased significantly at onset of reaction whereasIL15decreased. This multi-site study, situated in four leprosy endemic areas, demonstrates the potential of host transcriptomic biomarkers as correlates of risk for leprosy. Importantly, a prospective five-gene signature for reversal reactions could predict reversal reactions at least 2 weeks before onset. Thus, transcriptomic biomarkers provide promise for early detection of these acute inflammatory episodes and thereby help prevent permanent neuropathy and disability in leprosy patients.

A implementação da poliquimioterapia (PQT/OMS) - composta pelas drogas dapsona, clofazimina e rifampicina - possibilitou a cura da hanseníase, porém não foram priorizados o manejo dos efeitos adversos pelas equipes de saúde. Objetivando determinar a magnitude dos efeitos adversos da poliquimioterapia para hanseníase e relacioná-los como possível causa de não adesividade do paciente ao tratamento, revisou-se prontuários de 187 pacientes tratados com PQT, de 1995 a 2000, no Centro de Saúde Escola (CSE) -UFU, com registro de efeitos colaterais em 71 pacientes (37,9%). Dentre os 113 efeitos adversos, 80 (70,7%) relacionaram-se à dapsona, 7 (6,2%) à rifampicina, 26 (20,5%) à clofazimina. Esses efeitos levaram à mudança de esquema terapêutico em 28 (14,9%) dos 187 pacientes ou 39,4% dos 71 com efeitos adversos. Discute-se a importância de considerar os efeitos adversos da PQT na capacitação das equipes de saúde para maior adesão do paciente ao tratamento, colaborando para eliminar a hanseníase como problema de saúde pública.

Reversal reactions (RRs) in leprosy are characterized by a reduction in the number of bacilli in lesions associated with an increase in cell-mediated immunity against the intracellular bacterium Mycobacterium leprae, the causative pathogen of leprosy. To identify the mechanisms that contribute to cell-mediated immunity in leprosy, we measured changes in the whole blood-derived transcriptome of patients with leprosy before, during and after RR. We identified an ‘RR signature’ of 1017 genes that were upregulated at the time of the clinical diagnosis of RR. Using weighted gene correlated network analysis (WGCNA), we detected a module of 794 genes, bisque4, that was significantly correlated with RR, of which 434 genes were part of the RR signature. An enrichment for both IFN-γ and IFN-β downstream gene pathways was present in the RR signature as well as the RR upregulated genes in the bisque4 module, including those encoding proteins of the guanylate binding protein (GBP) family that contributes to antimicrobial responses against mycobacteria. Specifically, GBP1, GBP2, GBP3 and GBP5 mRNAs were upregulated in the RR peripheral blood transcriptome, with GBP1, GBP2 and GBP5 mRNAs also upregulated in the RR disease lesion transcriptome. These data indicate that RRs involve a systemic upregulation of IFN-γ downstream genes including GBP family members as part of the host antimicrobial response against mycobacteria. Reversal reaction (RR) is a major cause of tissue injury and disabilities in leprosy, resulting from the rapid onset of cell-mediated immune responses to the intracellular bacterium Mycobacterium leprae. To identify the mechanisms related to the increase in cell-mediated immunity in RR, we measured changes in the whole blood-derived transcriptome of patients with leprosy before, during and after RR. We identified that RRs are associated with an IFN-γ induced inflammatory response including an antimicrobial gene network containing the GBP1, GBP2, GBP3 and GBP5 mRNAs in the peripheral blood. Furthermore, we show that GBP1, GBP2 and GBP5 mRNAs are also upregulated at the site of disease in RR patients. In summary, our study suggests that RR involves a systemic induction of IFN-γ regulated genes that contributes to an antimicrobial response against the pathogen, releasing ligands and antigens that can further amplify the inflammatory response.

The establishment of therapeutic regimens for mycobacteriosis depends on the accurate identification of Mycobacterium species, and misdiagnosis can result in inappropriate treatment and increased mortality of patients. Differential diagnosis among Mycobacterium species has been made by conventional phenotypic and biochemical tests after a long culture period. Specialized molecular diagnostics of mycobacteria allows rapid detection and species identification; however, such tests are not available in public health programs. Our aim was to demonstrate the clinical implications of erroneous diagnosis by performing molecular genotyping of mycobacterial infections in patients that were diagnosed based on symptoms, culture and bacilloscopy. Culture samples of mycobacterial infections from 55 patients clinically diagnosed as tuberculosis in 2013 and 2014, based on conventional methods, were identified by PCR -RFLP and results are discussed. We have confirmed 35 (63.6 %) positive samples as M. tuberculosis, but 18 (32.7 %) were identified as non-tuberculous mycobacteria (M. avium type 1, M. avium type 2, M. kansasii type 1 type 1, M. mucogenicum, M. chelonae, M. terrae type 3, and 1 unknown RFLP pattern) and two were negative. Regarding clinical diagnosis, 61.8 % (34/55) was classified as pulmonary tuberculosis. It is important to emphasize that 36.4 % (20/55) of samples were misdiagnosed by conventional methods, and 11 (61.1 %) of the HIV positive patients (18/55) were NTM-coinfected. The identification of species in mycobacterial infections is essential for correct diagnosis and choice of treatment regimen, and misdiagnosis by conventional tools can lead to chronic disease, increased resistance and death.