Target product profiles: leprosy diagnostics.

The World Health Organization (WHO) aims to reduce new leprosy cases by 70% by 2030, necessitating advancements in leprosy diagnostics. Here we discuss the development of two WHO's target product profiles for such diagnostics. These profiles define criteria for product use, design, performance, configuration and distribution, with a focus on accessibility and affordability. The first target product profile outlines requirements for tests to confirm diagnosis of leprosy in individuals with clinical signs and symptoms, to guide multidrug treatment initiation. The second target product profile outlines requirements for tests to detect Mycobacterium leprae or M. lepromatosis infection among asymptomatic contacts of leprosy patients, aiding prophylactic interventions and prevention. Statistical modelling was used to assess sensitivity and specificity requirements for these diagnostic tests. The paper highlights challenges in achieving high specificity, given the varying endemicity of M. leprae, and identifying target analytes with robust performance across leprosy phenotypes. We conclude that diagnostics with appropriate product design and performance characteristics are crucial for early detection and preventive intervention, advocating for the transition from leprosy management to prevention.

L'Organisation mondiale de la Santé (OMS) vise à réduire le nombre de nouveaux cas de lèpre de 70% d'ici 2030, ce qui nécessite un meilleur diagnostic de la maladie. Dans le présent document, nous évoquons le développement de deux profils de produit cible établis par l'OMS à cette fin. Ces profils définissent des critères en matière d'utilisation, de conception, de performances, de configuration et de distribution du produit, en accordant une attention particulière à l'accessibilité et à l'abordabilité. Le premier profil de produit cible décrit les exigences pour les tests servant à confirmer le diagnostic de la lèpre chez les individus qui présentent des signes cliniques et des symptômes, afin d'orienter l'instauration d'un traitement à base de plusieurs médicaments. Le second profil de produit cible décrit les exigences pour les tests servant à détecter une infection à Mycobacterium leprae ou M. lepromatosis parmi les contacts asymptomatiques de patients lépreux, ce qui contribue à l'adoption de mesures prophylactiques et à la prévention. Nous avons eu recours à une modélisation statistique pour évaluer les exigences de sensibilité et de spécificité de ces tests diagnostiques. Cet article met en évidence les obstacles à l'atteinte d'un niveau élevé de spécificité en raison de l'endémicité variable de M. leprae, et à l'identification d'analytes cibles offrant de bons résultats chez les phénotypes lépreux. Nous concluons qu'un diagnostic reposant sur des caractéristiques de performance et de conception appropriées est essentiel pour détecter rapidement la maladie et intervenir en amont, et nous plaidons pour une prévention plutôt qu'une gestion de la lèpre.

La Organización Mundial de la Salud (OMS) pretende reducir los nuevos casos de lepra en un 70% para 2030, lo que requiere avances en el diagnóstico de la lepra. Aquí se analiza el desarrollo de dos perfiles de productos objetivo de la OMS para este tipo de diagnósticos. Estos perfiles definen los criterios de uso, diseño, rendimiento, configuración y distribución de los productos, centrándose en su accesibilidad y asequibilidad. El primer perfil de producto objetivo describe los requisitos de las pruebas para confirmar el diagnóstico de la lepra en personas con signos y síntomas clínicos, con el fin de orientar el inicio del tratamiento con múltiples fármacos. El segundo perfil de producto objetivo describe los requisitos de las pruebas para detectar la infección por Mycobacterium leprae o M. lepromatosis entre los contactos asintomáticos de los pacientes con lepra, para facilitar las intervenciones profilácticas y la prevención. Se utilizaron modelos estadísticos para evaluar los requisitos de sensibilidad y especificidad de estas pruebas diagnósticas. El artículo destaca las dificultades para lograr una alta especificidad, dada la diferente endemicidad de M. leprae, y para identificar analitos diana con un rendimiento sólido en todos los fenotipos de lepra. Concluimos que los diagnósticos con un diseño de producto y unas características de rendimiento adecuados son fundamentales para la detección precoz y la intervención preventiva, lo que favorece la transición del manejo de la lepra a la prevención.

A comparative study on the detection of Mycobacterium leprae DNA in urine samples of leprosy patients using Rlep-PCR with other conventional samples.

BACKGROUND: Mycobacterium leprae causes leprosy that is highly stigmatized and chronic infectious skin disease. Only some diagnostic tools are being used for the identification M. leprae in clinical samples, such as bacillary detection, and histopathological tests. These methods are invasive and often have low sensitivity. Currently, the PCR technique has been used as an effective tool fordetecting M. leprae DNA across different clinical samples. The current study aims to detect M. leprae DNA in urine samples of untreated and treated leprosy patients using the Rlep gene (129 bp) and compared the detection among Ridley-Jopling Classification. METHODS: Clinical samples (Blood, Urine, and Slit Skin Smears (SSS)) were collected from leprosy and Non-leprosy patients. DNA extraction was performed using standard laboratory protocol and Conventional PCR was carried out for all samples using Rlep gene target and the amplicons of urine samples were sequenced by Sanger sequencing to confirm the Rlep gene target. RESULTS: The M. leprae DNA was successfully detected in all clinical samples across all types of leprosy among all the study groups using RLEP-PCR. Rlep gene target was able to detect the presence of M. leprae DNA in 79.17% of urine, 58.33% of blood, and 50% of SSS samples of untreated Smear-Negative leprosy patients. The statistical significant difference (p = 0.004) was observed between BI Negative (Slit Skin Smear test) and RLEP PCR positivity in urine samples of untreated leprosy group. CONCLUSION: The PCR positivity using Rlep gene target (129 bp) was highest in all clinical samples among the study groups, across all types of leprosy. Untreated tuberculoid and PNL leprosy patients showed the highest PCR positivity in urine samples, indicating its potential as a non-invasive diagnostic tool for leprosy and even for contact screening.

Genetic diversity of Mycobacterium leprae: Need to move towards genome-wide approaches.

ABSTRACT: Leprosy, an ancient disease, continues to be a public health concern as it remains endemic in several countries. After reaching the elimination target (1/10,000) as a public health problem in 2005 in India, around 1.2 lakh cases have been detected every year over the last decade indicating active transmission of leprosy bacillus (Mycobacterium leprae). Single-nucleotide polymorphisms (SNPs), genomic insertions/deletions and variable-number tandem repeats (VNTRs) have been identified as genetic markers for tracking M. leprae transmission. As the leprosy bacilli cannot be cultured in vitro, molecular testing of M. leprae genotypes is done by polymerase chain reaction-based sequencing which provides a practical alternative for the identification of strains as well as drug resistance-associated mutations. Whole-genome sequencing (WGS) of M. leprae directly from clinical samples has also proven to be an effective tool for identifying genetic variations which can further help refine the molecular epidemiological schemes based on SNPs and VNTRs. However, the WGS data of M. leprae strains from India are scarce, being responsible for a gross under-representation of the genetic diversity of M. leprae strains present in India and need to be addressed suitably. Molecular studies of leprosy can provide better insight into phylogeographic markers to monitor the transmission dynamics and emergence of antimicrobial resistance. An improved understanding of M. leprae transmission is essential to guide efficient leprosy control strategies. Therefore, this review compiles and discusses the current status of molecular epidemiology, genotyping and the potential of genome-wide analysis of M. leprae strains in the Indian context.

Mitochondrial variants of complex I genes associated with leprosy clinical subtypes.

Leprosy is a chronic bacterial infection mainly caused by Mycobacterium leprae that primarily affects skin and peripheral nerves. Due to its ability to absorb carbon from the host cell, the bacillus became dependent on energy production, mainly through oxidative phosphorylation. In fact, variations in genes of Complex I of oxidative phosphorylation encoded by mtDNA have been associated with several diseases in humans, including bacterial infections, which are possible influencers in the host response to leprosy. Here, we investigated the presence of variants in the mtDNA genes encoding Complex I regarding leprosy, as well as the analysis of their pathogenicity in the studied cohort. We found an association of 74 mitochondrial variants with either of the polar forms, Pole T (Borderline Tuberculoid) or Pole L (Borderline Lepromatous and Lepromatous) of leprosy. Notably, six variants were exclusively found in both clinical poles of leprosy, including m.4158A>G and m.4248T>C in MT-ND1, m.13650C>A, m.13674T>C, m.12705C>T and m.13263A>G in MT-ND5, of which there are no previous reports in the global literature. Our observations reveal a substantial number of mutations among different groups of leprosy, highlighting a diverse range of consequences associated with mutations in genes across these groups. Furthermore, we suggest that the six specific variants exclusively identified in the case group could potentially play a crucial role in leprosy susceptibility and its clinical differentiation. These variants are believed to contribute to the instability and dysregulation of oxidative phosphorylation during the infection, further emphasizing their significance.

Epidemiological, clinical, and geographical characterization of Leprosy in the County of Santarém-Pará: Insights for effective control and targeted intervention.

Leprosy is an infectious disease characterized by slow and chronic evolution, caused by Mycobacterium leprae and or Mycobacterium lepromatosis, an intracellular alcohol-acid-resistant (BAAR) bacillus. The objective of this study was to provide an epidemiological, clinical, and geographic characterization of leprosy in the city of Santarém-Pará during the period 2011-2020. A cross-sectional, descriptive, and quantitative approach was used, employing maps and tables to illustrate clinical and epidemiological variables, including: sex, age, race, area of residence, operational classification, clinical form, number of skin lesions, number of affected nerves, and health units. During the analyzed period, 581 cases of leprosy were diagnosed, resulting in the following cumulative incidence rates: male (60%); age over 15 years (94%); urban area (73%); multibacillary (74%); borderline form (46%); skin lesions greater than 5 (34%); and no nerves affected (68%). In the urban perimeter, a higher cumulative incidence of cases was observed in the central area with 133 cases. However, the health unit reporting the largest number of cases belonged to the southern area, specifically the Basic Health Unit of Nova República, with 48 cases. This study highlights the need to characterize the nuances of leprosy and its variability within the urban environment, according to different areas. Further research is essential to inform the implementation of public policies aimed at addressing the population with the highest vulnerability index, thereby reducing leprosy rates in Santarém.

Non-Tuberculous Mycobacterial isolates from Panama: A retrospective 5-year analysis (2017-2021).

BACKGROUND: The genus Mycobacterium includes well-known bacteria such as M. tuberculosis causing tuberculosis and M. leprae causing leprosy. Additionally, various species collectively termed non-tuberculous mycobacteria (NTM) can cause infections in humans and animals, affecting individuals across all age groups and health conditions. However, information on NTM infection prevalence in Panama is limited. METHODS: This study conducted a retrospective analysis of clinical records from 2017 to 2021, specifically focusing on patients with NTM isolates. Data were categorized by variables like sex, age, HIV status, and sample source. RESULTS: Among the 4430 clinical records analyzed, 698 were linked to patients with NTM isolates. Of these patients, 397 were male, and 301 were female. Most female patients with NTM isolates (n = 190) were aged >45 to 85 years, while most male patients (n = 334) fell in the >25 to 75 years age group. A noteworthy proportion of male patients (n = 65) were aged 25-35 years. A significant age difference between male (median [min-max] = 53 years [3-90]) and female (median [61 years [6-94]) patients was observed (p < 0.001). Regarding HIV status, 77 positive individuals were male, and 19 were female (p < 0.001). Most samples (n = 566) were sputum samples, with additional pulmonary-associated samples such as broncho-alveolar lavage, tracheal secretions, and pleural fluid samples. Among extrapulmonary isolates (n = 48), sources included catheter secretions, intracellular fluids, peritoneal fluid, blood cultures, cerebrospinal fluid, bone marrow samples, and capillary transplant lesions. Specifically, the analysis identified the pathogenic microorganisms responsible for mycobacteriosis in Panama during the specific period 2017-2021, as M. fortuitum (34.4%), M. intracellulare (20.06%), and M. abscessus (13.75%), respectively. CONCLUSIONS: This study highlights the growing public health concern of NTM infections in Panama. The research provides valuable insights into the prevalence and distribution of NTM species in the country, offering a foundation for the development and implementation of effective prevention and control strategies for NTM infections in Panama.

Leprosy mimicking autoimmune diseases: a case series.

OBJECTIVES: Leprosy is a chronic granulomatous disease caused by Mycobacterium leprae. Less frequently, there is involvement of the musculoskeletal system, and occurrence of systemic manifestation with non-specific symptoms such as fever, fatigue and myalgia. Therefore, leprosy can often mimic autoimmune diseases such as arthritis, vasculitis, or collagenosis and be mis-diagnosed. METHODS: This study describes a series of cases of leprosy mimicking autoimmune diseases in patients treated in the Rheumatology Department of our centre in the period 2019 to 2023. All patients were investigated regarding leprosy criteria and had clinical evaluation, serum markers, and histopathological analyses recorded. The diagnosis of leprosy was confirmed using skin biopsy followed by testing for acid-fast bacillus (AFB) or smear microscopy. RESULTS: Six patients who were initially investigated for autoimmune diseases were identified as diagnosed as leprosy cases, fulfilling both clinical and histopathologic criteria, two of whom presented with symptoms of polyarthritis with an inflammatory characteristic, two diffuse erythematous-violaceous lesions, three recurrent fever, three arthralgia, and one Raynaud's phenomenon, which are all characteristics present most frequently in rheumatologic diseases. CONCLUSIONS: We must consider the bacillary infection as a differential diagnosis of autoimmune diseases. Histopathological analysis is an important tool and the gold standard for diagnostic confirmation.

Bioarchaeological investigation of individuals with suspected multibacillary leprosy from the mediaeval leprosarium of St Mary Magdalen, Winchester, Hampshire, UK.

Introduction. We have examined four burials from the St Mary Magdalen mediaeval leprosarium cemetery in Winchester, Hampshire, UK. One (Sk.8) was a male child, two (Sk.45 and Sk.52) were adolescent females and the fourth (Sk.512) was an adult male. The cemetery was in use between the 10th and 12th centuries. All showed skeletal lesions of leprosy. Additionally, one of the two females (Sk.45) had lesions suggestive of multi-cystic tuberculosis and the second (Sk.52) of leprogenic odontodysplasia (LO), a rare malformation of the roots of the permanent maxillary incisors.Gap statement. Relatively little is known of the manifestations of lepromatous leprosy (LL) in younger individuals from the archaeological record.Aims and Methodology. To address this, we have used ancient DNA testing and osteological examination of the individuals, supplemented with X-ray and microcomputed tomography (micro-CT) scan as necessary to assess the disease status.Results and Conclusions. The presence of Mycobacterium leprae DNA was confirmed in both females, and genotyping showed SNP type 3I-1 strains but with a clear genotypic variation. We could not confirm Mycobacterium tuberculosis complex DNA in the female individual SK.45. High levels of M. leprae DNA were found within the pulp cavities of four maxillary teeth from the male child (Sk.8) with LO, consistent with the theory that the replication of M. leprae in alveolar bone may interfere with root formation at key stages of development. We report our biomolecular findings in these individuals and review the evidence this site has contributed to our knowledge of mediaeval leprosy.

Molecular epidemiological characteristics of Mycobacterium leprae in highly endemic areas of China during the COVID-19 epidemic.

Objectives: The present study analyzed the impact of the COVID-19 pandemic on the prevalence and incidence of new leprosy cases, as well as the diversity, distribution, and temporal transmission of Mycobacterium leprae strains at the county level in leprae-endemic provinces in Southwest China. Methods: A total of 219 new leprosy cases during two periods, 2018-2019 and 2020-2021, were compared. We genetically characterized 83 clinical isolates of M. leprae in Guizhou using variable number tandem repeats (VNTRs) and single nucleotide polymorphisms (SNPs). The obtained genetic profiles and cluster consequences of M. leprae were compared between the two periods. Results: There was an 18.97% decrease in the number of counties and districts reporting cases. Considering the initial months (January-March) of virus emergence, the number of new cases in 2021 increased by 167% compared to 2020. The number of patients with a delay of >12 months before COVID-19 (63.56%) was significantly higher than that during COVID-19 (48.51%). Eighty-one clinical isolates (97.60%) were positive for all 17 VNTR types, whereas two (2.40%) clinical isolates were positive for 16 VNTR types. The (GTA)9, (TA)18, (TTC)21 and (TA)10 loci showed higher polymorphism than the other loci. The VNTR profile of these clinical isolates generated five clusters, among which the counties where the patients were located were adjacent or relatively close to each other. SNP typing revealed that all clinical isolates possessed the single SNP3K. Conclusion: COVID-19 may have a negative/imbalanced impact on the prevention and control measures of leprosy, which could be a considerable fact for official health departments. Isolates formed clusters among counties in Guizhou, indicating that the transmission chain remained during the epidemic and was less influenced by COVID-19 preventative policies.

Neural leprosy investigation using electroneuromyography and the ML Flow rapid test: a case report.

Neural leprosy, which is characterized by nerve involvement without visible skin lesions, presents a diagnostic challenge. This case report examined the significance of diverse diagnostic modalities in the identification of pure neural leprosy. A 28-year-old patient with symptoms of edema, pain, paresthesia, and diminished sensitivity in the lower limbs underwent various tests. A stilt skin smear yielded negative results on bacilloscopy, whereas a Fast ML Flow leprosy test and electroneuromyography supported the diagnosis. This discussion highlights the importance of accessible methods for early investigation. This study emphasizes the multidisciplinary approach and value of the Fast ML Flow leprosy test and electroneuromyography for diagnosing neural leprosy.

Different profiles of chemokines, cytokines and cell growth factors in plasma samples from patients with leprosy, leprosy reactions and households contacts.

BACKGROUND: Leprosy is a highly neglected disease that is considered a serious public health problem in many countries. This illness is characterised by a variety of clinical and histopathological manifestations that are related to the patient immune response. OBJECTIVES: This work aimed evaluate the profile of circulating immune mediators in the plasma from patients classified clinically as paucibacillary (PB), multibacillary (MB), households contacts (HHC), type1 leprosy reaction (T1R), type2 leprosy reaction (T2R) and control individuals without medical history of leprosy (CTL). METHODS: To assessment of the plasma immune mediators was used multiplex microbeads immunoassay "Luminex". FINDINGS: The results showed that patients (PB) had a regulatory-biased profile, while MB revealed a pro-inflammatory trend of highly expressed biomarkers. HHC display conspicuously increased levels in the plasma of the chemokines (CCL2, CCL3, CCL4, CCL5 and CXCL8), pro-inflammatory cytokines (IFN-γ,TNF and IL-1ß), modulating cytokines (IL-9 and IL-1Ra) and growth factors (PDGF, G-CSF and IL-2). Interestingly, HHC displayed superior production of IFN-γ as compared to other leprosy groups, indicating a putative protective role for this cytokine during chronic Mycobacterium leprae exposure. MAIN CONCLUSION: Further investigations are currently underway to elucidate the potential of these mediators as biomarkers applicable to the diagnosis/prognosis of leprosy and also T1R and T2R leprosy reactions.

Half a Century in Hiding: A Unique Case of Tuberculoid Leprosy with an Unprecedented Incubation Period.

BACKGROUND Leprosy, also known as Hansen's disease, is a neglected tropical disease with low prevalence in the United States. The disease's long incubation period can cause delayed presentation, and most affected individuals have a history of travel or work in leprosy-endemic regions. The immune response to Mycobacterium leprae determines the clinical characteristics of leprosy, with tuberculoid leprosy being characterized by well-defined granulomas and involvement of peripheral nerves. The recommended treatment is a combination of dapsone and rifampin for 12 months. CASE REPORT A 78-year-old man with a history of extensive travel to Africa and Asia 50 years ago, presented with a non-tender, non-pruritic, and hypopigmented skin lesion on his left knee. Biopsy results confirmed granulomatous inflammation and the presence of Mycobacterium leprae, leading to a diagnosis of tuberculoid/paucibacillary leprosy. The patient received dapsone and rifampin treatment, which resulted in symptom improvement. CONCLUSIONS The patient's long incubation period of 50 years between exposure and symptom onset is remarkable and possibly one of the longest reported for tuberculoid leprosy. It emphasizes the importance of considering leprosy in cases with an extensive travel history and long incubation periods. Our patient's case presented contradictory staining results, suggesting potential sampling variation or a rare mixed leprosy form. Based on his clinical findings, he was diagnosed with tuberculoid leprosy. Early diagnosis and treatment are crucial to prevent irreversible nerve damage and improve patient outcomes. Healthcare providers should be vigilant in acquiring a detailed travel history to facilitate early diagnosis and appropriate management of leprosy cases.

New threats from an old foe: Evaluating the risk to the blood supply due to increasing incidence and endemicity of leprosy in the United States.

Leprosy (i.e., Hansen's disease) is a chronic disease secondary to infection with either Mycobacterium leprae or M. lepromatosis. While the incidence of this disease is decreasing across the world, there is mounting evidence that it might be increasing, and becoming endemic, in the United States. Leprosy was once considered a potential threat to the blood supply, and while this threat has not borne out, it is worth revisiting the available data to assess whether it may pose a threat in the future. Herein, we discuss the evidence for and against the potential for transfusion-transmission of leprosy, and highlight future areas of research to further elucidate this possibility.

Unlocking Opportunities for Mycobacterium leprae and Mycobacterium ulcerans.

In the recent decade, scientific communities have toiled to tackle the emerging burden of drug-resistant tuberculosis (DR-TB) and rapidly growing opportunistic nontuberculous mycobacteria (NTM). Among these, two neglected mycobacteria species of the Acinetobacter family, Mycobacterium leprae and Mycobacterium ulcerans, are the etiological agents of leprosy and Buruli ulcer infections, respectively, and fall under the broad umbrella of neglected tropical diseases (NTDs). Unfortunately, lackluster drug discovery efforts have been made against these pathogenic bacteria in the recent decade, resulting in the discovery of only a few countable hits and majorly repurposing anti-TB drug candidates such as telacebec (Q203), P218, and TB47 for current therapeutic interventions. Major ignorance in drug candidate identification might aggravate the dramatic consequences of rapidly spreading mycobacterial NTDs in the coming days. Therefore, this Review focuses on an up-to-date account of drug discovery efforts targeting selected druggable targets from both bacilli, including the accompanying challenges that have been identified and are responsible for the slow drug discovery. Furthermore, a succinct discussion of the all-new possibilities that could be alternative solutions to mitigate the neglected mycobacterial NTD burden and subsequently accelerate the drug discovery effort is also included. We anticipate that the state-of-the-art strategies discussed here may attract major attention from the scientific community to navigate and expand the roadmap for the discovery of next-generation therapeutics against these NTDs.

The role of neurotrophin polymorphisms and susceptibility to neural damage in leprosy.

OBJECTIVES: Mycobacterium leprae is able to infect Schwann cells leading to neural damage. Neurotrophins are involved in nervous system plasticity and impact neural integrity during diseases. Investigate the association between single nucleotide polymorphisms in neurotrophin genes and leprosy phenotypes, especially neural damage. DESIGN: We selected single nucleotide polymorphisms in neurotrophins or their receptors genes associated with neural disorders: rs6265 and rs11030099 of brain-derived neurotrophic factor (BDNF), rs6330 of BDNF, rs6332 in NT3 and rs2072446 of P75NTR. The association of genetic frequencies with leprosy phenotypes was investigated in a case-control study. RESULTS: An association of the BDNF single nucleotide polymorphism rs11030099 with the number of affected nerves was demonstrated. The "AA+AC" genotypes were demonstrated to be protective against nerve impairment. However, this variation does not affect BDNF serum levels. BDNF is an important factor for myelination of Schwann cells and polymorphisms in this gene can be associated with leprosy outcome. Moreover, rs11030099 is located in the binding region for micro-RNA (miRNA) 26a that could be involved in control of BDNF expression. We demonstrated different expression levels of this miRNA in polar forms of leprosy. CONCLUSION: Our findings demonstrate for the first time an association between the polymorphism rs11030099 in the BDNF gene and neural commitment in leprosy and may indicate a possible role of miRNA-26a acting synergistically to these genetic variants in neural damage development.

Antimicrobial Stewardship Program: Time to be Focused in Speciality Settings of Leprosy Institute and Related Health Care Setup.

Leprosy, often known as Hansen's disease is a contagious chronic infectious disease caused by Mycobacterium leprae (M. leprae). Our methodology is easily repeatable in tertiary care settings with diagnostic accuracy resources and staff capable of building a stewardship team. Comprehensive antimicrobial policies and programmes are required to properly alleviate the initial issue.

The spectrum of central nervous system manifestations in leprosy: a systematic review of published case reports and case series.

BACKGROUND: This systematic review aimed to investigate central nervous system (CNS) involvement in leprosy by analysing multiple cohort studies, individual cases and case series. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. PubMed, Scopus and Embase databases were searched up to 8 July 2023, using a predefined search strategy. Inclusion criteria included patients diagnosed with leprosy with evidence of CNS involvement. The quality of the included cases was evaluated using the Joanna Briggs Institute checklist. RESULTS: A total of 34 records were identified, including 18 cohort studies and 16 reports describing 27 isolated cases. Autopsies revealed macroscopic changes in the spinal cord, neurofibrillary tangles and senile plaques. Mycobacterium leprae was detected in neurons of the medulla oblongata and spinal cord using PCR and phenolic glycolipid 1 staining. Cerebrospinal fluid (CSF) analysis showed inflammatory changes, increased gamma globulins and detection of Mycobacterium leprae antigens and antibodies. In 21 patients (78%), spinal cord/brachial plexus abnormities were detected. In the majority, MRI revealed T2/fluid-attenuated inversion recovery (FLAIR) hyperintensity in the cervical cord. In patients with brainstem involvement, T2/FLAIR hyperintensity was noted in the cerebellar peduncles, facial nerve nuclei and/or other cranial nerve nuclei. Brain parenchymal involvement was noted in three patients. CONCLUSIONS: This systematic review provides evidence of CNS involvement in leprosy, based on autopsy findings, neuroimaging, CSF analysis and neurophysiological studies.

Mycobacterium leprae is able to infect adipocytes, inducing lipolysis and modulating the immune response.

Leprosy is a chronic infectious disease caused by the intracellular bacillus Mycobacterium leprae (M. leprae), which is known to infect skin macrophages and Schwann cells. Although adipose tissue is a recognized site of Mycobacterium tuberculosis infection, its role in the histopathology of leprosy was, until now, unknown. We analyzed the M. leprae capacity to infect and persist inside adipocytes, characterizing the induction of a lipolytic phenotype in adipocytes, as well as the effect of these infected cells on macrophage recruitment. We evaluated 3T3-L1-derived adipocytes, inguinal adipose tissue of SWR/J mice, and subcutaneous adipose tissue biopsies of leprosy patients. M. leprae was able to infect 3T3-L1-derived adipocytes in vitro, presenting a strong lipolytic profile after infection, followed by significant cholesterol efflux. This lipolytic phenotype was replicated in vivo by M. leprae injection into mice inguinal adipose tissue. Furthermore, M. leprae was detected inside crown-like structures in the subcutaneous adipose tissue of multibacillary patients. These data indicate that subcutaneous adipose tissue could be an important site of infection, and probably persistence, for M. leprae, being involved in the modulation of the innate immune control in leprosy via the release of cholesterol, MCP-1, and adiponectin.

Novel mutations found in Mycobacterium leprae DNA repair gene nth from central India.

INTRODUCTION: The importance of DNA repair enzymes in maintaining genomic integrity is highlighted by the hypothesis that DNA damage by reactive oxygen/nitrogen species produced inside the host cell is essential for the mutagenesis process. Endonuclease III (Nth), formamidopyrimide (Fpg) and endonuclease VIII (Nei) DNA glycosylases are essential components of the bacterial base excision repair process. Mycobacterium leprae lost both fpg/nei genes during the reductive evolution event and only has the nth (ML2301) gene. This study aims to characterize the mutations in the nth gene of M. leprae strains and explore its correlation with drug-resistance. METHOD: A total of 91 M. leprae positive DNA samples extracted from skin biopsy samples of newly diagnosed leprosy patients from NSCB Hospital Jabalpur were assessed for the nth gene as well as drug resistance-associated loci of the rpoB, gyrA and folP1 genes through PCR followed by Sanger sequencing. RESULTS: Of these 91 patients, a total of two insertion frameshift mutations, two synonymous and seven nonsynonymous mutations were found in nth in seven samples. Sixteen samples were found to be resistant to ofloxacin and one was found to be dapsone resistant as per the known DRDR mutations. No mutations were found in the rpoB region. Interestingly, none of the nth mutations were identified in the drug-resistant associated samples. CONCLUSION: The in-silico structural analysis of the non-synonymous mutations in the Nth predicted five of them were to be deleterious. Our results suggest that the mutations in the nth gene may be potential markers for phylogenetic and epidemiological studies.