Modulation of the Response to Mycobacterium leprae and Pathogenesis of Leprosy

Leprosy: Comprehensive insights into pathology, immunology, and cutting-edge treatment strategies, integrating nanoparticles and ethnomedicinal plants

Mycobacterium leprae is the causative agent responsible for the chronic disease known as leprosy. This condition is characterized by dermal involvement, often leading to peripheral nerve damage, sensory-motor loss, and related abnormalities. Both innate and acquired immunological responses play a role in the disease, and even in individuals with lepromatous leprosy, there can be a transient increase in T cell immunity during lepromatous reactions. Diagnosing of early-stage leprosy poses significant challenges. In this context, nanoparticles have emerged as a promising avenue for addressing various crucial issues related to leprosy. These include combatting drug resistance, mitigating adverse effects of conventional medications, and enhancing targeted drug delivery. This review serves as a comprehensive compilation, encompassing aspects of pathology, immunology, and adverse effects of multidrug delivery systems in the context of leprosy treatment. Furthermore, the review underscores the significance of ethnomedicinal plants, bioactive secondary metabolites, and nanotherapeutics in the management of leprosy. It emphasizes the potential to bridge the gap between existing literature and ongoing research efforts, with a profound scope for validating traditional claims, developing herbal medicines, and formulating nanoscale drug delivery systems that are safe, effective, and widely accepted.

Macrophage immunophenotypes in Jorge Lobo's disease and lepromatous leprosy- A comparative study

Jorge Lobo's disease (JLD) and lepromatous leprosy (LL) share several clinical, histological and immunological features, especially a deficiency in the cellular immune response. Macrophages participate in innate and adaptive inflammatory immune responses, as well as in tissue regeneration and repair. Macrophage function deficiency results in maintenance of diseases. M1 macrophages produce pro-inflammatory mediators and M2 produce anti-inflammatory cytokines. To better understand JLD and LL pathogenesis, we studied the immunophenotype profile of macrophage subtypes in 52 JLD skin lesions, in comparison with 16 LL samples, using a panmacrophage (CD68) antibody and selective immunohistochemical markers for M1 (iNOS) and M2 (CD163, CD204) responses, HAM56 (resident/fixed macrophage) and MAC 387 (recently infiltrating macrophage) antibodies. We found no differences between the groups regarding the density of the CD163, CD204, MAC387+ immunostained cells, including iNOS, considered a M1 marker. But HAM56+ cell density was higher in LL samples. By comparing the M2 and M1 immunomarkers in each disease separately, some other differences were found. Our results reinforce a higher M2 response in JLD and LL patients, depicting predominant production of anti-inflammatory cytokines, but also some distinction in degree of macrophage activation. Significant amounts of iNOS + macrophages take part in the immune milieu of both LL and JLD samples, displaying impaired microbicidal activity, like alternatively activated M2 cells.

Early diagnosis of neural impairment in seropositive leprosy household contacts: The experience of a reference center in Brazil

Introduction

Leprosy is an infectious disease that remains with a high number of new cases in developing countries. Household contacts have a higher risk for the development of the disease, but the neural impairment in this group is not well elucidated yet. Here, we measured the chance of occurrence of peripheral neural impairment in asymptomatic leprosy household.

Methods

Contacts who present anti-PGL-I IgM seropositivity, through electroneuromyography (ENMG) evaluation. We recruited 361 seropositive contacts (SPC) from 2017 to 2021, who were subjected to an extensive protocol that included clinical, molecular, and electroneuromyographic evaluations.

Results

Our data revealed a positivity of slit skin smear and skin biopsy qPCR of 35.5% (128/361) and 25.8% (93/361) respectively. The electroneuromyographic evaluation of the SPC showed neural impairment in 23.5% (85/361), with the predominance of a mononeuropathy pattern in 62.3% (53/85). Clinical neural thickening was observed in 17.5% (63/361) of seropositive contacts, but among the individuals with abnormal ENMG, only 25.9% (22/85) presented neural thickening in the clinical exam.

Discussion

Ours results corroborates the need to make the approach to asymptomatic contacts in endemic countries more timely. Since leprosy in its early stages can present an indolent and subclinical evolution, serological, molecular, and neurophysiological tools are essential to break the disease transmission chain.

Interplay among differential exposure to Mycobacterium leprae and TLR4 polymorphism impacts the immune response in household contacts of leprosy patients

Introduction

The aim of the present study was to investigate the association between the single nucleotide polymorphism (SNP) rs1927914 A/G in TLR4 gene and the immunological profile of household contacts (HHC) of leprosy patients. Leprosy classification is usually complex and requires the assessment of several clinical and laboratorial features.

Methods

Herein, we have applied distinct models of descriptive analysis to explore qualitative/quantitative changes in chemokine and cytokine production in HHC further categorized according to operational classification [HHC(PB) and HHC(MB)] and according to TLR4SNP.

Results and discussion

Our results showed that M. leprae stimuli induced an outstanding production of chemokines (CXCL8;CCL2; CXCL9; CXCL10) by HHC(PB), while increase levels of pro-inflammatory cytokines (IL-6; TNF; IFN-γ; IL-17) were observed for HHC(MB). Moreover, the analysis of chemokine and cytokine signatures demonstrated that A allele was associated with a prominent soluble mediator secretion (CXCL8; CXCL9; IL-6; TNF; IFN-γ). Data analysis according to TLR4 SNP genotypes further demonstrated that AA and AG were associated with a more prominent secretion of soluble mediators as compared to GG, supporting the clustering of AA and AG genotypes into dominant genetic model. CXCL8, IL-6, TNF and IL-17 displayed distinct profiles in HHC(PB) vs HHC(MB) or AA+AG vs GG genotype. In general, chemokine/cytokine networks analysis showed an overall profile of AA+GA-selective (CXCL9-CXCL10) and GG-selective (CXCL10-IL-6) axis regardless of the operational classification. However, mirrored inverted CCL2-IL-10 axis and a (IFN-γ-IL-2)-selective axis were identified in HHC(MB). CXCL8 presented outstanding performance to classify AA+AG from GG genotypes and HHC(PB) from HHC(MB). TNF and IL-17 presented elevated accuracy to classify AA+AG from GG genotypes and HHC(PB) (low levels) from HHC(MB) (high levels), respectively. Our results highlighted that both factors: i) differential exposure to M. leprae and ii) TLR4 rs1927914 genetic background impact the immune response of HHC. Our main results reinforce the relevance of integrated studies of immunological and genetic biomarkers that may have implications to improve the classification and monitoring of HHC in future studies.

Systematic identification and characterization of clinical and socio-economical correlates of granulomatous nasal and para-nasal sinuses: A large-scale study among patients of Odisha, India

Granulomatous formation in the nose and paranasal sinuses still presents an unmet clinical challenge as it affects both the physical health and personality of patients, and the lack of a systematic diagnostic and disease management approach has further complicated the scenario. Occurrence of granulomatous nasal disorder in the rural Indian population is associated with several factors such as lack of proper medical care, lack of hygienic and clean working and living conditions, and limited financial abilities to access the already overburdened primary healthcare system. This study aims to understand the correlation disease incidence, manifestation of signs and symptoms and associated socio-epidemiological parameters for 104,000 patients over a period of 23 months in Odisha. Primarily the study used socio-epidemiological surveys collected, annotated, and curated independently for granulomatous nasal disorder patients and compared this with their clinical records for signs & symptoms and performed several statistical analyses to better understand the disease incidence correlation with age, socio-economic and gender based parameters. Overall results suggest that males from low socio-economic background living in rural areas are the most vulnerable population and commonly affected with granulomatous nasal disorder (commonly Rhinosporidiosis sub-type) with common origin of the disease reported at the nasal septum and floor. We also highlight that change in the mass of nose followed by bleeds on touch, nasal discharge and hanging mass in throat are the most common manifestations presented by patients with granulomatous nasal disorders. Together, this research work identifies and characterise clinical and socio-economic factors that lead to and exacerbate the incidence of granulomatous nasal disorders.

Clinical and radiological evaluation of maxillofacial and otorhinolaryngological manifestations of Hansen's disease

To characterize maxillofacial, otorhinolaryngological and oral manifestations of Hansen's disease (HD), we conducted a cross-sectional study in 21 current patients attending the Unidade Básica de Saúde de Jardim América, Espírito Santo, Brazil and 16 former patients resident at Pedro Fontes Hospital using data from computed tomography imaging, rhinoscopy, and oroscopy. Maxillofacial characteristics were compared with 37 controls. Differences in bone alterations across the three groups were determined mainly by severe resorption/atrophy being more frequent in former HD patients, with severe resorption/atrophy of the anterior alveolar process of maxilla in 50.0% (8/16) of former patients, 28.6% (6/21) of current patients and 10.8% (4/37) of controls and of nasal bones and aperture in 31.3% (5/16) of former patients compared with 0/21 current patients and two controls. There were no substantial differences in otorhinolaryngological and oroscopic findings between the two patient groups. HD patients had more tooth loss than the age-matched control group. Maxillofacial, otorhinolaryngological and oroscopic finding scores were strongly correlated only in current HD patients. Correlation between otorhinolaryngological and maxillofacial scores suggests that protocols for HD patient assessment and follow-up could include otorhinolaryngological evaluation, with radiological imaging where necessary, subject to replication of our findings in a larger study.