Leprosy Skin Lesions Research Articles

Leprosy knowledge among primary care physicians in Southern Brazil: are we underdiagnosing?

Leprosy is a chronic infection with high morbidity in Brazil. Primary care physicians' lack of knowledge about the disease may play a significant role in underdiagnosis. This study aimed to assess primary care physicians' ability to identify typical leprosy skin lesions and their knowledge of the subject. This cross-sectional study relied on a questionnaire in which participating doctors chose one main diagnostic hypothesis and two differential diagnoses for each skin lesion presented. Five leprosy lesions were included. Questions regarding management, follow-up, and diagnostic workup for the disease were also included. The questionnaire was sentto primary care physicians working in Curitiba, in the Southern Brazilian state of Paraná, and dermatologists, who constituted the control group. Thirty-two primary care physicians and 26 dermatologists agreed to participate in the study. Primary care physicians accurately identified a mean of 1.8 ± 1.2 of the five leprosy skin lesions, while dermatologists accurately identified 2.5 ± 0.9 (P = 0.009). The main misdiagnosed leprosy forms were the lepromatous and histoid variants. Among primary care physicians, 56.2% claimed to have little knowledge of the subject and a large share of participants was unaware of recent updates in treating paucibacillary forms, even within the dermatologist subgroup. Primary care physicians in Curitiba have little information regarding the diagnosis, treatment, and follow-up of leprosy. Even dermatologists had difficulties with treatment and patient management, emphasizing the constant need for education on this subject.

Dermatoscopic evaluation of leprosy: A multi-centre cross-sectional study.

Background Leprosy is known to be a great mimicker. Its dermatoscopic evaluation may be of value in establishing diagnosis. Objective To study the dermatoscopic findings encountered across the leprosy spectrum. Methods This was a multi-centre cross-sectional study of leprosy patients, where after a thorough cutaneous and neurological evaluation, representative skin lesions from the study patients were photographed in standard settings, and the most representative skin lesions were chosen for dermatoscopic evaluation. Data was entered in a structured proforma and a descriptive analysis of dermatoscopic patterns was carried out. Results A total of 53 cases of ages between 14 and 80 years, ranging from tuberculoid to the lepromatous spectrum of disease, with active skin lesions in the form of patches and plaques were included. The spectrum of leprosy as per Ridley-Jopling classification at diagnosis was indeterminate in 1 (1.9%), tuberculoid in 1 (1.9%), borderline tuberculoid in 25 (21.5%), borderline lepromatous in 9 (17%), lepromatous in 14 (26.4%) and histoid in 3 (5.7%). Dermatoscopic features included distorted pigment network in 48 (90.6%), focal white areas in 40 (75.5%), reduced eccrine and follicular openings in 43 (81.1%), widened skin lines in 28 (52.8%), circle hairs in 15 (28.3%) and white shiny streaks in 17 (32.1%). Conclusion Dermatoscopy is a practical, non-invasive device to assess skin lesions of leprosy and provide cues to its diagnosis, spectral classification and differentiating it from other granulomatous disorders. However, dermatoscopy alone cannot reliably differentiate between the various types of leprosy and future large-scale studies are required. Limitations of the study The numbers for each subtype were variable and few in some spectrum of leprosy patients. A dermatoscopic-histologic correlation was not done.

Immunohistochemical Characterization of M1, M2, and M4 Macrophages in Leprosy Skin Lesions.

Mycobacterium leprae is the etiological agent of leprosy. Macrophages (Mφs) are key players involved in the pathogenesis of leprosy. In this study, immunohistochemical analysis was performed to examine the phenotype of Mφ subpopulations, namely M1, M2, and M4, in the skin lesions of patients diagnosed with leprosy. Based on the database of treatment-naïve patients treated between 2015 and 2019 at the Department of Dermatology of the University of the State of Pará, Belém, routine clinical screening samples were identified. The monolabeling protocol was used for M1 macrophages (iNOS, IL-6, TNF-α) and M2 macrophages (IL-10, IL-13, CD163, Arginase 1, TGF-β, FGFb), and the double-labeling protocol was used for M4 macrophages (IL-6, MMP7, MRP8, TNF-α e CD68). To confirm the M4 macrophage lineage, double labeling of the monoclonal antibodies CD68 and MRP8 was also performed. Our results demonstrated a statistically significant difference for the M1 phenotype among the Virchowian (VV) (4.5 ± 1.3, p < 0.0001), Borderline (1.6 ± 0.4, p < 0.0001), and tuberculoid (TT) (12.5 ± 1.8, p < 0.0001) clinical forms of leprosy. Additionally, the M2 phenotype showed a statistically significant difference among the VV (12.5 ± 2.3, p < 0.0001), Borderline (1.3 ± 0.2, p < 0.0001), and TT (3.2 ± 0.7, p < 0.0001) forms. For the M4 phenotype, a statistically significant difference was observed in the VV (9.8 ± 1.7, p < 0.0001), Borderline (1.2 ± 0.2, p < 0.0001), and TT (2.6 ± 0.7, p < 0.0001) forms. A significant correlation was observed between the VV M1 and M4 (r = 0.8712; p = 0.0000) and between the VV M2 × TT M1 (r = 0.834; p = 0.0002) phenotypes. The M1 Mφs constituted the predominant Mφ subpopulation in the TT and Borderline forms of leprosy, whereas the M2 Mφs showed increased immunoexpression and M4 was the predominant Mφ phenotype in VV leprosy. These results confirm the relationship of the Mφ profile with chronic pathological processes of the inflammatory response in leprosy.

A cytohistopathological correlation study of skin lesions in leprosy: An experience in a tertiary care hospital in South India

Objectives: Leprosy is a granulomatous disease caused by Mycobacterium leprae. Early detection and clinical diagnosis remain a challenge, especially in paucibacillary cases and initial lesions during early phases of leprosy. Use of cytological methods can reduce time for diagnosis, especially in peripheral centers. The present study was taken up to calculate the correlation between cytology and histopathology of skin lesions in leprosy. Materials and Methods: This study is a 2-year retrospective observational study taken up in the Department of Pathology, Rangaraya Medical College and Government General Hospital, Kakinada, Andhra Pradesh. A total of 49 cases of clinically suspected leprosy were included in the study. Skin biopsies and cytological smears were examined in all cases. Results: A total of 49 cases of clinically suspected leprosy were included in the study. The age incidence ranged between 9 and 72 years. There was a male preponderance. The overall diagnostic accuracy of fine-needle aspiration smears was 83.3% and that of slit-skin smears was 62.1%. Conclusions: Cytological examination being a simple, less time-consuming, and easy technique can enhance the diagnostic accuracy in detection of leprosy and act as an adjunct to clinical diagnosis.

Study of mast cell density, distribution and morphology in skin lesions of leprosy

Background: Mast cells are found at all levels of dermis, grouped around blood vessels, nerves and appendages. An increase in the mast cell number has been reported in various cutaneous diseases. Mast cells respond to diverse range of stimuli like neuronal impulses, allergens, antigens, hormones, cytokines from T cells and keratinocytes and thus play a role in manifestation of dermatological disorders. The objective was to study mast cell density in various subsets of Hansen’s disease and analyse whether the distribution and density vary amongst the subsets. Methods: A total of 60 skin biopsies diagnosed as leprosy were included in this study. 10 control slides were also studied for mast cell density and distribution. Histopathological diagnosis was made on the biopsy and mast cell density and distribution was assessed on toluidine blue stained sections and compared with those of controls. Results: All the subsets of Hansen’s disease studied showed an increase in the number of mast cells. The highest mean mast cell count was noted in lepromatous leprosy (66/mm2), followed by erythema nodosum leprosum (42.6/mm2) and borderline lepromatous leprosy (40.8/mm2). The mean mast cell count showed progressive increase over the immunological spectrum of tuberculoid leprosy to lepromatous leprosy. The mast cells showed spindle and ovoid morphology in all the lesions (active) while round morphology was seen in controls. Conclusion: Tissue mast cell number, distribution and morphology vary depending on the degree of activation in different leprosy lesions. This may have a bearing on the diagnosis and management. Keywords: mast cells; lepromatous leprosy; tuberculoid leprosy; borderline tuberculoid; indeterminate leprosy

Dermatological Quality of Life among Leprosy Patients Residing at a Rehabilitation Center in North-Eastern India: A Cross-Sectional Study

Background: Leprosy has been affecting humans since ancient times. A chronic infectious disease, it affects skin, peripheral nervous system, and other tissues which lead to nerve damage, pain, and visible deformities. The characteristic skin lesions of leprosy can lead to significant social stigmatization and functional impairments which can affect the quality of life (QoL). Objective: The present study was conducted to assess the dermatological QoL among these leprosy patients. Materials and Methods: An observational cross-sectional study was conducted among 122 leprosy patients who were receiving treatments at a rehabilitation center in North-Eastern India in a 3-month time period. The dermatology QoL Index (DQLI) questionnaire was used to assess the QoL among these patients. Descriptive statistics and logistic regression analyses were used. Results: Among a total of 122 patients, leprosy had no effect on QoL in 4.9%, small effect in 11.5%, moderate effect in 37.7%, very large effect in 43.4%, and extremely large effect in 2.5% cases. Mean DQLI score was 10.5 ± 5.1. The most affected domain was leisure and social followed by symptoms and feelings. When adjusted for predictors, age and sex were found to have a significant association with QoL. Conclusions: Leprosy with dermatological manifestations had a very large effect on QoL. The impairment was more than other chronic skin diseases, such as chronic urticaria, vitiligo, and psoriasis. It is necessary that periodic assessment of QoL should be incorporated into the management of leprosy patients.

Covid-19 caseload in the UK—assessments and mitigations

The variability of mast cell density within and between leprosy skin lesions was examined as a basis for future studies, and whether the number of mast cells in the lesion...

The expression of FOXP3 in lesions of several forms of leprosy in patients co-infected with HIV.

BackgroundBrazil remains endemic for infection by the human immunodeficiency virus (HIV) and leprosy, having a major impact on public health and the life quality of affected patients. Although the relevance of this co-infection is recognized, several aspects, such as the immune response, are not yet fully understood. The objective of this study was to investigate the expression of FOXP3+ Treg cells in leprosy skin lesions and to correlate their clinical forms, laboratory characteristics (CD4, CD8, and CV), and the immune reconstitution syndrome in HIV-leprosy co-infection.Methodology/Principal findingsAn observational, cross-sectional, and analytical study was carried out comparing four groups of patients: those with concomitant diagnosis of leprosy and HIV infection without a leprosy reaction, those with leprosy and HIV co-infection patients with a reverse reaction (RR), those with leprosy without HIV and without reaction, and those with leprosywithout HIV and with RR. The patients were diagnosed at a dermatology outpatient clinic located in Belém, Pará, Brazil, from 2003 to 2017. In the sample studied, there was a positive correlation between FOXP3+ cell density and viral load, negative correlation with blood CD4+ (not statistically significant), significant positive correlation in CD8 count in patients with leprosy reaction, and positive relationship in patients with IRIS. The density of cells expressing FOXP3 was higher in the BL/LL forms in patients without HIV, although the difference was not statistically significant. However, the cell mean was higher in the TT/BT forms in patients co-infected with leprosy and HIV, showing contradictory results.Conclusions/SignificanceThese findings support that higher activity of the HIV may stimulate or result in a higher expression of FOXP3-Tregs and that they may be involved in active immunosuppression observed at the infection site at the tissue level. This supports the need to expand studies on FOXP3+ Treg cells in co-infected patients.

Comparison between fine-needle aspiration cytology and histopathology in leprosy: A cross-sectional study

Objectives: The objectives of the study were (1) to study the fine-needle aspiration cytology (FNAC) features of skin lesions of leprosy, (2) to determine the agreement between FNAC and histopathology to classify leprosy into different groups of the spectrum, and (3) to determine the sensitivity and specificity of FNAC to classify leprosy into different groups of the spectrum against the gold standard of histopathology. Materials and Methods: All newly diagnosed cases of leprosy who attended the outpatient department of dermatology and venereology of a tertiary referral center during the 16 months study period were included in this cross-sectional study. Based on FNAC and histopathology, patients were classified into different groups of the spectrum. Agreement between FNAC and histopathology to classify leprosy was determined by Kappa statistics. Sensitivity and specificity of FNAC to classify leprosy were determined against the gold standard of histopathology. Results: All the 47 study participants had histopathology features of leprosy. FNAC could obtain adequate aspirate in 30 patients (63.8%), who were considered for further analysis. There was moderate agreement (76.6%) between classification of leprosy by FNAC and histopathology on Kappa statistics (Kappa value 0.766). FNAC showed 80–100% sensitivity and 84–100% specificity to classify leprosy against the gold standard of histopathology. Limitation: Small sample size. Conclusion: When adequate aspirate is obtained, FNAC could serve as a useful tool in classification of leprosy.

Mycobacterium leprae promotes triacylglycerol de novo synthesis through induction of GPAT3 expression in human premonocytic THP-1 cells.

Mycobacterium leprae (M. leprae) is the etiological agent of leprosy, and the skin lesions of lepromatous leprosy are filled with numerous foamy or xanthomatous histiocytes that are parasitized by M. leprae. Lipids are an important nutrient for the intracellular survival of M. leprae. In this study, we attempted to determine the intracellular lipid composition and underlying mechanisms for changes in host cell lipid metabolism induced by M. leprae infection. Using high-performance thin-layer chromatography (HPTLC), we demonstrated specific induction of triacylglycerol (TAG) production in human macrophage THP-1 cells following M. leprae infection. We then used [14C] stearic acid tracing to show incorporation of this newly synthesized host cell TAG into M. leprae. In parallel with TAG accumulation, expression of host glycerol-3-phosphate acyltransferase 3 (GPAT3), a key enzyme in de novo TAG synthesis, was significantly increased in M. leprae-infected cells. CRISPR/Cas9 genome editing of GPAT3 in THP-1 cells (GPAT3 KO) dramatically reduced accumulation of TAG following M. leprae infection, intracellular mycobacterial load, and bacteria viability. These results together suggest that M. leprae induces host GPAT3 expression to facilitate TAG accumulation within macrophages to maintain a suitable environment that is crucial for intracellular survival of these bacilli.

Mapping leprosy‐associated coding variants of interleukin genes by targeted sequencing

Previous genotyping-based assays have identified non-coding variants of several interleukins (ILs) being associated with genetic susceptibility to leprosy. However, understanding of the involvement of coding variants within all IL family genes in leprosy was still limited. To obtain the full mutation spectrum of all ILs in leprosy, we performed a targeted deep sequencing of coding regions of 58 ILs genes in 798 leprosy patients (age 56.2 ± 14.4; female 31.5%) and 990 healthy controls (age 38.1 ± 14.0; female 44.3%) from Yunnan, Southwest China. mRNA expression alterations of ILs in leprosy skin lesions or in response to M. leprae treatment were estimated by using publicly available expression datasets. Two coding variants in IL27 (rs17855750, p.S59A, p = 4.02 × 10-8 , odds ratio [OR] = 1.748) and IL1RN (rs45507693, p.A106T, p = 1.45 × 10-5 , OR = 3.629) were significantly associated with leprosy risk. mRNA levels of IL27 and IL1RN were upregulated in whole blood cells after M. leprae stimulation. These data showed that IL27 and IL1RN are leprosy risk genes. Further functional study is required for characterizing the exact role of ILs in leprosy.

Leprosy piRnome: exploring new possibilities for an old disease

Leprosy, which is caused by the human pathogen Mycobacterium leprae, causes nerve damage, deformity and disability in over 200,000 people every year. Because of the long doubling time of M. leprae (13 days) and the delayed onset of detectable symptoms, which is estimated to be approximately 3–7 years after infection, there is always a large percentage of subclinically infected individuals in the population who will eventually develop the disease, mainly in endemic countries. piRNAs comprise the largest group of small noncoding RNAs found in humans, and they are distinct from microRNAs (miRNAs) and small interfering RNAs (siRNAs). piRNAs function in transposon silencing, epigenetic regulation, and germline development. The functional role of piRNAs and their associated PIWI proteins have started to emerge in the development of human cancers and viral infections, but their relevance to bacterial diseases has not been investigated. The present study reports the piRNome of human skin, revealing that all but one of the piRNAs examined are downregulated in leprosy skin lesions. Considering that one of the best characterized functions of piRNAs in humans is posttranscriptional mRNA silencing, their functions are similar to what we have described for miRNAs, including acting on apoptosis, M. leprae recognition and engulfment, Schwann cell (SC) demyelination, epithelial–mesenchymal transition (EMT), loss of sensation and neuropathic pain. In addition to new findings on leprosy physiopathology, the discovery of relevant piRNAs involved in disease processes in human skin may provide new clues for therapeutic targets, specifically to control nerve damage, a prominent feature of leprosy that has no currently available pharmaceutical treatment.

190 Highly efficient, massively-parallel single-cell RNA-seq analysis of leprosy skin lesions identifies IL-1β as a key regulator of an antimicrobial gene network linked to host defense

Reversal reactions (RR) in leprosy provide an opportunity to investigate mechanisms of host defense against bacterial infections in skin, as patients upgrade from the disseminated lepromatous (L-lep) form to the self-limiting tuberculoid (T-lep) form, often associated with significant tissue injury. Here we performed single-cell RNA-seq to study gene networks associated with host defense comparing lesions from RR vs. L-lep patients (n=10). We detected 43,363 genes in 21,318 cells, with an average of 741 genes and 3,556 transcripts per cell. The 11 subclusters of T cells, myeloid cells, keratinocytes (KC), endothelial cells (EC) and fibroblasts (FB) that were enriched in RR lesions contained 567 genes that encoded programs known to be involved in antimicrobial responses. In addition, pseudotime analysis identified differentiation of macrophages (MF) and KC in the progression from L-lep to RR. We identified IL-1β as a key upstream regulator of the antimicrobial gene network as well as the differentiation programs of both MF and KC. In addition to the direct regulation of genes involved in the vitamin D antimicrobial pathway (IFNG, CD40LG, CD40, IL32, VDR), IL-1β induced the antimicrobial chemokines (CCL2, CCL4, CCL8, CCL20; CXCL1, CXCL2, CXCL3, CXCL8, CXCL11; CX3CL1) and antimicrobial proteins (GBP2; MMP9, MMP14; S100A6, S100A10) in different cell types. IL-1β regulated Th17 cell responses including the antimicrobial protein IL-26. IL-1β coordinates the antimicrobial response from diverse cell types in leprosy as well as inducing differentiation of MF, KC and T cells, such that blockade of the IL-1 receptor could provide an opportunity to mitigate concomitant tissue damage that leads to permanent nerve injury in RR patients.

Single-cell RNA-sequencing of leprosy skin lesions reveals a titin (TTN) expressing T cell subset associated with the progressive disease

Abstract The immune response to intracellular bacteria is critical for host defense against the invading pathogen. This interaction can be studied in the human disease leprosy caused by the intracellular bacterium Mycobacterium leprae affecting primarily the skin compartments. Patients with tuberculoid leprosy (T-lep) express a Th1 cytokine pattern in skin lesions and develop a protective immunity that eliminates the infection, whereas those with lepromatous leprosy (L-lep) express Th2 cytokines in lesions and sustain a progressive infection. In the reversal reaction (RR) state, patients upgrade, either spontaneously or during chemotherapy, from the L-lep to the T-lep pole. Herein, we used unbiased single-cell RNA-sequencing to explore the breadth of potential immune cell states in leprosy. Unexpectedly, we identified a lymphocyte cluster marked by expression of titin (TTN), which is commonly found in the sarcomere of muscle cells. TTN+ T cells were predominantly enriched in L-lep lesions and RNA-FISH showed a higher number of TTN mRNA dots on CD3+ T cells from L-lep in comparison with RR patients. TTN gene expression decreased in the skin lesion cells of L-lep patients undergoing RR episodes associated with the onset of therapy. Protein expression was confirmed by analysis of T cell clones isolated from leprosy lesions and blood-derived CD3+ T cells from healthy donors. Indeed, immunohistochemical staining of lesions and healthy tonsil showed that TTN was present in the CD3+ T cell zones. Canonical pathways analysis revealed that TTN might be involved with T cell inhibitory RhoA signaling pathway. The role of TTN on T cells remains unknown, however, it could represent a novel mechanism in the skin immune response against cutaneous pathogens.

Sensitivity and specificity of traditional testing methods to detect sensory impairment in the skin lesions of leprosy compared to Semmes–Weinstein monofilaments

Objective: To determine the sensitivity and specificity of traditional testing methods to detect sensory deficit in the skin lesions of leprosy in comparison to Semmes Weinstein (SW) nylon monofilaments. Design: After ethical clearance and written informed consent from study subjects, a consecutive series of 50 patients aged &gt;12 years with leprosy skin lesions, who attended our institution, were evaluated in this cross sectional study. Results: 74 skin lesions of 50 patients were evaluated. Considering the monofilament test result as the gold standard, the sensitivity to detect sensory impairment was 95.9% for the ballpoint pen, 97.3% for a sterile needle and 100% for cotton wool, and cold and warm water. Limitation: Paucity of cases in the lepromatous spectrum of disease and the probable absence of early lesions of disease in the study group were the study limitations. Conclusions: The cotton wool and ballpoint pen methods are easy to perform in the field and have comparable sensitivity and specificity to the blue Semmes Weinstein nylon monofilament to detect sensory impairment in skin lesions, especially in tuberculoid cases.

Correlation of FNAC to Histopathology in Skin Lesions of Leprosy as Per Ridley-Jopling Spectrum

Correlation of FNAC to Histopathology in Skin Lesions of Leprosy as Per Ridley-Jopling Spectrum

A unique case of borderline lepromatous leprosy with psoriasis-like lesions all over the body and mycosis fungoides-like lesions on the face

sClinical manifestations of leprosy are various and may resemble other skin diseases. Skin lesions of leprosy mimicking psoriasis and mycosis fungoides (MF) that simultaneously occurs in one patient are rare. We reported a unique case of borderline lepromatous (BL) leprosy with severe reversal reaction manifested as psoriasis-like lesions and MF-like lesions in a 43-year-old-man. Psoriasis-like lesions all over the body accompanied by plaques and tumor-like lesions mimicking MF on the face could be found in this patient. Histopathological examination on an MF-like lesion from the face and psoriasis-like lesions from the posterior trunk and lower extremities revealed granulomatous reaction with epithelioid cells, Langhans giant cells, and foam cells which supported the diagnosis of BL leprosy. The patient was treated with multidrug therapy multibacillary (MDT-MB) regimen and 40 mg prednisone daily which was tapered off. Clinical improvement was observed on the 32nd day of observation as psoriasis-like and MF-like lesions became hyperpigmented macules and plaques, respectively. Due to the rarity of the multitype skin lesions of leprosy in one patient, a diagnosis of leprosy should be suspected by the clinicians in any patients with previously described skin disorders, especially in an endemic area.

IL-26 contributes to host defense against intracellular bacteria.

IL-26 is an antimicrobial protein secreted by Th17 cells that has the ability to directly kill extracellular bacteria. To ascertain whether IL-26 contributes to host defense against intracellular bacteria, we studied leprosy, caused by the obligate intracellular pathogen Mycobacterium leprae, as a model. Analysis of leprosy skin lesions by gene expression profiling and immunohistology revealed that IL-26 was more strongly expressed in lesions from the self-limited tuberculoid compared with expression in progressive lepromatous patients. IL-26 directly bound to M. leprae in axenic culture and reduced bacteria viability. Furthermore, IL-26, when added to human monocyte-derived macrophages infected with M. leprae, entered the infected cell, colocalized with the bacterium, and reduced bacteria viability. In addition, IL-26 induced autophagy via the cytoplasmic DNA receptor stimulator of IFN genes (STING), as well as fusion of phagosomes containing bacilli with lysosomal compartments. Altogether, our data suggest that the Th17 cytokine IL-26 contributes to host defense against intracellular bacteria.

Immunohistochemical characterization of the M4 macrophage population in leprosy skin lesions

BackgroundSince macrophages are one of the major cell types involved in the Mycobacterium leprae immune response, roles of the M1 and M2 macrophage subpopulations have been well defined. However, the role of M4 macrophages in leprosy or other infectious diseases caused by mycobacteria has not yet been clearly characterized. This study aimed to investigate the presence and potential role of M4 macrophages in the immunopathology of leprosy.MethodsWe analyzed the presence of M4 macrophage markers (CD68, MRP8, MMP7, IL-6, and TNF-α) in 33 leprosy skin lesion samples from 18 patients with tuberculoid leprosy and 15 with lepromatous leprosy by immunohistochemistry.ResultsThe M4 phenotype was more strongly expressed in patients with the lepromatous form of the disease, indicating that this subpopulation is less effective in the elimination of the bacillus and consequently is associated with the evolution to one of the multibacillary clinical forms of infection.ConclusionM4 macrophages are one of the cell types involved in the microbial response to M. leprae and probably are less effective in controlling bacillus replication, contributing to the evolution to the lepromatous form of the disease.

Immunohistochemistry of skin lesions in leprosy and leprosy reactions

Objectives: 1. To study the immunohistochemistry of leprosy granulomas in the skin biopsy specimens of patients with tuberculoid and lepromatous leprosy, with respect to the presence and arrangement of CD4+, CD8+ and CD28+ T cells, CD 68+ cells and CD1a+ cells. 2. To study the immunohistochemistry findings observed in leprosy reactions. Design: Descriptive study. Skin biopsies in which the clinical and histopathological diagnosis of leprosy was reported between 1.8.2016 to 31.5.2017 in the Government Medical College, Kozhikode, were selected for the study. Immunohistochemistry of the skin lesions in leprosy and leprosy reactions was studied, looking specifically for the distribution of CD4/ CD8/ CD28/ CD68/ CD1a positive cells in leprosy at different scenarios. Results: Twenty-six tuberculoid and 14 lepromatous cases were included in the study. All granulomas irrespective of disease type showed positive staining for CD4 and CD68. Two of the 14 lepromatous leprosy cases (14.3%), and 15/26 (57.7%) tuberculoid specimens manifested moderate to strong CD4 expression. CD28 negativity was documented in four tuberculoid (15.4%) and 10 lepromatous cases (71.4%). Moderate to strong CD4 expression was noted in more than 70% of upgrading T1R while a similar finding was documented in only 20%–50% of other groups. More than 80% of static and upgrading T1R showed CD28 positivity, which was higher than the 30%–50% positivity recorded in other groups. Conclusions: The observations of the current study indicate a role for immunohistochemistry analysis in delineating the complex immunological processes involved in leprosy and leprosy reactions.