Angiogenesis and lymphangiogenesis in the spectrum of leprosy and its reactional forms

Prevalence of oral manifestations of leprosy: a systematic review and meta-analysis

OBJECTIVE

To evaluate the prevalence of oral manifestations of leprosy.

STUDY DESIGN

This systematic review with meta-analysis was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and included cross-sectional studies by 2 independent reviewers in 2 phases, who reported bacilloscopic-confirmed oral manifestations of leprosy. Studies were selected based on predetermined eligibility criteria. Searches in 6 main databases were performed, such as PubMed/MEDLINE, Embase, Scopus, Web of Science, LILACS/BVS, and LIVIVO, in addition to the gray literature. The risk of bias was assessed using the JBI Checklist for Analytical Cross-Sectional Studies, and the quantitative synthesis of the data was performed using the Jamovi 2.3 application.

RESULTS

Ten studies were included, and the meta-analysis was performed with 917 patients with different types of leprosy. The overall prevalence of oral alterations was 6.0% (95% IC, 0.02-0.11; I2 = 97.01%; Q = 75.56), with plaques (27.2%), infiltrations (18.1%), and macules (15.1%) being the most prevalent fundamental lesions, especially in multibacillary patients.

CONCLUSIONS

Even though there is no oral pathognomonic lesion of leprosy, this infectious disease can manifest in oral tissues in different ways, depending mainly on the leprosy type and stage of treatment.

Differential Expression of MicroRNAs in Leprosy Skin Lesions

Leprosy, a chronic infectious disease caused by Mycobacterium leprae, is a major public health problem in poor and developing countries of the Americas, Africa, and Asia. MicroRNAs (miRNAs), which are small non-coding RNAs (18–24 nucleotides), play an important role in regulating cell and tissue homeostasis through translational downregulation of messenger RNAs (mRNAs). Deregulation of miRNA expression is important for the pathogenesis of various neoplastic and non-neoplastic diseases and has been the focus of many publications; however, studies on the expression of miRNAs in leprosy are rare. Herein, an extensive evaluation of differentially expressed miRNAs was performed on leprosy skin lesions using microarrays. Leprosy patients, classified according to Ridley and Jopling’s classification or reactional states (R1 and R2), and healthy controls (HCs) were included. Punch biopsies were collected from the borders of leprosy lesions (10 tuberculoid, 10 borderline tuberculoid, 10 borderline borderline, 10 borderline lepromatous, 4 lepromatous, 14 R1, and 9 R2) and from 9 HCs. miRNA expression profiles were obtained using the Agilent Microarray platform with miRBase, which consists of 1,368 Homo sapiens (hsa)-miRNA candidates. TaqMan quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) was used to validate differentially expressed miRNAs. Sixty-four differentially expressed miRNAs, including 50 upregulated and 14 downregulated (fold change ≥2.0, p-value ≤ 0.05) were identified after comparing samples from patients to those of controls. Twenty differentially expressed miRNAs were identified exclusively in the reactional samples (14 type 1 and 6 type 2). Eight miRNAs were validated by RT-PCR, including seven upregulated (hsa-miR-142-3p, hsa-miR-142-5p, hsa-miR-146b-5p, hsa-miR-342-3p, hsa-miR-361-3p, hsa-miR-3653, and hsa-miR-484) and one downregulated (hsa-miR-1290). These miRNAs were differentially expressed in leprosy and several other diseases, especially those related to the immune response. Moreover, the integration of analysis of validated mi/mRNAs obtained from the same samples allowed target pairs opposite expression pattern of hsa-miRNA-142-3p and AKR1B10, hsa-miRNA-342-3p and FAM180b, and hsa-miRNA-484 and FASN. This study identified several miRNAs that might play an important role in the molecular pathogenesis of the disease. Moreover, these deregulated miRNAs and their respective signaling pathways might be useful as therapeutic markers, therapeutic targets, which could help in the development of drugs to treat leprosy.

The involvement of endothelial mediators in leprosy

Leprosy is a chronic infectious disease that requires better understanding since it continues to be a significant health problem in many parts of the world. Leprosy reactions are acute inflammatory episodes regarded as the central etiology of nerve damage in the disease. The activation of endothelium is a relevant phenomenon to be investigated in leprosy reactions. The present study evaluated the expression of endothelial factors in skin lesions and serum samples of leprosy patients. Immunohistochemical analysis of skin samples and serum measurements of VCAM-1, VEGF, tissue factor and thrombomodulin were performed in 77 leprosy patients and 12 controls. We observed significant increase of VCAM-1 circulating levels in non-reactional leprosy (p = 0.0009). The immunostaining of VEGF and tissue factor was higher in endothelium of non-reactional leprosy (p = 0.02 for both) than healthy controls. Patients with type 1 reaction presented increased thrombomodulin serum levels, compared with non-reactional leprosy (p = 0.02). In type 2 reaction, no significant modifications were observed for the endothelial factors investigated. The anti-inflammatory and antimicrobial activities of the endotfhelial factors may play key-roles in the pathogenesis of leprosy and should be enrolled in studies focusing on alternative targets to improve the management of leprosy and its reactions.

Cell-type deconvolution with immune pathways identifies gene networks of host defense and immunopathology in leprosy

Transcriptome profiles derived from the site of human disease have led to the identification of genes that contribute to pathogenesis, yet the complex mixture of cell types in these lesions has been an obstacle for defining specific mechanisms. Leprosy provides an outstanding model to study host defense and pathogenesis in a human infectious disease, given its clinical spectrum, which interrelates with the host immunologic and pathologic responses. Here, we investigated gene expression profiles derived from skin lesions for each clinical subtype of leprosy, analyzing gene coexpression modules by cell-type deconvolution. In lesions from tuberculoid leprosy patients, those with the self-limited form of the disease, dendritic cells were linked with MMP12 as part of a tissue remodeling network that contributes to granuloma formation. In lesions from lepromatous leprosy patients, those with disseminated disease, macrophages were linked with a gene network that programs phagocytosis. In erythema nodosum leprosum, neutrophil and endothelial cell gene networks were identified as part of the vasculitis that results in tissue injury. The present integrated computational approach provides a systems approach toward identifying cell-defined functional networks that contribute to host defense and immunopathology at the site of human infectious disease.

Chronic hand infections

Chronic infections of the hand are uncommon, and a high index of suspension is required for their early diagnosis. These can be grouped based on the microorganism. Mycobacterial infections include tuberculosis, atypical mycobacterial infections, and leprosy. Other bacterial infections include actinomycosis, cat-scratch disease, syphilis, tularemia, bacillary angiomatosis, and actinomycetoma. Fungal infections may be classified as cutaneous (affecting the skin, the paronychia or nail plate), subcutaneous (mainly lymphocutaneous sporotrichosis and dermatiaceous infections), and deep fungal infections. Each type of deep fungal infection has a "classic" presentation and this is emphasized. Finally, common chronic viral infections of the hand include warts and orf.