B-cell subsets in leprosy lesions: unraveling the complex interplay.

Background: Leprosy is a chronic infectious disease marked by complex immune interactions, yet the roles of specific B-lymphocyte subsets in its pathology are poorly understood.

Objectives: To investigate the presence and distribution of B-cell subsets, including B1 cells, Marginal Zone (MZ) B-cells, Regulatory B-cells (Bregs), and Effector-1 B-cells (Be1), across different clinical forms of leprosy and reactional states.

Methods: Immunohistochemical and morphometric analyses were performed on skin lesions from patients with various clinical presentations of leprosy.

Heightened Innate Immune and Inflammatory Gene Expression in the Skin of Severe COVID-19 Cases.

Purpose: Cutaneous manifestations of SARS-CoV-2 infection exhibit significant variability, yet the role of innate immune responses in the skin of COVID-19 patients remains poorly understood. In this study, we investigated the transcriptomic profile of skin samples from patients who succumbed to COVID-19.

Patients And Methods: Skin autopsies from COVID-19 patients with post-mortem time of less than 20 hours were obtained from University of São Paulo Medical School Hospital and healthy skin samples, were submitted to RNA sequencing analysis.

Type I Interferons in SARS-CoV-2 Cutaneous Infection: Is There a Role in Antiviral Defense?

SARS-CoV-2, a β-coronavirus, primarily affects the lungs, with non-specific lesions and no cytopathic viral effect in the skin. Cutaneous antiviral mechanisms include activation of TLR/IRF pathways and production of type I IFN. We evaluated the antiviral mechanisms involved in the skin of COVID-19 patients, including skin samples from 35 deceased patients who had contracted COVID-19 before the launch of the vaccine.

Evaluation of pruritus biomarkers expression in chronic spontaneous urticaria.

Chronic urticaria (CU) is a skin disease characterized by recurrent episodes of urticaria and/or angioedema, persisting for more than six weeks. Chronic urticaria is classified as chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU). Histamine, released by mast cells and basophils, is the central mediator in the development of signs and symptoms, especially pruritus.

Histopathological analysis of the skin of renal transplant recipients submitted to three different immunosuppression regimens.

Background: Renal transplant recipients (RTRs) use a combination of immunosuppressive agents: a corticosteroid; a calcineurin inhibitor (cyclosporine or tacrolimus) and an antimetabolic agent (azathioprine [AZA] or a mycophenolic acid precursor [MPA] ‒ Mycophenolate mofetil or sodium) or an mTOR inhibitor (mTORi) ‒ sirolimus or everolimus. These treatments increase the incidence of various neoplasms, especially non-melanoma skin cancers (NMSCs).

Objectives: To evaluate the histopathological alterations in the skin of the RTRs under three different immunosuppressive regimens: one mTORi (sirolimus or everolimus); or one antimetabolic agent (MPA or AZA), comparing them by groups and with healthy controls.

The impact of cholesteryl ester transfer protein on the progression of cutaneous leishmaniasis.

Introduction: Pathogenesis of cutaneous leishmaniases involves parasite growth, persistent inflammation, and likely participation of lipoproteins (LP). The cholesteryl ester transfer protein (CETP), involved in LP remodeling, has been shown to participate in the inflammatory response and the evolution of infectious conditions.

Methods: We evaluated the impact of the presence of CETP on infection by in an experimental model of cutaneous leishmaniasis using C57BL6/J mice transgenic for human CETP (CETP), having as control their littermates that do not express the protein, wild-type (WT) mice.

Cutaneous inflammasome driving ASC / gasdermin-D activation and IL-1β-secreting macrophages in severe atopic dermatitis.

Atopic dermatitis (AD) is an inflammatory skin disease with intense pruritus, and chronic skin colonization by Staphylococcus aureus. To understand the inflammatory status in AD, we investigated the inflammasome complex, that activates ASC (Apoptosis-associated speck-like protein containing a CARD), caspase-1 and GSDMD (gasdermin-D), and production of IL-1β and IL-18. We aimed to evaluate the expression of the inflammasome pathway in the skin of adults with AD.

Outlining the skin-homing and circulating CLANK cells in patients with severe atopic dermatitis.

Atopic dermatitis (AD) is a complex, multifactorial skin disease, characterized by pruritus and predominant Th2 inflammation. Innate immune cells may play a role in AD development and are composed of granulocytes, macrophages, innate-like T cells, and innate lymphoid cells. This study investigates the phenotypic and functional profile of circulating CLA natural killer (NK) cells and its role in the skin-homing to NK cells infiltrated in adults' skin with AD.

Plasmacytoid Dendritic Cells, the Expression of the Stimulator of Interferon Genes Protein (STING) and a Possible Role of Th17 Immune Response in Cervical Lesions Mediated by Human Papillomavirus.

Human papillomavirus (HPV) is a virus with a DNA structure that specifically targets squamous epithelial cells. In individuals with a healthy immune system, HPV infection is typically resolved naturally, leading to spontaneous regression. However, when the viral genetic material integrates into the host DNA, it can disrupt the immune response and eventually give rise to neoplastic manifestations.

Contribution to the study of inflammasome and programmed cell death in paracoccidioidomycosis oral lesions.

Background: Paracoccidioidomycosis is the most prevalent systemic mycosis in Latin America, with a high incidence in Brazil, Colombia and Venezuela, and constitutes a serious public health problem, a frequent cause of morbidity and disability for work. Some mechanisms of cell death are described as important tools in infectious processes. When apoptosis is blocked, RIPK (Receptor-interacting protein kinase) 3 dependent, a caspase-independent form of cell death, can limit the replication and spread of pathogens.

Methotrexate for refractory adult atopic dermatitis leads to alterations in cutaneous IL-31 and IL-31RA expression.

Background: Methotrexate (MTX) is an alternative treatment for patients with moderate/severe atopic dermatitis (AD).

Objective: The authors evaluated the effect of MTX on the cutaneous expression of cytokines and chemokines that are involved in the inflammatory response in adult AD patients who received treatment with methotrexate for 24 weeks.

Methods: The authors conducted a prospective single-institution cohort study with 12 adults with moderate/severe AD who received oral MTX (15 mg/wk for 24 wks) and 10 non-atopic matched controls.

Imbalanced IL-1B and IL-18 Expression in Sézary Syndrome.

Sézary syndrome (SS) is a rare and aggressive type of cutaneous T-cell lymphoma, with an abnormal inflammatory response in affected skin. The cytokines IL-1B and IL-18, as key signaling molecules in the immune system, are produced in an inactive form and cleave to the active form by inflammasomes. In this study, we assessed the skin, serum, peripheral mononuclear blood cell (PBMC) and lymph-node samples of SS patients and control groups (healthy donors (HDs) and idiopathic erythroderma (IE) nodes) to investigate the inflammatory markers IL-1B and IL-18 at the protein and transcript expression levels, as potential markers of inflammasome activation.

Obesity Induces an Impaired Placental Antiviral Immune Response in Pregnant Women Infected with Zika Virus.

Obesity is increasing in incidence worldwide, especially in women, which can affect the outcome of pregnancy. During this period, viral infections represent a risk to the mother, the placental unit, and the fetus. The Zika virus (ZIKV) outbreak in Brazil has been the cause of congenital Zika syndrome (CZS), with devastating consequences such as microcephaly in newborns.

Inflammasome and Inflammatory Programmed Cell Death in Chromoblastomycosis.

Chromoblastomycosis (CBM) is a chronic, progressive fungal disease of the skin and subcutaneous tissue caused by a group of dematiaceous fungi. Verrucous lesions present parasite-rich granulomas and predominance of a Th2 patterns of cytokines. The inflammasome constitutes a macromolecular protein complex that play a role in the activation of caspase 1 that cleaves pro-IL1β and pro-IL18, essential mediators of inflammation, and also activates pyroptosis.

Leprosy: clinical and immunopathological characteristics.

Leprosy, a disease caused by Mycobacterium leprae, has polymorphic neurocutaneous manifestations strongly correlated with the host immune response. Peripheral neural damage can lead to sensory and motor losses, as well as deformities of the hands and feet. Both innate and acquired immune responses are involved, but the disease has been classically described along a Th1/Th2 spectrum, where the Th1 pole corresponds to the more limited presentations and the Th2 to the multibacillary ones.

Livedoid vasculopathy in 75 Brazilian patients in a single-center institution: Clinical, histopathological and therapy evaluation.

This study presents a single center experience with livedoid vasculopathy (LV). A rare disease that can lead to severe quality of life impairment. Characterize clinical data of LV patients at the Dermatology Division at the University of São Paulo.

Immunology of leprosy.

Leprosy is a disease caused by (ML) with diverse clinical manifestations, which are strongly correlated with the host's immune response. Skin lesions may be accompanied by peripheral neural damage, leading to sensory and motor losses, as well as deformities of the hands and feet. Both innate and acquired immune responses are involved, but the disease has been classically described along a Th1/Th2 spectrum, where the Th1 pole corresponds to the most limited presentations and the Th2 to the most disseminated ones.

Lacaziosis: immunohistochemical evaluation of elements of the humoral response in cutaneous lesions.

Lacaziosis is a cutaneous mycosis caused by the fungus Lacazia loboi, described in different countries of Latin America and prevalent in the Amazon region. The ineffective immune response against the agent seems to be related to a Th2 pattern of cytokines. There are few reports exploring elements of the humoral response in these lesions.

Update on vasculitis: overview and relevant dermatological aspects for the clinical and histopathological diagnosis - Part II.

Vasculitis is a group of several clinical conditions in which the main histopathological finding is fibrinoid necrosis in the walls of blood vessels. This article assesses the main dermatological aspects relevant to the clinical and laboratory diagnosis of small- and medium-vessel cutaneous and systemic vasculitis syndromes. The most important aspects of treatment are also discussed.

M2-Polarized Macrophages Determine Human Cutaneous Lesions in Lacaziosis.

Lacaziosis is a cutaneous chronic mycosis caused by Lacazia loboi. Macrophages are important cells in the host immune response in fungal infections. The macrophage population exhibits strong plasticity that varies according to the stimuli in the microenvironment of lesions M1 profile promotes a Th1 pattern of cytokines and a microbicidal function and M2 is related to Th2 cytokines and immunomodulatory response.

Update on vasculitis: an overview and dermatological clues for clinical and histopathological diagnosis - part I.

The term vasculitis refers to the inflammation of vessel walls. It may range in severity from a self-limited disorder in one single organ to a life-threatening disease due to multiple organ failure. It has many causes, although they result in only a few histological patterns of vascular inflammation.