Animesh A. Sinha

Profile of 513 patients with alopecia areata: associations of disease subtypes with atopy, autoimmune disease and positive family history

Background  Several lines of evidence support a genetic component to alopecia areata (AA), including differences in patients based on severity of AA, associated diseases and family history.

Definitions and outcome measures for bullous pemphigoid: recommendations by an international panel of experts

Our scientific knowledge of bullous pemphigoid (BP) has dramatically progressed in recent years. However, despite the availability of various therapeutic options for the treatment of inflammatory diseases, only a few multicenter controlled trials have helped to define effective therapies in BP. A major obstacle in sharing multicenter-based evidences for therapeutic efforts is the lack of generally accepted definitions for the clinical evaluation of patients with BP. Common terms and end points of BP are needed so that experts in the field can accurately measure and assess disease extent, activity, severity, and therapeutic response, and thus facilitate and advance clinical trials. These recommendations from the International Pemphigoid Committee represent 2 years of collaborative efforts to attain mutually acceptable common definitions for BP and proposes a disease extent score, the BP Disease Area Index. These items should assist in the development of consistent reporting of outcomes in future BP reports and studies.

Modeling the bound conformation of Pemphigus Vulgaris-associated peptides to MHC Class II DR and DQ Alleles

BackgroundPemphigus vulgaris (PV) is a severe autoimmune blistering disorder characterized by the presence of pathogenic autoantibodies directed against desmoglein-3 (Dsg3), involving specific DR4 and DR6 alleles in Caucasians and DQ5 allele in Asians. The development of sequence-based predictive algorithms to identify potential Dsg3 epitopes has encountered limited success due to the paucity of PV-associated allele-specific peptides as training data.ResultsIn this work we constructed atomic models of ten PV associated, non-associated and protective alleles. Nine previously identified stimulatory Dsg3 peptides, Dsg3 96–112, Dsg3 191–205, Dsg3 206–220, Dsg3 252–266, Dsg3 342–356, Dsg3 380–394, Dsg3 763–777, Dsg3 810–824 and Dsg3 963–977, were docked into the binding groove of each model to analyze the structural aspects of allele-specific binding.ConclusionOur docking simulations are entirely consistent with functional data obtained from in vitro competitive binding assays and T cell proliferation studies in DR4 and DR6 PV patients. Our findings ascertain that DRB1*0402 plays a crucial role in the selection of specific self-peptides in DR4 PV. DRB1*0402 and DQB1*0503 do not necessarily share the same core residues, indicating that both alleles may have different binding specificities. In addition, our results lend credence to the hypothesis that the alleles DQB1*0201 and *0202 play a protective role by binding Dsg3 peptides with greater affinity than the susceptible alleles, allowing for efficient deletion of autoreactive T cells.

Investigation of human keratinocyte cell adhesion using atomic force microscopy

UNLABELLED Desmosomal junctions are specialized structures critical to cellular adhesion within epithelial tissues. Disassembly of these junctions is seen consequent to the development of autoantibodies directed at specific desmosomal proteins in blistering skin diseases such as pemphigus. However, many details regarding cell junction activity under normal physiological and disease conditions remain to be elucidated. Because of their complex structure, desmosomal junctions are not well suited to existing techniques for high-resolution three-dimensional structure-function analyses. Here, atomic force microscopy (AFM) is used for detailed characterization and visualization of the cell junctions of human epithelial cells. We demonstrate the ability to image the detailed three-dimensional structure of the cell junction at high magnification. In addition, the effect of specific antibody binding to desmosomal components of the cell junction is studied in longitudinal analyses before and after antibody treatment. We show that antibodies directed against desmoglein 3 (a major component of the desmosomal structural unit, and the major target of autoantibodies in patients with pemphigus vulgaris) are associated with changes at the cell surface of the human keratinocytes and alterations within keratinocyte intercellular adhesion structures, supporting the assertion that cell structures and junctions are modified by antibody binding. The present study indicates that the molecular structure of gap junctions can be more completely analyzed and characterized by AFM, offering a new technological approach to facilitate a better understanding of disease mechanisms and potentially monitor therapeutic strategies in blistering skin diseases. FROM THE CLINICAL EDITOR Disassembly of desmosomal junctions is seen in blistering skin diseases such as Pemphigus. This present study demonstrates that the molecular structure of gap junctions can be more completely analyzed and characterized by atomic force microscopy.

Cutaneous lupus erythematosus: Understanding of clinical features, genetic basis, and pathobiology of disease guides therapeutic strategies

Cutaneous features of the protean disease lupus erythematous (LE) constitute 4 of 11 diagnostic criteria for systemic lupus erythematosus (SLE) and are exhibited by approximately 3/4 of patients during the course of their disease. Because the pathogenesis of LE is multifactorial and polygenic, many of the details of the pathogenesis remain unclear. We review here the clinical features of cutaneous lupus and recent genetic data that elucidate potential candidate genes for both cutaneous lupus erythematosus (CLE) and SLE. We discuss advances in elucidating the autoimmune pathogenesis of CLE and SLE. Furthermore, promising experimental therapies based on these advances are reviewed in the context of B cell directed therapies, T cell directed therapies, disruption of B and T cell interactions, cytokine directed therapies and finally, end-effector targeted therapies.

Direct characterization of human T cells in pemphigus vulgaris reveals elevated autoantigen‐specific Th2 activity in association with active disease

Pemphigus vulgaris (PV) is a blistering skin disorder mediated by autoantibodies targeting the epidermal adhesion molecule desmoglein 3 (Dsg3). As Th2‐associated cytokines are necessary for directing antibody production, it is hypothesized that Dsg3‐specific Th2 activity is associated with active disease. We used cell‐surface‐matrix technology in combination with flow cytometry to characterize the Dsg3‐reactive T‐cell population using peripheral blood mononucleocytes sampled from PV patients stratified by active (n = 9) or remittent disease (n = 6), and healthy human leucocyte antigen‐matched controls (n = 5). We evaluated interferon‐γ‐producing CD4+ cells (Th1) and interleukin (IL)‐10‐ or IL‐4‐producing CD4+ cells (Th2). The mean frequency of Th2 CD4+ T cells was significantly elevated for five of nine PV patients with active disease. No significant Th2 responses were detected for patients with remittent disease or controls. There was a significant association of Th2 activity with active disease compared with remittent and control groups (P = 0.026 and P =0.012, respectively), and Th2 activity was significantly correlated with anti‐Dsg3 IgG titre (P = 0.044). One patient with remittent disease converted from a Th2‐negative to a Th2‐positive response with the initiation of disease activity. An antigen‐specific CD4− lymphocyte response was detected in five PV patients (36%), and was shown to correlate closely with the CD8+ population. These results are consistent with the hypothesis that Th2 response directs autoantibody production and is therefore associated with disease activity in PV.

Aspirin is associated with lower melanoma risk among postmenopausal Caucasian women: the Women's Health Initiative.

Nonsteroidal anti‐inflammatory drugs (NSAIDs) have been associated with decreased risk of gastric, colorectal, and breast cancer. However, the impact of NSAIDs on the risk of melanoma has been inconsistent. The authors evaluated the association between NSAID use and cutaneous melanoma risk in the Womens Health Initiative (WHI) Observational Study (OS).

Transcriptional profiling in alopecia areata defines immune and cell cycle control related genes within disease-specific signatures

Alopecia areata (AA) is a non-scarring inflammatory hair loss disease with a complex autoimmune etiopathogenesis that is poorly understood. In order to investigate the pathogenesis of AA at the molecular level, we examined the gene expression profiles in skin samples from lesional (n=10) and non-lesional sites (n=10) of AA patients using Affymetrix Hu95A-v2 arrays. 363 genes were found to be differentially expressed in AA skin compared to non-lesional skin; 97 were up-regulated and 266 were down-regulated. Functional classification of the differentially expressed genes (DEGs) provides evidence for T-cell mediated immune response (CCL5, CXCL10, CD27, ICAM2, ICAM3, IL7R, and CX3CL1), and a possible humoral mechanism (IGHG3, IGHM, and CXCR5) in AA. We also find modulation in gene expression favoring cellular proliferation arrest at various levels (FGF5, FGF18, EREG, and FOXC2) with apoptotic dysregulation (LCK, TNF, TRAF2, and SFN) and decreased expression of hair follicle structural proteins. Further analysis of patients with AAT (<1 year duration, n=4) and AAP (>1 year duration, n=6) of disease revealed 262 DEGs distinctly separating the 2 groups, indicating the existence of gene profiles unique to the initial and later stages of disease.

The Genetics of Pemphigus

Pemphigus vulgaris (PV) is an autoimmune blistering disorder with a complex etiology involving an interplay of genetic as well as environmental factors, most of which remain unknown. Despite the identification of several human leukocyte antigen (HLA) alleles as risk factors for disease, no other non-HLA genes have clearly been implicated in disease susceptibility. Newer candidate gene and whole-genome approaches are needed to illuminate the full palate of genetic risk elements in PV. Based on this information, genetic-based tools can be expected to provide a scientific rationale for future clinical decision-making by physicians and facilitate an era of personalized medicine.

Oxidative stress and autoimmune skin disease

Antioxidants play the important role in our body of neutralizing free radicals and peroxides that are formed during normal physiologic events. While these reactive oxygen species are necessary for numerous biological processes, when created in excess they can have deleterious effects. The skin as an organ is constantly under attack by reactive oxygen species from both endogenous and exogenous sources. The pathophysiology of many autoimmune diseases is unknown and recently oxidative stress has come to light as a possible triggering mechanism. Recent investigations attempting to link autoimmune skin diseases and oxidative stress have had varying degrees of success. In this article, we review the current literature regarding antioxidants in alopecia areata, pemphigus vulgaris and other blistering diseases, vitiligo, and psoriasis, and suggest possible future studies and treatment options.