Myeloid-related proteins-8 and -14 are expressed but dispensable in the pathogenesis of experimental epidermolysis bullosa acquisita and bullous pemphigoid

Serum Calprotectin Levels in Vitiligo Patients and Disease Relation

INTRODUCTION

Vitiligo is characterized as melanocyte loss in skin and mucous membranes, the pathogenesis of which has not yet been clarified. Calprotectin is a protein secreted from neutrophils, monocytes, and dendritic cells which has an effect on cytokine receptor regulation and the production of reactive oxygen radicals. It has been the subject of research in various inflammatory and autoimmune diseases, yet not investigated in vitiligo.

OBJECTIVE

The aim of our study was to investigate the role of calprotectin in the etiopathogenesis of vitiligo and its relationship with clinical subtypes and disease scores.

METHODS

Forty-four vitiligo patients with lack of autoimmune disease and 36 age- and sex-matched healthy controls were involved in the study. Serum calprotectin levels were measured by ELISA. The results were compared with the control group, and the relationship between patients' demographic characteristics, skin phototypes, disease type, disease scores (Vitiligo Area Scoring Index and Vitiligo Disease Activity Score), disease duration, and age at onset were evaluated.

RESULTS

The median serum calprotectin level was 454.08 pg/ml (41.19-873.41) in the patient group, and the median serum calprotectin level was 223.17 pg/ml (44.88-1044.43) in the control group. Serum calprotectin level was significantly higher in the patient group than in the control group (P = 0.016). No correlation was found between serum calprotectin level and disease scores, disease duration, age, or age of onset of disease (P > 0.05).

CONCLUSIONS

In our study, serum calprotectin levels in the patient group were found to be significantly higher than in the control group. Our findings and the existing literature on calprotectin suggest its potential involvement in the pathogenesis of vitiligo, independent of disease progression and patient characteristics.

Circulating Calprotectin (cCLP) in autoimmune diseases

BACKGROUND AND AIM

Calprotectin (CLP) is a heterodimeric complex formed by two S100 proteins (S100A8/A9), which plays a pivotal role in innate immunity. Due to its intrinsic cytotoxic and proinflammatory properties, CLP controls cell differentiation, proliferation and NETosis and has been associated with a wide range of rheumatic diseases. Our review summarizes the widespread interest in circulating CLP (cCLP) as a biomarker of neutrophil-related inflammation, in autoimmune rheumatic disease (ARD) and non-ARD.

METHODS

A thorough literature review was performed using PubMed and EMBASE databases searching for circulating calprotectin and synonyms S100A8/A9, myeloid-related protein 8/14 (MRP8/MRP14), calgranulin A/B and L1 protein in addition to specific ARDs and autoimmune non-rheumatic diseases. We selected only English-language articles and excluded abstracts without the main text.

RESULTS

High cCLP serum levels are associated with worse structural outcomes in rheumatoid arthritis and to a lesser extent, in spondyloarthritis. In addition, cCLP can predict disease relapse in some autoimmune diseases including systemic lupus erythematosus (SLE), anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) and some severe manifestations of connective tissue diseases, such as glomerulonephritis in SLE, AAV, juvenile idiopathic arthritis, adult-onset Still's disease and lung fibrosis in systemic sclerosis. Therefore, cCLP levels enable the identification of patients who need an accurate and tight follow-up. The clinical usefulness of cCLP as an inflammatory marker has been suggested for inflammatory/autoimmune non-rheumatic diseases, and especially for the monitoring of the inflammatory bowel diseases patients. Currently, there are only a few studies that evaluated the cCLP efficacy as a clinical biomarker in inflammatory/autoimmune non-rheumatic diseases with controversial results. Future studies are warranted to better clarify the role of cCLP in relation to the disease severity in myasthenia gravis, multiple sclerosis, chronic inflammatory demyelinating polyneuropathy, Graves' orbitopathy, autoimmune bullous diseases and uveitis.

CONCLUSION

Our literature review supports a relevant role of cCLP as potential prognostic biomarker mirroring local or systemic inflammation, especially in chronic inflammatory rheumatic diseases.

Preventive but Not Therapeutic Topical Application of Local Anesthetics Can Inhibit Experimental Epidermolysis Bullosa Acquisita in Mice

Epidermolysis bullosa acquisita (EBA) is an autoimmune blistering disorder characterized and caused by autoantibodies against type VII collagen (COL7). Although it has been noticed that EBA in both patients and mice is associated with an increased scratching, it is not clear whether and how the scratching contributes to disease manifestation. Hence, we here aimed to validate this clinical observation and also to investigate the potential contribution of increased scratching in EBA pathogenesis in mice. Longitudinal assessment of scratching behavior revealed an increased frequency of scratching as early as 12 hours after injection of anti-COL7 IgG into the skin of mice. Subsequently, scratching events became even more frequent in mice. In contrast, mice injected with a control antibody showed an unaltered scratching behavior throughout the observation period. Based on these observations, we hypothesized that mechanical irritation may promote the induction of inflammation in experimental EBA. To challenge this assumption, the local anesthetic dyclonine hydrochloride was topically applied before injection of anti-COL7 IgG. Dyclonine hydrochloride reduced the scratching events and impaired clinical disease manifestation. In therapeutic experimental settings, i.e. administration of the local anesthetic 24 hours after injection of anti-COL7 IgG, dyclonine hydrochloride only inhibited the scratching behavior, but had no significant effect on clinical disease development. In addition, eosinophils were detected in the skin before the injection of anti-COL7 IgG and significantly increased 48 hours after the antibody injection. Collectively, our results suggest that scratching behavior contributes to the initiation phase of disease manifestation in experimental EBA.

Epidermolysis Bullosa Acquisita: The 2019 Update

Epidermolysis bullosa acquisita (EBA) is an orphan autoimmune disease. Patients with EBA suffer from chronic inflammation as well as blistering and scarring of the skin and mucous membranes. Current treatment options rely on non-specific immunosuppression, which in many cases, does not lead to a remission of treatment. Hence, novel treatment options are urgently needed for the care of EBA patients. During the past decade, decisive clinical observations, and frequent use of pre-clinical model systems have tremendously increased our understanding of EBA pathogenesis. Herein, we review all of the aspects of EBA, starting with a detailed description of epidemiology, clinical presentation, diagnosis, and current treatment options. Of note, pattern analysis via direct immunofluorescence microscopy of a perilesional skin lesion and novel serological test systems have significantly facilitated diagnosis of the disease. Next, a state-of the art review of the current understanding of EBA pathogenesis, emerging treatments and future perspectives is provided. Based on pre-clinical model systems, cytokines and kinases are among the most promising therapeutic targets, whereas high doses of IgG (IVIG) and the anti-CD20 antibody rituximab are among the most promising "established" EBA therapeutics. We also aim to raise awareness of EBA, as well as initiate basic and clinical research in this field, to further improve the already improved but still unsatisfactory conditions for those diagnosed with this condition.