Osteopontin, a protein with cytokine-like properties: a possible involvement in pemphigus vulgaris

Skin - a vast organ with immunological function (Review)

The skin is an organ with multiple functions, where important inflammatory and immunological processes take place. The integrity of the skin barrier is necessary for it to fulfill its roles. An intact skin barrier requires a physiological keratinization process, but also a normal cutaneous microbial flora. Any change in the proliferation and differentiation of keratinocytes entails the disruption of the skin barrier and the triggering of inflammatory and immunological processes at this level, in response to the aggression of external pathogens. Also, there are several specialised immune cells in the skin (Langerhans cells, T regulator cells, T helper cells), that maintain a balance between pro-inflammatory and anti-inflammatory processes at this level. Disturbing the immune homeostasis causes inflammation and allergic skin reaction. Psoriasis and atopic dermatitis are two inflammatory diseases of the skin, characterized by perturbation of the mechanisms of skin barrier formation. The immune system of the skin is also involved in the pathophysiology of vitiligo and pemphigus. The aim of this review is to offer a brief presentation of the inflammatory and immunological processes that occur in the skin.

Effects of l-carnitine supplementation on cardiovascular and bone turnover markers in patients with pemphigus vulgaris under corticosteroids treatment: A randomized, double-blind, controlled trial

Pemphigus vulgaris (PV) is a severe, bullous, autoimmune disease of the skin and mucous membranes. Corticosteroids are usually the main core treatment for controlling PV, which could lead to several side effects such as insulin resistance, osteoporosis, and cardiovascular disorders. The aim of this study is to evaluate the protective effects of l-carnitine (LC) supplementation in PV patients under corticosteroid treatment. In this randomized, double-blind, placebo-controlled clinical trial, 48 patients with PV were divided randomly into two groups to receive 2 g LC (n = 24) or a placebo (n = 24) for 8 weeks, respectively. Serum levels of osteopontin (OPN), bone morphogenic protein 4 (BMP4), cystatin C, systolic and diastolic blood pressure, 25 hydroxyvitamin D3, and LC were evaluated at the beginning and at the end of the study. LC supplementation demonstrated a significant increase in serum carnitine (p < .001). In addition, at the end of the trial, LC supplementation significantly decreased serum BMP4 (p = .003), OPN (p = .03), and cystatin C (p = .001) levels. There was no significant effect on blood pressure in comparison with the placebo. During study, no harmful side effects were reported by patients. These findings indicate that LC supplementation significantly leads to favorable changes in OPN, BMP4, and cystatin C in PV patients under corticosteroid therapy. However, further investigations are required to confirm these results.

The elevated level of osteopontin in patients with pemphigus vulgaris: A cytokine-like protein with a therapeutic potential

BACKGROUND

Pemphigus vulgaris (PV) is a life-threatening autoimmune disease with no certain treatment. Anticytokine therapy is being increasingly discussed in multiple autoimmune diseases. Osteopontin (OPN) is a glycoprotein produced by a variety of immune cells. Increased OPN serum levels have been reported in several autoimmune diseases, with targeting OPN considered as a promising therapy in these diseases. However, the role of OPN in PV has not been well studied so far.

OBJECTIVE

To investigate whether OPN level is elevated in PV patients in the active stage of the disease and to examine its possible relationship with disease severity and anti-desmoglein (anti-Dsg) antibodies levels.

MATERIALS AND METHODS

This study included 53 consecutive subjects affected by PV and 38 age- and sex-matched healthy controls. Clinical characteristics and Autoimmune Bullous Skin Disorder Intensity Score (ABSIS) were assessed. Serum OPN levels (pg/mL) and anti-Dsg antibodies were also measured.

RESULTS

The serum OPN level of the patient group proved to be statistically higher than that of the control group (11.08 ± 5.24 vs 8.47 ± 5.68; p = .02). No significant relationship were detected between the serum OPN level and anti-Dsg1 or anti-Dsg3 antibodies (r = 0.1, p = .2 and r = 0.1, p = .4), respectively. In addition, no correlation was found between serum OPN levels and severity of PV as measured by ABSIS (r = 0.08 and p = .5).

CONCLUSION

The growth observed in OPN levels in pemphigus patients suggests the role of OPN in pemphigus pathogenesis, but there is a need for more extensive studies to show how OPN can be associated with the PV pathogenesis and whether OPN could be used as an important therapeutic target in pemphigus disease.

Emerging role of immune cell network in autoimmune skin disorders: An update on pemphigus, vitiligo and psoriasis

Autoimmune skin diseases are a group of disorders that arise due to a deregulated immune system resulting in skin tissue destruction. In the majority of these conditions, either autoreactive immune cells or the autoantibodies are generated against self-antigens of the skin. Although the etiology of these diseases remains elusive, biochemical, genetic, and environmental factors such as infectious agents, toxins damage the skin tissue leading to self-antigen generation, autoantibody attack and finally results in autoimmunity of skin. Immune dysregulation, which involves predominantly T helper 1/17 (Th1/Th17) polarization and the inability of regulatory T cells to regress immune response, is implicated in autoimmune skin diseases. The emerging roles of immune cells, cytokines, and chemokines in the pathogenesis of common autoimmune skin diseases like pemphigus, vitiligo, and psoriasis are discussed in this review. The main focus is on the interplay between immune cell network including the innate and adaptive immune system, regulatory cells, immune checkpoints and recently identified tissue-resident memory cells (TRMs) in disease pathogenesis and relapse. We also attempt to highlight on the immune mechanisms common to these diseases which can be targeted for designing novel therapeutics.