The role of dermal fibroblasts in autoimmune skin diseases

Fibroblasts are an important subset of mesenchymal cells in maintaining skin homeostasis and resisting harmful stimuli. Meanwhile, fibroblasts modulate immune cell function by secreting cytokines, thereby implicating their involvement in various dermatological conditions such as psoriasis, vitiligo, and atopic dermatitis. Recently, variations in the subtypes of fibroblasts and their expression profiles have been identified in these prevalent autoimmune skin diseases, implying that fibroblasts may exhibit distinct functionalities across different diseases. In this review, from the perspective of their fundamental functions and remarkable heterogeneity, we have comprehensively collected evidence on the role of fibroblasts and their distinct subpopulations in psoriasis, vitiligo, atopic dermatitis, and scleroderma. Importantly, these findings hold promise for guiding future research directions and identifying novel therapeutic targets for treating these diseases.

Exosomal miRNAs in autoimmune skin diseases

Exosomes, bilaterally phospholipid-coated small vesicles, are produced and released by nearly all cells, which comprise diverse biological macromolecules, including proteins, DNA, RNA, and others, that participate in the regulation of their biological functions. An increasing number of studies have revealed that the contents of exosomes, particularly microRNA(miRNA), play a significant role in the pathogenesis of various diseases, including autoimmune skin diseases. MiRNA is a class of single-stranded non-coding RNA molecules that possess approximately 22 nucleotides in length with the capability of binding to the untranslated as well as coding regions of target mRNA to regulate gene expression precisely at the post-transcriptional level. Various exosomal miRNAs have been found to be significantly expressed in some autoimmune skin diseases and involved in the pathogenesis of conditions via regulating the secretion of crucial pathogenic cytokines and the direction of immune cell differentiation. Thus, exosomal miRNAs might be promising biomarkers for monitoring disease progression, relapse and reflection to treatment based on their functions and changes. This review summarized the current studies on exosomal miRNAs in several common autoimmune skin diseases, aiming to dissect the underlying mechanism from a new perspective, seek novel biomarkers for disease monitoring and lay the foundation for developing innovative target therapy in the future.

JAK-STAT inhibitors in Immune mediated diseases: An Overview

For any biological response, transmission of extracellular signals to the nucleus is required for DNA transcription and gene expression. In that respect, cytokines/chemokines are well-known inflammatory agents which play a critical role in signalling pathways by activating the Janus kinase-signal transducers and activators of transcription (JAK-STAT) signalling proteins (Janus kinase-signal transducers and activators of transcription) which are a group of intracellular kinase molecules. Cytokines are a category of small proteins (∼5-25 kDa) that play a major role in cell signalling and are major drivers of an autoimmune response. Here we will discuss the role of Janus kinase-signal transducers and activators of transcription kinase cascades in the inflammatory-proliferative cascades of autoimmune disease and about the recent progress in the development of oral synthetic Janus kinase inhibitors (JAKi) and their therapeutic efficacies in dermatologic and systemic autoimmune diseases. Therapeutic efficacy of Janus kinase inhibitors is now well established in the treatment of array of autoimmune and inflammatory disease: spondylarthritis with a special focus on psoriatic arthritis (PsA) and its dermatologic manifestations (psoriasis) and ankylosing spondylitis (AS), atopic dermatitis (AD), alopecia areata (AA), rheumatoid arthritis (RA) and inflammatory bowel disease (IBD). In addition to the first-generation Janus kinase inhibitors several new-generation Janus kinase inhibitors are currently being evaluated. It is expected that these Janus kinase inhibitors likely have higher potency and less adverse effects as compared to their predecessors. Here we have discussed: (1) the functional significance of the Janus kinase-signal transducers and activators of transcription kinase cascades in the inflammatory-proliferative processes of autoimmune diseases and its cellular/molecular mechanisms and (2) progress in the development of oral synthetic Janus kinase inhibitors and their therapeutic efficacies in several systemic and cutaneous autoimmune diseases.

Granzyme B in Autoimmune Skin Disease

Autoimmune diseases often present with cutaneous symptoms that contribute to dysfunction, disfigurement, and in many cases, reduced quality-of-life. Unfortunately, treatment options for many autoimmune skin diseases are limited. Local and systemic corticosteroids remain the current standard-of-care but are associated with significant adverse effects. Hence, there is an unmet need for novel therapies that block molecular drivers of disease in a local and/or targeted manner. Granzyme B (GzmB) is a serine protease with known cytotoxic activity and emerging extracellular functions, including the cleavage of cell-cell junctions, basement membranes, cell receptors, and other structural proteins. While minimal to absent in healthy skin, GzmB is markedly elevated in alopecia areata, interface dermatitis, pemphigoid disease, psoriasis, systemic sclerosis, and vitiligo. This review will discuss the role of GzmB in immunity, blistering, apoptosis, and barrier dysfunction in the context of autoimmune skin disease. GzmB plays a causal role in the development of pemphigoid disease and carries diagnostic and prognostic significance in cutaneous lupus erythematosus, vitiligo, and alopecia areata. Taken together, these data support GzmB as a promising therapeutic target for autoimmune skin diseases impacted by impaired barrier function, inflammation, and/or blistering.

Clinical effect of omalizumab as an adjuvant treatment to rituximab in patient with refractory bullous pemphigoid

Patients with refractory bullous pemphigoid (BP) achieve remission after rituximab treatment but require high-dose systemic corticosteroids until the remission. The aim of this retrospective study was to examine the clinical efficacy of omalizumab as an adjuvant treatment to rituximab in patients with refractory BP. Patients with BP receiving treatment with either rituximab monotherapy or rituximab plus omalizumab were considered for the study. The total dose of corticosteroids received for 60 days after administration of rituximab, mortality and relapse rates, and median time to relapse were also investigated. Of 49 patients included in the study, 25 received rituximab monotherapy and 17 received the combination therapy with rituximab and omalizumab. The rituximab plus omalizumab group showed shorter time to disease control with minimal treatment (15 days vs. 67.5 days, p < 0.001) and lower corticosteroid dose for 60 days after administration of rituximab (698.4 mg vs. 1087.4 mg of methylprednisolone, p < 0.001) compared to the rituximab monotherapy group. The results of this study suggest that combination therapy with rituximab and omalizumab can achieve disease control status faster than the rituximab monotherapy, reducing the total dose of corticosteroids.

Challenge of hepatitis B testing following intravenous immunoglobulin therapy in patients with autoimmune skin diseases

Intravenous immunoglobulin (IVIg) contains pooled immunoglobulins from the plasma of healthy blood donors. All plasma samples are tested for HIV, hepatitis viruses (A, B, and C), and parvovirus B19. As part of this screening step, nucleic acid amplification technology (NAT) is used and allows the presence of specific antibodies targeting viral structures that are commonly used to test for infection status, such as anti-hepatitis B surface antigen (HBs) or anti-hepatitis B virus core (HBc) antibodies. For this reason, manufacturers point to the possibility of false-positive viral serological test results following IVIg treatment due to the passive transfer of antibodies. IVIg therapy is commonly used to manage patients with severe, treatment-refractory autoimmune skin diseases. The aim of this cohort study was to retrospectively quantify newly-discovered positive serological HBV test results after IVIg treatment in patients with autoimmune skin diseases. Between March 2018 and June 2021, 28 patients with autoimmune skin diseases received IVIg therapy, of whom 17 were longitudinally followed-up. None of the patients had evidence of active HBV infection prior to IVIg therapy. All patients (n = 17) had detectable anti-HBs antibodies and 12 patients had anti-HBc antibodies 4 weeks after commencing IVIg treatment. Passive antibody transfer seems the most likely interpretation. Nevertheless, complete serological hepatitis assessment should be performed to exclude a new infection. We recommend hepatitis screening before IVIg therapy to prevent diagnostic confusion which may arise due to passive antibody transfer.

Characterization and In Vitro and In Vivo Evaluation of Tacrolimus-Loaded Poly(ε-Caprolactone) Nanocapsules for the Management of Atopic Dermatitis

BACKGROUND

Tacrolimus (TAC) is a drug of natural origin used in conventional topical dosage forms to control atopic dermatitis. However, direct application of the drug often causes adverse side effects in some patients. Hence, drug nanoencapsulation could be used as an improved novel therapy to mitigate the adverse effects and enhance bioavailability of the drug.

METHODS

Physicochemical properties, in vitro drug release experiments, and in vivo anti-inflammatory activity studies were performed.

RESULTS

TAC-loaded nanocapsules were successfully prepared by the interfacial deposition of preformed polymer using poly(ε-caprolactone) (PCL). The nanoparticulate systems presented a spherical shape with a smooth and regular surface, adequate diameter (226 to 250 nm), polydispersity index below 0.3, and suitable electrical stability (-38 to -42 mV). X-ray diffraction confirmed that the encapsulation method provided mainly the drug molecular dispersion in the nanocapsule oily core. Fourier-transform infrared spectra suggested that nanoencapsulation did not result in chemical bonds between drug and polymer. In vitro drug dissolution experiments showed a controlled release with a slight initial burst. The release kinetics showed zero-order kinetics. As per the Korsmeyer-Peppas model, anomalous transport features were observed. TAC-loaded PCL nanocapsules exhibited excellent anti-inflammatory activity when compared to the free drug.

CONCLUSIONS

TAC-loaded PCL nanocapsules can be suitably used as a novel nano-based dosage form to control atopic dermatitis.

The CLASI, a validated tool for the evaluation of skin disease in lupus erythematosus: a narrative review

Cutaneous lupus erythematosus (CLE) can present with or without features of systemic lupus erythematosus (SLE), with estimates of the incidence of isolated skin disease almost equaling the incidence of those with systemic disease. However, despite the impact CLE has on a patient’s quality of life (QoL), there has been no US Food and Drug Administration (FDA) approved treatment for the disease in the past 50 years. In addition, patients with skin predominant LE are often excluded from clinical SLE trials. In the rare trials that include patients with skin predominant LE, disease activity and progression in the skin are often difficult to evaluate using multi-organ outcome measures. The need for new therapies for CLE and the lack of focus on skin outcomes has led to the development of the Cutaneous Lupus Disease Area and Severity Index (CLASI), a validated organ-specific outcome measure that is not only responsive to change in disease activity and damage but also correlated to changes in a patient’s QoL. This paper will emphasize the extensive validation studies performed in developing the CLASI, as well as the importance of clinical trials using the CLASI to address the need for improved therapies for patients with lupus skin manifestations.

Evaluating change in disease activity needed to reflect meaningful improvement in quality of life for clinical trials in cutaneous lupus erythematosus

BACKGROUND

Outcome measures of clinical trials in cutaneous lupus erythematosus (CLE) should reflect clinically meaningful improvement in disease activity, as measured by the Cutaneous Lupus Disease Area and Severity Index activity score (CLASI-A).

OBJECTIVE

We aimed to define the degree of improvement in disease activity meaningful to a patient's quality of life.

METHODS

The change in the CLASI-A in 126 patients needed to predict meaningful change in QoL, as defined by the Emotions and Symptoms subscales of the Skindex-29, was evaluated by linear regression models.

RESULTS

In patients with an initial CLASI-A of ≥8, a 42.1% or ≥7-point and a 31.0% or ≥5-point decrease in CLASI-A predicts meaningful improvement in the Emotions and the Symptoms subscales, respectively.

LIMITATIONS

This is a retrospective study of prospectively collected data at a single site.

CONCLUSIONS

A CLASI-A score of ≥8 for trial entry allows for inclusion of patients with milder disease where CLASI-A improvement by ≥50% is clinically significant and meaningful.

Concurrent extrahepatic autoimmunity in autoimmune hepatitis: implications for diagnosis, clinical course and long-term outcomes

BACKGROUND

Concurrent extrahepatic autoimmune disease (CEHAID) associated with autoimmune hepatitis (AIH) have been incorporated into the diagnostic criteria stipulated by the International Autoimmune Hepatitis Group (IAIHG). Large comprehensive cohort data on the extrahepatic autoimmunity in AIH remain scanty.

AIM

To systematically assess features and clinical impact of CEHAID on AIH.

METHODS

Clinical records of 562 patients with AIH from two tertiary centres in the UK were retrospectively reviewed.

RESULTS

Prevalence of CEHAID in patients with AIH was 42%. Autoimmune thyroid disease was the commonest CEHAID associated with AIH (101/562, 18%). Autoimmune skin diseases were more prevalent in AIH-2 than AIH-1 (21.9% vs 7%, P=.009). Personal history of CEHAID was more commonly found in AIH patients with than without first-degree family history of CEHAID [48/86 (55.8%) vs 169/446 (37.9%), P=.002]. AIH patients with CEHAID were more often women (85.2% vs 76.1%, P=.008), had higher post-treatment IAIHG score (22 vs 20, P<.001), less reactivity to smooth muscle antibodies (49.8% vs 65%, P<.001), more likely to have mild fibrosis at diagnosis (20.9% vs 6.5%, P<.001) and less often had ascites (6.3% vs 13.6%, P=.008) and coagulopathy (1.18 vs 1.27, P=.013) at presentation. Presence of CEHAID, however, did not significantly affect disease progression, prognosis and survival in AIH.

CONCLUSIONS

Our study confirms the strong association of CEHAID with AIH. Association between personal and familial extrahepatic autoimmunity especially among first-degree relatives was evident. Presence of CEHAID may influence clinical phenotype of AIH at presentation, but without notable impact on the long-term clinical outcomes.