A family of eleven proteins comprises the Janus kinases (JAK) and signal transducers and activators of transcription (STAT) signaling pathway, which enables transduction of signal from cytokine receptor to the nucleus and activation of transcription of target genes. Irregular functioning of the cascade may contribute to pathogenesis of autoimmune diseases; however, there are no reports concerning autoimmune bullous diseases yet to be published. The aim of this study was to evaluate the expression of proteins constituting the JAK/STAT signaling pathway in skin lesions and perilesional area in dermatitis herpetiformis (DH) and bullous pemphigoid (BP), as well as in the control group. Skin biopsies were collected from 21 DH patients, from 20 BP patients, and from 10 healthy volunteers. The localization and expression of selected STAT and JAK proteins were examined by immunohistochemistry and immunoblotting. We found significantly higher expression of JAK/STAT proteins in skin lesions in patients with BP and DH, in comparison to perilesional skin and the control group, which may be related to proinflammatory cytokine network and induction of inflammatory infiltrate in tissues. Our findings suggest that differences in the JAK and STAT expression may be related to distinct cytokines activating them and mediating neutrophilic and/or eosinophilic infiltrate.

Dermatitis herpetiformis (DH), bullous pemphigoid (BP), and pemphigus vulgaris (PV) are autoimmune bullous skin conditions with eosinophilic and neutrophilic infiltrations. While cytokines are crucial for the affinity and activation of different leukocyte cells in the inflammation and blister formation, there are no studies concerning a role of IL-36. The goal of the study was to analyze whether interleukin 36 is involved in pathogenesis of DH, BP, and PV. And the second aim of the study was the estimation of correlation between IL-36 and IL-17 and titers of specific antibodies in these diseases. Expression of IL-36 and IL-17 was detected in serum in all DH, BP, and PV samples. Serum levels of IL-36 and IL-17α were statistically higher in DH, BP, and PV groups as compared to the control group. IL-36α levels were statistically higher in DH patients, as compared to patients with PV and BP. Our results showed that IL-36 may be helpful in the diagnostic and monitoring of the activity of the disease. IL-36 may play a relevant role of enrolling eosinophils and neutrophils in DH, BP, and PV and finally provoke tissue injury.

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease. In recent decades, an increasing incidence of BP has been reported. The rationale for this study arises from the limited availability of advanced immunopathological and serological assays for assessing disease activity in bullous pemphigoid across many clinical centers. This systematic review evaluates evidence regarding hematological markers derived from complete blood count (CBC), such as eosinophil count and neutrophil-to-lymphocyte ratio (NLR), in BP patients. The Ovid MEDLINE and EMBASE databases were searched for English-language peer-reviewed papers published until 2 May 2025. Sixteen studies involving 1775 patients were included. Eosinophil count consistently correlated with disease severity, clinical phenotype, treatment response, and relapse risk, while NLR showed potential as a prognostic and therapeutic marker. Given their accessibility and cost-effectiveness, these parameters may have practical value in the routine clinical management of BP.

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease, predominantly affecting elderly patients with multiple comorbidities. This multicentre retrospective cohort study aimed to characterize the clinical profile, treatment patterns, and drug-associated cases of BP in a real-world setting. The study included 156 patients newly diagnosed with BP between 2020 and 2024 in four dermatology departments in Poland. Diagnosis was based on clinical features, and immunological assessment, including direct immunofluorescence (DIF), ELISA, and BIOCHIP-based indirect immunofluorescence. The mean age at diagnosis was 75.5 ± 10.9 years, and 78.85% of patients had at least one comorbidity, most commonly arterial hypertension, type 2 diabetes mellitus, and dyslipidemia. Severe pruritus was reported in 74.14% of evaluated patients. Blisters and erosions were the predominant clinical manifestations. Topical glucocorticosteroids were the most frequently used treatment, followed by systemic glucocorticosteroids and methotrexate. New drug exposure within 6 months before disease onset was identified in 14.74% of patients and was associated with a shorter time to diagnosis. Drug-associated cases showed lower BP180 ELISA positivity, although this did not remain significant after correction for multiple testing. These findings highlight the clinical complexity of BP and the importance of medication review and direct immunofluorescence in diagnostic evaluation.