miRNA implication in the pathogenesis and the outcome of Tunisian endemic pemphigus foliaceus

Area of Science:

• Immunodermatology
• Molecular Biology
• Biomarker Discovery

Background:

• Pemphigus foliaceus (PF) is an autoimmune blistering skin disease with unpredictable prognosis.
• MicroRNAs (miRNAs) are immune regulators and potential biomarkers for autoimmune conditions.
• Current PF diagnosis relies on sera and skin analyses, with limited prognostic markers.

Purpose of the Study:

• To evaluate specific microRNA (miRNA) expression levels (miR-17-5p, miR-21-5p, miR-146a-5p, miR-155-5p, miR-338-3p) in peripheral blood mononuclear cells (PBMCs) and lesional skin of PF patients.
• To assess the diagnostic and prognostic potential of these miRNAs in relation to disease activity and treatment response.
• To correlate miRNA expression with established PF biomarkers like anti-Dsg1 antibodies and the Pemphigus Disease Area Index (PDAI).

Main Methods:

• Quantitative real-time PCR was used to measure miRNA expression in PBMCs and lesional skin biopsies.
• Samples were collected from untreated, treated remittent, and treated chronic PF patients over a 3-month period.
• Statistical analyses, including Area Under the Curve (AUC) calculations, were performed to determine diagnostic and predictive values.

Main Results:

• Overall miRNA expression was higher in PBMCs than in skin biopsies.
• Blood miR-21 expression was elevated in untreated PF patients (AUC=0.78) and decreased with treatment, correlating with disease activity.
• Cutaneous miR-155 expression was higher in chronic PF patients and positively correlated with disease activity (AUC=0.86), suggesting predictive potential.

Conclusions:

• Blood miR-21 serves as a potential supplemental biomarker for PF diagnosis.
• Cutaneous miR-155 shows promise as a predictive marker for PF activity and clinical stratification.
• These miRNAs offer additional tools alongside traditional parameters for managing PF.