Distinct profiles of circulating lymphocytes reflect clinical and serological variations in idiopathic inflammatory myopathies.

Abstract

Introduction: Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of autoimmune diseases characterized by muscle inflammation and systemic involvement. The study aimed to evaluate the immunophenotypic profile of circulating lymphocytes in patients with IIM and investigate its association with clinical manifestations, serological profiles, treatment regimens, and disease outcomes.

Material and methods: This single-center, cross-sectional study included 40 patients with IIM and 5 age- and sex-matched healthy controls. Peripheral blood samples were collected and processed to isolate peripheral blood mononuclear cells using the density gradient centrifugation method. Flow cytometry analysis was performed to phenotype lymphocyte subpopulations, including T cells (CD3+CD4+ and CD3+CD8+), B cells (CD3-CD19+), and natural killer (NK) cells (CD3-CD16+CD56+). Statistical analysis was conducted to compare lymphocyte profiles between the study and control groups and to assess correlations with clinical features, serological markers, and treatment regimens.

Results: The IIM group had a mean age of 58.55 ±12.70 years, with a predominance of females (60%). The most common IIM subtypes were antisynthetase syndrome (35%) and dermatomyositis (30%). No significant differences in the profiles of circulating lymphocytes were found between IIM patients and healthy controls. Patients with cardiac involvement had significantly higher proportions of double-positive T cells (p = 0.0035), while those with cutaneous ulcers and dysphagia showed significantly lower proportions of CD4+CD8+ T cells. Natural killer cells were significantly lower in patients with anti-Mi2 antibodies (p = 0.0155) but higher in anti-Ro52 positive patients (p = 0.0150). In contrast, B cells were notably higher in patients with anti-Mi2 (p = 0.0182) and lower in individuals with anti-Ro52 (p = 0.0124). Patients with anti-Ro52 positivity were also characterized by higher proportions of double-negative T cells (p = 0.0465). Treatment regimens did not impact the profiles of circulating lymphocytes.

Conclusion: Patients with IIM exhibit distinct alterations in lymphocyte subpopulations, with specific immune cell profiles associated with clinical phenotypes and serological profiles.