Anti-RNA polymerase III antibodies in systemic sclerosis: Multicentric study from Argentina

Area of Science:

• Rheumatology and Immunology
• Autoimmune Diseases
• Systemic Sclerosis Pathogenesis

Background:

• Systemic Sclerosis (SSc) is a complex autoimmune disease characterized by fibrosis, vasculopathy, and autoantibody production.
• Anti-RNA polymerase III antibodies are associated with specific SSc phenotypes, but their frequency and clinical significance in diverse ethnic populations require further investigation.

Purpose of the Study:

• To determine the prevalence of anti-RNA polymerase III antibodies in a cohort of Argentinian patients with Systemic Sclerosis.
• To investigate clinical differences between SSc patients with positive and negative anti-RNA polymerase III antibody status.

Main Methods:

• Retrospective analysis of clinical data from 135 SSc patients (ACR/EULAR 2013 criteria) from Argentinian healthcare centers.
• Detection of anti-RNA polymerase III IgG antibodies using ELISA.
• Correlation of antibody status with clinical features, including limited cutaneous SSc (lcSSC), diffuse cutaneous SSc (dcSSC), pitting scars, pulmonary artery hypertension, and renal crisis.

Main Results:

• Anti-RNA polymerase III antibodies were detected in 5.9% of the SSc cohort.
• In patients negative for anticentromere (ACA) and anti-Scl70 antibodies, anti-RNA polymerase III positivity was observed in 16.7%.
• Anti-RNA polymerase III positive patients were older at diagnosis and exhibited a higher frequency of pitting scars and pulmonary artery hypertension. The single case of scleroderma renal crisis was anti-RNA polymerase III positive.

Conclusions:

• The observed low frequency of anti-RNA polymerase III antibodies may be influenced by the predominant Amerindian and Mestizo ethnic background of the study population.
• Detection of anti-RNA polymerase III antibodies may aid in classifying SSc patients, predicting prognosis, and optimizing clinical management.
• Further research is warranted to fully elucidate the role of anti-RNA polymerase III antibodies in SSc.