Prevalence and clinical associations of anti-rods and rings antibodies in ANA-tested patients.

Anti-rods and rings (anti-RR) antibodies represent a rare cytoplasmic antinuclear antibody (ANA) pattern typically associated with hepatitis C virus (HCV) infection and interferon-based therapy. However, emerging evidence suggests a broader clinical relevance beyond HCV. This study aimed to investigate the prevalence, immunofluorescence characteristics, autoantibody associations, and clinical contexts of anti-RR antibodies in a large Turkish patient cohort undergoing routine ANA screening. Serum samples were retrospectively analysed for ANA using indirect immunofluorescence (IIF) between January 2022 and October 2024. Samples displaying anti-RR patterns were further evaluated for specific ANA profiles using line immunoassay. Clinical and demographic data were collected from medical records. Among 57,644 patients tested for ANA, 11,752 (20.39%) were ANA-positive, with only 91 cases (0.16%) exhibiting an anti-RR pattern. These cases were predominantly female (60.44%) with a median age of 52 years. Isolated anti-RR patterns were observed in 70.33% of patients, while the remainder showed mixed patterns, most commonly with AC-4,5,31 and AC-1 ANA patterns. Anti-RR positivity showed no significant association with classical ANA-specific autoantibodies. Clinically, anti-RR-positive patients displayed diverse diagnoses, including autoimmune diseases (21.98%), nephropathic conditions (9.89%), hepatic (7.69%) and pulmonary (6.59%) disorders, with the majority (53.85%) categorized under other conditions. Anti-RR antibodies, while rare, occur across a spectrum of diseases and may be associated with heterogeneous clinical conditions beyond hepatitis C infection. Their detection warrants careful interpretation within the appropriate clinical and laboratory context. Prospective studies are needed to explore their pathophysiological roles and diagnostic utility in diverse patient populations.