Clin Rheumatol. 2026 Jan 27. doi: 10.1007/s10067-026-07962-x. Online ahead of print.
ABSTRACT
OBJECTIVE: The study aimed to evaluate Antinuclear antibody detection by indirect immunofluorescence and line immunoassay in patients with suspected autoimmune diseases and to correlate immunofluorescence patterns and autoantibody profiles with their clinical features to improve diagnostic interpretation.
METHODS: A retrospective cross-sectional study was conducted on 1,342 patients clinically suspected of autoimmune diseases over nine months at a tertiary care hospital in North India. All samples were tested using indirect immunofluorescence on HEp-2 cells. Line immunoassay was performed on samples showing nuclear immunofluorescence patterns. Associations between serological findings, demographic variables, clinical features, and final diagnoses were statistically analysed.
RESULTS: Of the 1,342 patients clinically suspected of autoimmune diseases, antinuclear antibodies by indirect immunofluorescence assay were detected in 308 patients (22.95%). Among these positive samples, nuclear patterns were observed in 206 (66.88%) cases and cytoplasmic patterns in 102 (33.11%). The speckled nuclear pattern was the most frequent (151/206; 73.30%), followed by homogeneous (9.22%), nucleolar (8.74%), and centromere (4.85%) patterns. Line immunoassay performed on nuclear pattern-positive samples identified antigen-specific autoantibodies in 67 cases (32.52%), while no autoantibodies were identified in 139 cases (67.48%). The most commonly detected autoantibodies were anti-Ro52, anti-Ro60, and anti-dsDNA. A statistically significant association was observed between indirect immunofluorescence assay patterns and autoantibody profiles (χ2 = 597.587, p < 0.001). Antinuclear antibody positivity showed significant correlation with joint-related symptoms (p < 0.001) and swollen glands (p = 0.004). Distinct immunofluorescence patterns and autoantibody profiles demonstrated disease-specific associations, including centromere pattern with systemic sclerosis and homogeneous and speckled patterns with systemic lupus erythematosus and Sjögren’s disease.
CONCLUSION: A combined diagnostic approach using indirect immunofluorescence for screening and line immunoassay for antigen-specific profiling improves diagnostic accuracy. This strategy is particularly valuable in resource-limited settings, enabling targeted diagnosis and clinical decision-making. Key Points • A dual methodology combining indirect immunofluorescence with Line immunoassay enhances diagnostic specificity in the identification of autoimmune diseases. • Significant associations were identified among Antinuclear antibody patterns, autoantibody profiles, and specific autoimmune diseases. • The study reinforces the utility of integrating indirect immunofluorescence and Line immunoassay in routine autoimmune diagnostics, especially in resource-limited healthcare settings.
PMID:41591621 | DOI:10.1007/s10067-026-07962-x
