AbstractIntroduction: Antinuclear antibodies (ANA’s), are one of the most important tests in immunology, although very informative it faces major challenges. Confronting a positive ANA in a patient without clinical disease but consistent symptoms, is a game changer for the treating physician. This study aims to determine the rate & pattern of ANA positivity and understand its distribution pattern and clinical diagnosis in cases evaluated at a tertiary care centre. Materials and Methods: This observational analytical study was carried out for a period of one year. A single serum sample was collected from patients ranging from age groups 10 to 65 yrs suspected to have an autoimmune disease. Samples were tested by indirect immunofluoresence (IIF) and patterns were recorded and analysed. Results: Among the 150 tests done, 15 (10%) cases were ANA global test positive, with a mean age was 40 and greater positivity among females patients 16 (17.3%) (p-value <0.001). The most common pattern encountered was the nucleoplasm fine granular variety 10 (40%) followed by nucleoplasm coarse granular 5 (20%).Various other patterns were also observed with a predominance of cell nuclei homogenous pattern 4 (16%). ANA positivity was observed in 95% of Systemic lupus erythematosus (SLE) and mixed connective tissue disorders (MCTD) and in 25-70% of the cases with Sjögren syndrome, Systemic sclerosis (SS) and Rheumatoid arthritis (RA). Some ANA’s showed weak fluorescence detectable before the actual onset of clinical symptoms being apparent and was particularly seen in suspected cases of SLE. Conclusion: The rate and distribution of pattern types correlated well with the autoimmune condition and even borderline or weak intensity fluorescent patterns should be reported and the patients having them should be followed-up regularly.
Keywords: Antinuclear antibodies; Indirect immunofluoresence; Systemic lupus erythematosis.