Assessing the Prevalence of Disease-Specific Antinuclear Antibodies and their Detection in Diagnosis of Rheumatic Disorders in Syria

Background: Antinuclear antibodies (ANA) detection is a crucial laboratory test for diagnosing systemic autoimmune disorders and is commonly the initial step in autoantibodies screening. ANA are immunoglobulins that differentiate a wide range of nuclear and cytoplasmic components. ANAs are consistently present in the sera of patients with a variety of rheumatic disorders. The purpose of the study was to investigate the kinds and the expansion of disease-specific antinuclear antibodies (ANAs) and their link to rheumatic disorders in the general Syrian people.  Method: Immunofluorescence (IIF) was used for testing ANA in serum samples gained from 529 patients. Individualities positive for IF­ ANA were further tested for disease­ specific ANAs using line Immunoblot assay.  Results: Based on the result of the IF­ ANA assay, the rates of positive samples were 7.9%. Anti-SSA/Ro and anti-dsDNA antibodies were detected in 7and 6 individuals, respectively, anti Scl70, anti-Nucleosome, anti-U1-RNP, anti-CENP B were detected in 4 different individuals, but anti-Sm, anti-PCNA, and anti-Jo-1 antibodies were undetectable. Among 42 IF­ ANA­ positive individualities, 24 were found to have disease ­specific ANAs: nine SLE, three Sclerosis, and two rheumatoid arthritis. Conclusions ANA should generally not be examined without a clinical indication. Positive ANA finding in the absence of clinical symptoms and signs has limited diagnostic usefulness and should be interpreted by a rheumatologist constantly, in the context of clinical symptoms and the results of laboratory tests for specific autoantibodies.