Real World Evidence on the Availability of Anti-Nuclear Antibody (ANA) in Diagnosis of Connective Tissue Diseases; A Retropective Single Center Trial

Objectives: Antinuclear antibodies (ANA) are autoantibodies against the cellular compartments such as the nucleus, nucleolus, nuclear membrane and cytoplasm. Determining the significance of ANA in the diagnosis of connective tissue diseases was aimed.

Methods: The test results and diagnosis of the patients who applied to Şişli Etfal Research Hospital Rheumatology outpatient clinic between June 2011 and October 2012. The sensitivity, specificity, positive and negative predictive values of IIF-ANA in the diagnosis of connective tissue diseases were also calculated.

Results: It was determined that for every 1 out of 5 patients who applied to Rheumatology Outpatient Clinic, ANA test was ordered and for one third of those patients for whom the order was made, ANA test results were positive. For titres of 1/320 and higher, the specificity and positive predictive value of ANA in the diagnosis was found to be 99% and 96% respectively. For 1/100 and higher as the titer, sensitivity was 65%, specificity was 88% and positive and negative predictive values were 64% and 88% respectively. These values showed that 1/100 titer was suitable to use in screening.

Conclusion: Positive ANA results, clinical findings and symptoms of the patient are important in diagnosis of connective tissue diseases.