Browsing by Author "Ece, GT"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Investigation of the dual cascade algorithm in the diagnosis of antinuclear antibodies
    Ecemis, T; Farasat, VT; Dugan, Y; Sener, AG; Ece, GT; Dündar, PE; Sanlidag, T
    Background: The dual cascade algorithm which involves screening and confirmation of antinuclear antibodies (ANAs) by further reflex testing is widely used in the detection of ANAs. We aimed to investigate this algorithm which is commonly used in many laboratories. Methods: A total of 475 sera obtained from patients with a clinical suspicion of systemic autoimmune rheumatic diseases (SARDs) upon which three expert assessors agreed for interpretation in the indirect immunofluorescence (IIF) test were determined and tested by the line immunoassay (LIA) containing 16 antigens. The results of the tests were statistically compared and evaluated. Results: In 141 of the sera (29.7%), there was an agreement between ANA-IIF(+) and LIA(+) results. The overall agreement rate between the two tests for positivity and negativity only was 85.5% with a Cohen's lc coefficient of 0.69. In 118 of these 141 sera (83.7%), pattern and associated ANA agreement was detected with an overall agreement rate of 80.6% and a Cohen's kappa coefficient of 0.57. The highest agreement between the pattern and associated ANAs was seen in centromere, dense fine speckled (DFS) and cytoplasmic reticular patterns. In these patterns, the rate of anti-centromere-associated protein B (CENP-B), anti-DFS and anti-antimitochondrial antibody M2 (anti-AMA-M2) antibodies were 93.4%, 92.3% and 66.7%, respectively. Conclusions: We found an overall moderate agreement between IIF screening and LIA confirmation tests. However, the level of agreement varies according to the pattern type. The discrepancy in agreement rates may cause false reflex test requests. Our results highlight the need for collaboration between clinical and laboratory professionals in selected cases instead of the reflex testing approach.
  • No Thumbnail Available
    Item
    A Multicenter Analysis of Subjectivity of Indirect Immunofluorescence Test in Antinuclear Antibody Screening
    Farasat, VT; Ecemis, T; Dogan, Y; Sener, AG; Ece, GT; Dündar, PE; Sanlidag, T
    Objectives: This study aims to evaluate the interpretation of the antinuclear antibody (ANA)-indirect immunofluorescence (IIF) test results based on the interpreter-related subjectivity and to examine the inter-center agreement rates with the performance of each laboratory. Patients and methods: The ANA-IIF testing was carried out in a total of 600 sera and evaluated by four laboratories. The inter-center agreement rates were detected. The same results given by the four centers were accepted as gold standard and the predictive values of each center were calculated. Results: The inter-center agreement was reported for ANA-IIF test results from 392 of 600 (65.3%) sera, while 154 of 392 results were positive. Four study centers reported 213 (35.5%), 222 (37.0%), 266 (44.3%), and 361 (60.2%) positive test results, respectively. In terms of the patterns, the highest and lowest positive predictive values were 72.3% and 42.7%, respectively, while the highest and lowest negative predictive values were 99.6% and 61.5%, respectively. The agreement for semi-quantitative evaluation at three levels of fluorescence intensity stated by four centers was detected in 100 sera at 87% 3(+), while the other two levels were 6% and 7%. The highest predictive value for the highest fluorescence intensity of 3(+) was found to be 71.9%. Conclusion: Significant differences may be observed among laboratories in terms of qualitative results, patterns, and semi-quantitative determination of the fluorescence intensity in the ANA-IIF testing, particularly at low fluorescence intensity levels and in those with speckled patterns. In case of any discrepancy between ANA-IIF test and clinical prediagnosis, the test should be repeated in another laboratory, if necessary.