[Evaluation of Anti-Endomysial Antibodies Using Monkey Esophagus and Liver Specimens in Celiac Disease Patients: Diagnostic Performance of IgA Detection Tests].

This study aimed to compare the diagnostic performances of monkey esophagus (ME) and monkey liver (MK) preparations in the detection of anti-endomysium (EMA) IgA antibodies used in the diagnosis of celiac disease (CD) and to evaluate their relationship with anti-tissue transglutaminase (anti-TTG) IgA and anti-deamine gliadin peptide (GAF3X) IgA levels.This methodological and cross-sectional study included 123 patients with a preliminary diagnosis of CD who did not have selective IgA deficiency. EMA IgA tests were evaluated using the indirect immunofluorescence microscopy (IIF) method with ME and ML preparations. Serological tests (anti-TTG IgA and GAF3X IgA) were analyzed using the ELISA method and intestinal biopsy results were categorized according to the Marsh classification. The diagnostic performance of the tests was evaluated using sensitivity, specificity, positive and negative predictive values. Differences between groups were analyzed using statistical methods. Among 90 patients with anti-TTG IgA positivity, 96.67% were positive with ML testing, while 88.89% were positive with ME testing. A high agreement was observed between ME and ML tests (Kappa= 0.692, p< 0.001) and both preparations demonstrated similar effectiveness in detecting EMA IgA positivity. A strong relationship was identified between Marsh positivity and serological test results. ML testing showed 100% sensitivity and 50% specificity, with positive and negative predictive values of 86% and 100%, respectively. ME testing exhibited 97.7% sensitivity and 64.3% specificity, with positive and negative predictive values of 89.4% and 90%, respectively. Quantitative test results revealed significant differences between pediatric and adult groups (ML: p= 0.006; ME: p= 0.048). However, age (p= 0.268) and gender (p= 0.775) had no statistically significant impact on Marsh positivity. Correspondence analysis indicated a statistically significant relationship between ME and ML categories (p< 0.001) and a high level of correlation was detected in the positive categories. As a result of the receiver operating characteristic analysis for the antiTTG IgA test, the area under the curve value was calculated as 0.822 which revealed that the test has a good capacity to distinguish between Marsh score positivity and negativity. An optimal cutoff value of 223.84 RU/mL was identified, with sensitivity of 60.5% and specificity of 100%, emphasizing its clinical utility in reducing biopsy requirements. These findings supported the high diagnostic value of EMA IgA and other serological tests in CD diagnosis. The use of EMA IgA tests with ME and ML preparations was shown to be an effective serological method in the diagnosis of CD. ML preparations demonstrated higher sensitivity compared to ME but were more limited in specificity. The optimal cutoff value for anti-TTG IgA testing in relation to Marsh score positivity may assist in clinical decision-making processes. These findings have shed light on diagnostic approaches aimed at reducing the need for biopsy