USE OF A THRESHOLD SERUM LEVEL OF ANTIGLIADIN ANTIBODIES IMPROVES DIAGNOSTIC EFFICIENCY OF THE TEST IN ADULT CELIAC-DISEASE BUT IS UNRELIABLE AS A SCREENING REST

Measurement of anti-gliadin antibodies is considered a highly sensitiv e test for coeliac disease in children, Specificity, however, appears to vary due to the presence of anti-gliadin antibodies in other diseas es, Sensitivity and specificity of anti-gliadin antibody measurement f or coeliac disease in adults has, thus, been assessed using the ratio of the densitometric unit test/the mean +3SD of densitometric unit val ues of a pool of sera of healthy biopsy-proven controls, Anti-gliadin antibodies-A and G mere measured separately with an enzyme-linked immu nosorbent assay in 64 coeliacs (20 males; 44 females; age range 14-71 years) with diagnosis confirmed at jejunal biopsy; and in 60 controls (25 males; 35 females; age range 16-69 years) with normal jejunal biop sy, Detection of anti-gliadin antibodies-A and G had a sensitivity of 58% and 61%, respectively, and a specificity of 85% and 94%. For the p rocedure a Receiver Operating Characteristic analysis was used, Consid ering anti-gliadin antibodies-A and G values of at least 0.9 densitome tric unit, sensitivity was 50% and 60%, respectively, whereas specific ity was 100% for both, These findings confirm the low sensitivity of t hese measurements in adult coeliacs and thus the unreliability for scr eening, The high specificity, when using a threshold value of 0.9 dens itometric unit, may be useful in the evaluation of adults with suspect ed coeliac disease.