Which of the following circulating antibodies has the best sensitivity and specificity for the diagnosis of celiac disease.'
Answer is A (Antiendomysial antibody) Antiendomysial antibodies have a high sensitivity and specificity for diagnosis of celiac sprue and show best performance for detection of celiac sprue. Antiendomysial antibody > Anti tissue transglutaminase antibody > Antireticular antibody> Antigliadin antibody Antigliadin (UP) Anti reticulin LIP Antiendomvsial Anti tissue Antibodies (AGM Antibodies (ARA) Antibiotics (Anti EMA) transglutaminase * First immunological * Second antibody * Antiendomysial antibodies antibody (Anti-tTGA) assay to be tested identified in literature have high sensitivity and * Major breakthrough for were antigliadin was the antireticulin specificity for the serological diagnosis of antibodies. antibodies. diagnosis of celiac disease. celiac disease. * The variability and * There are atleast 5 types * These antibodies are * Antitissue lower accuracy make of antireticulin antibodies directed against transglutaminase them unsuitable for but only one type is endomysium or antibodies (Anti-tTGA ) diagnostic and associated with celiac `Intermyofibril substance' are also highly sensitive screening purposes disease. of smooth muscle. and specific but * Antigliadin assays * These antibodies are not * The antigen recognized by performance of anti have been replaced very sensitive and are not these antibodies is 'tissue EMA is superior to Anti? by more specific and sensitive tests using other antibodies used in routine practice. transglutaminase'. tTGA Anti EMA and Anti-tTGA While the performance of Anti-EMA is superior to Anti - tTGA, the discovery of Anti-tTGA is seen as a major breakthrough. Why ? Anti-EMA Anti - tTGA * * Anti EMA are species specific reacting only with gastrointestinal tract of primates. They are identified using indirect immunoflorescence on frozen section of monkey esophagus. Interpretation of immunoflorescence assay is operator dependent and more liable to errors in less experienced hands. * * * ELISA based assays are available for detection of anti - tTGA. Initial tests used guinea pig antigen but now human recombinant tTGA are available. ELISA based detection is simpler and more accessible diagnostic test Recommended reading : Aicle on 'Diagnosis of celiac disease' by AIIMS faculty published in 'Indian Journal of Pediatric' 2006; volume 73 issue 8 (Available on internet) A recent systemic review of the diagnostic performance of the serological tests repoed in studies from 1996 to 2003 showed that in children: Parameter Anti-EMA Anti-tTGA (Human Recombinant) Specificity 100% (pooled monkey esophagus and human 95 - 95% (pooled + TG guinea pig and umbilical cord) human recombinant) Sensitivity 96% (monkey esophagus) 96% (human recombinant) Anti-tTGA is highly sensitive and specific but performance of anti EMA is superior to Anti-tTGA
Anti-endomysial antibody
Anti-tissue transglutaminase antibody
Anti-gliadin antibody
Anti-reticulin antibody