THE VALUE OF ENDOSCOPIC BIOPSIES FROM FIRST AND SECOND PARTS OF DUODENUM IN THE DIAGNOSIS OF CELIAC DISEASE IN CORRELATION WITH A SEROLOGICAL TESTZahraa A Hashim*, Sura A AL-Namil@, Wassan M Jazi# & Sarkis K Strak$*MB,ChB, Postgraduate board student. @MB,ChB, FIBMS, Consultant pathologist. #MB,ChB, FIBMS, Consultant pathologist, Al-Sadir Teaching Hospital. $MRCP, FRCPLond., FRCPI., Professor of Medicine, University of Basrah, IRAQ.Abstract Celiac disease is a chronic immune-mediated enteropathy of the small intestine caused by environmental exposure to gluten in genetically susceptible individuals. This study was conducted to evaluate and correlate the serological with histopathological findings of duodenal biopsies for the diagnosis of celiac disease. Sixty-eight patients, 40 (59%) females whose ages ranged from 13-75 year (mean age 36.4 years), and 28 (41%) males whose ages ranged from 13-65 year (mean age 37.8 years), with symptoms of chronic diarrhea, weight loss, bloating and unexplained iron deficiency anemia, were tested for anti-tissue transglutaminase IgA tTG, and correlated with histopathological findings of duodenal biopsies obtained from 1st and 2nd parts according to modified Marsh's classification. Histopathological findings from the 1st and 2nd duodenal parts were also compared with each other. The results of the 68 patients who were enrolled in the study showed that: 24(35.3%) patients tested positive for anti-tissue transglutaminase (titer >18U/ml), 37(55.8%) patients had positive histopathological changes (stage I–III). Twenty-three (33.8%) patients who had both positive anti tTG and histopathological changes were classified as a celiac disease. The sensitivity of 1st and 2nd parts of duodenal biopsies in detecting celiac disease were 83.7% and 100% respectively. In conclusion; the histopathological changes from the 1st and 2nd parts of duodenum in detecting celiac disease were equally representative especially in stage IIIa, b, and c.