Diagnostic Accuracy of IgA anti-Tissue Transglutaminase
in Patients Suspected of Having Coeliac Disease in Iran
Full Article (PDF file)
1) Poursina Hakim Research Institute & Isfahan, University
of Medical Science;
2) Isfahan Medical Student Research Committee & Isfahan,University
of Medical Science;
3) MD, Isfahan University of Medical Science, Isfahan, Iran
Background and aim. As there are little data about the
sensitivity of the IgA anti-tissue transglutaminase (IgA anti-tTG)
antibody test in the clinical practice setting, we evaluated the
sensitivity of this serologic test in a group of patients who
were suspected of having coeliac disease and had serologic testing
performed at commercial laboratories.
Patients and methods. The study was performed
at Poursina Hakim Research Institute in Isfahan-Iran. A total
number of 350 consecutive patients were enrolled in our study.
They were divided into 3 groups: classical mode of presentation,
atypical mode of presentation and patients with non specific prolonged
gastrointestinal symptoms. Upper gastrointestinal endoscopy, histopathologic
examination of biopsies from the second part of duodenum and serologic
evaluation were performed for every patient. Biopsy specimens
were evaluated according to Marsh (1992, revised in 1997).
Results. The overall sensitivity and specificity
of IgA anti-tTG antibody were 38% and 98%. The positive and negative
predictive values for the anti-tTG antibodies were 57% and 96%,
respectively. The sensitivity was 80% in patients with Marsh IIIC.
Conclusion. In contrast to other reports suggesting
a diagnostic accuracy of more than 90% for anti-tTG antibody in
coeliac disease patients, our data showed that we are still far
from an ideal screening serologic tool which can rely on the antibody
test as the sole way of identifying patients with coeliac disease.
This could result in many missed diagnoses, in particular in patients
with lesser degrees of Marsh classification.
Anti-tissue transglutaminase antibody - coeliac disease - duodenal
biopsy - sensitivity.