SEROLOGICAL SCREENING OF CELIAC-DISEASE - CHOOSING THE OPTIMAL PROCEDURE ACCORDING TO VARIOUS PREVALENCE VALUES

Citation
G. Corrao et al., SEROLOGICAL SCREENING OF CELIAC-DISEASE - CHOOSING THE OPTIMAL PROCEDURE ACCORDING TO VARIOUS PREVALENCE VALUES, Gut, 35(6), 1994, pp. 771-775
Citations number
32
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Gastroenterology & Hepatology
Journal title
GutACNP
ISSN journal
0017-5749
Volume
35
Issue
6
Year of publication
1994
Pages
771 - 775
Database
ISI
SICI code
0017-5749(1994)35:6<771:SSOC-C>2.0.ZU;2-S
Abstract
The aim of this study was to select the best approach for screening co eliac disease patients among populations with different grades of dise ase prevalence. The diagnostic performance was assessed of class A and G antigliadin antibodies and class A antiendomysium antibodies in 93 consecutive outpatients with suspected malabsorption, 44 of whom (47%) had coeliac disease according to duodenal histological tests. Class G antigliadin antibodies provided the worst diagnostic values, whereas a high diagnostic validity was found for the other two tests. The posi tive predictive value corrected for the disease prevalence expected in coeliac disease relatives (5%) and the general population (0.2%) fell to 30% and < 2% respectively for class A antigliadin antibodies, wher eas it remained 100% for antiendomysium antibodies in both situations, providing an optimal value for their use as a screening test and as a valid alternative to duodenal biopsy when this is not feasible. The h igh cost of antiendomysium antibodies and the invasive nature of duode nal biopsy prevent them being used widely as screening procedures. A c ost effective two step approach was simulated measuring class A antigl iadin antibodies in all subjects of the target population (first step) , and performing a confirmation test (antiendomysium antibodies or duo denal biopsy) only in subjects positive for antigliadin antibodies. Th e results show that such a procedure should be recommended only for su bjects with an expected low disease prevalence - that is, 5% for coeli ac disease relatives and 0.2% for the general population - as the posi tive predictive value was always 100% with an acceptable false negativ e rate (6% and 11% respectively), irrespective of which of the two con firmation tests was used. This approach avoids the use of the confirma tion test in 63% and 89% of subjects respectively for the two levels o f prevalence, resulting in a considerable reduction of the cost. Patie nts seen for suspected malabsorption with an expected high prevalence of coeliac disease should not have such a serological screening proced ure. In conclusion, antigliadin antibodies are useful to screen for as ymptomatic coeliac disease in non-hospital. communities if antiendomys ium antibodies are used as a confirmation test: the latter is a reason able valid alternative to duodenal biopsy.