Specificity of leucocyte migration inhibition test in coeliac disease. A reassessment using different gluten subfractions.

Production of leucocyte migration inhibition factor by peripheral blood leucocytes in response to challenge with gluten fractions has been proposed as a reliable in vitro test for the diagnosis of coeliac disease. We have performed the leucocyte migration inhibition test with two different gluten fractions, GFIII and B2, in untreated and treated coeliac patients, patients with other intestinal diseases (abnormal controls) and healthy controls, and evaluated the sensitivity, specificity and positive and negative predictability of the test for the diagnosis of coeliac disease. Using GFIII as antigen leucocyte migration was significantly inhibited, compared to healthy controls, not only in treated and untreated coeliacs but also in abnormal controls. Using B2 gluten subfraction as antigen only treated coeliacs and abnormal controls differed significantly from healthy controls. The elevated number of abnormal controls showing migration inhibition consistently affected the diagnostic value of the test, which did not vary using B2 subfraction instead of GFIII as antigen. Our study confirms previous observations of gluten sensitization, as detected by leucocyte migration inhibition, in coeliac patients but strongly questions the claim that coeliac disease can be diagnosed on the basis of a positive leucocyte migration inhibition test without the need for intestinal biopsy.