Coeliac disease is an autoimmune digestive disease caused by permanent intolerance to gluten. Patients produce several antibodies including gliadin ( an alcohol soluble fragment of gluten), endomysial ( levels diminish quickly if the patient is on a gluten free diet/GFD and this does not form part of routine screening ) and tissue transglutaminase ( levels fall slowly 6-12 months once GFD commenced ). Antibodies correlate with severity of enteropathy. Both IgA and IgG antibodies are produced - note Coeliac patients have increased likelhood to be IgA deficient ( approx. 2% of patients ).
A diagnosis of Coeliac d. should not be based on positive serology tests alone. Where the tests results are uncertain HLA DQ typing can stratify patients to high or low risk. More than 90% are HLA DQ2 positive and , <10% are DQ8 positive. Therefore an individual who is negative is extremely unlikely to have coeliac d.. DQ typing cannot be used as a screen as 40% of the general population also carry these markers.
4.4.11 CR |