Coeliac disease HLA typing
Also known as: Coeliac tissue typing, variants of HLA-DQ and DR
Familial - Gastrointestinal; Paediatric - Gastrointestinal; Immunology - Gastrointestinal
Use of test
Patients with coeliac disease almost always have specific variants of the human leukocyte antigens, HLA-DQ2 and HLA-DQ8. These variants are necessary, but not sufficient, for the disease to occur. Up to 30% of some Caucasian populations have these specific variants, but only 5-10% of such people ever develop coeliac disease.
The presence of these variants indicates that a person is at increased risk of developing coeliac disease. Nonetheless, the majority of people with these variants will not develop coeliac disease.
The absence of these variants effectively excludes a diagnosis of coeliac disease in the patient now or in the future. This is the principle value of the test i.e. excluding the current or potential diagnosis of coeliac disease in a symptomatic patient, a patient on a gluten-free diet, or in the relatives of a person with coeliac disease.
This is an assay for heritable variants which can alter the probability that a person will develop a disorder. The test result is not, in isolation, diagnostic of a disease and the test result is not necessarily clinically significant for the patient's relatives.
Analysis of the gene sequence of the HLA-DQ and DR genes for the presence of specific variants.
Requesting the test
This test can be requested by any medical practitioner.
4 mL blood in EDTA. Specimens may be collected by the requesting practitioner or at any Sonic Healthcare collection centre (see link below).
To help ensure the quality of the test, a genetic test should be done with a dedicated sample whenever possible i.e. a sample collected specifically for that test rather than a sample that is used for multiple tests.
We recommend that the patient or another adult check the labelling of request forms and sample tubes.
5 business days.
This test has a Medicare rebate which, subject to the requirements of the Medicare descriptor being met, may cover all or part of the cost.
The Medicare details, including descriptor and schedule fee, are listed under MBS item 71151.