HLA-DQ2/DQ8

Diagnostic Use

UPDATE: 1 October 2025

HLA DQ2/8 testing is not available at Canterbury Health Laboratories. All referrals for DQ2/DQ8 testing are being triaged prior to onward referral to either Waikato DHB or the NZ Blood Service.

Testing of HLA DQ2/8 for the exclusion of Coeliac Disease is only available where at least one of the following criteria are met:
o Referral is from a specialist service such as Gastroenterology or Paediatrics
o Exclusion of a diagnosis of coeliac disease in a patient on a gluten free diet and unwilling to have a gluten challenge to allow serological testing
o For diagnostic clarity following equivocal serology/biopsy results
o Screening of at-risk groups eg. siblings of index cases, or other higher risk groups such as IDDM and Down syndrome.

Please ensure that local Coeliac Disease testing guidelines are updated, as HLA testing recommendations may have changed since pathways were introduced.

Changes to guidelines mean that coeliac disease can be diagnosed in some children without the need for a biopsy.

Coeliac disease can be diagnosed by a paediatric gastroenterologist without a biopsy if both the following are present:
• Anti-tissue transglutaminase (tTG) immunoglobulin A (IgA) more than 10 times the upper limit of normal on 2 different samples
• Positive endomysial antibodies (EMA)

Department

Genetics - Molecular Pathology

Delphic Registration Code

MOLP

Constituent Tests

• Tissue Transglutaminase IgA antibodies
• Tissue Transglutaminase IgG antibodies

Synonyms

Coeliac Gene Screen
DQ typing for coeliac disease
HLA-DQ

Specimen Type

• Whole Blood

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred if West Coast

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

4

No of Samples Required

1

Additional Specimen Information

This genetic test needs nucleated cells. Please don’t centrifuge or freeze the EDTA blood tube.

If storing blood tube prior to delivery, please refrigerate at 4 degrees (transport at ambient temperature).

Aliquot Instructions

Additional Referral/Aliquot Information

Samples must be in a dedicated tube for this testing.

Interpretation

Coeliac disease is associated with HLA DQ2 and/or HLA DQ8. The presence of at least one of these alleles means that coeliac disease cannot be excluded. However only a minority of people with these alleles have coeliac disease.
If HLA-DQ2 and DQ8 are not detected, Coeliac disease is highly unlikely. In <1% of cases, coeliac disease may occur in the absence of the alleles tested. (Dr Marianne Empson, Immunopathologist)

Test Method

PCR at Waikato DHB

Alleles detected by this PCR: HLA-DQB*02 and HLA-DQB*03:02

Contact Canterbury Health Laboratories on +64 3 364 0484 or email LabInfo@cdhb.health.nz

Contact Information

Enquiry Form