HLA-DQ Typing

HLA‑DQ alleles are strongly linked to immune‑mediated conditions—most notably celiac disease (HLA‑DQ2 and DQ8) and dermatitis herpetiformis. They also increase risk of type 1 diabetes and are associated with narcolepsy type 1 (HLA‑DQB1*06:02). Certain HLA‑DQ variants contribute to autoimmune hepatitis and susceptibility to other autoimmune disorders, often in combination with specific HLA‑DR alleles.

HLA typing tests identify a person’s human leukocyte antigen (HLA) gene variants. It’s used to assess tissue- and organ-transplant compatibility, find matched stem-cell/bone marrow donors, evaluate susceptibility to certain autoimmune disorders, and screen for genetic markers linked to drug hypersensitivity. Results help clinicians predict immune compatibility and risk of immune-mediated reactions, guiding transplant decisions, donor selection, and some medication choices.

HLA‑DQA1*02 denotes a specific allele group of the HLA‑DQA1 gene, which encodes the alpha chain of the HLA‑DQ class II molecule. These proteins present peptides to CD4+ T cells and shape immune responses. The *02 allele series indicates particular sequence variants; specific subtypes (for example *02:01) are linked to varying risks for autoimmune disease, drug hypersensitivity, and transplant compatibility.

The HLA‑DQ2/DQ8 test is a genetic typing assay done on blood or a buccal (cheek) swab using PCR‑based methods to detect HLA‑DQ2 and HLA‑DQ8 alleles. It assesses genetic susceptibility to celiac disease: a negative result makes celiac disease very unlikely, while a positive result indicates risk but does not confirm the disease; serology or biopsy is required for diagnosis.

HLA is not an autoimmune disease. It is a set of genes that produce proteins presenting antigens to the immune system. Certain HLA variants (for example HLA‑B27 or HLA‑DR4) are associated with higher risk of some autoimmune conditions, but having an HLA type does not mean you will develop disease. HLA testing aids diagnosis, risk assessment, and transplant matching.

HLA‑DQ testing identifies genetic predisposition to celiac disease. Presence of DQ2 and/or DQ8 alleles indicates susceptibility (higher risk if homozygous) but does not confirm disease; many carriers never develop celiac. Absence of both alleles makes celiac very unlikely. Use results with symptoms, serology and biopsy, and discuss next steps (monitoring, further testing or family screening) with your clinician.