| Category: |
Immunogenetics |
|---|---|
| Test Code: | 143 |
| Disease: | Pharmacogenetics/Ocular Immunogenetics |
| Methodology: | Sequence Specific Primers |
| Reference Range: | Reported positive or negative. |
| CPT Code: | 83891; 83898(x31); 83894; 83912. |
| Schedule / Turnaround Time: | Assay performed daily. Report availability is within 48 hours from the time of specimen receipt. |
| Specimen Requirements: |
Specimen must be kept in ambient temperature and should not be refrigerated or frozen. Collect 5 ml of blood in a lavender top Hemogard (EDTA) tube. |
| Sample Stability: |
Sample is stable at ambient temperature and should be analyzed within 76 hours. |
| Relevance: |
Type I diabetes has a high association with DQ2 and there appears to be a link between celiac disease and early onset of male Type 1 diabetes. Recent studies indicate a combination of DQ2 and DQ8 (both acid peptide presenters) greatly increase the risk of adult onset Type 1 diabetes and ambiguous type I/II diabetes. HLA DR3 plays a prominent role in autoimmune diabetes. However, DQ2 presence with DR3 decreases the age of onset and the severity of the autoimmune disorder. DQ2 represents the second highest risk factor for celiac disease; the highest risk is a close family member with the disease. Due to its link to celiac disease, DQ2 has the highest association of any HLA serotype with autoimmune disease. Close to 95% of all celiacs have DQ2, and of this group, 30% have 2 copies of DQ2. Of the DQ2 homozygotes who eat wheat, lifelong risk is between 20 and 40% for celiac disease. |