Equivocal small-bowel histologic finding (Marsh I-II) in seronegative individuals
Evaluation of individuals on a gluten-free diet (GFD) in whom no testing for CD was done before GFD
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics: Celiac disease is a systemic autoimmune disorder that may be associated with gastrointestinal symptoms including: diarrhea, weight loss, anorexia, lactose intolerance, and abdominal distention and discomfort. Non-gastrointestinal characteristics are highly variable and include: chronic fatigue, joint pain/inflammation, migraines, epilepsy, depression, attention deficit disorder, iron-deficiency anemia, vitamin deficiency, osteoporosis/osteopenia, short stature, delayed puberty, dental enamel defects, infertility, recurrent fetal loss, and dermatitis herpetiformis.
Incidence: One in 133 individuals in the US is affected.
Cause: The presence of either the HLA-DQ2 or the HLA-DQ8 allele in combination with dietary gluten.
Alleles tested: HLA-DQ2 (encoded by HLA-DQA1*05 and HLA-DQB1*02) and HLA-DQ8 (encoded by HLA-DQB1*03:02).
Clinical Sensitivity and Specificity: Approximately 100 percent and 3 percent, respectively.
Methodology: PCR with melting curve analysis.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Rare diagnostic errors may occur due to primer site mutations. Copy number of each detected allele will not be determined. Alleles other than HLA-DQ2 and HLA-DQ8 will not be identified. Other genetic and non-genetic factors that influence celiac disease are not evaluated.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|2005022||Celiac HLA Interpretation|
|2011755||HLA Celiac Specimen|
- Celiac Disease genotyping
- HLA Celiac Disease Testing
- HLA DQ
- HLA genotyping for Celiac Disease
- HLA-DQ; HLA DQ
- HLA-DQA1*05, HLA-DQB1*02, & *03