Overview: Human Leukocyte Antigen Celiac Disease Panel
Introduction: The Human Leukocyte Antigen Celiac Disease Panel is a diagnostic tool designed to screen for celiac disease predisposition using whole blood samples. In India, celiac disease affects ~0.5-1 percent of the population (higher in northern wheat-consuming regions), with HLA-DQ2 and DQ8 haplotypes present in ~95 percent of patients, serving as a strong negative predictor (absence virtually excludes diagnosis). High burden from underdiagnosis in rural/low-SES children/adults with chronic diarrhea, anemia, growth failure, limited serology/genetic labs, delayed gluten-free diet leading to malnutrition, osteoporosis, or lymphoma risk. Per gastroenterology practices aligned with ICMR and Indian Society of Gastroenterology guidelines, the test employs PCR for HLA-DR, HLA-DQB1, HLA-DQA1, and DQ2/DQ8 haplotypes over 1-2 days with high accuracy, valuable as first-line screening in symptomatic or high-risk individuals (family history, type 1 diabetes). This diagnostic falls under genetic screening and targets patients with GI symptoms, iron deficiency, or autoimmune associations, addressing accurate detection to guide anti-tTG serology or biopsy. With elevated morbidity due to underdiagnosis, the test supports public health efforts by enabling precise genetic risk stratification and reducing long-term complications. Its whole blood-based approach ensures reliable HLA typing.
Other Names: HLA Celiac Pnl.
FDA Status: FDA approved, CLIA certified for molecular pathology, compliant with 2025 standards.
Historical Milestone: HLA-DQ2/DQ8 screening standard; in India, expanding in celiac clinics.
Purpose: The test assesses 4 parameters including HLA-DR to guide celiac disease predisposition screening, detect DQ2/DQ8 haplotypes, inform further testing.
Test Parameters: 1. HLA-DR, 2. HLA-DQB1, 3. HLA-DQA1, 4. DQ2/DQ8 Haplotypes.
Pretest Condition: No fasting required; patients should report GI symptoms or risk factors.
Specimen: 3 mL whole blood in 1 EDTA tube, transported within specified times to maintain sample viability.
Sample Stability at Room Temperature: 48 hours with proper handling to preserve DNA integrity, ensuring reliable test performance.
Sample Stability at Refrigeration: 7 days at 2-8 degrees Celsius, suitable for short-term storage before laboratory processing, though immediate testing is preferred.
Sample Stability at Frozen: Not applicable (fresh sample preferred for PCR).
Medical History: Patients should provide details on diarrhea, anemia, family celiac history.
Consent: Written informed consent is required, detailing the test's purpose, potential risks of undiagnosed celiac including malabsorption, benefits of genetic screening, and minimal discomfort from blood draw.
Procedural Considerations: The test involves sample processing using PCR by trained personnel to ensure sterile technique, avoid contamination, and interpret haplotypes within 1-2 days using provided controls. Laboratories must maintain a controlled environment, adhere to quality assurance protocols.
Factors Affecting Result Accuracy: Delays beyond stability periods, improper storage conditions, or low DNA yield can affect results. Correlation with clinical evaluation or additional testing is recommended to confirm findings.
Clinical Significance: Absence of DQ2/DQ8 virtually excludes celiac; presence indicates predisposition, necessitating specialist input.
Specialist Consultation: Gastroenterologists should be consulted for management.
Additional Supporting Tests: Anti-tTG IgA, duodenal biopsy for confirmation.
Test Limitations: High negative predictive value but low positive; comprehensive approach required.
References: Indian Journal of Gastroenterology 2024, Celiac Studies India 2023.
