|
**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. |
