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**Overview**: Human Leukocyte Antigen PRA Screen Panel**Introduction**: The Human Leukocyte Antigen PRA Screen Panel is a diagnostic tool designed to screen for transplant antibodies using serum samples. In India, PRA screening (Class I/II) detects pre-formed anti-HLA antibodies, critical for transplant candidates to avoid incompatible donors and reduce rejection risk. High morbidity from under-screening in rural/low-SES patients awaiting transplant, limited transplant immunology labs, delayed virtual crossmatch leading to prolonged waiting or graft loss. Per immunology practices aligned with ICMR and Indian Society of Organ Transplantation guidelines, the test employs immunoassay for PRA Class I/II antibodies (qualitative) over 1-2 days with high accuracy, valuable for pre-transplant sensitization assessment. This diagnostic falls under transplant screening and targets all transplant candidates, addressing accurate detection to guide donor allocation or desensitization. With elevated morbidity due to under-screening, the test supports public health efforts by enabling precise antibody profiling and improving transplant outcomes. Its serum-based approach ensures reliable screening.**Other Names**: HLA PRA Scr Pnl.**FDA Status**: FDA approved, CLIA certified for immunology, compliant with 2025 standards.**Historical Milestone**: PRA screen standard; in India, used in transplant registries.**Purpose**: The test assesses 2 parameters including PRA Class I/II antibodies to guide transplant antibody screening, detect sensitization, inform donor matching.**Test Parameters**: 1. PRA Class I/II Antibodies, 2. Qualitative Result.**Pretest Condition**: No fasting required; patients should be transplant candidates.**Specimen**: 3 mL serum in 1 SST, transported within specified times to maintain sample viability.**Sample Stability at Room Temperature**: 8 hours with proper handling to preserve analyte 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**: 6 months at -20 degrees Celsius, allowing long-term storage for retesting, though freezing may affect some analytes.**Medical History**: Patients should provide details on prior transplants, transfusions, pregnancies.**Consent**: Written informed consent is required, detailing the test's purpose, potential risks of undetected antibodies including rejection, benefits of screening, and minimal discomfort from venipuncture.**Procedural Considerations**: The test involves sample processing using immunoassay by trained personnel to ensure sterile technique, avoid hemolysis, and interpret results 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, hemolysis, or recent transfusion can affect results. Correlation with clinical evaluation or additional testing is recommended to confirm findings.**Clinical Significance**: Positive PRA indicates sensitization, necessitating specialist input.**Specialist Consultation**: Transplant immunologists should be consulted for management.**Additional Supporting Tests**: Single antigen bead for specificity.**Test Limitations**: Qualitative screen; comprehensive approach required.**References**: Indian Journal of Transplantation 2024, Transplant Studies India 2023. |
