Overview: DSA-SAB Class I IgG C1q TestIntroduction: The DSA-SAB Class I IgG C1q Test detects class I HLA antibodies with C1q-binding to assess transplant rejection risk, preventing organ failure. Aligned with 2023 AST guidelines, it uses PCR for high specificity, aiding in transplant screening. This test is critical for guiding immunosuppressive therapy, monitoring rejection risk, and improving outcomes in immunology for transplant patients.
Other Names: DSA-SAB Class I Assay, HLA Class I C1q Test.
FDA Status: Laboratory-developed test (LDT), meeting immunology standards for diagnostic accuracy.
Historical Milestone: HLA antibody testing began in the 1970s with transplant research. C1q-binding assays emerged in the 2000s, improving rejection risk assessment by 2020.
Purpose: Detects class I HLA antibodies, guides immunosuppressive therapy, and monitors rejection risk in transplant patients.
Test Parameters: 1. Class I IgG + C1q
Pretest Condition: No fasting required. Collect serum or saliva at any time. Report transplant history, organ dysfunction, or immunosuppressive medications.
Specimen: 2-5 mL serum (SST) or 1-2 mL saliva (sterile container). Centrifuge serum within 1 hour. Transport in a biohazard bag within 24 hours.
Sample Stability at Room Temperature: 24 hours
Sample Stability at Refrigeration: 48 hours
Sample Stability at Frozen: Not frozen
Medical History: Document transplant history, organ dysfunction, or immunosuppressive therapy. Include current medications, especially immunosuppressants.
Consent: Written consent required, detailing the tests purpose, implications for transplant management, and potential need for therapy adjustments.
Procedural Considerations: Uses PCR-based single antigen bead (SAB) assay to detect class I HLA IgG antibodies with C1q-binding. Results are available in 3-5 days, supporting clinical decisions.
Factors Affecting Result Accuracy: Contamination or low antibody levels can affect results. Improper storage may reduce sensitivity.
Clinical Significance: Positive C1q-binding antibodies indicate high rejection risk, prompting therapy adjustments. Negative results support stable graft function.
Specialist Consultation: Consult a transplant specialist or immunologist for result interpretation.
Additional Supporting Tests: HLA typing, donor-derived cfDNA, or biopsy to confirm rejection risk.
Test Limitations: False negatives may occur with low antibody levels. Results require clinical correlation.
References: AST Transplant Guidelines, 2023; American Journal of Transplantation, Loupy A, 2022.
