Overview: CD127 Test
Introduction: The CD127 Test tests CD127 expression on immune cells to assess immune system disorders or monitor conditions like HIV, helping evaluate immune function and treatment response. Affecting 1 in 1,000 HIV patients annually, immune dysfunction poses diagnostic challenges. Following 2023 International AIDS Society (IAS) guidelines, it uses flow cytometry for high accuracy, supporting hematology screening. This test is vital for diagnosis, monitoring, and improving outcomes in infectious disease management.

Other Names: IL-7R Alpha Test, CD127 Expression Assay.

FDA Status: Laboratory-developed test (LDT), meeting hematology standards for diagnostic reliability.

Historical Milestone: Immune marker testing began in the 1990s with research by Leonard, who linked CD127 to immune regulation. Flow cytometry advancements in the 2000s by BD Biosciences improved detection, surpassing earlier ELISA methods.

Purpose: Measures CD127 expression to assess immune disorders, guides antiretroviral therapy, and evaluates patients with infections, aiming to enhance immune recovery.

Test Parameters: CD127 expression

Pretest Condition: No special preparation required. Collect whole blood. Report history of immune issues.

Specimen: Whole Blood (EDTA, 2-5 mL); 4 mL whole blood in Na Heparin tube. Transport in a biohazard container.

Sample Stability at Room Temperature: 24 hours

Sample Stability at Refrigeration: 48 hours

Sample Stability at Frozen: Not recommended

Medical History: Document recurrent infections or HIV history. Include current medications or treatment history.

Consent: Written consent required, detailing the test's purpose, disease risks (e.g., AIDS), and sample collection risks.

Procedural Considerations: Uses flow cytometry to measure CD127, requiring labs with flow cytometers. Results available in 1-2 days. Performed in labs with strict handling.

Factors Affecting Result Accuracy: Sample degradation or contamination can affect results. Medications may alter expression, requiring correlation.

Clinical Significance: Low CD127 indicates immune dysfunction, guiding therapy. Early intervention might prevent progression, while untreated cases lead to AIDS. Normal levels may suggest recovery.

Specialist Consultation: Consult an infectious disease specialist for interpretation.

Additional Supporting Tests: CD4 count, viral load, or immune panel to confirm diagnosis.

Test Limitations: Specific to CD127; correlation with other markers needed. False negatives possible with sample issues.

References: IAS Guidelines, 2023; Journal of Immunology, Leonard WJ, 2022.