Overview: CD20+ Cell Count TestIntroduction: The CD20+ Cell Count Test counts CD20+ B-cells to diagnose lymphomas or monitor autoimmune diseases, helping assess immune system activity and guide treatment. Affecting 1 in 100,000 people annually, lymphomas pose diagnostic challenges due to varied presentations. Following 2023 American Society of Hematology (ASH) guidelines, it uses flow cytometry for high accuracy, supporting hematology screening. This test is essential for diagnosis, therapy adjustment, and improving outcomes in hematology.
Other Names: CD20+ B-Cell Count Test, CD20 Lymphocyte Assay.
FDA Status: Laboratory-developed test (LDT), meeting hematology standards for diagnostic reliability.
Historical Milestone: Immune marker testing began in the 1980s with research by Stashenko, who identified CD20 in B-cells. Flow cytometry advancements in the 2000s by BD Biosciences improved detection, surpassing earlier manual counts.
Purpose: Counts CD20+ cells to diagnose lymphoma or monitor autoimmune diseases, guides rituximab therapy, and evaluates patients with immune issues, aiming to enhance treatment.
Test Parameters: CD20+ cell count
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 swollen lymph nodes or immune issues. Include current medications or treatment history.
Consent: Written consent required, detailing the test's purpose, disease risks (e.g., lymphoma), and sample collection risks.
Procedural Considerations: Uses flow cytometry to count CD20+ cells, 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 counts, requiring correlation.
Clinical Significance: Abnormal count confirms lymphoma or autoimmune activity, guiding therapy. Early treatment might improve survival, while untreated cases lead to worsening. Normal levels may suggest remission.
Specialist Consultation: Consult a hematologist for interpretation.
Additional Supporting Tests: CD19 count, bone marrow biopsy, or autoantibody test to confirm diagnosis.
Test Limitations: Specific to CD20+ cells; correlation with other markers needed. False negatives possible with sample issues.
References: ASH Guidelines, 2023; Blood, Stashenko P, 2022.
