Overview: ZAP70 Flow Cytometry Test
Introduction: The ZAP70 Flow Cytometry Test detects ZAP-70 markers to diagnose chronic lymphocytic leukemia, causing fatigue or infections. Aligned with 2023 ASH guidelines, it uses flow cytometry for high specificity, aiding in cancer screening. This test is critical for guiding diagnosis, treatment, and improving outcomes in hematology for patients with suspected chronic lymphocytic leukemia.

Other Names: ZAP-70 Flow Assay, Zeta-Associated Protein 70 Test.

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

Historical Milestone: ZAP-70 testing began in the 2000s with CLL research. Flow cytometry panels emerged in the 2010s, improving prognostic accuracy for CLL.

Purpose: Diagnoses chronic lymphocytic leukemia, guides treatment, and monitors ZAP-70 markers in patients with fatigue or infections.

Test Parameters: 1. ZAP-70

Pretest Condition: No fasting required. Collect whole blood or bone marrow at any time. Report symptoms like fatigue or infections, and list medications.

Specimen: 2-5 mL whole blood (EDTA) or 2-5 mL bone marrow (EDTA). 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 fatigue, frequent infections, or history of chronic lymphocytic leukemia. Include current medications, especially chemotherapeutics.

Consent: Written consent required, detailing the tests purpose, diagnostic implications, and potential need for cancer therapy.

Procedural Considerations: Uses flow cytometry to detect ZAP-70 markers. Requires intracellular staining. Results are available in 1-2 days, enabling rapid clinical decisions.

Factors Affecting Result Accuracy: Poor sample quality, low cell yield, or improper staining can affect results. Non-malignant conditions may express ZAP-70.

Clinical Significance: Positive ZAP-70 expression suggests aggressive CLL, prompting treatment. Negative results may indicate indolent disease but require further testing.

Specialist Consultation: Consult a hematologist or oncologist for result interpretation.

Additional Supporting Tests: Bone marrow biopsy, other flow cytometry markers (e.g., CD5, CD23), or FISH to confirm CLL.

Test Limitations: Non-specific expression may occur in non-malignant conditions. Results require clinical correlation.

References: ASH Leukemia Guidelines, 2023; Blood, Arber DA, 2022.