Overview: CD68 Immunohistochemistry TestIntroduction: The CD68 Immunohistochemistry Test detects CD68 protein to diagnose histiocytic disorders or lymphomas, causing swelling or fever. Following 2023 WHO guidelines, it uses immunohistochemistry for high specificity, supporting cancer screening. This test is critical for guiding diagnosis, treatment planning, and improving outcomes in histopathology for patients with suspected histiocytic disorders or lymphomas.
Other Names: CD68 IHC Assay, Histiocytic Disorder IHC Test.
FDA Status: Laboratory-developed test (LDT), meeting histopathology standards for diagnostic accuracy.
Historical Milestone: CD68 testing began in the 1990s with histiocytic research. Immunohistochemistry-based methods improved in the 2000s, enhancing diagnostic precision.
Purpose: Detects CD68 to diagnose histiocytic disorders or lymphomas, guides treatment, and evaluates patients with swelling or fever.
Test Parameters: 1. CD68 Protein
Pretest Condition: No fasting required. Collect tissue via biopsy. Report history of swelling, fever, or histiocytic symptoms.
Specimen: 0.5-2 cma³ tissue (FFPE). Transport in a biohazard container.
Sample Stability at Room Temperature: 7 days
Sample Stability at Refrigeration: Not refrigerated
Sample Stability at Frozen: Not frozen
Medical History: Document swelling, fever, organ enlargement, or family history of histiocytic disorders or lymphomas. Include current medications, especially chemotherapy.
Consent: Written consent required, detailing the tests purpose, histiocytic or lymphoma implications, and risks of biopsy.
Procedural Considerations: Uses immunohistochemistry to detect CD68 in tissue. Results are available in 1-2 days, supporting rapid clinical decisions. Performed in laboratories, often for histiocytic disorder diagnosis.
Factors Affecting Result Accuracy: Improper tissue fixation or processing can affect results. Low tissue quality may reduce staining accuracy.
Clinical Significance: Positive CD68 staining suggests histiocytic disorders (e.g., Langerhans cell histiocytosis) or lymphomas, guiding treatment. Negative staining may require further marker testing.
Specialist Consultation: Consult a hematologist or oncologist for result interpretation and treatment planning.
Additional Supporting Tests: S100 IHC, BRAF mutation testing, or bone marrow biopsy to confirm histiocytic disorder diagnosis.
Test Limitations: Not specific to one histiocytic disorder; other conditions may express CD68. Clinical correlation is needed.
References: WHO Histiocytic Guidelines, 2023; Blood, Emile JF, 2022.
