CD335 (NKp46) Specifically Identifies Natural Killer Cells by Diagnostic Flow Cytometry
Aharon G Freud, Sibing Wei, Gary M Gitana, Yasodha Natkunam, Susan K Atwater. Stanford University, Stanford, CA
Background: CD335 (NKp46) is a surface activation receptor that is expressed on natural killer (NK) cells. Few studies have reported aberrant CD335 expression on T cell neoplasms; however, the clinical application of CD335 in routine diagnostic flow cytometry is unknown.
Design: A 6-color cocktail containing CD3 APC-H7, CD16 V450, CD45 PerCP, CD56 FITC, CD161 (NKRP1A) APC, and CD335 PE antibodies was optimized and evaluated on patient specimens submitted for diagnostic flow cytometry. Patient samples were processed and analyzed by clinical laboratory scientists. Populations were gated using CD45 expression and forward and side scatter characteristics. Diagnoses were made using WHO 2008 criteria.
Results: A total of 223 specimens, including blood (n=71), bone marrow (n=103), and lymph node (n=32), were stained with the 6-color antibody cocktail. Diagnoses included reactive conditions as well as B cell, T cell, plasma cell, and myeloid neoplasms.
|Percent of cases with positive CD335 expression|
|Diagnosis||Neoplastic/atypical population||Background T cells||Background NK cells|
|Atypical T or B lymphocytosis (n=17)||0%||0%||100%|
|Atypical NK lymphocytosis (n=3)||66.7%||0%||100%|
|B lymphoblastic leukemia (n=4)||0%||0%||100%|
|B cell leukemia/lymphoma (n=35)||0%||0%||100%|
|T lymphoblastic leukemia (n=3)||0%||0%||100%|
|T cell leukemia/lymphoma (n=16)||12.5%||0%||93.8%|
|Plasma cell dyscrasia (n=7)||0%||0%||100%|
|Myeloid neoplasm (n=14)||0%||0%||100%|