Expression of the activating receptor, NKp46 (CD335), in human natural killer and T-cell neoplasia.

OBJECTIVES

To evaluate the expression of CD335 (NKp46), an activation receptor that is selectively expressed on natural killer (NK) cells.

METHODS

We assessed CD335's potential utility as a diagnostic marker in 657 cases by flow cytometry and 410 cases by immunohistochemistry.

RESULTS

We observed that CD335 was highly specific for NK cells in nonneoplastic tissues. Moreover, 61 (90%) of 68 of NK cell neoplasms demonstrated CD335 expression, whereas B-cell, myelomonocytic, and plasma cell neoplasms lacked expression. Notably, 16 (20%) of 82 mature T-cell neoplasms, particularly T-cell large granular lymphocytic leukemia, mycosis fungoides, and ALK+ anaplastic large cell lymphoma, aberrantly expressed CD335.

CONCLUSIONS

Collectively, these data support the diagnostic utility of CD335 in evaluating hematopoietic malignancies and suggest that CD335 could be a useful target for selective immunotherapy in patients with mature NK and T-cell neoplasms.