Natural killer cells in human peripheral blood and primary cutaneous natural killer cell lymphomas may express cutaneous lymphocyte antigen.

In normal human peripheral blood, cutaneous lymphocyte antigen is expressed by memory T cells, suggesting a specific tissue-homing population of T cells. In this study it is demonstrated that 6% of CD56 + natural killer cells in peripheral blood also express cutaneous lymphocyte antigen (CLA). It was also detected that most of the tumor cells in primary cutaneous nasal-type natural killer cell lymphomas were CLA-positive, whereas primary nasal natural killer cell lymphomas were CLA-negative. Although natural killer cells traditionally are known to be non-specific immune cells without antigen specificity and little is known about the role of natural killer cells in skin diseases, the results of this study suggest the existence of a subset of skin-associated CLA+ CD56+ natural killer cells. These natural killer cells may be related to the pathogenesis of primary cutaneous natural killer cell lymphomas.