The comparison of expression of cutaneous lymphocyte-associated antigen (CLA), and Th1- and Th2-associated antigens in mycosis fungoides and cutaneous lesions of adult T-cell leukemia/lymphoma

Mycosis fungoides (MF) is morphologically similar to cutaneous lesions of adult T cell leukemia/lymphoma (ATLL) of human T-cell lymphotropic virus-type I (HTLV-1). In addition, the Th1 or Th2 characteristic of MF and ATLL is still controversial. In the present study, to discriminate MF and cutaneous lesion of ATLL using immunohistochemical markers, and to elucidate Th1 or Th2 dominancy in both disorders, CLA (cutaneous lymphocyte associated antigen) was expressed on epidermotrophic lymphoma cells in all early stage MF. In contrast, all ATLL were negative for CLA. CXCR3 was especially expressed in epidermotropic small lymphoma cells of MF. CCR5 was expressed in both disorders with variable sized lymphoma cells. ST2 was expressed on large transformed lymphoma cells with ATLL, but not in any MF cases. OX40 was expressed in the large transformed cell population in both disorders. These findings suggest that CLA and ST2 could be potentially useful immunohistochemical markers for discrimination of mycosis fungoides and cutaneous lesions of ATLL. And OX40 could be a useful immunohistochemical marker for the histopathological progression of both disorders.