Proliferation cell nuclear antigen and soluble interleukin 2 receptor levels in cutaneous T cell lymphoma: correlation with advanced clinical diseases.

Cutaneous T-cell lymphoma and leukemias (CTCL) are malignant clonal proliferation of T lymphocytes which have a predilection to home to and proliferate in skin. There are no clinical and laboratory parameters which consistently correlate with stage of disease, which varies from patch, plaque, tumor, or erythroderma. Soluble IL-2 receptor (sIL2-R) levels are elevated both in benign and malignant diseases involving immune activation. Proliferation cell nuclear antigen (PCNA) is a marker of the G1 and G/S phases of cell cycle and can be used to quantitate proliferation. We studied 43 skin biopsies of CTCL in various clinical stages for the presence of PCNA via immunoperoxidase techniques to establish a relationship between PCNA and the stage of disease. In addition, sIL2-R levels were determined in 14 patients. PCNA reactivity was detected in the nuclei of infiltrating cells in a total of 25 patients (58%). According to clinical stage there were 2/12 patch (12%), 9/17 plaque (53%), 4/4 tumor (100%) and 9/10 erythrodermic (90%) stage patients with PCNA positive cells. Thus PCNA positivity correlated with advanced clinical stage. sIL2-R levels were elevated in 14 of 14 patients and the degree of elevation correlated with advanced clinical stage of disease and with increased numbers of PCNA positive cells. Immunohistochemical studies for PCNA and serum sIL2-R levels can be used as laboratory parameters to correlate with clinical stage of disease and enhance prognostication in CTCL.