Stage-dependent expression of CD7, CD45RO, CD45RA and CD25 on CD4-positive peripheral blood T-lymphocytes in cutaneous T-cell lymphoma.

Flow cytometric analysis of T-cell surface markers in peripheral blood has revealed abnormal patterns in patients with cutaneous T-cell lymphomas (CTCL). Here we investigated CD7, CD25, CD45RO and CD45RA expression on CD4+ T-lymphocytes in patients with CTCL stage I/II and III/IV and in patients with severe inflammatory skin diseases (ISD), as well as in healthy controls. Only late stage CTCL (III/IV) showed a lymphocytosis with a distinct surface marker pattern: CD3+, CD4+, CD8-, CD7-, CD45RO+, CD45RA-. Early stage CTCL (I/II) showed normal lymphocyte counts, a normal T-helper cell expression of CD7, CD45RO and CD45RA, and a slightly increased percentage of CD4+ CD25+ lymphocytes, which was also found in ISD. It is concluded that flow cytometric analysis of the above T-cell surface markers may be useful in the diagnosis of patients with late stage CTCL. However it does not allow us to distinguish patients with early stage CTCL from patients with ISD or controls.