[Use of the multiparametric panel CD3/CD4/CD8/CD7/CD26/CD158k in the detection and use of flow cytometry of Sezary cells].

The Sezary syndrome has been defined by a triad combining erythrodermia, generalized lymphadenopathy, and the presence of circulating Sezary cells > 1 × 109/L characterized by a CD4+/CD8- phenotype with loss of one or more T antigens (mainly CD7 and/or CD26). We retrospectively reviewed the immunophenotypic profiles of 10 SS patients followed in our institution (University Hospital at Nancy, France). The application of the WHO criteria resulted in a diagnostic confirmation for 9 out of 10 cases. Since 2008, new diagnostic and staging criteria have been proposed, including the CD158k/KIR3DL2 receptor detection. The application of these new criteria to our cohort led us to notice a phenotypic heterogeneity of our cases but allowed to achieve a relevant diagnosis of Sezary syndrome in all cases, especially for patients with lymphopenia. The use of such a panel of monoclonal antibodies also optimized the follow-up of the patients.