CD27 IN B-CELL CHRONIC LYMPHOCYTIC-LEUKEMIA - CELLULAR EXPRESSION, SERUM RELEASE AND CORRELATION WITH OTHER SOLUBLE MOLECULES BELONGING TO NERVE GROWTH-FACTOR RECEPTORS (NGFR) SUPERFAMILY

Background and Objective. CD27, a transmembrane homodimer belonging to the nerve growth factor (NGF) receptor superfamily, is typically expr essed on leukemic CD5(+) cells in B-cell chronic lymphocytic leukemia (CLL) and found in soluble form in the serum of CLL patients. Therefor e, we investigated clinico-biological implications of increased serum levels of sCD27 in an unselected series of B-CLL patients. Design and Methods. Serum CD27 (sCD27) levels were determined at the time of diag nosis in 82 previously untreated B-CLL patients using a sandwich enzym e-linked immunoassay (ELISA). Results were correlated with either clin ico-hematological or biological features. Finally, quantitative flow c ytometric analyses of membrane CD27 (mCD27) expression were carried ou t on peripheral blood (PB) cells of 22 B-CLL patients and 5 healthy co ntrols, respectively. Results. CD27 was found to be expressed on the s urface of both resting normal and leukemic B cells. sCD27 levels were significantly higher in B-CLL patients (median value 2150 U/mL) than i n healthy controls (median value 220 U/mL)(p < 0.0001). There was a cl ose relationship between sCD27 and soluble TNF-alpha, another molecule belonging to the NGF receptor superfamily. Changes in sCD27 level cor related with clinical stage, beta(2) microglobulin and LDH. interpreta tion and Conclusions. These findings indicate that sCD27 is a reliable marker of tumor mass in B-CLL. Its potential prognostic value should be tested in prospective studies. (C)1998, Ferrata Storti Foundation.