Adhesion molecule expression in CD5-negative/CD10-negative chronic B-cell leukemias: Comparison with non-Hodgkin's lymphomas and CD5-positive B-cell chronic lymphocytic leukemia

The classification of CD5-negative/CD10-negative chronic B-cell leukemias ( CD5-/CD10- CBL) can be problematic, Most of these cases may represent leuke mic non-Hodgkin's lymphoma (NHL) other than B-cell chronic lymphocytic leuk emia (BCLL); nonetheless, some investigators still advocate the term " CD5- negative BCLL." Because adhesion molecule (AdMol) expression patterns refle ct the biology of lymphoid neoplasms, we studied a series of 106 B-cell lym phoproliferative disorders, including CD5+ BCLL (n = 56), NHL other than BC LL (n = 35), and CD5-/CD10- CBL (excluding hairy cell leukemia and prolymph ocytic leukemia) with no prior history of NHL (n = 15) for expression of co mponents of the very late antigen-4 complex (alpha4/beta1 integrin (CD49d/C D29)), components of the mucosal addressin-cell adhesion molecule receptor (alpha4(CD49d)/beta7 integrin), and L-selectin (CD62L). CD62L expression wa s significantly greater in CD5+ BCLL than in NHL (P < .001). Conversely, CD 29, CD49d, and <beta>7-integrin expression were significantly greater in NH L than in CD5+ BCLL (P < .001 for each marker). These differences persisted when only blood and bone marrow samples were analyzed, with the exception of differences in CD62L expression, which approached, but did not reach, st atistical significance (P = .08). The group of CD5-/CD10- CBL displayed an AdMol profile similar to NHL and was significantly different than CD5+ BCLL in expression of <beta>7 integrin, CD29, CD49d, and CD62L (P range <.001-. 011). In summary, CD5-/CD10- CBL display an AdMol profile resembling NHL an d significantly different from CD5+ BCLL, supporting the growing notion tha t "CD5-negative BCLL" generally represents leukemic NHL rather than a varia nt of true CD5+ BCLL. Copyright (C) 2001 by W.B. Saunders Company.