CD49d/␣4-integrin is variably expressed in chronic lymphocytic leukemia (CLL

The clinical course of B-cell chronic lymphocytic leukemia (B-CLL) is variable, and novel biologic parameters need to be added to the clinical staging systems to predict an indolent or aggressive outcome. We investigated the 70-kDa zetaassociated protein (ZAP-70), CD38, soluble CD23 (sCD23), and cytogenetics in 289 patients with B-CLL. Both a shorter progression-free survival (PFS) and overall survival (OS) were observed in ZAP-70 ؉ (P < .001), in CD38 ؉ (P < .001) and in sCD23 ؉ patients (P < .001 and P ‫؍‬ .013, respectively). ZAP-70 ؉ CD38 ؉ or ZAP-70 ؉ patients with an unmutated IgV H status showed both a shorter PFS (P < .001) and OS (P < .001 and P < .001, respectively) as compared with ZAP-70 ؊ /CD38 ؊ or ZAP-70 ؊ patients with mutated IgV H genes. Discordant patients showed an intermediate outcome. Note, ZAP-70 ؉ patients even if CD38 ؊ or mutated showed a shorter PFS, whereas ZAP-70 ؊ patients even if CD38 ؉ or unmutated had a longer PFS. Furthermore, ZAP-70 positivity was associated with a shorter PFS both within normal karyotype (P < .001) and within the poor-risk cytogenetic subset (P ‫؍‬ .02).

A fraction of chronic lymphocytic leukaemia (CLL) cases carry highly homologous B-cell receptors (BCR), i.e. characterized by non-random combinations of immunoglobulin heavy-chain variable (IGHV) genes and heavy-chain complementarity determining region-3 (HCDR3), often associated with a restricted selection of IGVK/L light chains. Such 'stereotyped' BCR occur more frequently in CLL with unmutated (UM) than mutated (M) IGHV genes. We analysed 1426 IG rearrangements (from 1398 CLL cases) by a clustering driven by HCDR3 similarities. Molecular findings were correlated to time-to-treatment (TTT) and presence of known prognosticators. Sixty-nine clusters (319 IG-rearrangements, 22AE4%) with stereotyped BCR were identified. Among 30 confirmed clusters ( ‡3 IG-rearrangements/cluster), we found 14 novel clusters, of which 11 had M IG rearrangements (M clusters) and predominantly (8/11) used IGHV3 subgroup genes. Recurrent cluster-biased amino acid changes were found throughout IGHV sequences of these 'M clusters'. Regarding clinical outcome: (i) UM CLL from the IGHV1-2/1-3/1-18/1-46/7-4-1/IGKV1-39 cluster had poorer prognosis than UM/M cases, or UM cases using the same IGHV genes but not in clusters; (ii) M CLL from the IGHV3-21/IGLV3-21 cluster had TTT similar to UM CLL, and shorter than M CLL expressing IGHV3-21 but not in cluster. Altogether, our analysis identified additional molecular and clinical features for CLL expressing stereotyped BCR.

CCR1 and, to a lesser extent, CCR5, the receptors for CCL3 and CCL4, were found in CLL-derived monocyte-macrophages. Consistently, CCL3 increased monocyte migration, and CD68 + macrophage infiltration was particularly high in BMB from CD38 + CD49d + CLL. Conditioned media from CCL3-stimulated macrophages induced endothelial cells to express vascular cell adhesion molecule-1 (VCAM-1), the CD49d ligand, likely through tumor necrosis factor A overproduction. These effects were apparent in BMB from CD38 + CD49d + CLL, where lymphoid infiltrates were characterized by a prominent meshwork of VCAM-1 + stromal/endothelial cells. Lastly, CD49d engagement by VCAM-1 transfectants increased viability of CD38 + CD49d + CLL cells. Altogether, CD38 and CD49d can be thought of as parts of a consecutive chain of events ultimately leading to improved survival of CLL cells. [Cancer Res 2009;69(9):4001-9]