Leukemic B-chronic lymphoproliferative disorders (B-CLPDs) are generally believed to derive from a monoclonal B cell; biclonality has only occasionally been reported. In this study, we have explored the incidence of B-CLPD cases with 2 or more B-cell clones and established both the phenotypic differences between the coexisting clones and the clinicobiologic features of these patients. In total, 53 B-CLPD cases with 2 or more B-cell clones were studied. Presence of 2 or more Bcell clones was suspected by immunophenotype and confirmed by molecular/ genetic techniques in leukemic samples (n ‫؍‬ 42) and purified B-cell subpopulations (n ‫؍‬ 10). Overall, 4.8% of 477 consecutive B-CLPDs had 2 or more B-cell clones, their incidence being especially higher among hairy cell leukemia (3 of 13), large cell lymphoma (2 of 10), and atypical chronic lymphocytic leukemia (CLL) (4 of 29). In most cases the 2 B-cell subsets displayed either different surface immunoglobulin (sIg) light chain (n ‫؍‬ 37 of 53) or different levels of the same sIg (n ‫؍‬ 9 of 53), usually associated with other phenotypic differences. Compared with monoclonal cases, B-CLL patients with 2 or more clones had lower white blood cell (WBC) and lymphocyte counts, more frequently displayed splenomegaly, and required early treatment. Among these, the cases in which a CLL clone coexisted with a non-CLL clone were older and more often displayed B symptoms, a monoclonal component, and diffuse infiltration of bone marrow and required early treatment more frequently than cases with monoclonal CLL or 2 CLL clones. (Blood. 2003;102:2994-3002)

Multiparametric flow cytometry of MRD in ALL patients is a valuable tool for relapse prediction and for the identification of a cohort of patients with very poor prognosis.

Splenic marginal zone lymphoma (SMZL) is considered to be an indolent extranodal B-cell lymphoma. Despite its low aggressivity, histologic progression has been described in sporadic reports, although the frequency, characteristics, and underlying molecular abnormalities of this phenomenon are largely unknown. We review here the clinical, morphologic, immunohistochemical, and molecular features of a series of 12 SMZL cases that showed progression to large B-cell lymphoma (LBCL). The most frequent location of secondary LBCL was in peripheral lymph node. This occurred between 12 and 85 months after diagnosis of SMZL. However, in two cases LBCL was diagnosed at the initial stage of the disease (one spleen tumoral nodule and one hilar lymph node). The histologic and immunophenotypic features of these cases were similar to those of transformed LBCL at other sites. In four cases the immunoglobulin heavy chain gene polymerase chain study revealed the same rearrangement pattern in both primary and secondary tumors, thereby confirming their identity and excluding the possibility of a second malignancy. As is the case with other low-grade lymphoproliferative disorders, SMZL may undergo high-grade transformation. These 12 cases represent 13% of our series of SMZL with adequate follow-up. The incidence of large cell transformation in SMZL seems to be lower than in follicular lymphoma (25-60%) and mantle cell lymphoma (11-39%), although it is similar to the frequency of transformation in B-chronic lymphocytic lymphoma/small lymphocytic lymphoma (1-10%). The mean proliferative index (MIB1 staining) in initial SMZL specimens of cases with LBCL transformation was 28.6%, higher than that of MIB1 staining in the overall SMZL series (21.8%), although not statistically significantly so. p53 or p16INK4a inactivation in this series was observed in only one case, in contrast with the situation observed in chronic lymphocytic leukemia, follicular lymphoma, and mantle cell lymphoma. It seems that progression in SMZL is mainly independent of p53 or p16INK4a inactivation. The frequency of the 7q deletion in this series was 3 of 7 (42%). 7q loss may play an alternative role in the inactivation of the p53 and p16INK4a pathway, thereby favoring tumoral progression.

The aim of this study was to analyse the expression of NK-associated antigens in both peripheral blood and bone marrow lymphocytes from a large series of newly diagnosed multiple myeloma patients. 112 patients with untreated multiple myeloma (MM) were included in the study. 36 sex- and age-matched healthy volunteers were used as controls for peripheral blood (PB) studies and 14 for the bone marrow (BM) studies. Simultaneous stainings with the CD3/CD56, CD2/CD16 and CD8/CD57 monoclonal antibodies were systematically performed in PB and CD3/CD56 and CD2/CD16 in BM in order to analyse their relationship with the clinical and biological characteristics of the disease and survival. The expression of NK-associated antigens (CD56, CD16 and CD57) assessed within the lymphoid gate, was significantly increased (P < 0.001) in the PB of MM patients both in relative and absolute numbers. In the BM a significant increase in the percentage of CD56+ lymphocytes (P < 0.001) was also observed; in contrast, the proportion of CD16+ cells did not differ significantly from that of normal BM samples. The number of CD56+CD3- lymphocytes increased significantly within high-risk patients (869 +/- 671) as compared to intermediate (388 +/- 212) and low-risk patients (274 +/- 199) (P = 0.04). Moreover, patients with high values of CD56+CD3- lymphocytes showed a statistically significant association with several adverse prognostic factors including anaemia, hypoalbuminaemia, renal failure, high beta 2M, DNA diploidy and high S-phase plasma cells. In addition, patients with higher absolute numbers of PB CD56+CD3-lymphocytes displayed a poorer prognosis, whereas patients with higher values of CD57+CD8- cells had a better outcome.