Summary:We investigated the use of 'prophylactic' donor lymphocyte infusions (DLI) containing 1 ؋ 10 7 CD3 ؉ cells, given at 30, 60 and 90 days post-allogeneic blood and marrow transplantation (BMT), following conditioning with fludarabine 30 mg/m 2 /4 days and melphalan 70 mg/m 2 /2 days. GVHD prophylaxis consisted of cyclosporin A (CsA) 2 mg/kg daily with early tapering by day 60. Our goals were the rapid achievement of chimerism and disease control, providing an immunological platform for DLIs to treat refractory patients with hematological malignancies. Twelve heavily pre-treated patients with life expectancy less than 6 months were studied; none were in remission. Diagnoses were AML (n ‫؍‬ 4), MDS (n ‫؍‬ 1), ALL (n ‫؍‬ 3), CML (n ‫؍‬ 3) and multiple myeloma (n ‫؍‬ 1). Response rate was 75%. Three patients are alive at a median of 450 days (range, 450-540). Two patients are in remission of CML in blast crisis and AML for more than 14 months. Median survival is 116 days (range, 25-648). Six patients received 12 DLIs; three patients developed acute GVHD after the first infusion and were excluded from further DLIs, but no GVHD occurred among patients receiving subsequent DLIs. One patient with CML in blast crisis went into CR after the first DLI. The overall incidence of acute GVHD was 70%. Primary causes of death were infections (n ‫؍‬ 3), acute GVHD (n ‫؍‬ 3), chronic GVHD (n ‫؍‬ 1) and disease relapse (n ‫؍‬ 2). We observed high response and chimerism rates at the expense of an excessive incidence of GVHD. DLI given at day ؉30 post BMT caused GVHD in 50% of the patients, and its role in this setting remains unclear. The therapeutic benefit of allogeneic BMT is in part related to an immunological graft-versus-leukemia (GVL) effect that frequently evolves in the context of graft-versus-host disease (GVHD). The ability of donor lymphocytes to induce remission in patients relapsing after allogeneic transplantation illustrates the potency of this effect.1 Establishing donor-recipient tolerance with less toxic regimens may provide the basis for further immunological manipulations in order to maximize the GVL effect. However, rapidly evolving diseases may not be amenable to this strategy, considering that the immune-mediated elimination of malignant cells may take weeks or months to occur. This fact suggests the need for strategies to reinforce the immune-mediated phenomena in the post-transplant period.Groups in Jerusalem and Houston pioneered the use of sub-lethal doses of fludarabine-based conditioning regimens. These regimens have been shown to be less toxic and to provide enough immunosuppression to prevent graft rejection and establish stable mixed or complete chimerism.2,3 The combination of melphalan and fludarabine has enabled allogeneic stem cell engraftment in the majority of patients treated, at least in the setting of HLA-identical transplantation. Patients with refractory relapses of advanced leukemias appear to benefit the least.

Abnormalities of chromosome 1q21 are common in B-cell malignancies and have been associated with a poor response to therapy. The nature of the involved gene(s) on chromosome 1q21 remains unknown. A cell line (CEMO-1) has recently been established from a patient with precursor-B–cell acute lymphoblastic leukemia (ALL), which exhibited a t(1;14)(q21;q32). To identify the gene involved in this translocation, we have cloned both rearranged IGHJ alleles using long-distance inverse polymerase chain reaction (LDI-PCR). TwoIGHJ fragments were amplified from CEMO-1 DNA and sequenced. One allele showed novel sequences upstream of JH5 with no homology to either IGH or any other sequences on the databases. Using a single-copy Xho I fragment immediately 5′ ofJH5, PAC clones were isolated and mapped to chromosome 1q21 on normal metaphases by fluorescence in situ hybridization (FISH), confirming that this allele represented the t(1;14)(q21;q32) breakpoint. Sequence analysis of the 1q21 XhoI fragment showed identity with an expressed sequence tag (EST), and this probe was therefore used to probe Northern blots. Two transcripts of 6.3 kb and 4.2 kb expressed at low level in mRNA from all tissues were detected: a third transcript of 1.6 kb was expressed only in thymus, spleen, and small intestine. Full-lengthBCL9 cDNA clones were obtained from a normal human fetal brain cDNA library supplemented by 5′ and 3′ RACE. Sequence analysis predicted a protein of 1394 amino acids containing 18% proline, 11% glycine, 11% serine, and 6% methionine, but no recognizable protein motifs or significant homologies to any other known proteins. The CEMO-1 1q21 breakpoint fell within the 3′ UTR of the BCL9 gene. Low-level expression of BCL9 was detected in Epstein-Barr virus-transformed normal B cells by Northern blot; in contrast, abundant BCL9 expression was observed in CEMO-1, indicating that deregulated expression of this gene was one pathological consequence of the translocation. Screening of a panel of 39 B-cell malignancies with 1q abnormalities by Southern blot showed one additional case with a breakpoint in the 3′ UTR ofBCL9, indicating that this was a recurrent breakpoint. FISH analysis using an 850-kb YAC spanning BCL9 identified a further case with t(1;22)(q21;q11) causing juxtaposition of BCL9 to theIGλ locus. Other breakpoints were heterogeneous, falling both centromeric (10 cases) and telomeric (10 cases) of the BCL9gene. These data suggest that BCL9 may be the target of translocation in some B-cell malignancies with abnormalities of 1q21 and that deregulated BCL9 expression may be important in their pathogenesis.