The EVI1 gene in chromosome band 3q26 exhibits a number of properties consistent with a role as an oncogene, and its expression is activated in most myeloid leukemia patients with, as well as in a minority of patients without, 3q26 rearrangements. A splice variant of this gene, MDS1/EVI1, acts as its antagonist at least in some tissue culture assays. We established real-time quantitative reverse transcriptase polymerase chain reaction (RTQ-RT-PCR) assays for these mRNA variants to compare their expression levels in a quantitatively reliable manner. EVI1 was overexpressed to highly variable extents in all patients with, as well as in 14% of patients without, 3q26 rearrangements. In some of these samples, MDS1/EVI1 was also transcribed at elevated levels compared to those of healthy controls. However, although the induction of MDS1/EVI1 was comparable to, or higher than, that of EVI1 in three of five samples with a normal EVI1 locus, this was true for only two of 13 patients with a 3q26 aberration. We further provide preliminary evidence that the RTQ-RT-PCR assay may be useful for disease monitoring in patients overexpressing EVI1.

The translocation t(8;16)(p11;p13) is associated with acute myeloid leukemia displaying monocytic differentiation (AML FAB M4/5) and fuses the MOZ (also named MYST3) gene (8p11) with the CBP (also named CREBBP) gene (16p13). Detection of the chimeric RNA fusions has proven difficult; only three studies have described successful amplification of the chimeric MOZ-CBP and CBP-MOZ fusions by reverse transcriptasepolymerase chain reaction (RT-PCR). We analyzed four cases of AML M4/5 with t(8;16)(p11;p13) by RT-PCR and fluorescence in situ hybridization (FISH) and characterized the reciprocal RNA fusions from three cases. We cloned both genomic translocation breakpoints from one case by long-range PCR and successfully applied RT-PCR to monitor minimal residual disease (MRD) between clinical complete remission and relapse. In three cases, the genomic breakpoints occurred in MOZ intron 16 and CBP intron 2. In one case, no fusion transcript was detected. The available data suggest clustering of t(8;16)(p11;p13) breakpoints in these introns leading to reciprocal in-frame MOZ exon 16/CBP exon 3 and in-frame CBP exon 2/MOZ exon 17 chimeric transcripts in the majority of cases. The described RT-PCR strategy may be valuable both for the routine detection of the t(8;16)(p11;p13) as well as for monitoring of MRD in this prognostically unfavorable patient group.

No abstract

Primary central nervous system (pCNS) posttransplant lymphoproliferative disorder (PTLD) is a complication of solid organ transplantation characterized by poor outcome. In contrast to systemic PTLD, Epstein-Barr virus (EBV)-association of pCNS PTLD is almost universal, yet viral and cellular data are limited. To identify differences in the pattern of EBV-association of pCNS and systemic PTLD, we analyzed the expression of latent and lytic EBV transcripts and the viral and cellular microRNAome in nine pCNS (eight EBV-associated) and in 16 systemic PTLD samples (eight EBV-associated). Notably although 15/16 EBV-associated samples exhibited a viral type III latency pattern, lytic transcripts were also strongly expressed. Members of the ebv-miR-BHRF1 and ebv-miR-BART clusters were expressed in virtually all EBV-associated PTLD samples. There were 28 cellular microRNAs differentially expressed between systemic and pCNS PTLD. pCNS PTLD expressed lower hsa-miR-199a-5p/3p and hsa-miR-143/145 (implicated in nuclear factor kappa beta and c-myc signaling) as compared to systemic PTLD. Unsupervised nonhierarchical clustering of the viral and cellular microRNAome distinguished non-EBV-associated from EBV-associated samples and identified a separate group of EBV-associated pCNS PTLD that displayed reduced levels of B cell lymphoma associated oncomiRs such as hsa-miR-155, -21, -221 and the hsa-miR-17-92 cluster. EBV has a major impact on viral and cellular microRNA expression in EBV-associated pCNS PTLD.

Summary:Infectious complications are frequent events in patients undergoing high-dose cytotoxic chemotherapy with subsequent autologous peripheral blood stem cell transplantation (PBSCT). To evaluate whether a single subcutaneous injection of pegfilgrastim (6 mg) is as safe and effective as daily filgrastim (5 lg/kg/day), 60 consecutive autologous stem cell transplantations performed for various haematological malignancies have been analysed. In total, 24 patients undergoing 30 consecutive PBSCT received a single subcutaneous injection of 6 mg pegfilgrastim on day 5 after transplantation and were compared retrospectively with 30 patients receiving 5 lg/kg/day of filgrastim starting from day 7 post transplantation. The mean duration of grade 4 neutropenia in the pegfilgrastim and filgrastim groups was 8.3 and 9.5 days, respectively (P ¼ 0.047). The results of the two groups were not significantly different for incidence of febrile neutropenia and toxicity profile. However, duration of febrile neutropenia (1.6 vs 3.0 days) and total days of fever (1.73 vs 4.1) were different (P ¼ 0.017 and 0.003, respectively), favouring the pegfilgrastim arm. Consequently, a higher incidence of transplants with documented infectious complications associated with the filgrastim group could be observed (56 vs 26%) (P ¼ 0.02). A single injection of pegfilgrastim administered at day 5 post transplant shows comparable safety and efficacy profiles to daily injections of filgrastim. Bone Marrow Transplantation (2005) 35, 889-893.