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.
The microRNA expression profile of primary central nervous system posttransplant lymphoproliferative disorders that develop in solid organ transplant recipients significantly differs from its systemic counterparts, suggesting that both entities result from distinct pathogenic mechanisms.
Abstract Recently developed molecular prognostic tests in patients with early Binet stage chronic lymphocytic leukemia (B-CLL) are costly and often require a high level of technologic expertise. ...Recent data give evidence for the prognostic relevance of the percentage of smudge cells in B-CLL. In our study we analysed the prognostic potential of this novel marker in a cohort of 100 CLL patients. The percentage of smudge cells ranged from 0% to 70% (median 21%). Patients with ≤20% smudge cells (according to ROC analysis) had a significantly shorter time to first treatment and overall survival than patients with >20% smudge cells. Multivariate Cox regression analysis identified percentages of smudge cells, stage according to Binet and CD38 expression as independent prognostic markers. The percentage of smudge cells was significantly lower in CD38+, ZAP-70+ and unmutated IgVH patients. Combined analysis of smudge cell percentages with CD38 expression provided complementary prognostic information identifying three patient subgroups with good, intermediate and poor prognosis. Comparing gene expression profiles in a subset of 12 patients we identified eight differentially expressed genes in groups with high vs. low percentage of smudge cells suggesting a role of these differentially expressed genes, especially for Tribbles homolog 2 (Trib2), in the disease progression of high risk CLL patients. In conclusion, our data confirm previous studies showing that the simple and inexpensive microscopic detection of smudge cells on blood smears prepared for routine diagnostic purposes is a novel independent factor predicting overall survival in CLL.
: Objective: The possible contribution of surface molecules to the development of leukostasis syndrome in hyperleukocytic acute myeloid leukaemia (AML) was assessed by routine immunophenotyping and ...grading of the probability of clinical leukostasis. Methods: Fifty‐three patients (23 women, 30 men, median age 59 yr) with hyperleukocytic AML white blood count (WBC) above 50 × 109/L were graded for the probability of clinical leukostasis according to the severity of neurologic, pulmonary and other symptoms possibly caused by leukostasis using a recently published scoring system. Age, WBC, absolute blast count, haemoglobin, cytogenetic risk group, infection, relative CD56 expression and absolute count of CD56 positive blasts were analyzed in multivariate stepwise backward logistic regression analysis. Results: In patients with acute monocytic leukaemia (AML M4/M5) the absolute count of leukaemic blasts expressing CD56/NCAM was highly associated with the development of symptoms graded as highly probable leukostasis and all three patients succumbing to early death were CD56 positive. Only the absolute count of CD56 positive blasts was a significant predictor of risk of severe leukostasis (P = 0.020). This was not found in AML without monocytic involvement (AML M1, M2, M3v). Conclusions: The expression of CD56/NCAM, a surface marker used in routine immunophenotyping of AML, may help to predict severe and potentially fatal leukostasis in hyperleukocytic acute myelomonocytic leukaemia. These results emphasize the usefulness of this four‐stage clinical grading scale for analysing the factors, which lead to severe leukostasis in hyperleukocytic patients. We extend previous findings that the mechanisms of leukostasis are different depending on the involvement of the monocytic lineage.
Genetic and epigenetic aberrations contribute to the initiation and progression of acute myeloid leukemia (AML). GFI1, a zinc-finger transcriptional repressor, exerts its function by recruiting ...histone deacetylases to target genes. We present data that low expression of GFI1 is associated with an inferior prognosis of AML patients. To elucidate the mechanism behind this, we generated a humanized mouse strain with reduced GFI1 expression (GFI1-KD). Here we show that AML development induced by onco-fusion proteins such as MLL-AF9 or NUP98-HOXD13 is accelerated in mice with low human GFI1 expression. Leukemic cells from animals that express low levels of GFI1 show increased H3K9 acetylation compared to leukemic cells from mice with normal human GFI1 expression, resulting in the upregulation of genes involved in leukemogenesis. We investigated a new epigenetic therapy approach for this subgroup of AML patients. We could show that AML blasts from GFI1-KD mice and from AML patients with low GFI1 levels were more sensitive to treatment with histone acetyltransferase inhibitors than cells with normal GFI1 expression levels. We suggest therefore that GFI1 has a dose-dependent role in AML progression and development. GFI1 levels are involved in epigenetic regulation, which could open new therapeutic approaches for AML patients.
Methylenetetrahydrofolate reductase (MTHFR) regulates the metabolism of folate and methionine, essential components of DNA synthesis and methylation. We investigated whether the two genetic MTHFR ...polymorphisms (677C>T and 1298A>C) are associated with an increased risk for chronic lymphocytic leukemia (CLL) or may predict disease progression. Moreover, we measured potential genotype effects on apoptosis of B-CLL cells.Allele frequencies and genotype distributions for both polymorphisms were not significantly different in 111 patients vs 92 healthy controls. While progression-free survival (PFS) was not significantly different in individuals with CLL including all stages, in patients with Binet stage A PFS was significantly longer in patients displaying the MTHFR 677CC (P=0.043) and the MTHFR 1298A/C or CC genotypes (P=0.019). In a multivariate analysis, MTHFR haplotype (677CC plus 1298CC or A/C) was the best independent prognostic factor for PFS compared with other known prognostic factors. Spontaneous apoptosis of B-CLL cells in vitro was significantly increased in the favorable risk group with MTHFR 677CC and MTHFR 1298AC, which may constitute the cellular basis of the observed associations. While MTHFR polymorphisms do not affect the risk for B-CLL, they may be independent prognostic markers that influence the PFS in patients with early-stage B-CLL.
Hematopoietic progenitor cell levels were monitored in the peripheral blood and bone marrow of 30 cancer patients receiving recombinant human granulocyte-colony stimulating-factor (rG-CSF) in a phase ...I/II clinical trial. The absolute number of circulating progenitor cells of granulocyte-macrophage, erythroid, and megakaryocyte lineages showed a dose-related increase up to 100-fold after four days of treatment with rG-CSF and often remained elevated two days after the cessation of therapy. The relative frequency of different types of progenitor cells in peripheral blood remained unchanged. The frequency of progenitor cells in the marrow was variable after rG-CSF treatment but in most patients was slightly decreased. The responsiveness of bone marrow progenitor cells to stimulation in vitro by rG-CSF and granulocyte-macrophage colony-stimulating factor did not change significantly during rG-CSF treatment. In patients nine days after treatment with melphalan and then rG-CSF, progenitor cell levels were very low with doses of rG-CSF at or below 10 µg/kg/d, but equaled or exceeded pretreatment values when 30 or 60 µg/kg/d of rG-CSF was given,
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