Vasiliki Pappa

Effect of lenalidomide therapy on hematopoiesis of patients with myelodysplastic syndrome associated with chromosome 5q deletion

Background Lenalidomide improves erythropoiesis in patients with low/intermediate-1 risk myelodysplastic syndrome and interstitial deletion of the long arm of chromosome 5 [del(5q)]. The aim of this study was to explore the effect of lenalidomide treatment on the reserves and functional characteristics of bone marrow hematopoietic progenitor/precursor cells, bone marrow stromal cells and peripheral blood lymphocytes in patients with low/intermediate-1 risk myelodysplastic syndrome with del(5q). Design and Methods We evaluated the number and clonogenic potential of bone marrow erythroid/myeloid/megakaryocytic progenitor cells using clonogenic assays, the apoptotic characteristics and adhesion molecule expression of CD34+ cells by flow cytometry, the hematopoiesis-supporting capacity of bone marrow stromal cells using long-term bone marrow cultures and the number and activation status of peripheral blood lymphocytes in ten patients with low/intermediate-1 risk myelodysplastic syndrome with del(5q) receiving lenalidomide. Results Compared to baseline, lenalidomide treatment significantly decreased the proportion of bone marrow CD34+ cells, increased the proportion of CD36+/GlycoA+ and CD36−/GlycoA+ erythroid cells and the percentage of apoptotic cells within these cell compartments. Treatment significantly improved the clonogenic potential of bone marrow erythroid, myeloid, megakaryocytic colony-forming cells and increased the proportion of CD34+ cells expressing the adhesion molecules CD11a, CD49d, CD54, CXCR4 and the SLAM antigen CD48. The hematopoiesis-supporting capacity of bone marrow stroma improved significantly following treatment, as demonstrated by the number of colony-forming cells and the level of stromal-derived factor-1α and intercellular adhesion molecule-1 in long-term bone marrow culture supernatants. Lenalidomide treatment also increased the proportion of activated peripheral blood T lymphocytes. Conclusions The beneficial effect of lenalidomide in patients with lower risk myelodysplastic syndrome with del(5q) is associated with significant increases in the proportion of bone marrow erythroid precursor cells and in the frequency of clonogenic progenitor cells, a substantial improvement in the hematopoiesis-supporting potential of bone marrow stroma and significant alterations in the adhesion profile of bone marrow CD34+ cells.

Keratinocyte growth factor is effective in the prevention of intestinal mucositis in patients with hematological malignancies treated with high-dose chemotherapy and autologous hematopoietic SCT: a video-capsule endoscopy study.

Oral and/or intestinal mucositis is a severe complication of hematopoietic SCT. Keratinocyte growth factor (KGF) has proven activity in the prevention of oral mucositis. We examined the efficacy of KGF in the prevention of intestinal mucositis. From January 2006 until December 2007, 35 consecutive patients underwent autologous SCT (auto-SCT) in our institution. A total of 15 consecutive patients who underwent auto-SCT from March 2007 to December 2007 received KGF for the prevention of mucositis and were included in the study group A, whereas 20 consecutive patients treated from January 2006 to March 2007, were included in the historical control group B. Oral and intestinal mucositis were significantly less severe in group A (P=0.002 and P<0.001, respectively). These results were confirmed with the use of video-capsule endoscopy. Patients in group A had a significantly lower incidence of neutropenic fever (P=0.026). Severe intestinal mucositis was significantly associated with a higher incidence of documented infections too (P=0.019). KGF is effective in the prevention of intestinal mucositis in patients undergoing auto-SCT. Patients with severe intestinal mucositis run a higher risk to develop infections.

Expression analysis of mir-17-5p, mir-20a and let-7a microRNAs and their target proteins in CD34+ bone marrow cells of patients with myelodysplastic syndromes.

Mir-17-5p and mir-20a, members of the mir-17-92 family, down-regulate E2F1, which is over-expressed in myelodysplastic syndromes (MDS). Moreover, let-7a down-regulates KRAS, which is aberrantly expressed in MDS. We evaluated the expression of the aforementioned microRNAs in CD34+ cells of 43 MDS patients using real-time PCR and their target proteins (E2F1, MYC, BCL2, CCND1, and KRAS) by Western blot. Mir-17-5p and mir-20a were under expressed in high risk MDS patients, compared to low risk MDS patients. Similarly, let-7a was under expressed in patients with intermediate or high-risk karyotype. Interestingly, there was an inverse correlation between microRNA and the expression levels of their targets. Importantly, mir-17-5p and mir-20a constitute favorable prognostic factors in MDS, since their expression was associated with increased overall survival of MDS patients.

Epigenetic alterations and microRNAs: New players in the pathogenesis of myelodysplastic syndromes

The term epigenetics refers to the heritable changes in gene expression that do not represent changes in DNA sequence. DNA methylation and histone modification are the best studied epigenetic mechanisms. However, microRNAs, which affect gene expression at the posttranscriptional level, should be considered as members of the epigenetic machinery too. Myelodysplastic syndromes (MDS) are clone disorders of the hematopoietic stem cell with increased risk of leukemic transformation. Over the years, increased number of studies indicates the role of epigenetic mechanisms, including microRNAs, in MDS pathogenesis and prognosis. Indeed, epigenetic therapy with demethylating agents has already been applied to MDS. In this review we summarize current knowledge on the role of epigenetic alterations in MDS pathogenesis and treatment.

Monoclonal gammopathies in B-cell non-Hodgkin's lymphomas

The association of monoclonal gammopathy (MG) with B-cell non-Hodgkins lymphomas (NHL) is a well known phenomenon. The aim of the present work was to study the incidence, type of monoclonal component and prognostic significance of MG in a population of 255 cases with B-cell NHL. Among 255 evaluable patients with B-cell NHL, 145 were males and 110 females with a median age of 58 years (range 18-85). There were 166 patients with the various subtypes of aggressive (intermediate/high grade) NHL and 89 with the various subtypes of low risk. MG was detected in 44 patients (17.2%) with a median age of 61 years (range 23-79). There were 22 cases (8.6%) with IgG type (IgG/(k) 15, IgG/(lambda) 7), 4 cases (1.6%) with (IgA/(k) 3, IgA/(lambda) 1) and 18 cases (7.0%) with IgM (IgM/(k) 12 IgM/(lambda) 6). MG was found in 15.6% of the patients with aggressive NHL, while in low risk NHL the incidence was 20.2% (N.S.). The type of MG according to histological classification was as follows: Aggressive NHL: IgG 17 cases, IgA 2 cases, IgM 7 cases: low risk NHL: IgG 5 cases, IgA 2 cases, IgM 11 cases. The distribution of MG according to stage of the disease was as follows: stage I (4.5%), stage II (18%), stage III (6.8%) and stage IV (70.4%). The median survival of patients with aggressive NHL with MG was 17 months compared to 40 months of those without (P=0.22). Similarly the median survival of patients with low risk NHL and MG was 51.5 months compared to 38.5 months of those without (P=0.90). In conclusion MG was detected in 17.2% of cases with B-cell NHL. IgG-MG was more frequent in cases with aggressive NHL, while IgM in cases with low risk NHL. MG was mostly associated with advanced stage and had not any prognostic significance on survival.

Dasatinib inhibits proliferation and induces apoptosis in the KASUMI-1 cell line bearing the t(8;21)(q22;q22) and the N822K c-kit mutation

Activating mutations of the c-kit gene are frequently found in CBF (core binding factor) leukemias. We evaluated the effect of tyrosine kinase inhibitor dasatinib in leukemic cell lines bearing or not c-kit mutations. Our data demonstrate that in the AML Kasumi-1 cell line, bearing the N822K c-kit mutation, dasatinib is a potent suppressor of c-kit and Src kinase activity and inhibits the phosphorylation of their downstream target AKT, possibly through the Src-mediated VEGF/VEGFR receptor type 2 pathway. Dasatinib also effectively blocks proliferation and induces apoptosis through caspase-3 activation in Kasumi-1 cells. These data further encourage the integration of dasatinib in the treatment of CBF AML with c-kit mutations in the context of clinical trials, which are eagerly anticipated.

2-Deoxycoformycin in the treatment of T-large granular lymphocyte leukemia

A 52-year-old woman presented to our clinic for investigation of agranulocytosis and mild lymphocytosis. A diagnosis of T-large granular lymphocyte leukemia was made, based on immunophenotyping findings of the peripheral blood lymphocytes (CD3, CD8, CD16, CD57). Flow cytometric analysis of TCR-Vbeta repertoire showed single Vbeta9 expression on peripheral T-cells. Clonality was also demonstrated with PCR analysis which revealed clonal rearrangement of TCRgamma-chain gene. Granulocyte-macrophage colony-stimulating factor (G-CSF) (G-CSF), cyclosporine, methylprednisolone and oral methotrexate failed to correct the neutropenia. Finally, treatment with 2-deoxycoformycin (DCF) was successful and resulted in complete correction of the neutrophil count. Flow cytometric analysis of TCR-Vbeta repertoire proved to be an effective method to assess the therapeutic response to various treatments and to evaluate residual disease.

Monoclonal gammopathy in chronic myeloproliferative disorders

SummaryThe incidence of monoclonal gammopathy in 61 patients with chronic myeloproliferative disorders (CMPD) was studied. The distribution of patients among the CMPD subgroups was: chronic myelocytic leukemia, 24 patients; myelofibrosis, 11; polycythemia vera, 15; essential thrombocythemia, 7; unclassified MPD, 4 patients. Monoclonal gammopathy was found in 5 patients (8.2%). Two of these patients (1 IgA/k and 1 IgM/k) had myelofibrosis and 3 (2 IgG/k and 1 IgG/λ) polycythemia vera.The presence of monoclonal gammopathy indicates an involvement of the lymphoplasmatic system in CMPD.

Management of cutaneous T-Cell lymphoma patients with extracorporeal photopheresis. The hellenic experience

Extracorporeal photopheresis (ECP) is an established therapy for cutaneous T-cell lymphoma (CTCL). The objective of this study was to further explore the clinical efficacy of ECP combined with immunomodulatory agents. Eighteen patients with histologically proven CTCL were followed-up after therapy with ECP, mainly combined with interferon-α or bexarotene. A total of 61% of patients responded to therapy (n=11; CR: 5, PR: 6). Median survival was 51 months, progression free survival was 28 months and response duration was 29 ± 23.9 months. ECP combined therapy was highly effective or had a palliative effect in CTCL resistant to previous treatments.

Rhodotorula mucilaginosa associacted meningitis: A subacute entity with high mortality. Case report and review.

A fatal case of meningitis due to Rhodotorula mucilaginosa in a 28 year-old HIV-negative male with a history of Hodgkin lymphoma who underwent salvage chemotherapy is presented. Reviewing the literature we identified 13 cases with central nervous system infection due Rhodotorula spp. The disease usually occurs in HIV negative immunosupressed middle-aged males. It takes the form of subacute or chronic meningitis accompanied by fever with an overall mortality of 46.2% despite antifungal therapy.