Itai Levi

Elevated growth differentiation factor 15 expression in patients with congenital dyserythropoietic anemia type I

Congenital dyserythropoietic anemia (CDA) is a rare group of red blood cell disorders characterized by ineffective erythropoiesis and increased iron absorption. To determine whether growth differentation factor 15 (GDF15) hyper-expression is associated with the ineffective erythropoiesis and iron-loading complications of CDA type I (CDA I), GDF15 levels and other markers of erythropoiesis and iron overload were studied in blood from 17 CDA I patients. Significantly higher levels of GDF15 were detected among the CDA I patients (10 239 +/- 3049 pg/mL) compared with healthy volunteers (269 +/- 238 pg/mL). In addition, GDF15 correlated significantly with several erythropoietic and iron parameters including Hepcidin-25, Ferritin, and Hepcidin-25/Ferritin ratios. These novel results suggest that CDA I patients express very high levels of serum GDF15, and that GDF15 contributes to the inappropriate suppression of hepcidin with subsequent secondary hemochromatosis.

A randomized study comparing yttrium‐90 ibritumomab tiuxetan (Zevalin) and high‐dose BEAM chemotherapy versus BEAM alone as the conditioning regimen before autologous stem cell transplantation in patients with aggressive lymphoma

High‐dose chemotherapy combined with autologous stem‐cell transplantation (ASCT) is the standard therapy for refractory/relapsed aggressive lymphoma. In the era of rituximab‐containing frontline regimens, it is becoming more challenging to salvage patients in this setting, and novel approaches are required. This is a randomized study evaluating the safety and efficacy of standard‐dose ibritumomab tiuxetan (Zevalin) combined with high‐dose BEAM chemotherapy (Z‐BEAM) and ASCT in refractory/relapsed aggressive lymphoma.

The Nrf2 transcription factor is a positive regulator of myeloid differentiation of acute myeloid leukemia cells

1α,25-dihydroxyvitamin D3 (1,25D) is a powerful differentiation agent, which has potential for treatment of acute myeloid leukemia (AML), but induces severe hypercalcemia at pharmacologically active doses. We have previously shown that carnosic acid (CA), the polyphenolic antioxidant from rosemary plant, markedly potentiates differentiation induced by low concentrations of 1,25D in human AML cell lines. Here, we demonstrated similar enhanced differentiation responses to the 1,25D/CA combination in primary leukemic cells derived from patients with AML, and determined the role of the Nrf2/antioxidant response element (Nrf2/ARE) pathway in these effects using U937 human monoblastic leukemia cells as the model. CA strongly transactivated the ARE-luciferase reporter gene, induced the ARE-responsive genes, NADP(H)-quinone oxidoreductase and the γ-glutamylcysteine synthetase heavy subunit, and elevated cellular glutathione levels. Interestingly, 1,25D potentiated the effects of CA on these activities. Stable transfection of wild-type (wt) Nrf2 resulted in the enhancement, while transfection of dominant-negative (dn) Nrf2 produced suppression of differentiation induced by the 1,25D/CA combination and, surprisingly, by 1,25D alone. These opposite effects were associated with a corresponding increase or decrease in vitamin D receptor and retinoid X receptor-α protein levels, and in vitamin D responsive element transactivation. Cells transfected with wtNrf2 and dnNrf2 also displayed opposing changes in the levels of the AP-1 family proteins (c-Jun and ATF2) and AP-1 transcriptional activity. Pretreatment with AP-1 decoy oligodeoxynucleotide markedly attenuated the differentiation in wtNrf2-transfected cells, suggesting that the pro-differentiation action of Nrf2 is mediated by functional AP-1. Our findings suggest that the Nrf2/ARE pathway plays an important part in the cooperative induction of myeloid leukemia cell differentiation by 1,25D and a plant polyphenol.

Diffuse Alveolar Hemorrhage in Acute Promyelocytic Leukemia Patients Treated with ATRA - A Manifestation of the Basic Disease or the Treatment

All-trans-retinoic acid (ATRA) is considered the recommended induction treatment for acute promyelocytic leukemia. In the pre-ATRA era pulmonary bleeding was a common cause of death in these patients, mostly due to disseminated intravascular coagulation which was further exacerbated by the administration of chemotherapy. Although ATRA syndrome, the most serious adverse effect of ATRA treatment, involves the lungs, pulmonary hemorrhage has only rarely been reported as a manifestation of ATRA syndrome. Here we describe 2 patients who developed diffuse alveolar hemorrhage during treatment with ATRA. The possible mechanisms of pulmonary bleeding in these cases are discussed.

Rituximab in a Patient with Acute Renal Failure due to B-cell Lymphomatous Infiltration of the Kidneys

Renal failure is known to occur in lymphoproliferative disorders because of ureteral obstruction or parenchymal infiltration by disease. Rituximab is a genetically engineered chimeric murine/human monoclonal antibody directed against the CD20 antigen found on the surface of normal and malignant B-lymphocytes. The pharmacokinetics and metabolism of rituximab is not well established. The extent of renal clearance is not fully known, with little experience reported on the use of rituximab in patients with renal failure. We present a case where rituximab was administered to a patient with acute renal failure due to bilateral kidney infiltration by non-Hodgkins lymphoma (NHL). The patients renal function improved on therapy, with no need for hemodialysis and there were no significant toxicities. Rituximab may be used as a treatment option for NHL patients with impaired renal function.

Low dose palliative radiotherapy for splenomegaly in hematologic disorders

Abstract Splenomegaly (SM) is a common complication in hematologic disorders often associated with hypersplenism, and may cause pain, epigastric discomfort and variable systemic effects due to cytopenias. We retrospectively evaluated the results of palliative splenic irradiation (PSI) in terms of symptomatic relief in patients with hematologic disorders. In 1998–2006, 32 patients with hematologic disorders (median age 57) received 52 courses of PSI for SM. Twenty-one patients (66%) were diagnosed with myeloproliferative disorders (MPD), five patients (16%) had malignant lymphoma (ML), five patients (16%) had chronic lymphocytic leukemia (CLL) and one patient (3%) had hairy cell leukemia. Splenomegaly was accompanied by pain, anemia, thrombocytopenia and cachexia. Radiation therapy to the entire spleen was delivered by two parallel opposed fields using 0.5 Gy daily fractions given 5 days per week to a total dose of 6–10 Gy. PSI resulted in splenic size reduction in 78.8%, improvement of anemia in 75% and improvement of thrombocytopenia in 63.5% of PSI courses. The median survival (MS) of patients with MPD, CLL and ML was 45, 10 and 5 months, respectively. The MS of responders to PSI versus non-responders was 45 and 16 months, respectively (hazard ratio 0.17; p = 0.03; 95% confidence interval 0.035–0.84). In our hands, low dose PSI provided effective palliation for patients with hematologic disorders with SM. Splenic re-irradiation was feasible without excessive toxicity.

Engraftment-associated hypophosphatemia--the role of cytokine release and steep leukocyte rise post stem cell transplantation.

Hypophosphatemia associated with bone marrow transplantation has been infrequently reported. The suggested mechanism is phosphate uptake by the replicating cells. Various cytokines are associated with the development of hypophosphatemia. The present study evaluated the interrelationship between cytokine release, the rise in WBC and the development of hypophosphatemia during the engraftment period. Blood samples were obtained from 60 patients undergoing peripheral blood stem cell transplant, on the day of admission and then daily from the day of transplant until discharge. Hypophosphatemia developed in 62% of the patients. The median day of minimal phosphorus level was +8 and it antedated engraftment by 2 days. There was a significant correlation between the day of minimal phosphorus level and the day of maximal WBC and a significant correlation between the fall in phosphorus level and WBC rise. IL-6 and IL-8 showed similar kinetics. Higher IL-6 and IL-8 levels were directly associated with lower phosphorus levels. In conclusion, hypophosphatemia commonly occurs in the post-transplant period. We assume that both a direct effect of cytokine release and an increased consumption by the dividing WBCs contribute to its appearance. As its occurrence usually antedates engraftment it can be used as a forerunner for WBC recovery. Bone Marrow Transplantation (2001) 27, 311–317.

Mechanism of the antitumoral activity of deferasirox, an iron chelation agent, on mantle cell lymphoma.

Abstract Mantle cell lymphoma (MCL) characterized by the t(11;14)(q13;q32) translocation, resulting in cyclin D1 overexpression, is one of the most challenging lymphomas to treat. Iron chelators, such as deferasirox, have previously been shown to exhibit anti-proliferative properties; however, their effect on MCL cells has never been investigated. We showed that deferasirox exhibited antitumoral activity against the MCL cell lines HBL-2, Granta-519 and Jeko-1, with 50% inhibitory concentration (IC50) values of 7.99 ± 2.46 μM, 8.93 ± 2.25 μM and 31.86 ± 7.26 μM, respectively. Deferasirox induced apoptosis mediated through caspase-3 activation and decreased cyclin D1 protein levels resulting from increased proteasomal degradation. We also demonstrated down-regulation of phosphor-RB (Ser780) expression, which resulted in increasing levels of the E2F/RB complex and G1/S arrest. Finally, we showed that deferasirox activity was dependent on its iron chelating ability. The present data indicate that deferasirox, by down-regulating cyclin D1 and inhibiting its related signals, may constitute a promising adjuvant therapeutic molecule in the strategy for MCL treatment.

High levels of soluble serum hemojuvelin in patients with congenital dyserythropoietic anemia type I.

Congenital dyserythropoietic anemia (CDA) is a rare group of red blood cell disorders with ineffective erythropoiesis and secondary hemochromatosis. Inappropriate suppression of hepcidin and high levels of growth differentiation factor 15 (GDF15) have been described in CDA I and II patients, probably contributing to secondary hemochromatosis. Hemojuvelin (HJV) is an important regulator of serum hepcidin, while soluble form of HJV (s‐HJV) competitively down‐regulates hepcidin.

Pregnancy outcome in congenital dyserythropoietic anemia type I.

Objectives:  Congenital dyserythropoietic anemia type I (CDA I) is a rare inherited disease characterized by moderate to severe macrocytic anemia and abnormal erythroid precursors with nuclear chromatin bridges and spongy heterochromatin. Moderate to severe maternal anemia is a recognized independent risk factor for low birth weight (LBW) and complicated delivery. The aim of the study was to review the outcome of pregnancies in women with CDA I.