The TRPV4 channel links calcium influx to DDX3X activity and viral infectivity.

Ion channels are well placed to transduce environmental cues into signals used by cells to generate a wide range of responses, but little is known about their role in the regulation of RNA metabolism. Here we show that the TRPV4 cation channel binds the DEAD-box RNA helicase DDX3X and regulates its function. TRPV4-mediated Ca2+ influx releases DDX3X from the channel and drives DDX3X nuclear translocation, a process that involves calmodulin (CaM) and the CaM-dependent kinase II. Genetic depletion or pharmacological inhibition of TRPV4 diminishes DDX3X-dependent functions, including nuclear viral export and translation. Furthermore, TRPV4 mediates Ca2+ influx and nuclear accumulation of DDX3X in cells exposed to the Zika virus or the purified viral envelope protein. Consequently, targeting of TRPV4 reduces infectivity of dengue, hepatitis C and Zika viruses. Together, our results highlight the role of TRPV4 in the regulation of DDX3X-dependent control of RNA metabolism and viral infectivity.

Impact of NADPH oxidase functional polymorphisms in acute myeloid leukemia induction chemotherapy.

Efficacy and toxicity of anthracycline treatment in acute myeloid leukemia (AML) is mediated by reactive oxygen species (ROS). NADPH oxidase is the major endogenous source of ROS and a key mediator of oxidative cardiac damage. The impact of NADPH oxidase polymorphisms (CYBA:rs4673, NCF4:rs1883112, RAC2:rs13058338) was evaluated in 225 adult de novo AML patients. Variant alleles of NCF4 and RAC2 were related to higher complete remission (P=0.035, P=0.016), and CYBA homozygous variant showed lower overall survival with recessive model (P=0.045). Anthracycline-induced cardiotoxicity was associated to NCF4 homozygous variant (P=0.012) and CYBA heterozygous genotype (P=0.027). Novel associations were found between variant allele of CYBA and lower lung and gastrointestinal toxicities, and a protective effect in nephrotoxicity and RAC2 homozygous variant. Moreover, RAC2 homozygous variant was related to delayed thrombocytopenia recovery. This study supports the interest of NADPH oxidase polymorphisms regarding efficacy and toxicity of AML induction therapy, in a coherent integrated manner.

A systematic review and meta-analysis of the impact of WT1 polymorphism rs16754 in the effectiveness of standard chemotherapy in patients with acute myeloid leukemia.

The polymorphism rs16754 of the WT1 gene has been described as a possible prognostic marker in different acute myeloid leukemia (AML) cohorts; however, it is not supported by all the studies. We performed the first meta-analysis evaluating the effect of this polymorphism upon the effectiveness of standard AML therapy. Fourteen cohort studies were included (3618 patients). Patients with the variant allele showed a significant higher overall survival (OS) at 5 years (OR:1.24, 95% CI: 1.06-1.45, P=0.007, with dominant model). WT1 did not influence complete remission, but a higher disease-free survival was observed with the variant allele. In the subgroup analysis, Caucasians, pediatric and patients treated with idarubicin and etoposide carrying the variant allele showed consistent results in OS, whereas patients with cytogenetically normal AML did not show differences. To verify the effect of this polymorphism upon other outcomes, studies in larger and multiracial populations are needed.

Influence of ABCB1 polymorphisms upon the effectiveness of standard treatment for acute myeloid leukemia: a systematic review and meta-analysis of observational studies.

The ABCB1 gene encodes for P-glycoprotein (P-gp), an efflux pump for a variety of xenobiotics. The role of ABCB1 polymorphisms in acute myeloid leukemia (AML) outcomes of standard chemotherapy (cytarabine plus anthracyclines) remains controversial. A systematic search was made of studies evaluating the association between ABCB1 polymorphisms 1236C>T, 2677G>T/A and 3435C>T and effectiveness variables. We found seven cohort studies (1241 patients) showing a significantly higher overall survival (OS) among carriers of the variant allele of 1236C>T at year 4 (odds ratio (OR): 1.47, 95% confidence interval (CI): 1.07-2.01), 2677G>T/A at years 4-5 (OR: 1.37, 95% CI: 1.01-1.86) and 3435C>T at years 3 (OR: 1.41, 95% CI: 1.03-1.94) and 4-5 (OR: 1.42, 95% CI: 1.05-1.91). In the subgroup analysis according to ethnicity, Caucasians carrying variant allele showed consistent results in OS. ABCB1 influence upon complete remission could not be demonstrated. Future studies based on larger populations and multiethnic groups should help clarify the effect of P-gp polymorphisms upon other outcomes.

Autoimmune cytopenias after umbilical cord blood transplantation in adults with hematological malignancies: a single-center experience.

We describe incidence, clinical features, serological data, response to therapy and outcome of autoimmune cytopenias (ACs), including autoimmune hemolytic anemia (AIHA) and autoimmune thrombocytopenia (AIT) in a series of 281 consecutive adults with hematological malignancies that received single-unit umbilical cord blood transplantation (UCBT) at a single institution. AIHA was diagnosed in 15 patients at a median time of 181 days (range, 25-543), 12 of them had cold antibodies (IgM). The 3-year cumulative incidence (CI) of AIHA was 5.4% (CI 95% 2.7-8.1). Concomitant infections at the time of AIHA were present in 10 patients. Five out of nine patients that received corticosteroids achieved either a PR or a CR, whereas six out of eight patients that received rituximab responded. Four patients developed AIT giving a 3-year CI of 1.4% (CI 95% 0-2.8), concomitant infections were present in three of them. Multivariable analysis showed that development of chronic GVHD (relative risk (RR) 4; 95% CI 1.1-13.7; P=0.03) and diagnosis of CML (RR 4.3; 95% CI 1.5-12.7; P=0.008) were associated with an increased risk of AC. In conclusion, AIHA and AIT are relevant and clinically significant complications in UCBT recipients, especially among those that develop chronic GVHD. Response to therapy is sub-optimal, and rituximab should be considered as a therapeutic option, in this setting were most patients had cold AIHA and a serological profile similar to that seen in cold agglutinin disease.

EBV-associated post-transplant lymphoproliferative disorder after umbilical cord blood transplantation in adults with hematological diseases.

We analyzed the incidence, clinicopathological features, risk factors and prognosis of patients with EBV-associated post-transplant lymphoproliferative disorder (EBV-PTLD) in 288 adults undergoing umbilical cord blood transplantation (UCBT) at a single institution. Twelve patients developed proven EBV-PTLD at a median time of 73 days (range, 36-812). Three-year cumulative incidence (CI) of EBV-PTLD was 4.3% (95% CI: 1.9-6.7). All patients presented with extranodal involvement. Most frequently affected sites were the liver, spleen, central nervous system (CNS), Waldeyer's ring and BM in 7, 6, 4, 3 and 3 patients, respectively. One patient had polymorphic and 11 had monomorphic EBV-PTLD (7 diffuse large B-cell lymphomas not otherwise specified, 4 plasmablastic lymphomas). We confirmed donor origin and EBV infection in all histological samples. EBV-PTLD was the cause of death in 11 patients at a median time of 23 days (range, 1-84). The 3-year CI of EBV-PTLD was 12.9% (95% CI: 3.2-22.5) and 2.6% (95% CI: 0.5-4.7) for patients receiving reduced-intensity conditioning (RIC) and myeloablative conditioning, respectively (P<0.0001). In conclusion, adults with EBV-PTLD after UCBT showed frequent visceral and CNS involvement. The prognosis was poor despite routine viral monitoring and early intervention. An increased risk of EBV-PTLD was noted among recipients of RIC regimens.

Peripheral nerve hyperexcitability: a clinical and immunologic study of 38 patients.

OBJECTIVE: We studied a case series of peripheral nerve hyperexcitability (PNH) aiming to describe clinical characteristics, immunologic and cancer associations, antibodies against neuronal antigens (voltage-gated potassium channel antibodies [VGKC-Abs] and other), and muscle biopsy findings. METHODS: Patients presenting with clinical and electrophysiologic signs of PNH were selected. We studied clinical and electrophysiologic features; a panel of non-neuronal organ-specific antibodies, immunofluorescence on rat nervous tissues, and radioimmunoprecipitation for VGKC-Abs; and muscle biopsies. RESULTS: Thirty-eight patients were included. After the exclusion of 6 cases with axonopathy of known origin, patients were subdivided according to the presence of electrophysiologic findings of motor axonopathy and association with cancer: axonopathic-PNH (group A: 12 patients), isolated nonparaneoplastic PNH (group B: 16 patients), and isolated paraneoplastic PNH (3 with thymoma and myasthenia gravis, 1 with thyroid carcinoma). PNH clinical features were similar in groups A and B. We found an overall high prevalence of clinical autoimmunity (33% of group A and 63% of group B) and systemic non-neuronal autoantibodies (42% of group A and 75% of group B). However, VGKC-Abs were only positive in 2 patients of group B. Ten patients underwent muscle biopsy, which showed inflammatory changes in 2 cases and nonspecific myopathic features in 8. CONCLUSIONS: PNH is a heterogeneous disorder involving the peripheral nerves in patients with a high propensity for developing autoimmunity. Associated muscle diseases are frequent in the form of myositis, myasthenia gravis, or nonspecific myopathic pathologic findings. VGKC-Abs were uncommon in this series.

Wnt signaling pathway is epigenetically regulated by methylation of Wnt antagonists in acute myeloid leukemia.

Activation of the Wnt signaling pathway has been implicated recently in the pathogenesis of leukemia. We studied the function of epigenetic regulation of the Wnt pathway and its prognostic relevance in acute myelogenous leukemia (AML). We used a methylation-specific polymerase chain reaction approach to analyze the promoter methylation status of a panel of Wnt antagonists including sFRP1, sFRP2, sFRP4, sFRP5, DKK1 and DKK3. Aberrant methylation of Wnt antagonists was detected in four AML cell lines and in up to 64% of AML marrow samples. Treatment of the cell lines with 5-aza-2'-deoxycytidine induced reexpression of methylated Wnt antagonists and inactivation of the Wnt pathway by downregulating the Wnt pathway genes cyclin D1, TCF1 and LEF1 and reducing nuclear localization of beta-catenin. In a subgroup of patients 60 years and younger with newly diagnosed AML and intermediate-risk cytogenetics, abnormal methylation of Wnt antagonists was associated with decreased 4-year relapse-free survival (28 vs 61%, respectively, P=0.03). Our results indicate a function of the epigenetic regulation of the Wnt pathway in predicting relapse in a subgroup of AML patients.

Autoimmune hemolytic anemia following allogeneic hematopoietic stem cell transplantation in adult patients.

Autoimmune hemolytic anemia (AIHA) after allogeneic hematopoietic stem cell transplantation (HSCT) is still not well characterized. The aim of this study was to analyze the incidence and risk factors for the development of AIHA, as well as its prognosis and response to treatment in a series of patients undergoing allogeneic HSCT at a single institution. Between 1996 and 2004, 272 adult patients with a variety of malignant hematopoietic disorders underwent allogeneic HSCT. Direct antiglobulin testing was performed in routine pretransfusion compatibility testing or after clinical suspicion of AIHA. Twelve patients developed AIHA after HSCT at a median time of 147 days (range, 41-170). The 3-year cumulative incidence of AIHA was 4.44%. Eight cold antibodies and four warm antibodies were detected. Multivariate analysis shows that HSCT from unrelated donors (P=0.02) and the development of chronic extensive graft-versus-host disease (GVHD) (P=0.0004) were the only independent factors associated with AIHA. Two patients are still alive. AIHA was never the primary cause of death but added morbidity in patients with other concomitant complications. Patients undergoing HSCT from unrelated donors and those who develop chronic extensive GVHD are especially predisposed for this complication.

Transplantation of CD34+ selected peripheral blood to HLA-identical sibling patients with aplastic anaemia: results from a single institution.

We evaluated the use of CD34+ selected allogeneic peripheral blood as a source of hematopoietic progenitors for allogeneic transplantation in 11 patients with aplastic anemia (AA). The median age was 17 years (range, 6--9), and the median time between diagnosis and transplant 1 month (range, 1--4). Conditioning consisted of cyclophosphamide (50 mg/kg per day) on days--7 to--4 and antithymocyte globulin (30 mg/kg per day) on days--4 to--2 in nine patients. Total lymphoid irradiation was added to the preparative regimen for two. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine A and prednisone. Median doses of CD34+ and CD3+ cells infused were 3.91 x 10(6) and 0.3 x 10(6)/kg, respectively. The median time taken to achieve a neutrophil count >0.5 x 10(9)/l was 12 days and to recover a platelet count >20 x 10(9)/l, 13 days. Two patients developed acute GVHD grade I--II and one developed limited chronic GVHD. There were two treatment-related deaths. At a median follow-up of 44 months (range, 4--3), nine patients were alive with sustained and complete engraftment. This is a promising procedure in patients with AA, resulting in a rapid hematopoietic recovery, a low transplant-related mortality, and a low incidence of GVHD.

Peripheral blood stem cell collection after intermediate-dose cytarabine in adult patients with acute myeloblastic leukemia undergoing autologous blood stem cell transplantation in first complete remission.

Different strategies for collecting peripheral blood stem cells (PBSC) for autologous blood stem cell transplantation (ABSCT) have been reported for patients with acute myeloblastic leukemia (AML). We compared the clinical results of 2 consecutive protocols in 75 adult patients with AML in first complete remission who underwent ABSCT. In the first 56 patients (group A), PBSC were collected after induction and/or consolidation chemotherapy courses. In the subsequent 19 patients (group B), PBSC collection was done after a further intensification course with intermediate-dose cytarabine and mitoxantrone. Hematopoietic engraftment was similar in the 2 groups, with the median times to reach 0.5 x 10(9) neutrophils/L and 20 x 10(9) platelets/L being 13 days each in group A, and 12 days and 24 days, respectively, in group B. There were 3 graft failures (all in group A) and 5 transplantation-related deaths (6.6%, 4 in group A and 1 in group B). Although not statistically significant, the 3-year probabilities of both relapse (31% versus 66%; P = .12) and disease-free survival (60% versus 36%; P = .1) compared favorably for group B. Our study suggests that collection of PBSC after additional intensification can result in a better outcome for AML patients who undergo ABSCT.

Bcl-6 mutation status provides clinically valuable information in early-stage B-cell chronic lymphocytic leukemia.

In B-cell chronic lymphocytic leukemia (B-CLL), somatic mutation of IgVH genes defines a subgroup with favorable prognosis, whereas the absence of IgVH mutations is correlated with a worse outcome. Mutations of the BCL-6 gene are also observed in a subset of B-CLL, but the clinical significance of this molecular alteration remains uncertain. We examined the distribution of IgVH and BCL-6 gene mutations in 95 well-characterized patients with Binet stage A B-CLL, and correlated them with clinical, laboratory, cytogenetic findings and disease progression. Mutations of the BCL-6 gene were observed only in cases harboring mutated IgVH. Unexpectedly, coexistence of IgVH and BCL-6 mutations was correlated with shorter treatment-free interval (TFI) compared to cases harboring only IgVH mutation (median, 55 months vs not reached; P=0.01), resembling the clinical course of unmutated IgVH cases (median TFI, 44 months). As expected, deletions of 17p13 (P53 locus) and 11q22 (ATM locus) were observed in cases with unmutated IgVH, except one patient who showed mutations of both IgVH and BCL-6. No other statistically significant differences were observed among the genetic subgroups. Our data indicate that BCL-6 mutations identify a subgroup of Binet stage A B-CLL patients with a high risk of progression despite the presence of mutated IgVH gene.

Early infections in adult patients undergoing unrelated donor cord blood transplantation.

Early transplant-related mortality after cord blood transplantation from unrelated donors (UD-CBT) is close to 50%, mainly due to infectious complications. We have studied the incidence and characteristics of early infections (before day 100) in a series of 27 adult patients (median age 30 years, range 16-46) undergoing UD-CBT at a single institution. All 27 patients experienced at least one infectious episode and 18 (66%) suffered a severe infection. Bacteremia occurred in 55% of patients (13 with Gram-positive and 11 with Gram-negative microorganisms). Eleven of 19 CMV-seropositive patients (58%) developed CMV antigenemia and one patient had CMV disease. Fungal infections were documented in three patients (11%), comprising invasive fungal infections in two cases and a localized esophagitis in one. Ten patients (37%) died before day 100 after transplantation. Infection was considered the primary cause of death in four patients (sepsis by Acinetobacter spp. bacteremia in three cases) and contributed to death in another four. The most striking findings in this series were the high incidence of, and mortality due to multiresistant Acinetobacter spp. and the low incidence of and lack of mortality due to CMV disease. This report confirms that infection is a major complication in adults undergoing UD-CBT.

Infectious complications in patients undergoing unrelated donor bone marrow transplantation: experience from a single institution.

OBJECTIVE: To analyze the incidence and characteristics of documented infections in patients with hematologic malignancies undergoing unrelated donor bone marrow transplantation (UD-BMT). METHODS: We studied the occurrence of infections in 22 patients with hematologic malignancies or severe aplastic anemia who underwent UD-BMT from April 1990 to December 2000. The median age was 26 years (range 13-46). Acyclovir-ganciclovir, co-trimoxazole, fluconazole-nystatin and ciprofloxacin were administered for anti-infectious prophylaxis. RESULTS: We registered 61 infectious episodes. During the early post-transplant period, there were eight clinically documented infections (CDIs), four cases of fever of unknown origin (FUO), seven cases of bacteremia, two cases of cytomegalovirus (CMV) antigenemia, and one case of CMV disease. In the intermediate period (days 30-100 after BMT), there were nine cases of CMV antigenemia, three bacterial infections, two fungal infections, one case of disseminated toxoplasmosis, and one case of FUO. In the late period (day 100 and later), we documented 13 viral infections, eight bacterial infections, one CDI, and one case of invasive aspergillosis. Infections contributed to death in 10 of 17 patients. Citrobacter bacteremia and sepsis of unknown origin were the main causes of infectious mortality in the early period. Infection was the main cause of death in six of seven patients in the late period. CONCLUSION: A high incidence of life-threatening infections and infection-related mortality was observed. A high rate of CMV infection in the early period, and death caused by multiresistant Gram-negative microorganisms in the late period, were the main findings in this series.

Loss of a novel tumor suppressor gene locus at chromosome 8p is associated with leukemic mantle cell lymphoma.

Patients with mantle cell lymphoma (MCL) may present with either nodal or leukemic disease. The molecular determinants underlying this different biologic behavior are not known. This study compared the pattern of genetic abnormalities in patients with nodal and leukemic phases of MCL using comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) for specific gene loci. Although both leukemic and nodal MCL showed similar genomic patterns of losses (involving 6q, 11q22-q23, 13q14, and 17p13) and gains (affecting 3q and 8q), genomic loss of chromosome 8p occurred more frequently in patients with leukemic disease (79% versus 11%, P <.001). Subsequent CGH analysis confirmed the genomic loss of 8p21-p23 in 6 of 8 MCL cell lines. Interestingly, MYC gene amplification was restricted to cases with 8p deletion. These data indicate the presence of a novel tumor suppressor gene locus on 8p, whose deletion may be associated with leukemic dissemination and poor prognosis in patients with MCL.

Standardized, unrelated donor cord blood transplantation in adults with hematologic malignancies.

The potential role of unrelated donor cord blood transplantation (UD-CBT) in adults remains unclear. This study reports the results of UD-CBT in 22 adults with hematologic malignancies following conditioning with thiotepa, busulfan, cyclophosphamide, and antithymocyte globulin in 21, with thiotepa, fludarabine, and antithymocyte globulin in 1, and graft-versus-host disease (GVHD) prophylaxis with cyclosporine and prednisone. Median age was 29 years (range, 18-46 years), and median weight was 69.5 kg (range, 41-85 kg). HLA match was 6 of 6 in 1 case, 5 of 6 in 13 cases, and 4 of 6 in 8 cases. Median number of nucleated cells infused was 1.71 x 10(7)/kg (range, 1.01 x 10(7)/kg to 4.96 x 10(7)/kg). All 20 patients surviving more than 30 days had myeloid engraftment, and only 1, who received the lowest cell dose, developed secondary graft failure. Median time to reach an absolute neutrophil count of at least 0.5 x 10(9)/L was 22 days (range, 13-52 days). Median time to platelets numbered at least 20 x 10(9)/L was 69 days (range, 49-153 days). Seven patients (32%) developed acute GVHD above grade II, and 9 of 10 patients at risk developed chronic GVHD, which became extensive in 4 patients. Twelve patients remained alive and disease-free 3 to 45 months after transplantation. Disease-free survival (DFS) at 1 year was 53%. Age strongly influenced DFS (P =.01). For patients aged 30 years or younger, the DFS at 1 year was 73%. These preliminary results suggest that UD-CBT should be considered a reasonable alternative in young adults with hematologic malignancy and no appropriate bone marrow donor.

Marked reduction in the incidence of hepatic veno-occlusive disease after allogeneic hematopoietic stem cell transplantation with CD34(+) positive selection.

Veno-occlusive disease of the liver (VOD) is a common and severe complication of allogeneic hematopoietic stem cell transplantation (HSCT). To determine the incidence of, and the risk factors for the development of VOD, we performed a retrospective analysis of a series of 178 patients, who underwent allogeneic HSCT at our institution between 1990 and 1999. Busulfan and cyclophosphamide constituted the conditioning regimen most frequently administered. Bone marrow was the source of stem cells in 129 patients (73%), and peripheral blood (PBSC) in 49 patients (27%). Thirty-one patients of the PBSC group received CD34(+) positively selected grafts. Most patients were given cyclosporin A and methotrexate (MTX) as graft-versus-host disease (GVHD) prophylaxis. Overall, 30 patients (17%) developed VOD. In univariate analyses, the incidence of VOD was significantly higher in recipients of unmanipulated grafts (20% vs 0%; P = 0.01), in patients with active malignant disease at transplantation (24% vs 9%; P = 0.03), in recipients of marrow from unrelated donors (33% vs 15%; P = 0.03), in patients grafted with bone marrow (21% vs 6%; P = 0.03), and in those receiving MTX as GVHD prophylaxis (21% vs 6%; P = 0.05). Under multivariate analysis, only CD34(+) positive selection (P = 0.0004) and the status of the disease at transplant (P = 0.03) were statistically significant variables for the development of VOD. We conclude that CD34(+) positively selected PBSC transplantation could result in a marked reduction in the incidence of VOD after allogeneic HSCT.