Montserrat Batlle

Profile of polymorphisms of drug-metabolising enzymes and the risk of therapy-related leukaemia

Therapy‐related acute myeloid leukaemia/myelodysplastic syndrome (t‐AML/t‐MDS) results from an impaired ability to detoxify chemotherapeutic drugs or repair drug‐induced genetic damage caused by genetic polymorphisms in enzymes involved in the metabolism of drugs. We analysed the prevalence of genetic polymorphisms of CYP1A1*2A(T6235C), CYP2E1*5B(C‐1019T), CYP3A4*1B(A‐290G), del{GSTT1}, del{GSTM1}, NQO1*2(C609T), MTHFR(C677T) and TYMS 2R/3R in 78 t‐AML/t‐MDS and 458 normal individuals (control group, CG) using real‐time and conventional polymerase chain reaction (PCR)‐based methods. The incidences of polymorphisms among t‐AML/t‐MDS patients and CG individuals were similar. However, a polymorphism profile consisting of CYP1A1*2A, del{GSTT1} and NQO1*2 strongly modified the risk of t‐AML/t‐MDS. The absence of all three polymorphisms decreased the risk of t‐AML/t‐MDS 18‐fold (odds ratio (OR) = 0·054, 95% confidence interval (CI) = 0·005–0·63, P = 0·02), whereas the presence of only NQO1*2 or all three polymorphisms enhanced the risk of t‐AML/t‐MDS (OR = 2·09, 95% CI = 1·08–4·03, P = 0·03 and OR = 18·42, 95% CI = 1·59–212·76, P = 0·02 respectively). Thus, the profiles of genetic polymorphisms of drug‐metabolising enzymes might explain the increased risk to t‐AML/t‐MDS observed in some patients treated with polychemotherapy.

Prognostic impact of highly active antiretroviral therapy in HIV-related Hodgkin's disease.

To evaluate the influence of highly active antiretroviral therapy (HAART) on the outcome of HIV-related Hodgkins disease (HD), two groups were studied: patients without previous HAART, and patients treated with HAART previously or concomitantly with HD therapy. In the second group, the complete response was higher and the disease-free survival and overall survival probabilities were significantly longer. HAART is thus associated with an improvement in response to therapy and survival in patients with HIV-related HD.

Analysis of mRNA from human heart tissue and putative applications in forensic molecular pathology

The usefulness of post-mortem mRNA analysis and its potential applications in forensic casework is currently of interest, especially because of several factors affecting the quality of RNA samples that are not practically predictable. In fact, post-mortem RNA degradation is a complex process that has not been studied systematically. The purpose of this work is to establish whether RNA analysis from post-mortem heart tissue could be used as a forensic tool to investigate the cause of death, with special regard to those cases where a cardiac disease is suspected as the manner of death. We analysed heart tissue from 16 individuals with normal cardiac function, 9 with long post-mortem intervals (L-PMI) and 7 from organ donors with very short PMIs (S-PMIs). Right ventricle tissue was homogenised, and the RNA was isolated and reverse transcribed. The resulting cDNA was used in real-time PCR reactions to quantify the gene expression of beta-glucuronidase (GUSB), Nitric Oxide Synthase 3 (NOS3), Collagen 1 (COL1A1) and Collagen 3 (COL3A1). The percentage of samples with high-quality RNA was higher in samples with S-PMI (7 out of 7) than in samples with L-PMI (4 out of 9, p<0.05). No differences in PMI time or cause of exitus were found between samples with degraded or non-degraded RNA in the L-PMI group. When comparing mRNA levels in samples with non-degraded RNA, we found similar values between the L-PMI and S-PMI groups for GUSB, COL1A1 and COL3A1. The NOS3 gene expression in the L-PMI subgroup was less than half that in the S-PMI. These results suggest that high-quality mRNA can be extracted from post-mortem human hearts only in some cases. Moreover, our data show that mRNA levels are independent from the PMI, even though there are mRNAs in which the expression levels are very susceptible to ischemia times. Clear knowledge about the relationship between mRNA integrity and expression and PMI could allow the use of several mRNAs as forensic tools to contribute to the determination of the cause of death with special regard to cardiovascular diseases.

Pulmonary Hypertension Is Related to Peripheral Endothelial Dysfunction in Heart Failure With Preserved Ejection Fraction

Background—Pulmonary hypertension (PH) and collagen metabolism abnormalities are prevalent in patients with heart failure with preserved ejection fraction (HFpEF). Peripheral endothelial dysfunction (PED) has been described in HF and in pulmonary arterial hypertension. Our aim is to determine whether PH is associated with PED and impaired collagen metabolism in patients with HFpEF.; Methods and Results—Flow-mediated dilation of the brachial artery, matrix metalloproteinase-2 and matrix metalloproteinase-9, tissue metalloproteinase inhibitor 1, and C-terminal propeptide of type I procollagen were determined in 28 patients with HFpEF and 42 hypertensive controls. Patients with systolic pulmonary artery pressure >35 mm Hg on echocardiogram underwent a right heart catheterization. Patients with HFpEF had more severe PED than controls: flow-mediated dilation 1.95% (−0.81 to 4.92) versus 5.02% (3.90 to 10.12), P=0.002. Twenty patients with PH underwent right heart catheterization: mean pulmonary artery pressure 38 (27–52) mm Hg, wedge capillary pressure 18 (16–22) mm Hg, pulmonary vascular resistance 362 (235–603) dyn s cm-5. There was a significant inverse correlation between flow-mediated dilation and pulmonary vascular resistance in patients with HFpEF and PH (r=−0.679; P=0.002). Patients with HFpEF showed higher matrix metalloproteinase-2 and C-terminal propeptide of type I procollagen values than hypertensive controls. Patients with HFpEF and higher C-terminal propeptide of type I procollagen values also had higher mean pulmonary artery pressure (r=0.553; P=0.014), transpulmonary gradient (r=0.560; P=0.013), and pulmonary vascular resistance (r=0.626; P=0.004). Conclusions—In patients with HFpEF, there is a significant correlation between PED and pulmonary vascular resistance. Collagen metabolism was more impaired in patients with HFpEF and PH. PED and collagen metabolism assessment could be useful tools to identify patients with HFpEF at risk of developing PH.

Protein arginine methyl transferases-3 and -5 increase cell surface expression of cardiac sodium channel

The α‐subunit of the cardiac voltage‐gated sodium channel (NaV1.5) plays a central role in cardiomyocyte excitability. We have recently reported that NaV1.5 is post‐translationally modified by arginine methylation. Here, we aimed to identify the enzymes that methylate NaV1.5, and to describe the role of arginine methylation on NaV1.5 function. Our results show that protein arginine methyl transferase (PRMT)‐3 and ‐5 methylate NaV1.5 in vitro, interact with NaV1.5 in human embryonic kidney (HEK) cells, and increase NaV1.5 current density by enhancing NaV1.5 cell surface expression. Our observations are the first evidence of regulation of a voltage‐gated ion channel, including calcium, potassium, sodium and TRP channels, by arginine methylation.

Identification of N-terminal protein acetylation and arginine methylation of the voltage-gated sodium channel in end-stage heart failure human heart.

The α subunit of the cardiac voltage-gated sodium channel, NaV1.5, provides the rapid sodium inward current that initiates cardiomyocyte action potentials. Here, we analyzed for the first time the post-translational modifications of NaV1.5 purified from end-stage heart failure human cardiac tissue. We identified R526 methylation as the major post-translational modification of any NaV1.5 arginine or lysine residue. Unexpectedly, we found that the N terminus of NaV1.5 was: 1) devoid of the initiation methionine, and 2) acetylated at the resulting initial alanine residue. This is the first evidence for N-terminal acetylation in any member of the voltage-gated ion channel superfamily. Our results open the door to explore NaV1.5 N-terminal acetylation and arginine methylation levels as drivers or markers of end-stage heart failure.

Kinetics of recovery of dendritic cell subsets after reduced-intensity conditioning allogeneic stem cell transplantation and clinical outcome

Background and Objectives Dendritic cells (DC) play a critical role in the regulation of alloimmune responses and might influence the outcome of allogeneic stem cell transplantation (allo-SCT). We studied the clinical relevance of early reconstitution of DC after reduced-intensity conditioning allo-SCT (allo-RIC). Design and Methods This study included 79 adult patients undergoing allo-RIC from HLA-identical siblings. Peripheral blood samples were drawn from patients at 1 month (+1m) and 3 months (+3m) after the transplant. DC were identified as positive for HLA-DR and negative for CD3, CD19, CD14 and CD56. The expression of CD33, CD123 and CD16 was used to identify myeloid DC, plasmacytoid DC and CD16+ DC subpopulations, respectively. Results Patients whose DC count at +1m was lower than the median had a higher probability of treatment-related mortality (TRM) (60% vs 12%; p=0.02), poorer overall survival (OS) (15% vs 45%; p=0.002) and worse event-free survival (EFS) (20% vs 38%; p=0.03). A multivariate analysis confirmed that low DC counts had a detrimental effect on OS (RR 3.2; p=0.007), relapse (RR 4.1; p=0.01), and EFS (RR 6; p=0.001). Low CD16+ DC counts were observed to have a detrimental effect on EFS, which was due to both a higher incidence of deaths caused by infections (50% vs 0%, p=0.05) and a higher incidence of relapse (57% vs 50%; p=0.03). Indeed, the number of CD16+ DC at +3 m was the most important prognostic factor for EFS (RR 6; p=0.001). Interpretations and Conclusions This study shows the clinical importance of DC recovery, especially of the CD16+ DC subset, in the outcome of patients treated with allo-RIC.

A missense mutation in the sodium channel β1b subunit reveals SCN1B as a susceptibility gene underlying long QT syndrome

BACKGROUND Long QT syndrome (LQTS) is associated with sudden cardiac death and the prolongation of the QT interval on the electrocardiogram. A comprehensive screening of all genes previously associated with this disease leaves 30% of the patients without a genetic diagnosis. Pathogenic mutations in the sodium channel β subunits have been associated with cardiac channelopathies, including SCN4B mutations in LQTS. OBJECTIVE To evaluate the role of mutations in the sodium channel β subunits in LQTS. METHODS We screened for mutations in the genes encoding the 5 sodium β subunits (SCN1B isoforms a and b, SCN2B, SCN3B, and SCN4B) from 30 nonrelated patients who were clinically diagnosed with LQTS without mutations in common LQTS-related genes. We used the patch-clamp technique to study the properties of sodium currents and the action potential duration in human embryonic kidney and HL-1 cells, respectively, in the presence of β1b subunits. RESULTS The genetic screening revealed a novel mutation in the SCN1Bb gene (β1bP213T) in an 8-year-old boy. Our electrophysiological analysis revealed that β1bP213T increases late sodium current. In addition, β1bP213T subtly altered Nav1.5 function by shifting the window current, accelerating recovery from inactivation, and decreasing the slow inactivation rate. Moreover, experiments using HL-1 cells revealed that the action potential duration significantly increases when the mutant β1b was overexpressed compared with β1bWT. CONCLUSION These data revealed SCN1Bb as a susceptibility gene responsible for LQTS, highlighting the importance of continuing the search for new genes and mechanisms to decrease the percentage of patients with LQTS remaining without genetic diagnosis.

Favorable Impact of Virological Response to Highly Active Antiretroviral Therapy on Survival in Patients with AIDS-related Lymphoma

We have retrospectively studied the influence of highly active antiretroviral therapy (HAART) on the outcome of AIDS-related lymphomas (ARL) as well as the possible influence of the virological response to HAART on complete response (CR) rate and survival in our series of ARL treated with CHOP. Two groups of patients were studied: (1) 44 patients who did not take HAART when the lymphoma was diagnosed, and (2) 26 patients treated with HAART concomitantly and after chemotherapy. There were 4 (9%) women in group 1 versus 11 (42%) in group 2 (P =0.01), and serum lactate dehydrogenase (LDH) level was lower in group 2. The response rate to CHOP was higher in group 2 patients (15 out of 23, 65%) than in those of group 1 (16 out of 44, 36%) (P =0.025). The factors associated with improvement of CR in the multivariate analysis were the administration of HAART (P =0.004) and International Prognostic Index (IPI) score ≤ 2 (P =0.006). Among group 2 patients, those with a virological response to HAART and with IPI score ≤ 2 had better response rate to chemotherapy (odds ratios 9.3 and 11.8, respectively). The median (95% CI) overall survival (OS) for group 1 patients was 7 (3-11) months, whereas it has not been reached for group 2 (P =0.002). The only parameters influencing OS in the multivariate analysis were HAART (0.003), as a protective factor and IPI score>2 (P =0.015) with negative influence. Among patients treated with HAART, those with virological response had higher OS probability (P =0.004), whereas those with IPI score>2 had an unfavorable prognosis (P =0.014). The only variable with statistical significance for disease free survival (DFS) in the univariate and multivariate analyses was HAART (P =0.0168 and P =0.028, respectively). We conclude that HAART is an independent prognostic factor for CR attainment, OS and DFS in patients with ARL treated with CHOP. Those patients with virological response to HAART had a better survival.

Caspofungin for the treatment of invasive fungal disease in hematological patients (ProCAS Study)

Caspofungin is an echinocandin with proven efficacy in invasive candidiasis (IC) and invasive aspergillosis (IA). This multicenter, prospective, non-comparative, observational ProCAS study was aimed to assess the effectiveness and safety of caspofungin in adult hematological patients with IC or IA under everyday clinical conditions. Favorable outcomes included complete and partial responses on the last day of caspofungin therapy. Safety was assessed up to 14 days post-caspofungin. A total of 115 patients (69 male) with a median age of 52 years (range, 23-78 years) were analyzed. Underlying disease was acute myeloid leukemia in 45 patients (39%), and 21 (18%) were allogeneic stem cell transplant recipients. Thirty-four (29.5%) patients had a diagnosis of IA and 26 (22.6%) had IC (candidemia). The median duration of caspofungin therapy was 14 days (range, 1-100). The overall favorable response rate was 77% (20/26) for patients with IC (69% first-line) and 79% (27/34) for those with IA. Antifungal therapy with caspofungin was generally well tolerated, only two (1.7%) patients having a non-serious drug-related adverse reaction. These results suggest that caspofungin, either alone or in combination, should be considered an effective and safe option for the treatment of invasive mycoses in patients with severe hematological disorders.