Citations

OBJECTIVE: To describe a case of torsades de pointes (TdP) in a patient treated with aripiprazole. CASE SUMMARY: A 42-year-old white male with schizophrenia, diabetes, hypertension, and a history of stroke was admitted to the intensive care unit following 2 days of fever, diarrhea, and altered mental status. Following the resolution of his acute illness, previous therapy with quetiapine 400 mg orally at bedtime was resumed for schizophrenia and presumed delirium. Quetiapine was discontinued after 1 dose because of QTc interval prolongation. Twenty-three days later, with a baseline Q Tc interval of 414 milliseconds, aripiprazole 2.5 mg orally once daily was initiated. Following 5 days of aripiprazole therapy, the patient had a cardiac arrest due to TdP. Normal sinus rhythm was restored after 30 seconds of cardiopulmonary resuscitation, 1 shock of 200 Joules, and 4 g of intravenous magnesium sulfate. Serial electrocardiographs obtained after aripiprazole discontinuation revealed resolution of QTc interval prolongation. DISCUSSION: Aripiprazole is a second-generation antipsychotic that may be selected for patients with prolonged QTc intervals and at risk for TdP. Data from trials indicate that aripiprazole has minimal effects on the QTc interval. However, in this case, aripiprazole was associated with TdP in a patient with minimal risk factors. The Naranjo probability scale was used to determine a probable association between aripiprazole and the development of TdP. To our knowledge, this is the first reported case of TdP associated with the use of aripiprazole. CONCLUSIONS: Five days of low-dose aripiprazole therapy was associated with the development of TdP in a man with minimal risk factors. Clinicians should be aware of this potential adverse drug event with aripiprazole.

The aim of a phase I oncology trial is to identify a dose with an acceptable safety profile. Most phase I designs use the dose‐limiting toxicity, a binary endpoint, to assess the unacceptable level of toxicity. The dose‐limiting toxicity might be incomplete for investigating molecularly targeted therapies as much useful toxicity information is discarded. In this work, we propose a quasi‐continuous toxicity score, the total toxicity profile (TTP), to measure quantitatively and comprehensively the overall severity of multiple toxicities. We define the TTP as the Euclidean norm of the weights of toxicities experienced by a patient, where the weights reflect the relative clinical importance of each grade and toxicity type. We propose a dose‐finding design, the quasi‐likelihood continual reassessment method (CRM), incorporating the TTP score into the CRM, with a logistic model for the dose–toxicity relationship in a frequentist framework. Using simulations, we compared our design with three existing designs for quasi‐continuous toxicity score (the Bayesian quasi‐CRM with an empiric model and two nonparametric designs), all using the TTP score, under eight different scenarios. All designs using the TTP score to identify the recommended dose had good performance characteristics for most scenarios, with good overdosing control. For a sample size of 36, the percentage of correct selection for the quasi‐likelihood CRM ranged from 80% to 90%, with similar results for the quasi‐CRM design. These designs with TTP score present an appealing alternative to the conventional dose‐finding designs, especially in the context of molecularly targeted agents. Copyright © 2013 John Wiley & Sons, Ltd.

Background The contribution of copy-number variation (CNV) to disease has been highlighted with the widespread adoption of array-based comparative genomic hybridisation (aCGH) and microarray technology. Contiguous gene deletions involving ANKRD11 in 16q24.3 are associated with autism spectrum disorder (ASD) and intellectual disability (ID), while 16q24.1 deletions affecting FOXF1 are associated with congenital renal malformations, alveolar capillary dysplasia, and various other abnormalities. The disease associations of deletions in the intervening region, 16q24.2, have only been defined to a limited extent. Aim To determine whether deletions affecting 16q24.2 are correlated with congenital anomalies. Methods 35 individuals, each having a deletion in 16q24.2, were characterised clinically and by aCGH and/or SNP-genotyping microarray. Results Several of the 35 16q24.2 deletions identified here closely abut or overlap the coding regions of FOXF1 and ANKRD11, two genes that have been previously associated with the disease. 25 patients were reported to have ASD/ID, and three were found to have bilateral hydronephrosis. 14 of the deletions associated with ASD/ID overlap the coding regions of FBXO31 and MAP1LC3B. These same genes and two others, C16orf95 and ZCCHC14, are also included in the area of minimal overlap of the three deletions associated with hydronephrosis. Conclusions Our data highlight 16q24.2 as a region of interest for ASD, ID and congenital renal malformations. These conditions are associated, albeit without complete penetrance, with deletions affecting C16orf95, ZCCHC14, MAP1LC3B and FBXO31. The function of each gene in development and disease warrants further investigation.

BackgroundIdentifying antibodies to HLA (anti‐HLA) by solid‐phase assays is used to screen blood donors to mitigate transfusion‐related acute lung injury risk. Various cutoffs for detection assays have been proposed in the literature; however, these do not take into consideration lot‐to‐lot variability of commercially available assays.Study Design and MethodsSamples from 93 nontransfused males were tested using five different lots of a multiplex bead‐based anti‐HLA detection kit. A subset of 17 samples was tested on 5 days using a single lot. An additional 96 samples from donations with varied anti‐HLA levels were tested using kits from two different lots. Results were reported as a normalized background (NBG) ratio.ResultsFor the 93 nontransfused donors, NBG values generated using the reference lot were significantly higher than those obtained with three of the four comparator lots. However, for the 96 samples with low‐, moderate‐, and higher‐level anti‐HLA, Class I (CL‐I) values were 1.4 times lower and Class II (CL‐II) values were 1.2 times lower using the reference versus comparator lot. For CL‐I antibodies the between‐lot standard deviation (SD) was 1.36 (95% confidence interval [CI], 1.19‐1.60), while the between‐day SD was 1.27 (95% CI, 1.08‐1.52). Similarly, for CL‐II antibodies the between‐lot SD was 0.81 (95% CI, 0.70‐0.95), while the between‐day SD was 0.50 (95% CI, 0.43‐0.60).ConclusionsThere is interlot variability in the tested HLA detection assay as well as significant bias between lots. It may be reasonable to develop a new cutoff when a new lot is obtained.

Abstract Enhanced airway smooth muscle (ASM) contractility contributes to increased resistance to airflow in diseases such as bronchitis and asthma that occur in passive smokers exposed to secondhand smoke. Little information exists on the cellular mechanisms underlying such airway hyperreactivity. Sputum samples of patients with chronic sinusitis, bronchitis, and asthma show increased concentrations of growth factors called neurotrophins, including brain-derived growth factor (BDNF), but their physiological significance remains unknown. In human ASM, we tested the hypothesis that BDNF contributes to increased contractility with cigarette smoke exposure. The exposure of ASM to 1% or 2% cigarette smoke extract (CSE) for 24 hours increased intracellular calcium ([Ca2+]i) responses to histamine, and further potentiated the enhancing effects of a range of BDNF concentrations on such histamine responses. CSE exposure increased the expression of the both high-affinity and low-affinity neurotrophin receptors tropomyosin-related kinase (Trk)–B and p75 pan-neurotrophin receptor, respectively. Quantitative ELISA showed that CSE increased BDNF secretion by human ASM cells. BDNF small interfering (si)RNA and/or the chelation of extracellular BDNF, using TrkB-fragment crystallizable, blunted the effects of CSE on [Ca2+]i responses as well as the CSE enhancement of cell proliferation, whereas TrkB siRNA blunted the effects of CSE on ASM contractility. These data suggest that cigarette smoke is a potent inducer of BDNF and TrkB expression and signaling in ASM, which then contribute to cigarette smoke–induced airway hyperresponsiveness.

Key PointsCytokine-induced loss of murine as well as human HSPC homing during ex vivo culture can be prevented by addition of BMP4. In HSPCs, BMP4 directly regulates Integrin-α4 expression through SMAD-independent p38 MAPK-mediated signaling.