Evaluation of the use of direct oral anticoagulants for the management of heparin-induced thrombocytopenia

Journal of Thrombosis and Thrombolysis - Historically, treatment of heparin-induced thrombocytopenia (HIT) includes a non-heparin parenteral anticoagulant with bridging to warfarin once platelets...     

Decreased VMAT2 in the pancreas of humans with type 2 diabetes mellitus measured in vivo by PET imaging

Aims/hypothesis

The progressive loss of beta cell function is part of the natural history of type 2 diabetes. Autopsy studies suggest that this is, in part, due to loss of beta cell mass (BCM), but this has not been confirmed in vivo. Non-invasive methods to quantify BCM may contribute to a better understanding of type 2 diabetes pathophysiology and the development of therapeutic strategies. In humans, the localisation of vesicular monoamine transporter type 2 (VMAT2) in beta cells and pancreatic polypeptide cells, with minimal expression in other exocrine or endocrine pancreatic cells, has led to its development as a measure of BCM. We used the VMAT2 tracer [¹⁸F]fluoropropyl-(+)-dihydrotetrabenazine to quantify BCM in humans with impaired glucose tolerance (prediabetes) or type 2 diabetes, and in healthy obese volunteers (HOV).

Methods

Dynamic positron emission tomography (PET) data were obtained for 4 h with metabolite-corrected arterial blood measurement in 16 HOV, five prediabetic and 17 type 2 diabetic participants. Eleven participants (six HOV and five with type 2 diabetes) underwent two abdominal PET/computed tomography (CT) scans for the assessment of test–retest variability. Standardised uptake value ratio (SUVR) was calculated in pancreatic subregions (head, body and tail), with the spleen as a reference region to determine non-specific tracer uptake at 3–4 h. The outcome measure SUVR minus 1 (SUVR-1) accounts for non-specific tracer uptake. Functional beta cell capacity was assessed by C-peptide release following standard (arginine stimulus test [AST]) and acute insulin response to the glucose-enhanced AST (AIRargMAX). Pearson correlation analysis was performed between the binding variables and the C-peptide AUC post-AST and post-AIRargMAX.

Results

Absolute test–retest variability (aTRV) was ≤15% for all regions. Variability and overlap of SUVR-1 was measured in all groups; HOV and participants with prediabetes and with type 2 diabetes. SUVR-1 showed significant positive correlations with AIRargMAX (all groups) in all pancreas subregions (whole pancreas p?=?0.009 and pancreas head p?=?0.009; body p?=?0.019 and tail p?=?0.023). SUVR-1 inversely correlated with HbA_1c (all groups) in the whole pancreas (p?=?0.033) and pancreas head (p?=?0.008). SUVR-1 also inversely correlated with years since diagnosis of type 2 diabetes in the pancreas head (p?=?0.049) and pancreas tail (p?=?0.035).

Conclusions/interpretation

The observed correlations of VMAT2 density in the pancreas and pancreas regions with years since diagnosis of type 2 diabetes, glycaemic control and beta cell function suggest that loss of BCM contributes to deficient insulin secretion in humans with type 2 diabetes.

     

Use of a water-soluble busulfan formulation--pharmacokinetic studies in a canine model

In a canine model we investigated the toxicity and pharmacokinetics of a water soluble busulfan preparation. Busulfan was dissolved in dimethylsulfoxide (DMSO) and administered either orally or intravenously in a single dose of 1 mg/kg. The application in either preparation was well tolerated. In seven dogs, peak levels in the range of 730 ng/mL to 1,000 ng/mL were measured after intravenous injection with an area under curve (AUC) of 75 ng.h/kg.mL to 146 ng.h/kg.mL. It was of note that even the oral administration of the same busulfan preparation resulted in AUC values in the same range as observed after parenteral application. The absorption rate of busulfan tablets in our model was as unpredictable as documented in clinical trials. On the basis of the present study, clinical trials using busulfan dissolved in DMSO given either intravenously or orally appear warranted. This approach should lead to predictable blood levels, reduced toxicity, and increased efficacy of busulfan-containing regimens.     

Prevalence of Pulmonary Hypertension and its Influence on Survival in Patients With Advanced Chronic Obstructive Pulmonary Disease Prior to Lung Transplantation

Introduction: Prevalence of pulmonary hypertension (PH) and its influence on survival in chronic obstructive pulmonary disease (COPD) are not well studied in the lung allocation score (LAS) era.

Methods: The UNOS database was queried from 2005 to 2013 to identify first-time adult lung transplant candidates with COPD who were tracked from wait list entry date until death or censoring to determine both prevalence and influence of PH. Using right heart catheterization measurements, mild PH was defined as mean pulmonary artery pressure (mPAP) ≥ 25 mmHg and severe ≥ 35 mmHg.

Results: Of 1315 COPD candidates not transplanted, 1243 were used for survival analysis using Cox proportional hazards models, and 1010 (mild PH) and 244 (severe PH) were used for propensity score matching, respectively. A total of 52% (652) of subjects had PH mPAP ≥ 25 mmHg. Univariate analysis revealed significant differences in survival for mild PH (HR = 1.769; 95% CI: 1.331, 2.351; p < 0.001) and severe PH (HR = 3.271; 95% CI: 2.311, 4.630; p < 0.001). Kaplan–Meier survival function demonstrated significant disparities for mild PH (Log-rank test: Chi-square₁: 15.87, p < 0.0001) and severe PH (Log-rank test: Chi-square₁: 50.13, p < 0.0001). Multivariate Cox models identified significant risk for death for mild PH (HR = 1.987; 95% CI: 1.484, 2.662; p < 0.001) and severe PH (HR = 3.432; 95% CI: 2.410, 4.888; p < 0.001). Propensity score matching confirmed increased mortality hazard associated with mild PH (HR = 2.280; 95% CI: 1.425, 3.649; p = 0.001) and severe PH (HR = 7.000; 95% CI: 2.455, 19.957; p < 0.001).

Conclusions: PH is highly prevalent in advanced COPD and associated with a significantly higher risk for mortality.     

Systematic Review of Adrenalectomy and Lymph Node Dissection in Locally Advanced Renal Cell Carcinoma

Context

Controversy remains over whether adrenalectomy and lymph node dissection (LND) should be performed concomitantly with radical nephrectomy (RN) for locally advanced renal cell carcinoma (RCC) cT3–T4N0M0.

Objective

To systematically review all relevant literature comparing oncologic, perioperative, and quality-of-life (QoL) outcomes for locally advanced RCC managed with RN with or without concomitant adrenalectomy or LND.

Evidence acquisition

Relevant databases were searched up to August 2012. Randomised controlled trials (RCTs) and comparative studies were included. Outcome measures were overall survival, QoL, and perioperative adverse effects. Risks of bias (RoB) were assessed using Cochrane RoB tools. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach.

Evidence synthesis

A total of 3658 abstracts and 252 full-text articles were screened. Eight studies met the inclusion criteria: six LNDs (one RCT and five nonrandomised studies [NRSs]) and two adrenalectomies (two NRSs). RoB was high across the evidence base, and the quality of evidence from outcomes ranged from moderate to very low. Meta-analyses were not undertaken because of diverse study designs and data heterogeneity. There was no significant difference in survival between the groups, even though 5-yr overall survival appears better for the RN plus LND group compared with the no-LND group in one randomised study. There was no evidence of a difference in adverse events between the RN plus LND and no-LND groups. No studies reported QoL outcomes. There was no evidence of an oncologic difference between the RN with adrenalectomy and RN without adrenalectomy groups. No studies reported adverse events or QoL outcomes.

Conclusions

There is insufficient evidence to draw any conclusions on oncologic outcomes for patients having concomitant LND or ipsilateral adrenalectomy compared with patients having RN alone for cT3–T4N0M0 RCC. The quality of evidence is generally low and the results potentially biased. Further research in adequately powered trials is needed to answer these questions.     

The association between referral source and outcome in patients with colorectal cancer

AimThe colorectal two-week wait fast track (FT) referral system was nationally implemented in the UK in 2000 to ensure patients with colorectal cancer (CRC) received prompt access to specialized services. The aim of this study was to determine the association between the mechanism of referral to colorectal services and the 5-year outcomes for patients with CRC.MethodsConsecutive patients with newly diagnosed CRC presenting between October 2002 and September 2004 were identified retrospectively. Analysis for survival and recurrence of disease at 5 years from presentation was undertaken. Outcomes for patients were compared between fast track (FT), non-fast track (NFT) and emergency referral (ER) routes, using Kaplan–Meier survival estimates.ResultsOut of 189 patients, 96 (51%) presented via the FT, 41 (22.5%) via the NFT and 52 (27.5%) via the ER referral route. The 5-year overall survival was 52.6% ± 5.1, 41.5% ± 7.7 and 38.5% ± 6.7 for the FT-, NFT- and ER groups respectively (p = 0.075). The 5-year cancer specific survival was 60.3% ± 5.2, 58.8% ± 5.3 and 43.5% ± 7.2 for the FT-, NFT- and ER groups respectively (p = 0.056). Patients referred as emergencies had worse 5-year overall survival; 49.3% ± 4.3 (FT&NFT) vs. 38.5% ± 6.7 (ER) (p = 0.042) and 5-year cancer specific survival 59.8% ± 4.4 (FT&NFT) vs. 43.5% ± 7.2 (ER) (p = 0.016). A total of 136 patients (FT n = 71, NFT n = 34, ER n = 31) underwent potentially curative surgery. Differences in 5-year survival did not reach statistical significance in these patients.ConclusionReferral route to specialist services for patients with CRC via the fast track pathway compared to non-fast track pathway was not associated with improved survival.