Prescribing Errors With Low-Molecular-Weight Heparins

BACKGROUND: Low-molecular-weight heparins (LMWHs) are used in the prevention and treatment of venous thromboembolism (VTE). Bleeding is the primary major complication of LMWH therapy, which is associated with dose. The administration of appropriate dosages of LMWHs depends on the patient's risk of VTE, risk of bleeding, bodyweight, and renal function. Therefore, LMWH prescribing is prone to errors. However, no earlier study has explored the frequency of prescribing errors with LMWH. PURPOSE: The aim of the study was to determine the frequency and determinants of in-hospital LMWH-prescribing errors. METHODS: A cross-sectional study was conducted to examine the frequency and determinants of LMWH prescribing errors between April and August 2014. We randomly selected 500 patients 18 years and older with at least one LMWH prescription during inpatient hospitalization. A prescribing error was a deviation from the internal hospital guidelines. Logistic regression estimated determinants of prescribing error. RESULTS: A prescribing error was present with 34% of all LMWH users. The most frequently recorded error was a dose that was not adjusted to body weight and/or renal function (85%). Prophylactic LMWH prescribing in medical wards was associated with a higher risk of prescribing error as compared with surgical wards. CONCLUSIONS: The frequency of prescribing errors was 34% in a tertiary care hospital. Being a patient with prophylactic LMWH use on a medical ward is a determinant for LMWH prescribing error. Interventions that will lead to better electronic recording of body weight and more awareness among medical doctors may reduce the total number of prescribing errors

Empirically Reduced Dosages of Tinzaparin in Patients with Moderate-to-Severe Renal Insufficiency Lead to Inadequate Anti-Xa Levels

Background: Due to the higher molecular weight of tinzaparin, the low molecular weight heparin (LMWH) is less dependent on renal excretion than other LMWH preparations. However, several international guidelines recommend the same preemptive dosage reduction for all therapeutic dose LMWHs prescribed in renal insufficient patients, to ensure that there is no accumulation of anticoagulant activity and increased risk of bleeding. This study is aimed at assessing whether a preemptive dosage reduction of tinzaparin in all renal insufficient patients (comprising 25% reduction in patients with Modification of Diet in Renal Disease - estimated glomerular filtration rate (MDRD-eGFR) 30-60 mL/min/1.73 m(2) and 50% reduction in patients with MDRD-eGFR = 18 years) with moderate-to-severe renal insufficiency (MDRD-eGFR 0.85 IU/mL for therapeutic indications. Unadjusted dosages led to a median anti-Xa activity of 0.74 IU/mL (IQR 0.56-0.92). The preemptive dosage reduction was significantly associated with anti-Xa activity below therapeutic range (p = 0.007). No difference in anti-Xa activity was observed between patients with moderate (0.71 IU/mL, IQR 0.61-0.95) versus severe (0.65 IU/mL, IQR 0.41-1.06) renal insufficiency in whom an unadjusted dose had been administered (p = 0.77). None of the anti-Xa levels were above the upper margin of the presumed therapeutic range of 2.0 IU/mL. Conclusion: In renal insufficient patients, the preemptive dosage reduction of tinzaparin leads to inadequate anti-Xa levels. (C) 2017 S. Karger AG, Base

Prescribing Errors With Low-Molecular-Weight Heparins

BACKGROUND: Low-molecular-weight heparins (LMWHs) are used in the prevention and treatment of venous thromboembolism (VTE). Bleeding is the primary major complication of LMWH therapy, which is associated with dose. The administration of appropriate dosages of LMWHs depends on the patient's risk of VTE, risk of bleeding, bodyweight, and renal function. Therefore, LMWH prescribing is prone to errors. However, no earlier study has explored the frequency of prescribing errors with LMWH. PURPOSE: The aim of the study was to determine the frequency and determinants of in-hospital LMWH-prescribing errors. METHODS: A cross-sectional study was conducted to examine the frequency and determinants of LMWH prescribing errors between April and August 2014. We randomly selected 500 patients 18 years and older with at least one LMWH prescription during inpatient hospitalization. A prescribing error was a deviation from the internal hospital guidelines. Logistic regression estimated determinants of prescribing error. RESULTS: A prescribing error was present with 34% of all LMWH users. The most frequently recorded error was a dose that was not adjusted to body weight and/or renal function (85%). Prophylactic LMWH prescribing in medical wards was associated with a higher risk of prescribing error as compared with surgical wards. CONCLUSIONS: The frequency of prescribing errors was 34% in a tertiary care hospital. Being a patient with prophylactic LMWH use on a medical ward is a determinant for LMWH prescribing error. Interventions that will lead to better electronic recording of body weight and more awareness among medical doctors may reduce the total number of prescribing errors

Prescribing Errors With Low-Molecular-Weight Heparins

BACKGROUND: Low-molecular-weight heparins (LMWHs) are used in the prevention and treatment of venous thromboembolism (VTE). Bleeding is the primary major complication of LMWH therapy, which is associated with dose. The administration of appropriate dosages of LMWHs depends on the patient's risk of VTE, risk of bleeding, bodyweight, and renal function. Therefore, LMWH prescribing is prone to errors. However, no earlier study has explored the frequency of prescribing errors with LMWH. PURPOSE: The aim of the study was to determine the frequency and determinants of in-hospital LMWH-prescribing errors. METHODS: A cross-sectional study was conducted to examine the frequency and determinants of LMWH prescribing errors between April and August 2014. We randomly selected 500 patients 18 years and older with at least one LMWH prescription during inpatient hospitalization. A prescribing error was a deviation from the internal hospital guidelines. Logistic regression estimated determinants of prescribing error. RESULTS: A prescribing error was present with 34% of all LMWH users. The most frequently recorded error was a dose that was not adjusted to body weight and/or renal function (85%). Prophylactic LMWH prescribing in medical wards was associated with a higher risk of prescribing error as compared with surgical wards. CONCLUSIONS: The frequency of prescribing errors was 34% in a tertiary care hospital. Being a patient with prophylactic LMWH use on a medical ward is a determinant for LMWH prescribing error. Interventions that will lead to better electronic recording of body weight and more awareness among medical doctors may reduce the total number of prescribing errors

Vaccine and Wild-Type Strains of Yellow Fever Virus Engage Distinct Entry Mechanisms and Differentially Stimulate Antiviral Immune Responses

The live attenuated yellow fever virus (YFV) vaccine 17D stands as a “gold standard” for a successful vaccine. 17D was developed empirically by passaging the wild-type Asibi strain in mouse and chicken embryo tissues. Despite its immense success, the molecular determinants for virulence attenuation and immunogenicity of the 17D vaccine are poorly understood. 17D evolved several mutations in its genome, most of which lie within the envelope (E) protein. Given the major role played by the YFV E protein during virus entry, it has been hypothesized that the residues that diverge between the Asibi and 17D E proteins may be key determinants of attenuation. In this study, we define the process of YFV entry into target cells and investigate its implication in the activation of the antiviral cytokine response. We found that Asibi infects host cells exclusively via the classical clathrin-mediated endocytosis, while 17D exploits a clathrin-independent pathway for infectious entry. We demonstrate that the mutations in the 17D E protein acquired during the attenuation process are sufficient to explain the differential entry of Asibi versus 17D. Interestingly, we show that 17D binds to and infects host cells more efficiently than Asibi, which culminates in increased delivery of viral RNA into the cytosol and robust activation of the cytokine-mediated antiviral response. Overall, our study reveals that 17D vaccine and Asibi enter target cells through distinct mechanisms and highlights a link between 17D attenuation, virus entry, and immune activation

A genome-wide CRISPR-Cas9 screen identifies the dolichol-phosphate mannose synthase complex as a host dependency factor for dengue virus infection

Dengue virus (DENV) is a mosquito-borne flavivirus responsible for dengue disease, a major human health concern for which no specific therapies are available. Like other viruses, DENV relies heavily on the host cellular machinery for productive infection. Here, we performed a genome-wide CRISPR-Cas9 screen using haploid HAP1 cells to identify host genes important for DENV infection. We identified DPM1 and 3, two subunits of the ER resident DPM synthase (DPMS) complex, as host dependency factors for DENV and other related flaviviruses such as Zika virus (ZIKV). DPMS complex catalyzes the synthesis of dolichol-phosphate mannose (DPM) which serves as mannosyl donor in pathways leading to N-glycosylation, GPI anchor biosynthesis and C- or O-mannosylation of proteins in the ER lumen. Mutation in the DXD motif of DPM1, which is essential for its catalytic activity, abolished DPMS-mediated DENV infection. Similarly, genetic ablation of ALG3, a mannosyltransferase that transfers mannose to lipid-linked oligosaccharide (LLO), rendered cells poorly susceptible to DENV. We also established that in cells deficient for DPMS activity, viral RNA amplification is hampered and truncated oligosaccharides are transferred to the viral prM and E glycoproteins, affecting their proper folding. Overall, our study provides new insights into the host dependent mechanisms of DENV infection and supports current therapeutic approaches using glycosylation inhibitors to treat DENV infection.IMPORTANCE Dengue disease, which is caused by dengue virus (DENV), has emerged as the most important mosquito-borne viral disease in humans and is a major global health concern. DENV encodes only few proteins and relies on the host cell machinery to accomplish its life cycle. The identification of the host factors important for DENV infection is needed to propose new targets for antiviral intervention. Using a genome-wide CRISPR-Cas9 screen, we identified DPM1 and 3, two subunits of the DPMS complex, as important host factors for the replication of DENV as well as others related viruses such as Zika virus. We established that DPMS complex plays a dual role during viral infection, both regulating viral RNA replication and promoting viral structural glycoproteins folding/stability. These results provide insights into the host molecules exploited by DENV and other flaviviruses to facilitate their life cycle

A genome-wide CRISPR-Cas9 screen identifies the dolichol-phosphate mannose synthase complex as a host dependency factor for dengue virus infection

International audienceDengue virus (DENV) is a mosquito-borne flavivirus responsible for dengue disease, a major human health concern for which no specific therapies are available. Like other viruses, DENV relies heavily on the host cellular machinery for productive infection. Here, we performed a genome-wide CRISPR-Cas9 screen using haploid HAP1 cells to identify host genes important for DENV infection. We identified DPM1 and 3, two subunits of the ER resident DPM synthase (DPMS) complex, as host dependency factors for DENV and other related flaviviruses such as Zika virus (ZIKV). DPMS complex catalyzes the synthesis of dolichol-phosphate mannose (DPM) which serves as mannosyl donor in pathways leading to N-glycosylation, GPI anchor biosynthesis and C- or O-mannosylation of proteins in the ER lumen. Mutation in the DXD motif of DPM1, which is essential for its catalytic activity, abolished DPMS-mediated DENV infection. Similarly, genetic ablation of ALG3, a mannosyltransferase that transfers mannose to lipid-linked oligosaccharide (LLO), rendered cells poorly susceptible to DENV. We also established that in cells deficient for DPMS activity, viral RNA amplification is hampered and truncated oligosaccharides are transferred to the viral prM and E glycoproteins, affecting their proper folding. Overall, our study provides new insights into the host dependent mechanisms of DENV infection and supports current therapeutic approaches using glycosylation inhibitors to treat DENV infection.IMPORTANCE Dengue disease, which is caused by dengue virus (DENV), has emerged as the most important mosquito-borne viral disease in humans and is a major global health concern. DENV encodes only few proteins and relies on the host cell machinery to accomplish its life cycle. The identification of the host factors important for DENV infection is needed to propose new targets for antiviral intervention. Using a genome-wide CRISPR-Cas9 screen, we identified DPM1 and 3, two subunits of the DPMS complex, as important host factors for the replication of DENV as well as others related viruses such as Zika virus. We established that DPMS complex plays a dual role during viral infection, both regulating viral RNA replication and promoting viral structural glycoproteins folding/stability. These results provide insights into the host molecules exploited by DENV and other flaviviruses to facilitate their life cycle