A no-nonsense approach to hereditary kidney disease.

The advent of a new class of aminoglycosides with increased translational readthrough of nonsense mutations and reduced toxicity offers a new therapeutic strategy for a subset of patients with hereditary kidney disease. The renal uptake and retention of aminoglycosides at a high intracellular concentration makes the kidney an ideal target for this approach. In this review, we explore the potential of aminoglycoside readthrough therapy in a number of hereditary kidney diseases and discuss the therapeutic window of opportunity for subclasses of each disease, when caused by nonsense mutations.

Intra-Articular Injections of Platelet-Rich Plasma versus Hyaluronic Acid in the Treatment of Osteoarthritic Knee Pain: A Randomized Clinical Trial in the Context of the Spanish National Health Care System.

Intra-articular injection of platelet-rich plasma (PRP) has been established as a suitable treatment for knee osteoarthritis. Here, we present a double-blind randomized controlled clinical trial, conducted in a public Hospital of the Spanish National Health Care System, to evaluate the efficacy of injecting autologous PRP versus hyaluronic acid (HA) in knee osteoarthritis. PRP was manufactured in Malaga's Regional Blood Center (Spain). Patients that met the eligibility criteria were randomized into a PRP group or a HA group. Pain and functional improvements were assessed pre- and post-treatment (three and six months follow-up) using the Visual Analogue Scale (VAS); the Knee and Osteoarthritis Outcome System (KOOS) scale and the European Quality of Life scale (EUROQOL). Both groups presented pain reduction at six months. The VAS scores for the PRP group improved by at least 50% from their initial value, particularly at three months following the final infiltration, with results resembling those of the HA group at six months. PRP was more effective in patients with lower osteoarthritis grades. Both treatments improved pain in knee osteoarthritis patients without statistically significant differences between them. However, PRP injection was proved to improve pain three months after the final infiltration and to be more effective in lower osteoarthritis grades.

Phase 1 Healthy Volunteer Study of AL01211, an Oral, Non-brain Penetrant Glucosylceramide Synthase Inhibitor, to Treat Fabry Disease and Type 1 Gaucher Disease.

Glycosphingolipid (GSL) storage diseases are caused by deficiencies in the enzymes that metabolize different GSLs in the lysosome. Glucosylceramide synthase (GCS) inhibitors reduce GSL production and have potential to treat multiple GSL storage diseases. AL01211 is a potent, oral GCS inhibitor being developed for the treatment of Type 1 Gaucher disease and Fabry disease. AL01211 has minimal central nervous system penetration, allowing for treatment of peripheral organs without risking CNS-associated adverse effects. AL01211 was evaluated in a Phase 1 healthy volunteer study with single ascending dose (SAD) and multiple ascending dose (MAD) arms, to determine safety, pharmacokinetics including food effect, and pharmacodynamic effects on associated GSLs. In the SAD arm, AL01211 showed a Tmax of approximately 3.5 hours, mean clearance (CL/F) of 130.1 L/h, and t1/2 of 39.3 hours. Consuming a high-fat meal prior to dose administration reduced exposures 3.5-5.5-fold, indicating a food effect. In the MAD arm, AL01211 had an approximately 2-fold accumulation, reaching steady-state levels by 10 days. Increasing exposure inversely correlated with a decrease in GSL with plasma glucosylceramide and globotriacylceramide reduction from baseline levels, reaching 78% and 52% by day 14, respectively. AL01211 was generally well-tolerated with no AL01211 associated serious adverse events, thus supporting its further clinical development.

Changes in plasma and urine globotriaosylceramide levels do not predict Fabry disease progression over 1 year of agalsidase alfa.

PURPOSE: Globotriaosylceramide concentrations were assessed as potential predictors of change from baseline after 12 months by estimated glomerular filtration rate and left-ventricular mass index using pooled data from three randomized, placebo-controlled agalsidase alfa trials and open-label extensions of patients with Fabry disease. METHODS: Males (aged 18 years or older) with Fabry disease received agalsidase alfa (0.2 mg/kg every other week for 12 months). A backward-elimination approach evaluated potential predictors (baseline estimated glomerular filtration rate and left-ventricular mass index; age at first dose; baseline and change from baseline at 12 months of globotriaosylceramide (urine, plasma); urine protein excretion; and systolic and diastolic blood pressure). Subgroups included patients randomized to placebo or agalsidase alfa (double-blind phase), then to agalsidase alfa (open-label extensions; placebo→agalsidase alfa or agalsidase alfa→agalsidase alfa, respectively) and stage 2/3 chronic kidney disease patients. RESULTS: Baseline estimated glomerular filtration rate, age at first dose, baseline urine globotriaosylceramide excretion, and baseline and change from baseline urine protein excretion significantly predicted change from baseline estimated glomerular filtration rate in the analysis population (N = 73; all P<0.05), although not in all subgroups. Change from baseline urine and plasma globotriaosylceramide (baseline and change from baseline) concentrations did not predict change from baseline estimated glomerular filtration rate. No predictors of left-ventricular mass index were significant. CONCLUSION: Changes in globotriaosylceramide concentrations do not appear to be useful biomarkers for prediction of Fabry disease-related changes in estimated glomerular filtration rate or left-ventricular mass index.

Effects of food, fasting, and exercise on plasma pyrophosphate levels and ENPP1 activity in healthy adults.

BACKGROUND: Inorganic pyrophosphate (PPi) is highly regulated as it plays a critical role in the regulation of physiological mineralization. Dysregulation of plasma PPi is associated with skeletal hypomineralization and pathogenic mineralization in soft connective tissue, arteries, and heart valves. There is no standard approach to measuring PPi, making it difficult to establish PPi as a biomarker of mineralization disorders. This study aims to determine the impact of time of day, meals, or exercise on plasma PPi homeostasis using a highly sensitive PPi assay. METHODS: In this single-center trial, a clinical laboratory improvement amendment (CLIA) validated modified sulfurylase-based adenosine 5-triphosphate (ATP) assay was used to measure PPi levels throughout the day in 10 healthy adults under 3 conditions; normal diet (non-fasting), fasting, and normal diet with exercise. Serum ectonucleotide pyrophosphatase/phosphodiesterase 1 activity (ENPP1; an enzyme that produces PPi) was also measured to determine whether these conditions influence PPi levels through ENPP1 activity. RESULTS: There is a circadian increase in mean PPi levels under fasting and non-fasting conditions between 8 am and 6 pm, followed by a rapid return to baseline overnight. A circadian increase in ENPP1 activity was also measured under fasting but was lost under non-fasting conditions. Meals increased the individual variability of PPi levels when compared to the same individual fasting. PPi levels and ENPP1 activity exhibited a short-term increase after intense exercise. We found PPi ranges from 1465 nM to 2969 nM (mean 2164 nM) after fasting overnight. Within this range, there was lower intra-subject variability in PPi, suggesting that each individual has a uniquely regulated normal PPi range. CONCLUSION: Plasma levels of PPi can be reliably measured after an overnight fast and show promise as a biomarker of mineralization disorders.

Lifelong impact of ENPP1 Deficiency and the early onset form of ABCC6 Deficiency from patient or caregiver perspective.

The ectonucleotide pyrophosphatase/phosphodiesterase family member 1 (ENPP1) and ATP-binding cassette subfamily C member 6 (ABCC6) proteins play a prominent role in inhibiting ectopic calcification and arterial stenosis. Patients with ENPP1 Deficiency or infant onset ABCC6 Deficiency often present with pathological calcification, narrowed blood vessels, multiorgan dysfunction and high infant mortality. The heterogenous presentation and progression is well documented. Our objective was to characterize how these morbidities lead to burden of illness and poor quality of life across ages from the patient/caregiver perspective. Patients/caregivers were interviewed via phone using Institutional Review Board-approved questionnaires. Patient-reported outcomes were collected via validated instruments. Thirty-one caregivers and 7 patients participated: infant onset ABCC6 Deficiency, n = 6 (infants/children); ENPP1 Deficiency, n = 32 (13 infants, 12 children, 7 adults). ENPP1 and ABCC6-deficient children aged <8 years and aged 8-18 years reported poor school functioning (0.69 vs 0.72 effect size, respectively) and poor physical health (0.88 vs 1, respectively). In the total ENPP1 cohort, 72% (23/32) reported bone/joint pain and/or mobility/fatigue issues. Three of seven ENPP1-deficient adults reported moderate to severe pain (>4), as measured by the Brief Pain Inventory (BPI), that interfered with daily activities despite pain medication. Top reported burdens for caregivers of infants with ABCC6/ENPP1 Deficiencies included heart-related issues and hospitalizations. Treatment/medications, and hearing loss were the highest burdens reported by caregivers/families of the pediatric ENPP1 Deficiency cohort, whereas adults reported bone/joint pain and mobility impairment as the greatest burdens. Individuals with ENPP1 Deficiency or infant onset ABCC6 Deficiency experience lifelong morbidity causing substantial physical and emotional burden to patients/caregivers.

Oral florid papillomatosis: Topical treatment with 5% imiquimod in orabase.

BACKGROUND: Florid oral papillomatosis is characterized by its tendency to local recurrence that requires multiple treatments, leading to important functional sequelae. METHODS: We present 74-year-old woman with oral florid papillomatosis (OFP) who refused a new surgical treatment, and was treated with imiquimod 5% in orabase on alternate days for 16 weeks. Treatment was complemented with application of hyaluronic acid gel. RESULTS: There were no side effects to the treatment, nor signs of local recurrence, in the treated area at 2 years of follow-up. CONCLUSIONS: After reviewing the literature and according to our knowledge, this is the first published case of oral florid papillomatosis treated topically with imiquimod 5% successfully. Topical treatment with imiquimod 5% in orabase may be a valid alternative for patients with recurrent OFP located in the anterior area of the oral cavity who refuse surgical treatment, although we must closely monitor the patient for the possibility of recurrence or malignant degeneration.

Ectopic Calcification and Hypophosphatemic Rickets: Natural History of ENPP1 and ABCC6 Deficiencies.

Generalized arterial calcification of infancy (GACI) is a rare disorder caused by ENPP1 or ABCC6 variants. GACI is characterized by low pyrophosphate, arterial calcification, and high mortality during the first year of life, but the natural course and possible differences between the causative genes remain unknown. In all, 247 individual records for patients with GACI (from birth to 58.3 years of age) across 19 countries were reviewed. Overall mortality was 54.7% (13.4% in utero or stillborn), with a 50.4% probability of death before the age of 6 months (critical period). Contrary to previous publications, we found that bisphosphonate treatment had no survival benefit based on a start-time matched analysis and inconclusive results when initiated within 2 weeks of birth. Despite a similar prevalence of GACI phenotypes between ENPP1 and ABCC6 deficiencies, including arterial calcification (77.2% and 89.5%, respectively), organ calcification (65.8% and 84.2%, respectively), and cardiovascular complications (58.4% and 78.9%, respectively), mortality was higher for ENPP1 versus ABCC6 variants (40.5% versus 10.5%, respectively; p = 0.0157). Higher prevalence of rickets was reported in 70.8% of surviving affected individuals with ENPP1 compared with that of ABCC6 (11.8%; p = 0.0001). Eleven affected individuals presenting with rickets and without a GACI diagnosis, termed autosomal recessive hypophosphatemic rickets type 2 (ARHR2), all had confirmed ENPP1 variants. Approximately 70% of these patients demonstrated evidence of ectopic calcification or complications similar to those seen in individuals with GACI, which shows that ARHR2 is not a distinct condition from GACI but represents part of the spectrum of ENPP1 deficiency. Overall, this study identified an early mortality risk in GACI patients despite attempts to treat with bisphosphonates, high prevalence of rickets almost exclusive to ENPP1 deficiency, and a spectrum of heterogenous calcification and multiple organ complications with both ENPP1 and ABCC6 variants, which suggests an overlapping pathology. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). This article has been contributed to by US Government employees and their work is in the public domain in the USA.

The novel aminoglycoside, ELX-02, permits CTNSW138X translational read-through and restores lysosomal cystine efflux in cystinosis.

BACKGROUND: Cystinosis is a rare disorder caused by recessive mutations of the CTNS gene. Current therapy decreases cystine accumulation, thus slowing organ deterioration without reversing renal Fanconi syndrome or preventing eventual need for a kidney transplant.15-20% of cystinosis patients harbour at least one nonsense mutation in CTNS, leading to premature end of translation of the transcript. Aminoglycosides have been shown to permit translational read-through but have high toxicity level, especially in the kidney and inner ear. ELX-02, a modified aminoglycoside, retains it read-through ability without the toxicity. METHODS AND FINDINGS: We ascertained the toxicity of ELX-02 in cells and in mice as well as the effect of ELX-02 on translational read-through of nonsense mutations in cystinotic mice and human cells. ELX-02 was not toxic in vitro or in vivo, and permitted read-through of nonsense mutations in cystinotic mice and human cells. CONCLUSIONS: ELX-02 has translational read-through activity and produces a functional CTNS protein, as evidenced by reduced cystine accumulation. This reduction is comparable to cysteamine treatment. ELX-02 accumulates in the kidney but neither cytotoxicity nor nephrotoxicity was observed.

Mechanism of Action and Clinical Application of Tafamidis in Hereditary Transthyretin Amyloidosis.

Transthyretin (TTR) transports the retinol-binding protein-vitamin A complex and is a minor transporter of thyroxine in blood. Its tetrameric structure undergoes rate-limiting dissociation and monomer misfolding, enabling TTR to aggregate or to become amyloidogenic. Mutations in the TTR gene generally destabilize the tetramer and/or accelerate tetramer dissociation, promoting amyloidogenesis. TTR-related amyloidoses are rare, fatal, protein-misfolding disorders, characterized by formation of soluble aggregates of variable structure and tissue deposition of amyloid. The TTR amyloidoses present with a spectrum of manifestations, encompassing progressive neuropathy and/or cardiomyopathy. Until recently, the only accepted treatment to halt progression of hereditary TTR amyloidosis was liver transplantation, which replaces the hepatic source of mutant TTR with the less amyloidogenic wild-type TTR. Tafamidis meglumine is a rationally designed, non-NSAID benzoxazole derivative that binds with high affinity and selectivity to TTR and kinetically stabilizes the tetramer, slowing monomer formation, misfolding, and amyloidogenesis. Tafamidis is the first pharmacotherapy approved to slow the progression of peripheral neurologic impairment in TTR familial amyloid polyneuropathy. Here we describe the mechanism of action of tafamidis and review the clinical data, demonstrating that tafamidis treatment slows neurologic deterioration and preserves nutritional status, as well as quality of life in patients with early-stage Val30Met amyloidosis.

Post hoc analysis of nutritional status in patients with transthyretin familial amyloid polyneuropathy: impact of tafamidis.

INTRODUCTION: Gastrointestinal symptoms are common among patients with transthyretin familial amyloid polyneuropathy (TTR-FAP). This post hoc analysis evaluated the nutritional status of TTR-FAP patients treated with tafamidis while enrolled in clinical trials. METHODS: Nutritional status was measured by the modified body mass index (mBMI = BMI × albumin level). Treatment-related changes in mBMI were reported for 71 Val30Met TTR-FAP patients who completed an 18-month, randomized, double-blind, placebo-controlled trial and who continued into its open-label, 12-month extension. RESULTS: At month 18, mBMI worsened in the placebo group (n = 33) (-33 ± 16 kg/m(2) g/l, P = 0.04 versus baseline) but improved in the tafamidis group (n = 38) (+37 ± 14 kg/m(2) g/l, P = 0.01 versus baseline) such that the effect size between the groups was statistically significant (P = 0.001). By month 30 (completion of the open-label extension), placebo patients with 12 months of tafamidis treatment and tafamidis-treated patients with 30 months of treatment both tended to increase their mBMI (28 ± 19 kg/m(2) g/l and 16 ± 18 kg/m(2) g/l, respectively). Increase in BMI was most pronounced in patients with low BMI at entry into the studies. CONCLUSIONS: mBMI is well suited to monitor disease progression in TTR-FAP patients. The delay in neurological deterioration brought about by tafamidis treatment in clinical trials is associated with improvements in, or maintenance of, mBMI. FUNDING: This study was sponsored by Pfizer Inc., New York, USA.

Incidence of different health factors and their influence on traffic accidents in the province of Madrid, Spain.

UNLABELLED: Most traffic accidents occur as a result of human dependent risk factors. The approach in this study focuses especially on health factors, which could have direct influence on these accidents. METHOD: A sample of 5430 and 2857 clinical histories were selected systematically from the total cases attended by the Emergency Service of the Community of Madrid (SUMMA 112) in 2006 and 2007. The cases of traffic accidents were studied. Statistical analyses of the correlation of the casualty accidents rate, mainly drivers' involved ones and the incidence of major risk factors was made. RESULTS: Traffic accidents occur more frequently among male drivers aged between 15 and 44. When males and females are considered, the rate of traffic accidents was higher for the age group 25-34 in 2006 and for the age group 15-24 in 2007. Coming off the road is the most frequent type of accident: 24.6% and 27.8%, respectively. During weekends, the rate of accidents represents approximately half that produced during weekdays. Fatigue or insufficient sleep was admitted in 3.2% in 2006 of the total of casualty accident victims. Among drivers' involved accidents, asthma and high blood pressure were each noted in 6.6% in 2006, epilepsy and depression were each detected in 2.8% in 2007. Abuse of alcohol and cocaine were noted in 10.6% and 4% of drivers' involved accidents in 2006. In 2007, drivers' abuse of alcohol and drugs was detected in 5.6% and 3.7%, respectively. CONCLUSION: Traffic accidents, especially coming off the road type, are more frequent among young adults and during weekends. Also, there is risky behaviour involved, such as driving under the influence of alcohol, abuse of drugs or having insufficient sleep or certain diseases.

Structure of acid beta-glucosidase with pharmacological chaperone provides insight into Gaucher disease.

Gaucher disease results from mutations in the lysosomal enzyme acid beta-glucosidase (GCase). Although enzyme replacement therapy has improved the health of some affected individuals, such as those with the prevalent N370S mutation, oral treatment with pharmacological chaperones may be therapeutic in a wider range of tissue compartments by restoring sufficient activity of endogenous mutant GCase. Here we demonstrate that isofagomine (IFG, 1) binds to the GCase active site, and both increases GCase activity in cell lysates and restores lysosomal trafficking in cells containing N370S mutant GCase. We also compare the crystal structures of IFG-bound GCase at low pH with those of glycerol-bound GCase at low pH and apo-GCase at neutral pH. Our data indicate that IFG induces active GCase, which is secured by interactions with Asn370. The design of small molecules that stabilize substrate-bound conformations of mutant proteins may be a general therapeutic strategy for diseases caused by protein misfolding and mistrafficking.