42 research outputs found
Adaptation of antiretroviral therapy in human immunodeficiency virus infection with central nervous system involvement
The authors describe a patient with known human immunodeficiency virus (HIV)-1 infection who presented with two generalized seizures and was found to have extensive white matter disease and a left/bilateral temporo-occipital focal slowing on electroencephalography (EEG). There were no magnetic resonance imaging (MRI) or cerebrospinal fluid (CSF) indications for opportunistic infection. Plasma viremia was controlled, whereas viral replication was uncontrolled in CSF. CSF-specific genotype-guided adaptation of the antiretroviral therapy in order to optimize central nervous system (CNS) penetration resulted in clinical improvement and normalization of MRI and EEG. Our case report illustrates the importance of individualized antiretroviral therapy in HIV infected patients with neurological complication
Gilbert Syndrome and the Development of Antiretroviral Therapy-Associated Hyperbilirubinemia
BackgroundUnconjugated hyperbilirubinemia results from Gilbert syndrome and from antiretroviral therapy (ART) containing protease inhibitors. An understanding of the interaction between genetic predisposition and ART may help to identify individuals at highest risk for developing jaundice MethodsWe quantified the contribution of UGT1A1*28 and ART to hyperbilirubinemia by longitudinally modeling 1386 total bilirubin levels in 96 human immunodeficiency virus (HIV)-infected individuals during a median of 6 years ResultsThe estimated average bilirubin level was 8.8 μmol/L (0.51 mg/dL). Atazanavir increased bilirubin levels by 15 μmol/L (0.87 mg/dL), and indinavir increased bilirubin levels by 8 μmol/L (0.46 mg/dL). Ritonavir, lopinavir, saquinavir, and nelfinavir had no or minimal effect on bilirubin levels. Homozygous UGT1A1*28 increased bilirubin levels by 5.2 μmol/L (0.3 mg/dL). As a consequence, 67% of individuals homozygous for UGT1A1*28 and receiving atazanavir or indinavir had ⩾2 episodes of hyperbilirubinemia in the jaundice range (>43 μmol/L [>2.5 mg/dL]), versus 7% of those with the common allele and not receiving either of those protease inhibitors (P<.001). Efavirenz resulted in decreased bilirubin levels, which is consistent with the induction of UDP-glucuronosyltransferase 1A1 ConclusionsGenotyping for UGT1A1*28 before initiation of ART would identify HIV-infected individuals at risk for hyperbilirubinemia and decrease episodes of jaundic
Mendelian Randomization analysis reveals a causal influence of circulating sclerostin levels on bone mineral density and fractures
In bone, sclerostin is mainly osteocyte-derived and plays an important local role in adaptive responses to mechanical loading. Whether circulating levels of sclerostin also play a functional role is currently unclear, which we aimed to examine by two-sample Mendelian randomization (MR). A genetic instrument for circulating sclerostin, derived from a genomewide association study (GWAS) meta-analysis of serum sclerostin in 10,584 European-descent individuals, was examined in relation to femoral neck bone mineral density (BMD; n = 32,744) in GEFOS and estimated bone mineral density (eBMD) by heel ultrasound (n = 426,824) and fracture risk (n = 426,795) in UK Biobank. Our GWAS identified two novel serum sclerostin loci, B4GALNT3 (standard deviation [SD]) change in sclerostin per A allele (β = 0.20, p = 4.6 × 10-49 ) and GALNT1 (β  = 0.11 per G allele, p = 4.4 × 10-11 ). B4GALNT3 is an N-acetyl-galactosaminyltransferase, adding a terminal LacdiNAc disaccharide to target glycocoproteins, found to be predominantly expressed in kidney, whereas GALNT1 is an enzyme causing mucin-type O-linked glycosylation. Using these two single-nucleotide polymorphisms (SNPs) as genetic instruments, MR revealed an inverse causal relationship between serum sclerostin and femoral neck BMD (β = -0.12, 95% confidence interval [CI] -0.20 to -0.05) and eBMD (β = -0.12, 95% CI -0.14 to -0.10), and a positive relationship with fracture risk (β = 0.11, 95% CI 0.01 to 0.21). Colocalization analysis demonstrated common genetic signals within the B4GALNT3 locus for higher sclerostin, lower eBMD, and greater B4GALNT3 expression in arterial tissue (probability >99%). Our findings suggest that higher sclerostin levels are causally related to lower BMD and greater fracture risk. Hence, strategies for reducing circulating sclerostin, for example by targeting glycosylation enzymes as suggested by our GWAS results, may prove valuable in treating osteoporosis. © 2019 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc
Mendelian Randomization Analysis Reveals a Causal Influence of Circulating Sclerostin Levels on Bone Mineral Density and Fractures
In bone, sclerostin is mainly osteocyte-derived and plays an important local role in adaptive responses to mechanical loading. Whether circulating levels of sclerostin also play a functional role is currently unclear, which we aimed to examine by two-sample Mendelian randomization (MR). A genetic instrument for circulating sclerostin, derived from a genomewide association study (GWAS) meta-analysis of serum sclerostin in 10,584 European-descent individuals, was examined in relation to femoral neck bone mineral density (BMD; n = 32,744) in GEFOS and estimated bone mineral density (eBMD) by heel ultrasound (n = 426,824) and fracture risk (n = 426,795) in UK Biobank. Our GWAS identified two novel serum sclerostin loci, B4GALNT3 (standard deviation [SD]) change in sclerostin per A allele (β = 0.20, p = 4.6 × 10−49) and GALNT1 (β = 0.11 per G allele, p = 4.4 × 10−11). B4GALNT3 is an N-acetyl-galactosaminyltransferase, adding a terminal LacdiNAc disaccharide to target glycocoproteins, found to be predominantly expressed in kidney, whereas GALNT1 is an enzyme causing mucin-type O-linked glycosylation. Using these two single-nucleotide polymorphisms (SNPs) as genetic instruments, MR revealed an inverse causal relationship between serum sclerostin and femoral neck BMD (β = –0.12, 95% confidence interval [CI] –0.20 to –0.05) and eBMD (β = –0.12, 95% CI –0.14 to –0.10), and a positive relationship with fracture risk (β = 0.11, 95% CI 0.01 to 0.21). Colocalization analysis demonstrated common genetic signals within the B4GALNT3 locus for higher sclerostin, lower eBMD, and greater B4GALNT3 expression in arterial tissue (probability >99%). Our findings suggest that higher sclerostin levels are causally related to lower BMD and greater fracture risk. Hence, strategies for reducing circulating sclerostin, for example by targeting glycosylation enzymes as suggested by our GWAS results, may prove valuable in treating osteoporosis
CD4 Counts and Mortality in Virologically Suppressed US Veterans
We used the Veterans Health Administration (VA) HIV Clinical Case Registry (CCR) to evaluate the association between annual CD4 averages and all-cause mortality in HIV-infected veterans during their initial episode of suppressive highly active antiretroviral therapy (HAART). We observed 1083 deaths in 14 769 patients. Unadjusted mortality rates in the top and bottom CD4 quintiles differed significantly from the mid CD4 strata. Mortality in the top CD4 quintile (≥720 cells/mm 3 ) was 14.1/1000 patient-years, 95% confidence interval (CI): 10.1-18.2, compared with 20.4 (CI: 15.5-25.3) in the next lower CD4 stratum (530-719 cells/mm 3 ). This difference was significant in Cox proportional hazards model, controlling for demographics, hepatitis co-infections, low-level viremia, HAART adherence, and refill rates of individual antiretrovirals (HR: 1.4, CI: 1.13-1.73). Our results support early HAART initiation as advocated by the current US treatment guidelines for HIV infection
Current use of statins reduces risk of HIV rebound on suppressive HAART
<div><p>Background</p><p>Despite compelling evidence for activity against HIV-1 <i>in vitro</i>, a virologic effect of statins has not been shown in clinical studies. Given their short plasma half-lives, such an effect may be transient and only apparent during ongoing exposure.</p><p>Methods</p><p>We studied all HIV infected US-Veterans who started HAART 1995–2011, had a documented HIV viral load (VL) >1000 copies/mL, reached an undetectable VL on HAART, and had ≥1 follow-up VL within 13 months. We defined virologic failure (VF) as the first VL >1,000 copies/mL or the first of 2 consecutive VL >200 copies/mL. We built a time-updated drug exposure model for antiretrovirals (ARVs), statins, and other cardiovascular drugs (CVMs), investigating current use (yes/no), recent use (proportion of days used), and categorical use (ever/never). We used both multiply adjusted and inverse-probability-weighted (IPW) Cox models to explore the association between statin and CVM use and VF.</p><p>Results</p><p>19,324 veterans met inclusion criteria. Median follow-up was 13 months (IQR: 5–32 months); 63% experienced VF after a median time of 9 months (IQR 4–21 months). Almost 1/3 patients ever used statins but exposure comprised only 41% of follow-up time covered after initial prescription. Unadjusted, current statin use was associated with a hazard ratio (HR) for VF of 0.60 (CI: 0.56–0.65). This remained statistically significant after multivariate adjustment (MVA) for demographics, HIV and HAART parameters [HR 0.81 (CI: 0.75–0.88), p<0.001] and IPW (truncation <1%/>99%) HR: 0.83 (CI: 0.75–0.92), p<0.001]. No independent association was observed for other CVMs. The association between categorical-statin use and VF after MVA was much weaker: HR 0.94 (CI: 0.88–1.00, p = 0.04).</p><p>Conclusion</p><p>Current statin exposure was associated with reduced risk of VF in univariate, multivariate, and inverse-probability-weighted models. Our results highlight the importance of time-updated medication exposure models for observational studies.</p></div
Proportion of patients experiencing virological failure by likelihood of statin exposure based on propensity score.
<p>Solid line: not on statins or CVMs, dotted line: on statins. Statin use was associated with a decreased probability of failure.</p
Cross-sectional Selection of Time-Updated Characteristics by Statin and CVM Use (all patients under observation).
<p>Cross-sectional Selection of Time-Updated Characteristics by Statin and CVM Use (all patients under observation).</p