Pharmacokinetics of Sofosbuvir/Velpatasvir and efficacy of an alternate-day treatment in hemodialysis patients with chronic hepatitis C infection.

Sofosbuvir/Velpatasvir (SOF/VEL) is a combination drug used for chronic hepatitis C (HCV) infection. However, limited information exists regarding the pharmacokinetics of SOF/VEL and its metabolites in hemodialysis patients. We conducted a prospective investigation of the pharmacokinetic parameters of SOF/VEL after a single dose of SOF/VEL (400/100 mg) on days with and without dialysis in 12 Thai hemodialysis patients with chronic HCV infection, who had been undergoing hemodialysis for a duration of 0.5-20 years. Blood samples were collected before dose (0) and 0.5, 1.0, 2.0, 2.5, 3.0, 3.5, 4.0, 5.0, 6.0, 8.0, and 12.0 h after dose. Dialysate samples were also collected before dose (0) and 1.0, 2.0, 3.0, and 4.0 h after dose. Plasma and dialysate samples were quantified for SOF and its metabolite, GS-331007, and VEL concentrations using a fully validated LCMS technique. In addition, a preliminary efficacy study was conducted using the proposed SOF/VEL dose reduction regimen in all patients. No differences in SOF/VEL PK parameters between on- and off-dialysis studies. On the contrary, GS-331007 exhibited a 30% reduction in the area under the plasma concentration-time curve from time 0 to 24 h (AUC0-24h) on dialysis days compared with non-dialysis days (AUC0-24h ratio 0.68 vs. 1.04, respectively). The dialysis clearance of SOF and GS-331007 was 9.35 (8.72-15.11) and 8.89 (8.52-14.07) mL/min, respectively. Subsequently, an alternate-day regimen of SOF/VEL (400/100 mg) was administered for 12 weeks, resulting in an undetectable plasma HCV viral load without side effects. Further clinical studies are warranted to validate the efficacy and safety of our proposed dose reduction regimen.

A Randomized Controlled Study of Efficacy and Safety of Accelerated Versus Standard Hepatitis B Vaccination in Patients With Advanced CKD.

Introduction: Hepatitis B virus (HBV) vaccination is crucial for seronegative patients with advanced chronic kidney disease (CKD) for protection during dialysis while preparing for transplantation. A standard regimen for HBV vaccination requires 24 weeks to be completed. An accelerated HBV vaccination regimen completed within 8 weeks has shown early effective seroconversion in healthcare workers. However, data for patients with advanced CKD are limited. Methods: A randomized controlled trial was conducted in patients with advanced CKD (estimated glomerular filtration rate [GFR] <30 ml/min per 1.73 m2) and patients on dialysis. The patients were randomly assigned to either a standard HBV vaccination regimen (Engerix B; 40 µg at 0, 4, 8, and 24 weeks) or an accelerated regimen (40 µg at 0, 1, 4, and 8 weeks). The hepatitis B surface antibodies (anti-HBs) were measured at 12, 28, and 52 weeks. Seroconversion were defined as anti-HBs ≥10 IU/l. Results: At 12 weeks, among the intention-to-treat (ITT) population of 133 participants (65 in the accelerated and 68 in the standard groups), the accelerated group demonstrated significantly higher rates of seroconversion (83.08% vs. 63.24%, P = 0.01). In the per-protocol (PP) analysis of 125 patients (62 in the standard and 63 in the accelerated groups), the accelerated group exhibited higher seroconversion rate compared with the standard group (85.71% vs. 69.35%, P = 0.03). At 28 and 52 weeks, the seroconversion rates were similar between the 2 groups. Conclusion: In patients with advanced CKD, the accelerated HBV vaccination regimen demonstrated a significantly higher seroconversion rate at 12 weeks of vaccination. This finding suggests that the accelerated regimen is an effective option to achieve rapid seroconversion before initiating hemodialysis or before undergoing kidney transplantation.

Quantitative assessment of glomerular basement membrane collagen IV α chains in paraffin sections from patients with focal segmental glomerulosclerosis and Alport gene variants.

Focal segmental glomerulosclerosis (FSGS) lesions have been linked to variants in COL4A3/A4/A5 genes, which are also mutated in Alport syndrome. Although it could be useful for diagnosis, quantitative evaluation of glomerular basement membrane (GBM) type IV collagen (colIV) networks is not widely used to assess these patients. To do so, we developed immunofluorescence imaging for collagen α5(IV) and α1/2(IV) on kidney paraffin sections with Airyscan confocal microscopy that clearly distinguishes GBM collagen α3α4α5(IV) and α1α1α2(IV) as two distinct layers, allowing quantitative assessment of both colIV networks. The ratios of collagen α5(IV):α1/2(IV) mean fluorescence intensities (α5:α1/2 intensity ratios) and thicknesses (α5:α1/2 thickness ratios) were calculated to represent the levels of collagen α3α4α5(IV) relative to α1α1α2(IV). The α5:α1/2 intensity and thickness ratios were comparable across all 11 control samples, while both ratios were significantly and markedly decreased in all patients with pathogenic or likely pathogenic Alport COL4A variants, supporting validity of this approach. Thus, with further validation of this technique, quantitative measurement of GBM colIV subtype abundance by immunofluorescence, may potentially serve to identify the subgroup of patients with FSGS lesions likely to harbor pathogenic COL4A variants who could benefit from genetic testing.

Prevalence of arterial stiffness and associated factors in Thai hemodialysis patients: A multicenter cross-sectional study.

BACKGROUND: Hemodialysis (HD) patients have higher risks of cardiovascular morbidity and mortality compared to the general population. Cardio-femoral pulse wave velocity (cfPWV) is associated with cardiovascular morbidity and mortality in HD patients. This study aimed to evaluate the prevalence and associated factors of arterial stiffness in Thai HD patients. MATERIALS AND METHODS: This cross-sectional multicenter study was conducted at 4 HD centers in Bangkok, Thailand. cfPWV and peripheral blood pressure were assessed using SphygmoCor XCEL Model EM4C (AtCor medical Inc., Sydney, Australia). Significant arterial stiffness was defined by cfPWV > 10 m/s. Univariate and multivariable regression models were used to identify factors associated with arterial stiffness. RESULTS: 144 HD patients were assessed for arterial stiffness by cfPWV measurement. The mean age of the patients was 57.8 ± 12.8 years, with 50% male and a mean dialysis vintage of 7.6 years. The mean cfPWV was 11.7 ± 3.0 m/s. The prevalence of increased arterial stiffness was 73.6%. Multivariable analysis showed that older age, hypertension, lower HD adequacy, and higher fasting plasma glucose were independently associated with arterial stiffness. CONCLUSION: There was a high prevalence of arterial stiffness among HD patients. Some modifiable factors found to be independently associated, including dialysis adequacy and glycemic control, should be further investigated to identify approaches to retard vascular stiffness.

Incremental versus conventional haemodialysis in end-stage kidney disease: a systematic review and meta-analysis.

Background: Appropriate dialysis prescription in the transitional setting from chronic kidney disease to end-stage kidney disease is still challenging. Conventional thrice-weekly haemodialysis (HD) might be associated with rapid loss of residual kidney function (RKF) and high mortality. The benefits and risks of incremental HD compared with conventional HD were explored in this systematic review and meta-analysis. Methods: We searched MEDLINE, Scopus and Cochrane Central Register of Controlled Trials up to April 2023 for studies that compared the impacts of incremental (once- or twice-weekly HD) and conventional thrice-weekly HD on cardiovascular events, RKF, vascular access complications, quality of life, hospitalization and mortality. Results: A total of 36 articles (138 939 participants) were included in this meta-analysis. The mortality rate and cardiovascular events were similar between incremental and conventional HD {odds ratio [OR] 0.87 [95% confidence interval (CI)] 0.72-1.04 and OR 0.67 [95% CI 0.43-1.05], respectively}. However, hospitalization and loss of RKF were significantly lower in patients treated with incremental HD [OR 0.44 (95% CI 0.27-0.72) and OR 0.31 (95% CI 0.25-0.39), respectively]. In a sensitivity analysis that included studies restricted to those with RKF or urine output criteria, incremental HD had significantly lower cardiovascular events [OR 0.22 (95% CI 0.08-0.63)] and mortality [OR 0.54 (95% CI 0.37-0.79)]. Vascular access complications, hyperkalaemia and volume overload were not statistically different between groups. Conclusions: Incremental HD has been shown to be safe and may provide superior benefits in clinical outcomes, particularly in appropriately selected patients. Large-scale randomized controlled trials are required to confirm these potential advantages.

HLA-B*46:01:01:01 and HLA-DRB1*09:01:02:01 are associated with anti-rHuEPO-induced pure red cell aplasia.

Treatment of anemia in patients with chronic kidney disease (CKD) with recombinant human erythropoietin (rHuEPO) can be disrupted by a severe complication, anti-rHuEPO-induced pure red cell aplasia (PRCA). Specific HLA genotypes may have played a role in the high incidence of PRCA in Thai patients (1.7/1,000 patient years vs. 0.03/10,000 patient years in Caucasians). We conducted a case-control study in 157 CKD patients with anti-rHuEPO-induced PRCA and 56 controls. The HLA typing was determined by sequencing using a highly accurate multiplex single-molecule, real-time, long-read sequencing platform. Four analytical models were deployed: Model 1 (additive: accounts for the number of alleles), Model 2 (dominant: accounts for only the presence or absence of alleles), Model 3 (adjusted additive with rHuEPO types) and Model 4 (adjusted dominant with rHuEPO types). HLA-B*46:01:01:01 and DRB1*09:01:02:01 were found to be independent risk markers for anti-rHuEPO-induced PRCA in all models [OR (95%CI), p-values for B*46:01:01:01: 4.58 (1.55-13.51), 0.006; 4.63 (1.56-13.75), 0.006; 5.72 (1.67-19.67), 0.006; and 5.81 (1.68-20.09), 0.005; for DRB1*09:01:02:01: 3.99 (1.28-12.49), 0.017, 4.50 (1.32-15.40), 0.016, 3.42 (1.09-10.74), 0.035, and 3.75 (1.08-13.07), 0.038, in Models 1-4, respectively. HLA-B*46:01:01:01 and DRB1*09:01:02:01 are susceptible alleles for anti-rHuEPO-induced PRCA. These findings support the role of HLA genotyping in helping to monitor patients receiving rHuEPO treatment.