Influence of SLCO1B1 polymorphisms on lopinavir Ctrough in Serbian HIV/AIDS patients

Inadequate Lopinavir Concentrations With Modified 8-Hourly Lopinavir/Ritonavir 4:1 Dosing During Rifampicin-based Tuberculosis Treatment in Children Living With HIV

BACKGROUND

Lopinavir/ritonavir plasma concentrations are profoundly reduced when co-administered with rifampicin. Super-boosting of lopinavir/ritonavir is limited by nonavailability of single-entity ritonavir, while double-dosing of co-formulated lopinavir/ritonavir given twice-daily produces suboptimal lopinavir concentrations in young children. We evaluated whether increased daily dosing with modified 8-hourly lopinavir/ritonavir 4:1 would maintain therapeutic plasma concentrations of lopinavir in children living with HIV receiving rifampicin-based antituberculosis treatment.

METHODS

Children with HIV/tuberculosis coinfection weighing 3.0 to 19.9 kg, on rifampicin-based antituberculosis treatment were commenced or switched to 8-hourly liquid lopinavir/ritonavir 4:1 with increased daily dosing using weight-band dosing approach. A standard twice-daily dosing of lopinavir/ritonavir was resumed 2 weeks after completing antituberculosis treatment. Plasma sampling was conducted during and 4 weeks after completing antituberculosis treatment.

RESULTS

Of 20 children enrolled; 15, 1-7 years old, had pharmacokinetics sampling available for analysis. Lopinavir concentrations (median [range]) on 8-hourly lopinavir/ritonavir co-administered with rifampicin (n = 15; area under the curve 0-24 55.32 mg/h/L [0.30-398.7 mg/h/L]; C max 3.04 mg/L [0.03-18.6 mg/L]; C 8hr 0.90 mg/L [0.01-13.7 mg/L]) were lower than on standard dosing without rifampicin (n = 12; area under the curve 24 121.63 mg/h/L [2.56-487.3 mg/h/L]; C max 9.45 mg/L [0.39-26.4 mg/L]; C 12hr 3.03 mg/L [0.01-17.7 mg/L]). During and after rifampicin cotreatment, only 7 of 15 (44.7%) and 8 of 12 (66.7%) children, respectively, achieved targeted pre-dose lopinavir concentrations ≥1mg/L.

CONCLUSIONS

Modified 8-hourly dosing of lopinavir/ritonavir failed to achieve adequate lopinavir concentrations with concurrent antituberculosis treatment. The subtherapeutic lopinavir exposures on standard dosing after antituberculosis treatment are of concern and requires further evaluation.

Effect of SLCO1B1 c.521T>C polymorphism on the lipid response to statins in people living with HIV on a boosted protease inhibitor-containing regimen

AIMS

We previously observed that some individuals on HIV boosted protease inhibitor-containing regimen do not achieve their lipid targets despite elevated statin concentrations. This study evaluated whether the common single polymorphism c.521T>C in SLCO1B1, associated with reduced statin uptake in the liver, could explain this observation.

METHODS

People living with HIV in the Swiss HIV Cohort Study were eligible if they were on a boosted protease inhibitor concomitantly with a statin for at least 6 months and if their SLCO1B1 genotype was available. Furthermore, their lipids had to be documented before and after the introduction of the statin. The statin efficacy was defined as % change in total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol and triglycerides levels after statin initiation compared to pretreatment levels. Lipid response was adjusted for differences in potency and dose between statins.

RESULTS

In total, 88 people living with HIV were included, of whom 58, 28 and 2 carried the SLCO1B1 TT, TC and CC genotypes, respectively. The change in lipid levels after statin initiation tended to be lower in carriers of the polymorphism although the difference was not statistically significant (TT vs. TC/CC: total cholesterol: -11.7 vs. -4.8%; low-density lipoprotein- cholesterol: -20.6 vs. -7.4%; high-density lipoprotein-cholesterol: 1.6 vs. 0%; triglycerides: -11.5 vs. -7.9%). In the multiple linear regression, change in total cholesterol was inversely correlated with the total cholesterol level prestatin treatment (coefficient -6.60, 95% confidence interval: -9.63 to -3.56, P < .001).

CONCLUSION

The lipid-lowering effect of statins tended to be attenuated by SLCO1B1 polymorphism and progressively declined as total cholesterol under the boosted protease inhibitor treatment decreased.

The role of pharmacogenetics in Efficacy and safety of protease inhibitor based therapy in human immunodeficiency virus type (HIV) infection

Antiretroviral therapy has markedly reduced morbidity and mortality for persons living with human immunodeficiency virus (HIV). HIV can now be classified as a chronic disease; until a cure is found, patients are likely to require life-long therapy. However, despite these undoubted advances, there are many issues that need to be resolved, including the problems associated with long-term efficacy and toxicity. Moreover, pharmacotherapy of patients infected with HIV is challenging because a great number of comorbidities increase polypharmacy and the risk for drug-drug interactions. There is considerable interindividual variability in patient outcomes in terms of drug disposition, drug efficacy and adverse events. The basis of these differences is multifactorial, but host genetics are believed to play a significant part. HIV-infected population consists of ethnically diverse individuals on complex and potentially toxic antiretroviral regimens on a long-term basis. These individuals would benefit greatly from predictive tests that identify the most durable regimens. Pharmacogenetics holds that promise. Thus, detailed understanding of the metabolism and transport of antiretrovirals and the influence of genetics on these pathways is important. To this end, this review provides an up-to-date overview of the metabolism of antiHIV therapeutics of the protease inhibitors Lopinavir and Ritonavir and the impact of genetic variation in drug metabolism and transport on the treatment of HIV.

The influence of recipient SLCO1B1 rs2291075 polymorphism on tacrolimus dose-corrected trough concentration in the early period after liver transplantation

Purpose

To explore the relationship between rs2291075 polymorphism in SLCO1B1 gene, which encodes an influx transmembrane protein transporter, and tacrolimus dose–corrected trough concentration (C/D, ng ml⁻¹ mg⁻¹ kg⁻¹) in the early period after liver transplantation.

Methods

CYP3A5 rs776746 and SLCO1B1 rs2291075 polymorphisms of 210 liver transplantation patients and their corresponding donor livers were assessed by PCR amplification and DNA sequencing. The influence of gene polymorphisms on C/D values of tacrolimus was analyzed. The early postoperative period after liver transplantation was divided into the convalescence phase (1–14 days) and stationary phase (15–28 days) according to the change of liver function and tacrolimus C/D values.

Results

The combined analysis of donor and recipient CYP3A5 rs776746 could distinguish the metabolic phenotype of tacrolimus into three groups: fast elimination (FE), intermediate elimination (IE), and slow elimination (SE), which was entitled the FIS classification system. Tacrolimus C/D ratios of recipient SLCO1B1 rs2291075 CT and TT carriers were very close and were significantly lower than those of recipient SLCO1B1 rs2291075 CC genotype carriers in convalescence phase (p = 0.0195) and in stationary phase (p = 0.0152). There were no statistically significant differences between tacrolimus C/D ratios of patients carried with SLCO1B1 rs2291075 CT, TT genotype donors, and those carried with SLCO1B1 rs2291075 CC genotype donors. A model consisting of tacrolimus daily dose, total bilirubin, FIS classification, and recipient SLCO1B1 rs2291075 could predict tacrolimus C/D ratios in the convalescence phase by multivariate analysis. However, recipient SLCO1B1 rs2291075 genotype failed to enter forecast model for C/D ratios in stationary phase. Recipient SLCO1B1 rs2291075 genotype had significant effect on tacrolimus C/D ratios in convalescence phase (p = 0.0300) and stationary phase (p = 0.0400) in subgroup, which excluded the interference come from donor and recipient CYP3A5 rs776746.

Conclusion

SLCO1B1 rs2291075 could be a novel genetic locus associated with tacrolimus metabolism. The combined analysis of donor and recipient CYP3A5 rs776746, recipient SLCO1B1 rs2291075 genotypes, could be helpful to guide the personalized administration of tacrolimus in early period after liver transplantation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00228-020-03058-w.

Influence of SLCO1B1 polymorphisms on lopinavir Ctrough in Serbian HIV/AIDS patients

AIMS

Lopinavir (LPV) is not a first-line regimen. According to recent WHO data, LPV usage in low- and middle-income countries accounted for approximately 52% of the adult and 23% of the paediatric protease inhibitor market in 2017. Since LPV is a substrate for the SLCO1B1 (OATP1B1) transporter, the aim of this study was to assess the impact of SLCO1B1 polymorphisms (rs11045819, rs4149032 and rs4149056) on LPV trough plasma concentrations (C_trough ) in Serbian patients.

METHODS

Plasma samples from 104 HIV/AIDS Caucasians were collected. LPV C_trough was quantified using liquid-chromatography-mass spectrometry. Genotyping was carried out using real-time-PCR-based allelic discrimination. One-way analysis of variance, t test and linear regression were used for data analysis.

RESULTS

The overall mean (SD) LPV C_trough was 5885 ± 2755 ng/mL. Significant differences were between patients with different rs11045819 genotypes: CC (LPV median C_trough = 6072 ng/mL, interquartile range (IQR) = 4318-7617 ng/mL), CA (LPV median C_trough = 4987 ng/mL, IQR = 4300-6295 ng/mL) and AA (LPV median C_trough = 3648 ng/mL, IQR = 1949-4072 ng/mL) (P = .005). Significant differences were also observed according to rs4149032 genotype: CC (LPV median C_trough = 6027 ng/mL, IQR =4548-8250 ng/mL), CT (LPV median C_trough = 5553 ng/mL, IQR = 4300-6888 ng/mL) and TT (LPV median C_trough = 4408 ng/mL, IQR = 3361-5233 ng/mL) (P = .007). For rs4149056 a statistically significant difference between T-homozygotes (LPV median C_trough = 5434 ng/mL, IQR = 3855-6830 ng/mL), heterozygotes (LPV median C_trough = 6707 ng/mL, IQR = 5088-8063 ng/mL) and C-homozygotes (LPV median C_trough = 13906 ng/mL, IQR = 12946-14866 ng/mL) was observed (P = .002). In multivariate regression analysis, only the SLCO1B1 rs4149056 polymorphism was independently associated with higher LPV C_trough (β = 2834.5 [1442-4226.9] ng/mL [P = .001]).

CONCLUSIONS

Our results demonstrate a statistically significant influence of the SLCO1B1 rs4149056 polymorphism on higher LPV C_trough in Caucasian HIV/AIDS patients.