Influence of MDR1 C1236T polymorphism on lopinavir plasma concentration and virological response in HIV-1-infected children

Genetic variability in the glucocorticoid pathway and treatment outcomes in hospitalized patients with COVID-19: a pilot study

Introduction: Corticosteroids are widely used for the treatment of coronavirus disease (COVID)-19. Genetic polymorphisms of the glucocorticoid receptor, metabolizing enzymes, or transporters may affect treatment response to dexamethasone. This study aimed to evaluate the association of the glucocorticoid pathway polymorphisms with the treatment response and short-term outcomes in patients with severe COVID-19. Methods: Our pilot study included 107 hospitalized patients with COVID-19 treated with dexamethasone and/or methylprednisolone, genotyped for 14 polymorphisms in the glucocorticoid pathway. Results: In total, 83% of patients had severe disease, 15.1% had critical disease and only 1.9% had moderate disease. CYP3A4 rs35599367 was the major genetic determinant of COVID-19 severity as carriers of this polymorphism had higher risk of critical disease (OR = 6.538; 95% confidence interval = 1.19-35.914: p = 0.031) and needed intensive care unit treatment more frequently (OR = 10; 95% CI = 1.754-57.021: p = 0.01). This polymorphism was also associated with worse disease outcomes, as those patients had to switch from dexamethasone to methylprednisolone more often (OR = 6.609; 95% CI = 1.137-38.424: p = 0.036), had longer hospitalization (p = 0.022) and needed longer oxygen supplementation (p = 0.040). Carriers of NR3C1 rs6198 polymorphic allele required shorter dexamethasone treatment (p = 0.043), but had higher odds for switching therapy with methylprednisolone (OR = 2.711; 95% CI = 1.018-7.22: p = 0.046). Furthermore, rs6198 was also associated with longer duration of hospitalization (p = 0.001) and longer oxygen supplementation (p = 0.001). NR3C1 rs33388 polymorphic allele was associated with shorter hospitalization (p = 0.025) and lower odds for ICU treatment (OR = 0.144; 95% CI = 0.027-0.769: p = 0.023). GSTP1 rs1695 was associated with duration of hospitalization (p = 0.015), oxygen supplementation and (p = 0.047) dexamethasone treatment (p = 0.022). Conclusion: Our pathway-based approach enabled us to identify novel candidate polymorphisms that can be used as predictive biomarkers associated with response to glucocorticoid treatment in COVID-19. This could contribute to the patient's stratification and personalized treatment approach.

Some pharmacogenetic aspects of the <i>ABCB1</i> gene in lopinavir / ritonavir concentration variability in children with HIV infection: A pilot study

   Polymorphic variants of the multidrug resistance gene (ABCB1 or MDR1) are associated with changes in the absorption and transport of drugs in the body. One of the substrates of the ABCB1 transporter is an antiretroviral drug from the class of protease inhibitors, lopinavir.   The aim. To research the effect of polymorphic variants C1236T and C3435T in the ABCB1 gene on the plasma concentration of lopinavir / ritonavir in children and adolescents living with HIV infection.   Methods. The genotypes of polymorphic variants of the ABCB1 gene were identified in 136 HIV infected children and adolescents; median age – 10 [7–12] years. The plasma concentration of lopinavir / ritonavir was measured from blood taken during the next scheduled appointment as part of dispensary observation at the Irkutsk Regional AIDS Centre using high performance liquid chromatography.   Results. The average duration of lopinavir/ritonavir use as part of an antiretroviral therapy was 55 months. Median viral load in patients was 1 [1–2.03] log 10  copies/ mL; the number of CD4 +  T cells – 38.36 %. The frequency of occurrence of the 3435T and 1236T alleles of the ABCB1 gene was ~50 %. In carriers of the 3435TT genotype, the median lopinavir concentrations 2 and 12 hours after drug intake were 5050.8 [3615.8–5847.7] and 2665.5 [216–4896.3] ng/mL, respectively. In carriers of the 1236TT genotype, median lopinavir concentrations 2 and 12 hours after drug intake were 4913.5 [3355.1–5733.7] and 3290.6 [159.1–4972.5] ng/mL, respectively.   Conclusions. The study did not reveal a significant relationship between the carriage of the C3435T and C1236T genotypes of the ABCB1 gene and the concentrations of lopinavir and ritonavir 2 and 12 hours after drug intake.

Pharmacogenetics of HIV therapy: State of the art in Latin American countries

The use of combined antiretroviral therapy (cART) has resulted in a remarkable reduction in morbidity and mortality of people living with HIV worldwide. Nevertheless, interindividual variations in drug response often impose a challenge to cART effectiveness. Although personalized therapeutic regimens may help overcome incidence of adverse reactions and therapeutic failure attributed to host factors, pharmacogenetic studies are often restricted to a few populations. Latin American countries accounted for 2.1 million people living with HIV and 1.4 million undergoing cART in 2020-21. The present review describes the state of art of HIV pharmacogenetics in this region and highlights that such analyses remain to be given the required relevance. A broad analysis of pharmacogenetic markers in Latin America could not only provide a better understanding of genetic structure of these populations, but might also be crucial to develop more informative dosing algorithms, applicable to non-European populations.

Predictive association of ABCB1 C3435T genetic polymorphism with the efficacy or safety of lopinavir and ritonavir in COVID-19 patients

Lopinavir and ritonavir are substrates of permeability glycoprotein encoded by ABCB1. The efficacy and safety of these drugs is unknown in COVID-19 patients affected by ABCB1 genetic variability. Patients carrying one or two copies of the ABCB1 C3435T were predictively considered as risk phenotypes. It was predicted that risk phenotypes due to carrying either one or two copies of ABCB1 C3435T were highly prevalent in Europe (76.8%; 95% CI: 75-78), followed by America (67%; 95% CI: 65-69), Asia (63.5%; 95% CI: 62-65) and Africa (41.4%; 95% CI: 37-46), respectively. It is hypothesized that a considerable proportion of COVID-19 patients treated with lopinavir/ritonavir inheriting ABCB1 C3435T genetic polymorphism may be predisposed to either therapeutic failure or toxicity.

Role of ABCB1 and glutathione S-transferase gene variants in the association of porphyria cutanea tarda and human immunodeficiency virus infection

In Argentina, porphyria cutanea tarda (PCT) is strongly associated with infection with human immunodeficiency virus (HIV); however, whether the onset of this disease is associated with HIV infection and/or the antiretroviral therapy has not been determined. The ABCB1 gene variants c.1236C>T, c.2677G>T/A and c.3435C>T affect drug efflux. The GSTT1 null, GSTM1 null and GSTP1 (c.313A>G) gene variants alter Glutathione S-transferase (GST) activity, modifying the levels of xenobiotics. The aim of the present study was to evaluate the role of genetic variants in initiation of PCT and to analyze the genetic basis of the PCT-HIV association. Control individuals, and HIV, PCT and PCT-HIV patients were recruited, PCR-restriction fragment length polymorphism was used to genotype the ABCB1 and GSTP1 variants, and multiplex PCR was used to study the GSTM1 and GSTT1 variants. The high frequency of c.3435C>T (PCT and PCT-HIV) and c.1236C>T (PCT) suggested that the onset of PCT were not specifically related to HIV infection or antiretroviral therapy for these variants. c.2677G>T/A frequencies in the PCT-HIV patients were higher compared with the other groups, suggesting that a mechanism involving antiretroviral therapy served a role in this association. PCT-HIV patients also had a high frequency of GSTT1 null and low frequency for GSTM1 null variants; thus, the genetic basis for PCT onset may involve a combination between the absence of GSTT1 and the presence of GSTM1. In conclusion, genes encoding for proteins involved in the flow and metabolism of xenobiotics may influence the PCT-HIV association. The present study is the first to investigate the possible role of GST and ABCB1 gene variants in the triggering of PCT in HIV-infected individuals, to the best of our knowledge, and may provide novel insights into the molecular basis of the association between PCT and HIV.

Pharmacogenomics of COVID-19 therapies

A new global pandemic of coronavirus disease 2019 (COVID-19) has resulted in high mortality and morbidity. Currently numerous drugs are under expedited investigations without well-established safety or efficacy data. Pharmacogenomics may allow individualization of these drugs thereby improving efficacy and safety. In this review, we summarized the pharmacogenomic literature available for COVID-19 drug therapies including hydroxychloroquine, chloroquine, azithromycin, remdesivir, favipiravir, ribavirin, lopinavir/ritonavir, darunavir/cobicistat, interferon beta-1b, tocilizumab, ruxolitinib, baricitinib, and corticosteroids. We searched PubMed, reviewed the Pharmacogenomics Knowledgebase (PharmGKB®) website, Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines, the U.S. Food and Drug Administration (FDA) pharmacogenomics information in the product labeling, and the FDA pharmacogenomics association table. We found several drug-gene variant pairs that may alter the pharmacokinetics of hydroxychloroquine/chloroquine (CYP2C8, CYP2D6, SLCO1A2, and SLCO1B1); azithromycin (ABCB1); ribavirin (SLC29A1, SLC28A2, and SLC28A3); and lopinavir/ritonavir (SLCO1B1, ABCC2, CYP3A). We also identified other variants, that are associated with adverse effects, most notable in hydroxychloroquine/chloroquine (G6PD; hemolysis), ribavirin (ITPA; hemolysis), and interferon β -1b (IRF6; liver toxicity). We also describe the complexity of the risk for QT prolongation in this setting because of additive effects of combining more than one QT-prolonging drug (i.e., hydroxychloroquine/chloroquine and azithromycin), increased concentrations of the drugs due to genetic variants, along with the risk of also combining therapy with potent inhibitors. In conclusion, although direct evidence in COVID-19 patients is lacking, we identified potential actionable genetic markers in COVID-19 therapies. Clinical studies in COVID-19 patients are deemed warranted to assess potential roles of these markers.

MDR1 in immunity: friend or foe?

MDR1 is an ATP-dependent transmembrane transporter primarily studied for its role in the detoxification of tissues and for its implication in resistance of tumor cells to chemotherapy treatment. Several studies also report on its expression on immune cells where it plays a protective role from xenobiotics and toxins. This review provides an overview of what is known on MDR1 expression in immune cells in human, and its implications in different pathologies and their treatment options.

Relationship between untimed plasma lopinavir concentrations and virological outcome on second-line antiretroviral therapy

BACKGROUND

Resource constraints in low and middle-income countries necessitate practical approaches to optimizing antiretroviral therapy outcomes. We hypothesised that an untimed plasma lopinavir concentration (UPLC) at week 12 would predict loss of virological response in those taking lopinavir as part of a second-line antiretroviral regimen.

METHODS

We measured plasma lopinavir concentration at week 12 on stored samples from the SECOND-LINE study. We characterized UPLC as: detectable and optimal (≥1000 μg/l); detectable but suboptimal (≥25 to < 1000 μg/l); and undetectable (<25 μg/l). We used Cox regression to explore the relationship between UPLC and loss of virological response over 48 weeks and backwards stepwise logistic regression to explore the relationship between UPLC and other predictors of virological failure at week 48.

RESULTS

At week 48, we observed virological failure in 15/32 (47%) and 53/485 (11%) of patients with undetectable and detectable UPLC, respectively, P < 0.001. Both suboptimal [adjusted hazard ratio (HR) 2.94; 95% confidence interval (CI) 1.54-5.62; P = 0.001], and undetectable (adjusted HR 3.55; 95% CI 1.89-6.64; P < 0.001) UPLC were associated with higher rates of loss of virological response over 48 weeks. In multivariate analysis, an independent association with virological failure at week 48 and undetectable UPLC was observed after adjustment (odds ratio 5.48; 95% CI 2.23-13.42; P < 0.01).

CONCLUSION

In low and middle-income countries implementing a public health approach to antiretroviral therapy treatment, an untimed plasma drug concentration may provide a practical method for early identification of patients with inadequate medication adherence and facilitate timely corrective interventions to prevent virological failure.

MDR1 polymorphisms affect the outcome of Chinese multiple myeloma patients

OBJECTIVE

To illustrate the association of MDR1 (Multidrug Resistance 1) polymorphisms at loci 1236, 2677, 3435 and the prognosis of multiple myeloma (MM) in Jiangsu population.

METHODS

A total of 129 MM patients were recruited from Jiangsu Province, China. The DNA was extracted from white blood cells (WBC) of peripheral blood and was amplified by polymerase chain reaction-allele specific primers (PCR-ASP). MDR1 polymorphisms at 3 loci were analyzed by electrophoresis followed by photograph or DNA direct sequencing. The association between the MDR1 and clinical outcomes were calculated by Graphpad and SPSS.

RESULTS

MDR1 alleles at locus C1236T with T had significant lower calcium level in MM patients compared with C. The genotype CT had a significantly prolonged progress free survival (PFS) compared genotype CC at locus C1236T (median time: 48 months vs. 28 months, respectively; p=0.0062; HR=0.21; 95%CI0.061-0.715) while patients carrying T allele (CT and TT) at locus C3435T had a longer PFS than patients without T allele (CC) (median time: 60 months vs. 29 months, respectively; p=0.038; HR=0.508; 95%CI 0.264-0.978). And a borderline significance was found in haplotype at loci 2677-3435 and PFS. No significant findings were revealed between OS and MDR1 polymorphisms.

CONCLUSION

MDR1 polymorphisms could affect the prognosis of multiple myeloma whereas more samples and a longer follow-up are also needed.

Up-regulation of ATP-binding cassette transporters in the THP-1 human macrophage cell line by the antichagasic benznidazole

The effect of benznidazole (BZL) on the expression and activity of P-glycoprotein (P-gp, ABCB1) and multidrug resistance-associated protein 2 (MRP2, ABCC2), the two major transporters of endogenous and exogenous compounds, was evaluated in differentiated THP-1 cells. BZL induced P-gp and MRP2 proteins in a concentration-dependent manner. The increase in mRNA levels of both transporters suggests transcriptional regulation. P-gp and MRP2 activities correlated with increased protein levels. BZL intracellular accumulation was significantly lower in BZL-pre-treated cells than in control cells. PSC833 (a P-gp inhibitor) increased the intracellular BZL concentration in both pre-treated and control cells, confirming P-gp participation in BZL efflux.

Does maternal MDR1 C1236T polymorphism have an effect on placental arsenic levels?

To detect whether maternal MDR1 C1236T polymorphism has an effect on placental arsenic levels, 112 mother-placenta pairs were examined. Venous blood samples from mothers were collected to investigate the C1236T polymorphism which was detected by standard PCR-RFLP technique. Placentas were collected to measure arsenic levels by GF-AAS. The MDR1 C1236T genotype frequencies of mothers were found as 30.3% homozygote typical (CC), 51.8% heterozygote (CT) and 17.9% homozygote atypical (TT). The mean placental arsenic level was 62.36±30.43 μg/kg. It was observed that the placental arsenic concentrations were higher in mothers with TT genotype than those with CC and CT genotypes, but this was not statistically significant (p=0.702). This finding was indicated that fetuses of mothers with TT genotype may be more susceptible to arsenic toxicity as compared to those of with CC and CT genotypes. We believe that this difference warrant further studies with larger study subjects.

Pin1 liberates the human immunodeficiency virus type-1 (HIV-1): Must we stop it?

Acquired immune deficiency syndrome (AIDS) is mainly caused by the human immunodeficiency virus type-1 (HIV-1). To our knowledge, this is the first review focusing on the vital role of Pin1 in the infection of HIV-1 and the development of AIDS. We and others have demonstrated that Pin1, the only known cis-to-trans isomerase recognizing the pThr/pSer-Pro motifs in proteins, plays striking roles in several human diseases. Interestingly, recent evidence gradually indicates that Pin1 regulates several key steps of the life cycle of HIV-1, including the uncoating of the HIV-1 core, the reverse transcription of the RNA genome of HIV-1, and the integration of the HIV-1 cDNA into human chromosomes. Whereas inhibiting Pin1 suppresses all of these key steps and attenuates the replication of HIV-1, at the same time different PIN1 gene variants are correlated with the susceptibility to HIV-1 infection. Furthermore, Pin1 potentially promotes HIV-1 infection by activating multiple oncogenes and inactivating multiple tumor suppressors, extending the life span of HIV-infected cells. These descriptions suggest Pin1 as a promising therapeutic target for the prevention of HIV-1 and highlight the possibility of blocking the development of AIDS by Pin1 inhibitors.

Role of SLCO1B1, ABCB1, and CHRNA1 gene polymorphisms on the efficacy of rocuronium in Chinese patients

This study explored the role of SLCO1B1, ABCB1, and CHRNA1 gene polymorphisms on the efficacy and duration of action of rocuronium in Chinese patients. Two hundred seven unrelated Chinese patients scheduled for elective surgery were recruited, and 200 completed the study. Their ABCB1, SLCO1B1, and CHRNA1 genotypes were determined. Demographic and clinical non-genetic data also were collected. The SLCO1B1, ABCB1, and CHRNA1 variants did not affect the onset time of rocuronium. Clinical duration and recovery time of rocuronium were prolonged in patients with the ABCB1 rs1128503TT and SLCO1B1 rs2306283 AG and GG genotypes. We demonstrate that the SLCO1B1 and ABCB1 gene variants could affect the pharmacodynamics of rocuronium. The ABCB1 rs1128503 C>T genotype was the most important factor on the efficacy of rocuronium.

Association of ABCB1 gene polymorphisms and haplotypes with therapeutic efficacy of glucocorticoids in Chinese patients with immune thrombocytopenia

Resistance to glucocorticoids (GCs) remains a tricky problem complicating the therapy of ITP. Recently, ATP binding cassette gene B1 gene (ABCB1) was reported to be correlated with susceptibility and therapeutic efficacy of autoimmune diseases through P-glycoprotein (Pgp). We investigated three single nucleotide polymorphisms (SNPs) of ABCB1 and their haplotypes by PCR-RFLP (restriction fragment length polymorphism) method in 471 ITP patients and 383 healthy controls, patients were further assigned into GCs-responsive and -non-responsive group according to the therapeutic effects of GCs. We observed a remarkable difference in genotypes of G2677T/A between GCs-responsive and non-responsive group, but not between patients and controls. A frequently expression of T/A allele within G2677T/A was recorded in GCs-responsive group. Furthermore, we found that some haplotypes (CGC, CTC/CAC, CTT/CAT, TGC, TGT, TTC/TAC and TTT/TAT, in the order of position 1236-2677-3435) were presented significantly differences between non-responsive and responsive group. No difference of C1236T and C3435T polymorphisms was observed between ITP and controls, and between the GCs-responsive and -non-responsive group. Our findings suggest that ABCB1 polymorphisms, as well as haplotypes derived from C1235T, G2677T/A and C3435T, are associated with inter-individual differences of GCs treatment in ITP.