Association Between Atazanavir-Induced Hyperbilirubinemia and Cardiovascular Disease in Patients Infected with HIV

Current drugs for HIV-1: from challenges to potential in HIV/AIDS

The human immunodeficiency virus (HIV) persists in latently infected CD4+T cells and integrates with the host genome until cell death. Acquired immunodeficiency syndrome (AIDS) is associated with HIV-1. Possibly, treating HIV/AIDS is an essential but challenging clinical goal. This review provides a detailed account of the types and mechanisms of monotherapy and combination therapy against HIV-1 and describes nanoparticle and hydrogel delivery systems. In particular, the recently developed capsid inhibitor (Lenacapavir) and the Ainuovirine/tenofovir disoproxil fumarate/lamivudine combination (ACC008) are described. It is interestingly to note that the lack of the multipass transmembrane proteins serine incorporator 3 (SERINC3) and the multipass transmembrane proteins serine incorporator 5 (SERINC5) may be one of the reasons for the enhanced infectivity of HIV-1. This discovery of SERINC3 and SERINC5 provides new ideas for HIV-1 medication development. Therefore, we believe that in treating AIDS, antiviral medications should be rationally selected for pre-exposure and post-exposure prophylaxis to avoid the emergence of drug resistance. Attention should be paid to the research and development of new drugs to predict HIV mutations as accurately as possible and to develop immune antibodies to provide multiple guarantees for the cure of AIDS.

Gilbert's syndrome revisited

Gilbert's syndrome, also known as benign hyperbilirubinaemia, was described more than 100 years ago. It has usually been considered a physiological abnormality characterised by a mild elevation of the systemic level of unconjugated bilirubin, in the absence of any underlying liver or overt haemolytic disease. However, since the re-discovery of the potent antioxidant effects of bilirubin in the late 1980s, as well as multiple intracellular signalling pathways affected by bilirubin, an ever-increasing body of evidence suggests that individuals with Gilbert's syndrome may benefit from the mild hyperbilirubinaemia and are actually protected from the development of a wide variety of "diseases of civilisation" such as cardiovascular diseases, certain cancers, and autoimmune or neurodegenerative diseases. This review analyses the current state of medical knowledge given recent discoveries in this rapidly developing field, as well as their possible clinical significance, and provides a new perspective on this condition.

Molecular Factors and Pathways of Hepatotoxicity Associated with HIV/SARS-CoV-2 Protease Inhibitors

Antiviral protease inhibitors are peptidomimetic molecules that block the active catalytic center of viral proteases and, thereby, prevent the cleavage of viral polyprotein precursors into maturation. They continue to be a key class of antiviral drugs that can be used either as boosters for other classes of antivirals or as major components of current regimens in therapies for the treatment of infections with human immunodeficiency virus (HIV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, sustained/lifelong treatment with the drugs or drugs combined with other substance(s) often leads to severe hepatic side effects such as lipid abnormalities, insulin resistance, and hepatotoxicity. The underlying pathogenic mechanisms are not fully known and are under continuous investigation. This review focuses on the general as well as specific molecular mechanisms of the protease inhibitor-induced hepatotoxicity involving transporter proteins, apolipoprotein B, cytochrome P450 isozymes, insulin-receptor substrate 1, Akt/PKB signaling, lipogenic factors, UDP-glucuronosyltransferase, pregnane X receptor, hepatocyte nuclear factor 4α, reactive oxygen species, inflammatory cytokines, off-target proteases, and small GTPase Rab proteins related to ER-Golgi trafficking, organelle stress, and liver injury. Potential pharmaceutical/therapeutic solutions to antiviral drug-induced hepatic side effects are also discussed.

The physiology of bilirubin: health and disease equilibrium

Bilirubin has several physiological functions, both beneficial and harmful. In addition to reactive oxygen species-scavenging activities, bilirubin has potent immunosuppressive effects associated with long-term pathophysiological sequelae. It has been recently recognized as a hormone with endocrine actions and interconnected effects on various cellular signaling pathways. Current studies show that bilirubin also decreases adiposity and prevents metabolic and cardiovascular diseases. All in all, the physiological importance of bilirubin is only now coming to light, and strategies for increasing plasma bilirubin levels to combat chronic diseases are starting to be considered. This review discusses the beneficial effects of increasing plasma bilirubin, incorporates emerging areas of bilirubin biology, and provides key concepts to advance the field.

Predictors of subclinical atherosclerosis in HIV

BACKGROUND

Cardiovascular disease is a major cause of morbidity and mortality in people with HIV. The detection of subclinical atherosclerosis through vascular ultrasound allows us to identify patients at an increased risk of cardiovascular disease as a primary prevention strategy; this test is not routine. Our objective is to identify predictors of subclinical atherosclerosis in a population with HIV.

METHODS

People with HIV infection were selected for primary prevention and underwent carotid and femoral ultrasound to detect atheromatous plaques. Logistic regression analysis including vascular risk factors was performed to predict the presence of atherosclerosis.

RESULTS

One hundred eighty-three patients were included, 54% of whom were smokers; the mean duration of HIV infection was 9.52 years, and all patients were undergoing antiretroviral treatment. Subclinical atherosclerosis was present in 62.29% of the patients; 83.32% had plaque in the carotid territory, 57.93% in the femoral territory and 25.6% in both vascular territories. Compared to those without atherosclerosis, patients with atherosclerosis were on average 5.35 years older (53.86 vs. 48.51, p < 0.001) and had a higher prevalence of smoking (63.23% vs. 39.12%, p = 0.020) and a CD4/CD8 ratio below 0.7 (44.23% vs. 29.02%, p = 0.043). A CD4/CD8 ratio lower than 0.3 was always associated with subclinical atherosclerosis (95% confidence interval (CI): 83.9-100%). The inclusion of smoking, the CD4/CD8 ratio and age in the logistic regression analysis led to a diagnostic yield of 72% measured by the area under the receiving operator characteristic (ROC) curve (95% CI: 64-80%).

CONCLUSIONS

Tobacco use, age and a CD4/CD8 ratio below 0.7 allow prediction of the presence of subclinical atherosclerosis in primary prevention. A CD4/CD8 ratio below 0.3 was a diagnostic indicator of atherosclerosis in HIV patients undergoing primary prevention in our sample.

Low incidence of advanced neurological burden but high incidence of age-related conditions that are dementia risk factors in aging people living with HIV: a data-linkage 10-year follow-up study

Although increasing research is focusing on age-related comorbidities (ARC) among people living with HIV (PLHIV), no studies have concomitantly assessed non-HIV age-related neurological disorders (e.g., Alzheimer’s dementia). A total of 254 PLHIV and 69 HIV-negative controls completed baseline medical history and cognitive testing. ARC data were collected from medical records over the subsequent 9-10 years and included all types of strokes, all types of dementia, mild cognitive impairment, Parkinson's disease, motor neuron disease (grouped into a non-HIV age-related neurological category), cardiovascular disease, chronic kidney disease, chronic liver disease, chronic lung disease, non-AIDS cancers, osteoporosis, and diabetes. Kaplan–Meier curves assessed differences in the incident rates (per 1000 person year) of groups of ARC as defined above and combined ARC (i.e., development of any of the ARC) among younger (baseline age < 50) and older (baseline age ≥ 50) PLHIV and younger and older controls. Cox-proportional hazard models assessed the individual and interaction effects of HIV status and chronological age, in addition to a range of demographic and clinical variables including historical and baseline HIV brain involvement on the risk of developing combined ARC. Older PLHIV had a higher incidence of cardiovascular disease, osteoporosis, and combined ARC compared to other groups (p < 0.05). Incident rate of non-HIV age-related neurological disorders was 2.3 [0.93, 4.79] per 1000 person year. While this incident rate was higher in older PLHIV (5.37 [1.97, 11.92]) than older HIV-negative participants (3.58 [0.18-17.67]), this was not significant. In multivariate analyses, HIV status and chronological age, but not their interaction, and smoking were associated with higher risk of combined ARC (p < 0.05). In analyses focusing on PLHIV, older age and taking abacavir/efavirenz/atazanavir/darunavir containing antiretroviral treatments at the time of diagnosis were associated with greater ARC (p < 0.05). Non-HIV age-related neurological disorders are uncommon in older PLHIV, where the majority were < 70 years of age at the end of follow-up. However, the greater burden of ARC among older PLHIV, most of which are established dementia risk factors, warrants the establishment of commensurate prevention strategies and greater attention to neurocognitive screening.

The impact of SARS-CoV-2 treatment on the cardiovascular system: an updated review

The coronavirus disease-2019 (COVID-19) pandemic has become a major global health problem. COVID-19 is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and exhibits pulmonary and extrapulmonary effects, including cardiovascular involvement. There are several attempts to identify drugs that could treat COVID-19. Moreover, many patients infected with COVID-19 have underlying diseases, particularly cardiovascular diseases. These patients are more likely to develop severe illnesses and would require optimized treatment strategies. The current study gathered information from various databases, including relevant studies, reviews, trials, or meta-analyses until April 2022 to identify the impact of SARS-CoV-2 treatment on the cardiovascular system. Studies have shown that the prognosis of patients with underlying cardiovascular disease is worsened by COVID-19, with some COVID-19 medications interfering with the cardiovascular system. The COVID-19 treatment strategy should consider many factors and parameters to avoid medication-induced cardiac injury, mainly in elderly patients. Therefore, this article provides a synthesis of evidence on the impact of different COVID-19 medications on the cardiovascular system and related disease conditions.

The Nonlinear Relationship Between Total Bilirubin and Coronary Heart Disease: A Dose-Response Meta-Analysis

Background: Evidence suggests that the total bilirubin has a protective effect on coronary heart disease (CHD), but the dose-response relationship remains controversial, and there is no meta-analysis to assess the relationship.

Methods: As of October 1, 2021, relevant literature was selected from four databases (PubMed, Web of Science, Cochrane Library, and Embase) by using a retrieval strategy. The dose-response curve between the total bilirubin and CHD was fitted by a restricted cubic spline. Stata 12.0 was used for statistical analysis.

Results: A total of 170,209 (6,342 cases) participants from 7 prospective studies were analyzed in our meta-analysis. We calculated the pooled relative risks (RRs) and 95% CIs for the association between serum bilirubin level and risk of CHD using random-effects models. Compared with the first quantile, the bilirubin level in the third quantile had a protective effect on the risk of CHD (RR, 0.90; 95% CI, 0.82–0.99). The restricted cubic spline functions depicted a U-type curve relationship between bilirubin (3.42–49 μmol/L) and CHD (P_linear < 0.001). When the bilirubin level was in the range of 3.42–13μmol/L, the protective effect of bilirubin on CHD was enhanced with increasing bilirubin levels. When the bilirubin level exceeded 13μmol/L, the protective effect of bilirubin weakened, and a dangerous effect gradually appeared with further increases in bilirubin levels.

Conclusions: Compared with a low bilirubin level, a high bilirubin level has a protective effect on the risk of CHD, and there was a U-shaped dose-response relationship between them.

Effectiveness and Safety of Atazanavir Use for the Treatment of Children and Adolescents Living With HIV: A Systematic Review

BACKGROUND

Atazanavir/ritonavir is recommended as a preferred second-line antiretroviral regimen in children older than 3 months, alternatively to lopinavir/ritonavir. We performed a systematic review to assess safety and effectiveness of atazanavir use in children and adolescents.

METHODS

We searched observational studies and clinical trials on Web of Science, Embase and Cochrane CENTRAL database between 2009/01/01 and 2020/10/01; as well as grey literature. We extracted safety (adverse events, grade 3 or 4 adverse events, treatment discontinuation) and effectiveness (CD4 cell counts and HIV viral load) outcomes. We estimated weighted summary pooled incidence with corresponding 95% confidence intervals.

RESULTS

Out of the 1,085 records screened, we included five studies (one comparative cohort, three single phase 2-3 trial arms, one retrospective cohort) reporting 975 children and adolescents, of whom 56% (544) received atazanavir. Three studies reported all-cause treatment discontinuation rates, yielding a pooled incidence of 19% [15-22] at 12 months. The comparative cohort compared atazanavir to darunavir, with few grade 3-4 adverse events, except transient hyperbilirubinemia, occurring in half (92/188) of the atazanavir patients. No death occurred (two studies reporting). Four studies described increased CD4 cell counts and decreased HIV viral load at 6 or 12 months.

CONCLUSION

Few safety and effectiveness data were available for children and adolescents exposed to atazanavir. Transient grade 3-4 hyperbilirubinemia was the main adverse outcome reported. Immune and viral responses were descriptive. The use of atazanavir/ritonavir in children and adolescents needs further investigation, but remains a suitable option for a preferred second-line antiretroviral regimen.

PROSPERO NUMBER

CRD42022309230.

Sex Differences in Non-AIDS Comorbidities Among People With Human Immunodeficiency Virus

Women are grossly underrepresented in human immunodeficiency virus (HIV) clinical and translational research. This is concerning given that people with HIV (PWH) are living longer, and thus accumulating aging-related non-AIDS comorbidities (NACMs); emerging evidence suggests that women are at higher risk of NACM development and progression compared with men. It is widely recognized that women vs men have greater immune activation in response to many viruses, including HIV-1; this likely influences sex-differential NACM development related to differences in HIV-associated chronic inflammation. Furthermore, many sociobehavioral factors that contribute to aging-related NACMs are known to differ by sex. The objectives of this review were to (1) synthesize sex-stratified data on 4 NACMs among PWH: bone disease, cardiovascular disease, metabolic dysfunction, and neurocognitive impairment; (2) evaluate the characteristics of key studies assessing sex differences in NACMs; and (3) introduce potential biological and psychosocial mechanisms contributing to emerging trends in sex-differential NACM risk and outcomes among PWH.

Bilirubin deficiency renders mice susceptible to hepatic steatosis in the absence of insulin resistance

Background & aims

Plasma concentrations of bilirubin, a product of heme catabolism formed by biliverdin reductase A (BVRA), inversely associate with the risk of metabolic diseases including hepatic steatosis and diabetes mellitus in humans. Bilirubin has antioxidant and anti-inflammatory activities and may also regulate insulin signaling and peroxisome proliferator-activated receptor alpha (PPARα) activity. However, a causal link between bilirubin and metabolic diseases remains to be established. Here, we used the global Bvra gene knockout (Bvra^–/–) mouse as a model of deficiency in bilirubin to assess its role in metabolic diseases.

Approach & results

We fed mice fat-rich diets to induce hepatic steatosis and insulin resistance. Bile pigments were measured by LC-MS/MS, and hepatic lipids by LC-MS/MS (non-targeted lipidomics), HPLC-UV and Oil-Red-O staining. Oxidative stress was evaluated measuring F₂-isoprostanes by GC-MS. Glucose metabolism and insulin sensitivity were verified by glucose and insulin tolerance tests, ex vivo and in vivo glucose uptake, and Western blotting for insulin signaling. Compared with wild type littermates, Bvra^–/– mice contained negligible bilirubin in plasma and liver, and they had comparable glucose metabolism and insulin sensitivity. However, Bvra^–/– mice exhibited an inflamed and fatty liver phenotype, accompanied by hepatic accumulation of oxidized triacylglycerols and F₂-isoprostanes, in association with depletion of α-tocopherol. α-Tocopherol supplementation reversed the hepatic phenotype and observed biochemical changes in Bvra^–/– mice.

Conclusions

Our data suggests that BVRA deficiency renders mice susceptible to oxidative stress-induced hepatic steatosis in the absence of insulin resistance.

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Low plasma levels of bilirubin associate with increased metabolic disease risk.

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A direct link between bilirubin and metabolic disease remains to be established.

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Global BVRA deficiency causes global bilirubin deficiency and a fatty, inflamed liver.

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This hepatic phenotype is linked to decreased vitamin E and increased lipid oxidation.

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Vitamin E supplements restore normal liver phenotype in BVRA deficiency.

Cardiovascular risks associated with protease inhibitors for the treatment of HIV

Introduction: Cumulative use of some first-generation protease inhibitors has been associated with higher rates of dyslipidemia and increased risk of cardiovascular disease. The protease inhibitors most commonly in use are atazanavir and darunavir, which have fewer detrimental lipid effects and greater tolerability. This paper aims to review the evidence of a potential association of these contemporary protease inhibitors with the risk of ischemic CVD and atherosclerotic markers.Areas covered: We searched for publications of randomized trials and observational studies on PubMed from 1 January 2000 onwards, using search terms including: protease inhibitors; darunavir; atazanavir; cardiovascular disease; cardiovascular events; dyslipidemia; mortality; carotid intima media thickness; arterial elasticity; arterial stiffness and drug discontinuation. Ongoing studies registered on clinicaltrials.gov as well as conference abstracts from major HIV conferences from 2015-2020 were also searched.Expert opinion: Atazanavir and darunavir are no longer part of first-line HIV treatment, but continue to be recommended as alternative first line, second- and third-line regimens, as part of two drug regimens, and darunavir is used as salvage therapy. Although these drugs will likely remain in use globally for several years to come, baseline CVD risk should be considered when considering their use, especially as the population with HIV ages.

Association Between Atazanavir-Induced Hyperbilirubinemia and Cardiovascular Disease in Patients Infected with HIV

BACKGROUND:

Serum bilirubin is inversely associated with cardiovascular risk. Atazanavir, an HIV protease inhibitor that competitively inhibits bilirubin conjugation, provides a unique opportunity to examine whether selectively increasing bilirubin is cardioprotective. We sought to determine whether patients receiving atazanavir manifest a reduced risk of cardiovascular disease compared with those receiving darunavir, an HIV protease inhibitor that does not increase serum bilirubin.

METHODS AND RESULTS:

This was a retrospective cohort study of 1020 patients with HIV. The main outcome was time to myocardial infarction or ischemic stroke. Mean follow‐up was 6.6±3.4 years, with 516 receiving atazanavir and 504 darunavir. Atazanavir patients exhibited significantly higher serum total bilirubin (1.7 versus 0.4 mg/dL; P<0.001) and longer mean time to ischemic event (10.2 versus 9.4 years; P<0.001). On Cox regression, atazanavir treatment (hazard ratio [HR], 0.38; 95% CI, 0.21–0.71; P=0.002) and serum bilirubin (HR, 0.60; 95% CI, 0.41–0.89; P=0.011) were independently associated with a lower risk of an ischemic event. Notably, when atazanavir and bilirubin were included together in the Cox regression model, atazanavir lost significance (HR, 0.55; 95% CI, 0.24–1.29; P=0.169) consistent with bilirubin being an intermediate variable on the causal pathway between atazanavir and its effect on cardiovascular disease. Patients on atazanavir also had a significantly lower risk of developing new cardiovascular disease (HR, 0.53; 95% CI, 0.33–0.86; P=0.010) and longer mean time to death (12.2 versus 10.8 years; P<0.001).

CONCLUSIONS:

Patients with HIV on atazanavir manifest a decreased risk of cardiovascular disease when compared with those on darunavir, an effect that appears to be mediated by serum bilirubin.