Adiponectin and the steatosis marker Chi3L1 decrease following switch to raltegravir compared to continued PI/NNRTI-based antiretroviral therapy

Relationship between weight gain and insulin resistance in people living with HIV switching to integrase strand transfer inhibitors-based regimens

OBJECTIVE

The primary objective was to explore weight and BMI changes in people with HIV (PWH) undergoing integrase strand transfer inhibitors (INSTI)-based regimens (vs. non-INSTI) in a large cohort and in the subsets of individuals without diabetes and insulin resistance (IR) at the time of switch to INSTI. The secondary objective was to identify risk factors for IR and cut-off of weight or BMI increase associated with IR in PWH switching to INSTI.

DESIGN

A longitudinal matched-cohort study including PWH attending Modena HIV Metabolic Clinic, Italy.

METHODS

PWH were divided into two groups: non-INSTI and INSTI-switch. The effect of switching to INSTI on weight and BMI change was tested through a linear mixed model. A mediation analysis explored the mediation effect of weight and BMI change in the association between the switch to INSTI and IR.

RESULTS

We analyzed 2437 PWH (1025 INSTI-switch, 1412 non-INSTI), in 54 826 weight assessments. Trends for weight increase were significantly higher in early-INSTI-switch (vs. early-non-INSTI), but no difference was observed in the late period after the switch. In the subset of 634 PWH without IR, switching to INSTI (vs. non-INSTI) was associated with a lower risk of IR (hazard ratio = 0.70, 95% confidence interval: 0.51, 0.98). A weight increase by 1% reduced the total protective effect of INSTI by 21.1% over 1 year of follow-up, which identifies a 5% weight increase as a clinically meaningful weight gain definition.

CONCLUSION

A cut-off of 5% weight gain from the time of INSTI-switch is associated with IR, which may be a clinically meaningful endpoint that could be used in clinical and research settings.

Contribution of Adipose Tissue to the Chronic Immune Activation and Inflammation Associated With HIV Infection and Its Treatment

White adipose tissue (AT) contributes significantly to inflammation – especially in the context of obesity. Several of AT’s intrinsic features favor its key role in local and systemic inflammation: (i) large distribution throughout the body, (ii) major endocrine activity, and (iii) presence of metabolic and immune cells in close proximity. In obesity, the concomitant pro-inflammatory signals produced by immune cells, adipocytes and adipose stem cells help to drive local inflammation in a vicious circle. Although the secretion of adipokines by AT is a prime contributor to systemic inflammation, the lipotoxicity associated with AT dysfunction might also be involved and could affect distant organs. In HIV-infected patients, the AT is targeted by both HIV infection and antiretroviral therapy (ART). During the primary phase of infection, the virus targets AT directly (by infecting AT CD4 T cells) and indirectly (via viral protein release, inflammatory signals, and gut disruption). The initiation of ART drastically changes the picture: ART reduces viral load, restores (at least partially) the CD4 T cell count, and dampens inflammatory processes on the whole-body level but also within the AT. However, ART induces AT dysfunction and metabolic side effects, which are highly dependent on the individual molecules and the combination used. First generation thymidine reverse transcriptase inhibitors predominantly target mitochondrial DNA and induce oxidative stress and adipocyte death. Protease inhibitors predominantly affect metabolic pathways (affecting adipogenesis and adipocyte homeostasis) resulting in insulin resistance. Recently marketed integrase strand transfer inhibitors induce both adipocyte adipogenesis, hypertrophy and fibrosis. It is challenging to distinguish between the respective effects of viral persistence, persistent immune defects and ART toxicity on the inflammatory profile present in ART-controlled HIV-infected patients. The host metabolic status, the size of the pre-established viral reservoir, the quality of the immune restoration, and the natural ageing with associated comorbidities may mitigate and/or reinforce the contribution of antiretrovirals (ARVs) toxicity to the development of low-grade inflammation in HIV-infected patients. Protecting AT functions appears highly relevant in ART-controlled HIV-infected patients. It requires lifestyle habits improvement in the absence of effective anti-inflammatory treatment. Besides, reducing ART toxicities remains a crucial therapeutic goal.

The Integrase Inhibitors Dolutegravir and Raltegravir Exert Proadipogenic and Profibrotic Effects and Induce Insulin Resistance in Human/Simian Adipose Tissue and Human Adipocytes

BACKGROUND

Although some integrase strand transfer inhibitors (INSTIs) promote peripheral and central adipose tissue/weight gain in people with human immunodeficiency virus (PHIV), the underlying mechanism has not been identified. Here, we used human and simian models to assess the impact of INSTIs on adipose tissue phenotype and function.

METHODS

Adipocyte size and fibrosis were determined in biopsies of subcutaneous and visceral adipose tissue (SCAT and VAT, respectively) from 14 noninfected macaques and 19 PHIV treated or not treated with an INSTI. Fibrosis, adipogenesis, oxidative stress, mitochondrial function, and insulin sensitivity were assessed in human proliferating or adipocyte-differentiated adipose stem cells after long-term exposure to dolutegravir or raltegravir.

RESULTS

We observed elevated fibrosis, adipocyte size, and adipogenic marker expression in SCAT and VAT from INSTI-treated noninfected macaques. Adiponectin expression was low in SCAT. Accordingly, SCAT and VAT samples from INSTI-exposed patients displayed higher levels of fibrosis than those from nonexposed patients. In vitro, dolutegravir and, to a lesser extent, raltegravir were associated with greater extracellular matrix production and lipid accumulation in adipose stem cells and/or adipocytes as observed in vivo. Despite the INSTIs' proadipogenic and prolipogenic effects, these drugs promoted oxidative stress, mitochondrial dysfunction, and insulin resistance.

CONCLUSIONS

Dolutegravir and raltegravir can directly impact adipocytes and adipose tissue. These INSTIs induced adipogenesis, lipogenesis, oxidative stress, fibrosis, and insulin resistance. The present study is the first to shed light on the fat modifications observed in INSTI-treated PHIV.

HIV antiretroviral drugs, dolutegravir, maraviroc and ritonavir-boosted atazanavir use different pathways to affect inflammation, senescence and insulin sensitivity in human coronary endothelial cells

OBJECTIVES

Aging HIV-infected antiretroviral-treatment (ART)-controlled patients often present cardiovascular and metabolic comorbidities. Thus, it is mandatory that life-long used ART has no cardiometabolic toxicity. Protease inhibitors have been associated with cardiometabolic risk, integrase-strand-transfer-inhibitors (INSTI) with weight gain and the CCR5 inhibitor maraviroc with improved vascular function. We have previously reported that the INSTI dolutegravir and maraviroc improved, and ritonavir-boosted atazanavir(atazanavir/r) worsened, inflammation and senescence in human coronary artery endothelial cells (HCAEC)s from adult controls. Here, we analyzed the pathways involved in the drugs' effects on inflammation, senescence and also insulin resistance.

METHODS

We analyzed the involvement of the anti-inflammatory SIRT-1 pathway in HCAECs. Then, we performed a transcriptomic analysis of the effect of dolutegravir, maraviroc and atazanavir/r and used siRNA-silencing to address ubiquitin-specific-peptidase-18 (USP18) involvement into ART effects.

RESULTS

Dolutegravir reduced inflammation by decreasing NFκB activation and IL-6/IL-8/sICAM-1/sVCAM-1 secretion, as did maraviroc with a milder effect. However, when SIRT-1 was inhibited by splitomicin, the drugs anti-inflammatory effects were maintained, indicating that they were SIRT-1-independant. From the transcriptomic analysis we selected USP18, previously shown to decrease inflammation and insulin-resistance. USP18-silencing enhanced basal inflammation and senescence. Maraviroc still inhibited NFκB activation, cytokine/adhesion molecules secretion and senescence but the effects of dolutegravir and atazanavir/r were lost, suggesting that they involved USP18. Otherwise, in HCAECs, dolutegravir improved and atazanavir/r worsened insulin resistance while maraviroc had no effect. In USP18-silenced cells, basal insulin resistance was increased, but dolutegravir and atazanavir/r kept their effect on insulin sensitivity, indicating that USP18 was dispensable.

CONCLUSION

USP18 reduced basal inflammation, senescence and insulin resistance in coronary endothelial cells. Dolutegravir and atazanavir/r, but not maraviroc, exerted opposite effects on inflammation and senescence that involved USP18. Otherwise, dolutegravir improved and atazanavir/r worsened insulin resistance independently of USP18. Thus, in endothelial cells, dolutegravir and atazanavir/r oppositely affected pathways leading to inflammation, senescence and insulin resistance.

Improvement in liver steatosis after the switch from a ritonavir-boosted protease inhibitor to raltegravir in HIV-infected patients with non-alcoholic fatty liver disease

Background: The ritonavir-boosted protease inhibitor (PI/r) use has been associated with several metabolic abnormalities, and the non-alcoholic fatty liver disease (NAFLD) is becoming a very frequent comorbidity among HIV-infected patients. Methods: We performed an observational, prospective study of HIV-infected patients with NAFLD, receiving one PI/r plus two nucleoside analogues, who switched from the PI/r to raltegravir or were treated only with lifestyle modification, maintaining antiretroviral therapy unchanged. Changes in liver steatosis after 12 months were evaluated by transient elastography and measurement of controlled attenuation parameter (CAP). Results: As a whole, 61 patients (46 males; median age, 55.4 years) were enrolled, and 32 of them have been switched from PI/r to raltegravir. At baseline, median CAP was 259 dB/m, 28 (45.9%) subjects had a moderate-to-severe hepatic steatosis (CAP ≥260 dB/m), and 19 patients (31.1%) had elevated aminotransferases. Type-2 diabetes mellitus was present in 5 persons, and chronic HCV coinfection in 4. At month 12, the median decrease in CAP values was -27 dB/m in patients switched to raltegravir and -11 dB/m in those with unchanged cART (p = .021). The number of patients with CAP ≥260 dB/m decreased from 16 to 6 (-62.5%) in patients switched to raltegravir and from 12 to 8 (-33.3%) in the other group (p = .037). Conclusion: After 12 months, HIV-infected patients with NAFLD switching from a PI/r to raltegravir showed a significantly greater decrease in the hepatic steatosis degreee in comparison with those with unchanged cART and treated only with lifestyle modification.