Pharmacogenetics of the lipodystrophy syndrome associated with HIV infection and combination antiretroviral therapy

miRNA Expression Profiling in Subcutaneous Adipose Tissue of Monozygotic Twins Discordant for HIV Infection: Validation of Differentially Expressed miRNA and Bioinformatic Analysis

Combined AntiRetroviral Treatments (cARTs) used for HIV infection may result in varied metabolic complications, which in some cases, may be related to patient genetic factors, particularly microRNAs. The use of monozygotic twins, differing only for HIV infection, presents a unique and powerful model for the controlled analysis of potential alterations of miRNAs regulation consequent to cART treatment. Profiling of 2578 mature miRNA in the subcutaneous (SC) adipose tissue and plasma of monozygotic twins was investigated by the GeneChip® miRNA 4.1 array. Real-time PCR and ddPCR experiments were performed in order to validate differentially expressed miRNAs. Target genes of deregulated miRNAs were predicted by the miRDB database (prediction score > 70) and enrichment analysis was carried out with g:Profiler. Processes in SC adipose tissue most greatly affected by miRNA up-regulation included (i) macromolecular metabolic processes, (ii) regulation of neurogenesis, and (iii) protein phosphorylation. Furthermore, KEGG analysis revealed miRNA up-regulation involvement in (i) insulin signaling pathways, (ii) neurotrophin signaling pathways, and (iii) pancreatic cancer. By contrast, miRNA up-regulation in plasma was involved in (i) melanoma, (ii) p53 signaling pathways, and (iii) focal adhesion. Our findings suggest a mechanism that may increase the predisposition of HIV+ patients to insulin resistance and cancer.

Can antiretroviral therapy be tailored to each human immunodeficiency virus-infected individual? Role of pharmacogenomics

Pharmacogenetics refers to the effect of single nucleotide polymorphisms (SNPs) within human genes on drug therapy outcome. Its study might help clinicians to increase the efficacy of antiretroviral drugs by improving their pharmacokinetics and pharmacodynamics and by decreasing their side effects. HLAB*5701 genotyping to avoid the abacavir-associated hypersensitivity reaction (HSR) is a cost-effective diagnostic tool, with a 100% of negative predictive value, and, therefore, it has been included in the guidelines for treatment of human immunodeficiency virus (HIV) infection. HALDRB*0101 associates with nevirapine-induced HSR. CYP2B6 SNPs modify efavirenz plasma levels and their genotyping help decreasing its central nervous system, hepatic and HSR toxicities. Cytokines SNPs might influence the development of drug-associated lipodystrophy. APOA5, APOB, APOC3 and APOE SNPs modify lipids plasma levels and might influence the coronary artery disease risk of HIV-infected individuals receiving antiretroviral therapy. UGT1A1*28 and ABCB1 (MDR1) 3435C > T SNPs modify atazanavir plasma levels and enhance hyperbilirubinemia. Much more effort needs to be still devoted to complete large prospective studies with multiple SNPs genotyping in order to reveal more clues about the role played by host genetics in antiretroviral drug efficacy and toxicity.

Contribution of genetic background and antiretroviral therapy to body fat changes in antiretroviral-naive HIV-infected adults

OBJECTIVES

To evaluate the association of host genetics with changes in limb or trunk fat in a group of antiretroviral therapy (ART)-naive HIV-infected patients prospectively followed up according to the initiation and the type of ART.

METHODS

Fifty single nucleotide polymorphisms (SNPs) in 26 genes, associated with obesity, insulin resistance, lipid metabolism or lipodystrophy in previously published genetic studies, were assessed in ART-naive HIV-infected Caucasian patients divided into three groups: 24 (27%) did not start ART, 29 (32.6%) received zidovudine or stavudine and 36 (40.4%) received neither zidovudine nor stavudine in their initial regimen. Patients underwent body fat measurements (using dual-energy X-ray absorptiometry) at baseline and Month 12. A multivariate model using backward stepwise elimination was used to assess the influence of SNPs and baseline levels of non-genetic covariates on changes in limb or trunk fat.

RESULTS

The baseline characteristics were: 73% men, 17% coinfected with hepatitis C virus and/or hepatitis B virus, median age 37 years, median CD4+ T cell count 228/mm(3), median HIV-RNA 5.2 log copies/mL, median plasma glucose 85 mg/dL, median plasma insulin 9.1 IU/mL, median limb fat 5.6 kg and median trunk fat 7.0 kg. There were no baseline differences among the three groups except for the CD4+ T cell count. The decrease in limb fat was greater in the no-ART group relative to the other two groups (P < 0.05). The multivariate model showed associations of rs1801278 in IRS1 (P = 0.029, OR = 0.13), baseline viral load (P = 0.006; OR = 4.453) and baseline glucose levels (P = 0.008, OR = 0.926) with loss of limb fat, and rs2228671 in LDLR (P = 0.012, OR = 0.108), rs405509 in APOE (P = 0.048, OR = 0.205), baseline viral load (P = 0.005, OR = 0.186) and baseline CD4+ T cell count (P = 0.01, OR = 1.008) with gain of trunk fat.

CONCLUSIONS

Specific polymorphisms in IRS1 (limb fat loss) and LDLR and APOE (trunk fat gain) were identified as independent markers of fat changes irrespective of the initiation of ART and the type of ART and deserve further validation.

Adipokines, hormones related to body composition, and insulin resistance in HIV fat redistribution syndrome

Background

Lipodystrophies are characterized by adipose tissue redistribution, insulin resistance (IR) and metabolic complications. Adipokines and hormones related to body composition may play an important role linking these alterations. Our aim was to evaluate adipocyte-derived hormones (adiponectin, leptin, resistin, TNF-α, PAI-1) and ghrelin plasma levels and their relationship with IR in HIV-infected patients according to the presence of lipodystrophy and fat redistribution.

Methods

Anthropometric and metabolic parameters, HOMA-IR, body composition by DXA and CT, and adipokines were evaluated in 217 HIV-infected patients on cART and 74 controls. Fat mass ratio defined lipodystrophy (L-FMR) was defined as the ratio of the percentage of the trunk fat mass to the percentage of the lower limb fat mass by DXA. Patient’s fat redistribution was classified into 4 different groups according the presence or absence of either clinical lipoatrophy or abdominal prominence: no lipodystrophy, isolated central fat accumulation (ICFA), isolated lipoatrophy and mixed forms (MXF). The associations between adipokines levels and anthropometric, metabolic and body composition were estimated by Spearman correlation.

Results

Leptin levels were lower in patients with FMR-L and isolated lipoatrophy, and higher in those with ICFA and MXF. Positive correlations were found between leptin and body fat (total, trunk, leg, arm fat evaluated by DXA, and total, visceral (VAT), subcutaneous adipose tissue (SAT), and VAT/SAT ratio evaluated by CT) regardless of FMR-L, and with HOMA-IR only in patients with FMR-L. Adiponectin correlated negatively with VAT, and its mean levels were lower in patients with ICFA and higher in those with no lipodystrophy. Resistin was not correlated with adipose tissue but positively correlated with HOMA-IR in FMR-L patients. PAI-1 levels were higher in MXF-patients and their levels were positively correlated with VAT in those with FMR-L. Ghrelin was higher in HIV-infected patients than controls despite BMI-matching.

Conclusion

The overall body fat reduction in HIV lipoatrophy was associated with low leptin plasma levels, and visceral fat accumulation was mainly associated with decreased plasma levels of adiponectin.

Involvement of the LPS-LPB-CD14-MD2-TLR4 inflammation pathway in HIV-1/HAART-associated lipodystrophy syndrome (HALS)

OBJECTIVES

A relationship between obesity and intestinal bacterial translocation has been reported. Very little information is available with respect to the involvement of the bacterial translocation mechanistic pathway in HIV-1/highly active antiretroviral therapy (HAART)-associated lipodystrophy syndrome (HALS). We determined whether lipopolysaccharide (LPS)-binding protein (LBP), cluster of differentiation 14 (CD14), myeloid differentiation protein 2 (MD2) and toll-like receptor 4 (TLR4) single-nucleotide polymorphisms and LPS, LBP and soluble CD14 (sCD14) plasma levels are involved in HALS.

PATIENTS AND METHODS

This cross-sectional multicentre study involved 558 treated HIV-1-infected patients, 240 with overt HALS and 318 without HALS. Anthropometric, clinical, immunovirological and metabolic variables were determined. Polymorphisms were assessed by genotyping. Plasma levels were determined by ELISA in 163 patients (81 with HALS and 82 without HALS) whose stored plasma samples were available. Student's t-test, one-way ANOVA, two-way repeated measures ANOVA, the χ(2) test and Pearson and Spearman correlation analyses were carried out for statistical analysis.

RESULTS

LBP rs2232582 T→C polymorphism was significantly associated with HALS (P = 0.01 and P = 0.048 for genotype and allele analyses, respectively). Plasma levels of LPS (P = 0.009) and LBP (P < 0.001) were significantly higher and sCD14 significantly lower (P < 0.001) in patients with HALS compared with subjects without HALS. LPS levels were independently predicted by triglycerides (P < 0.001) and hepatitis C virus (P = 0.038), LBP levels by HALS (P < 0.001) and sCD14 levels by age (P = 0.008), current HIV-1 viral load (P = 0.001) and protease inhibitor use (P = 0.018).

CONCLUSIONS

HALS is associated with LBP polymorphism and with higher bacterial translocation.

Lipodystrophy and reversal of facial lipoatrophy in perinatally HIV-infected children and adolescents after discontinuation of stavudine

Lipodystrophy (LD) was evaluated in 205 children receiving antiretroviral therapy by a single investigator: 51 (24.9%) had LD; 46 peripheral lipoatrophy, three central lipohypertrophy and two combined type. All cases of peripheral and combined LD also had facial lipoatrophy. Serial photographs were provided by the families to confirm the severity of facial lipoatrophy. Forty-six (95.8%) children with peripheral or combined LD, and 75 (48.7%) without LD were exposed to stavudine (d4T) for a median duration of 45.9 versus 26.4 months (P = 0.005). In multivariate analysis, exposure to d4T for more than three months was the only factor associated with peripheral or combined LD (P < 0.001). Noticeable improvement of facial lipoatrophy was found in 11/48 (22.9%) children after a mean duration of 45.6 months following d4T discontinuation, mostly occurring during early adolescence.