"Buffalo hump" in HIV-1 infection

Human immunodeficiency virus (HIV)-1 viral protein R suppresses transcriptional activity of peroxisome proliferator-activated receptor {gamma} and inhibits adipocyte differentiation: implications for HIV-associated lipodystrophy

HIV-1-infected patients may develop lipodystrophy and insulin resistance. We investigated the effect of the HIV-1 accessory protein viral protein R (Vpr) on the activity of the peroxisome proliferator-activating receptor-gamma (PPARgamma), a key regulator of adipocyte differentiation and tissue insulin sensitivity. We studied expression of PPARgamma-responsive reporter genes in 3T3-L1 mouse adipocytes. We investigated Vpr interaction with the PPAR/retinoid X receptor (RXR)-binding site of the c-Cbl-associating protein (CAP) gene using the chromatin immunoprecipitation assay as well as the interaction of Vpr and PPARgamma using coimmunoprecipitation. Finally, we studied the ability of exogenous Vpr protein to enter cultured adipocytes and retard differentiation. We found that Vpr suppressed PPARgamma-induced transactivation in both undifferentiated and differentiated 3T3-L1 cells. Transcriptional suppression by Vpr required an intact LXXLL coactivator motif. Vpr suppressed mRNA expression of PPARgamma-responsive genes in undifferentiated 3T3-L1 cells and associated with the PPAR/RXR-binding site located in the promoter region of the CAP gene. Vpr interacted with the ligand-binding domain of PPARgamma in an agonist-dependent fashion in vitro. Vpr delivered either by an expression plasmid or as protein added to media suppressed PPARgamma agonist-induced adipocyte differentiation, assessed as lipid accumulation and mRNA expression of the adipocyte differentiation marker adipocyte P2 in 3T3-L1 cells. In conclusion, circulating Vpr or, alternatively, Vpr produced as a consequence of direct infection of adipocytes could suppress in vivo differentiation of preadipocytes by acting as a corepressor of PPARgamma-mediated gene transcription. Vpr may alter sensitivity to insulin and thereby contribute to the development of lipodystrophy and insulin resistance observed in HIV-1-infected patients.

Appearance-related side effects of HIV-1 treatment

In the early years of the AIDS epidemic, HIV infection was associated with visible signs and symptoms, adding to the stigma associated with the disease. Physical manifestations associated with HIV infection included muscle wasting, lymphadenopathy, Kaposi's sarcoma, candidiasis, molluscum contagiosum, and hairy leukoplakia. With the advent of antiretroviral therapy, particularly the introduction of highly active antiretroviral therapy in 1996, many of these outward manifestations of the disease became rare. Ironically, however, the treatments used to control HIV infection (and its visible markers) have themselves been associated with appearance-related side effects. Patients may develop changes in fat distribution, rashes, skin hyperpigmentation, or paronychia. These effects not only have cosmetic and psychological consequences but also may decrease adherence to therapy, potentially causing regimen failure and drug resistance. Newer antiretroviral agents offer improved potency, more convenient dosing, and more treatment options with the potential for fewer side effects and drug interactions, which should foster optimal adherence by the patient. However, these newer drugs are also associated with appearance-related side effects, which must be considered in the selection of treatment regimens. This paper reviews the appearance-related side effects associated with classes of antiretroviral drugs as well as individual agents, including the newer antiretrovirals.

Hyperlipidaemia in patients with HIV-1 infection receiving highly active antiretroviral therapy: epidemiology, pathogenesis, clinical course and management

A wide range of abnormalities of lipid metabolism have been recently described in HIV-infected patients receiving a protease inhibitor (PI)-based highly active antiretroviral therapy, including hypertriglyceridaemia and hypercholesterolaemia. The increase of plasma lipid concentrations may involve up to 70-80% of HIV-positive subjects treated with a PI-containing regimen and are frequently (but not always) associated with the fat redistribution or the lipodystrophy syndrome. Multiple pathogenetic mechanisms by which antiretroviral agents lead to dyslipidaemia have been hypothesized, but they are still controversial. The potential clinicopathological consequences of HIV-associated hyperlipidaemia are not completely known, but several anecdotal observations report an increased risk of premature coronary artery diseases in young HIV-positive individuals receiving PIs, besides peripheral atherosclerosis and acute pancreatitis. A limited-to-significant improvement of increased triglyceride and cholesterol plasma levels was described in patients who replaced PIs with nevirapine, efavirenz or abacavir, but the risks of long-term toxicity and virological relapse of this treatment switching are not completely defined. A hypolipidaemic diet and regular physical exercise may act favorably on dyslipidaemia, but pharmacological therapy becomes necessary when hyperlipidaemia is severe or persists for a long time. The choice of hypolipidaemic drugs is problematic because of potential pharmacological interactions with antiretroviral compounds and other antimicrobial agents, associated with an increased risk of toxicity and intolerance. Statins are considered the first-line therapy for the PI-related hypercholesterolaemia, while fibrates are the cornerstone of drug therapy when predominant hypertriglyceridaemia is of concern.

Cutaneous manifestations of antiretroviral therapy

The pandemic created by HIV, a retrovirus, has stimulated increased research in viral diseases and has generated greater interest in the development of antiretroviral medications. These new medications are presently divided into 3 categories: protease inhibitors (PIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), and nucleoside reverse transcriptase inhibitors (NRTIs). These antiretroviral agents carry their own risk for causing adverse reactions, as well as drug interactions. The most recently approved class of antiretrovirals, PIs have been associated with lipodystrophy syndrome, hypersensitivity reactions, urticaria, morbilliform eruptions, and a large number of drug interactions. NNRTIs have resulted in various cutaneous eruptions, as well as a hypersensitivity syndrome. NRTIs have resulted in alterations of the nails, nail and mucocutaneous pigmentation, hair changes, vasculitis, and morbilliform eruptions. This article focuses on the cutaneous manifestations of antiretroviral therapy to help dermatologists recognize them.

Disorders of lipid metabolism in patients with HIV disease treated with antiretroviral agents: frequency, relationship with administered drugs, and role of hypolipidaemic therapy with bezafibrate

OBJECTIVES

To assess the correlation between antiretroviral treatment and dyslipidaemia in HIV-infected patients, and the role of bezafibrate as a lipid-lowering agent.

METHODS

We retrospectively compared serum lipid levels of five groups of 40 patients, each of them treated with either saquinavir hard gel, indinavir, or ritonavir (associated with two nucleoside analogues), or dual nucleoside reverse transcriptase inhibitors (NRTI) with or without a non-nucleoside reverse transcriptase inhibitor (NNRTI), or not treated with antiretrovirals, randomly selected from nearly 1000 HIV-infected patients followed-up for >or= 12 months, while on the relevant therapy. Hypertriglyceridaemia was defined by triglyceride levels >or= 172 mg/dl, and hypercholesterolaemia by cholesterol levels >or= 200 mg/dl. All patients with triglyceridaemia > 300 mg/dl and cholesterolaemia > 220 mg/dl for at least 6 months, and unresponsive to a >or= 3-month diet, started bezafibrate (400 mg/day), and were prospectively followed-up at a <or= 3-month interval, evaluating both efficacy and tolerability of the hypolipidaemic treatment, provided that they did not change their protease inhibitor treatment for reasons other than metabolic abnormalities.

RESULTS

Hypertrygliceridaemia occurred in 75 patients out of 200 (37.5%), but was significantly more frequent and severe with ritonavir vs. indinavir (P<0.001), and in subjects given indinavir vs. all remaining patients (either treated or not) (P<0.001), while isolated saquinavir use was associated with higher tri glyceride levels than NRTI-NNRTI treatment alone, or no antiretroviral therapy (P<0.03). Hypercholesterolaemia was found in 27 subjects (13.5%), and a significantly higher frequency and severity was shown in patients treated with indinavir and ritonavir vs. saquinavir, NRTI-NNRTI, and no anti-HIV therapy (P<0.05 to P<0.001). No appreciable difference was found between patients undergoing NRTI-NNRTI and untreated controls, for all evaluated variables. Bezafibrate was administered once daily for 6-18 months to 49 patients with elevated and diet-resistant hyperlipidaemia due to ritonavir or indinavir (27 and 22 subjects, respectively), and reduced triglyceride and cholesterol levels by 35% and 25%, respectively over 6 months, without differences between the underlying protease inhibitor regimen. Thirty-three patients (67.3%) reached a normal triglyceridaemia after 6-9 months, and normal cholesterol levels were obtained in all subjects. Bezafibrate proved safe and well tolerated.

CONCLUSIONS

Careful monitoring of the serum lipid profile is needed during antiretroviral therapy, including protease inhibitors, to identify the need for a diet and/or an hypolipidaemic treatment, and to prevent clinical sequelae related to long-term dyslipidaemia. Specific guidelines for the management of disorders of lipid metabolism in HIV-infected patients are needed.

Saquinavir Soft Gelatin Capsule

The HIV-1 protease inhibitor (PI) saquinavir is available as a soft gelatin capsule (SGC) formulation. At the recommended dosage of saquinavir SGC (1200mg 3 times daily), this formulation provides around 8-fold greater exposure than the established hard gelatin capsule (HGC) formulation at the recommended dosage of 600mg 3 times daily. As with the HGC formulation, the most common adverse events seen with saquinavir SGC are gastrointestinal symptoms (e.g. diarrhoea, abdominal discomfort and nausea). Some of these may occur with a slightly higher frequency with the SGC than with the HGC formulation. Saquinavir SGC has only a minimal effect on nonfasting serum lipid and cholesterol levels. Like other PIs, saquinavir is metabolised by the cytochrome P450 (CYP) 3A4 isoenzyme and is susceptible to interactions with inducers (e.g. rifabutin and rifampicin) and inhibitors (e.g. clarithromycin and ketoconazole) of this enzyme. Ritonavir, nelfinavir, indinavir and delavirdine, all CYP3A4 inhibitors, greatly increase saquinavir plasma concentrations and the therapeutic implications of these interactions continue to be evaluated. While saquinavir is the least potent CYP 3A inhibitor among the PIs, several drugs (notably terfenadine, astemizole and cisapride) should not be given in combination with saquinavir. Therefore, although the SGC formulation enhances saquinavir exposure, it has a similar safety profile to the HGC formulation.

Lipodystrophy, metabolic disorders, and human immunodeficiency virus infection: Aquitaine Cohort, France, 1999. Groupe d'Epidémiologie Clinique du Syndrome d'Immunodéficience Acquise en Aquitaine

The objective of this study was to estimate the prevalence of and risk factors for clinical lipodystrophy (LD) and metabolic disorders in human immunodeficiency virus (HIV) type 1-infected patients. A cross-sectional survey of the Aquitaine Cohort was performed in January 1999. The clinical diagnosis of LD was categorized as fat wasting (FW), peripheral fat accumulation (FA), and mixed syndromes (MS). Of the 581 patients studied, 61% were treated with protease inhibitors. The overall prevalence of LD was 38% (95% confidence interval [CI], 32-42): prevalence of FW was 16% (95% CI, 13-18); of FA, 12% (95% CI, 10-15); and of MS, 10% (95% CI, 8-13). The prevalences of metabolic abnormalities were 49% (95% CI, 44-53) for lipid disorders and 20% (95% CI, 17-23), for glucose disorders. Factors associated with LD were age (for FW and MS), male sex (for FW), AIDS stage (for MS), body mass index (for FW and FA), waist-to-hip ratio (for FA and MS), and duration of antiretroviral treatment (for FW).

Management of dyslipidemia in patients with HIV disease

The epidemiological, etiopathogenetic, laboratory and clinical features of serum lipid abnormalities occurring in the course of HIV disease are still poorly understood (especially when the supporting role of single antiretroviral compounds is considered), while limited literature data are to date available regarding the management of HIV-related dyslipidemia, as well as the efficacy and safety of dietary-exercise programs, and that of selected hypolipidemic agents. At this time, a careful monitoring of serum lipid profile is needed during combination antiretroviral therapy including protease inhibitors, in order to suggest a diet and hypolipidemic treatment when applicable, and to prevent clinical sequelae related to long-term dyslipidemia. The selection of an appropriate hypolipidemic agent is difficult, since no controlled studies are available in this field, and possibly increased risks of pharmacologic interactions, toxicity and impaired patient's adherence should be taken into consideration. Waiting for specific guidelines for the treatment of hypertriglyceridemia and hypercholesterolemia in the setting of HIV infection, all available literature reports dealing with the management of HIV-associated hyperlipidemia are briefly discussed, on the basis of personal clinical experience.

Lipodystrophy associated with protease inhibitors

Lipodystrophies, characterized by reduction of subcutaneous fat over part or all of the body surface, are uncommon. Their causes are unknown. Recently, lipodystrophy has been reported in human immunodeficiency virus (HIV)-infected patients taking protease inhibitors, which have been recommended since 1996 as standard therapy for HIV disease in combination with nucleoside analogues. In these cases, lipodystrophy consists of an association of peripheral lipoatrophy with central adiposity. We report four HIV-infected men on protease inhibitors who developed a disfiguring lipodystrophy. In three of them, the protease inhibitor was administered for a mean duration of 21.5 months (range 19-23) with good immunological and virological responses. Patient 4 had been treated for 2 years with successive combinations of protease inhibitors with nucleoside analogues without success. The four patients progressively developed an increase in abdominal girth associated with fat wasting of the face and legs. Two of them had recurrent paronychia of the great toes. Triglyceride levels were moderately increased in all patients, and one had a slightly increased cholesterol level. One patient had elevated glucose and insulin plasma levels during a glucose tolerance test. In two patients, a deep biopsy taken from the thigh showed thinning of the subcutaneous fat without other morphological changes. Computed tomographic scans of the face and abdomen confirmed the loss of almost all subcutaneous fat of the cheek and temporal regions, and abdominal perivisceral fat accumulation. For patients 1-3, the protease inhibitor was replaced by a non-nucleoside reverse transcriptase inhibitor. Nine months later, dysmorphic changes had not regressed, but lipid abnormalities had returned to normal and the paronychia had disappeared.

Indinavir: a review of its use in the management of HIV infection

Indinavir is a protease inhibitor used in the treatment of patients with HIV infection. Combination antiretroviral therapy with indinavir plus 2 nucleoside reverse transcriptase inhibitors (NRTIs) is associated with greater reductions in viral load, greater increases in CD4+ cell counts, and reduced morbidity and mortality when compared with 2 NRTIs alone. In the landmark clinical trial ACTG 320, the rate of progression to AIDS or death (primary end-point) among zidovudine-experienced patients treated with indinavir, zidovudine and lamivudine was approximately half that of patients who received only zidovudine plus lamivudine (6 vs 11%; p < 0.001). The durability of an indinavir-containing regimen was demonstrated in Merck protocol 035, an ongoing trial in which a significant proportion of patients had sustained viral suppression for up to 3 years. Merck protocol 039, also an ongoing trial, showed a greater effect on surrogate markers of HIV disease progression with indinavir-based triple therapy than with zidovudine plus lamivudine or indinavir monotherapy in patients with advanced disease (median baseline CD4+ count 15 cells/microL). Numerous additional clinical trials have established the beneficial antiviral and immunological effects of indinavir in both antiretroviral-naive and -experienced patients with HIV infection. Indinavir is associated with various drug class-related adverse events, including gastrointestinal disturbances (e.g. nausea, diarrhoea), headache and asthenia/fatigue. A lipodystrophy syndrome has been commonly reported with indinavir and other protease inhibitors combined with NRTIs, but it has also been reported in many protease inhibitor-naive patients, and a definitive causal link has not been established between the syndrome and protease inhibitors. Nephrolithiasis may develop in about 9% of patients receiving indinavir but does not appear to be associated with other protease inhibitors; <0.5% of patients receiving indinavir discontinue the drug because of nephrolithiasis, which may be the extreme end of a continuum of crystal-related renal syndromes. Additional renal problems (e.g. nephropathy) have been reported in small numbers of patients receiving indinavir. In summary, indinavir is a protease inhibitor with well documented efficacy when used as part of combined therapy in patients with HIV infection. Both US and UK treatment guidelines continue to recommend protease inhibitor-based regimens including indinavir as a first-line option. Indinavir is being studied as a twice daily and once daily regimen with a low dosage of ritonavir as a way to alleviate tolerability, drug interaction and patient compliance/adherence issues. Indinavir-containing triple therapy has demonstrated positive effects not only on surrogate markers of disease progression, but also on clinical end-points of mortality and morbidity in patients with HIV disease. Protease inhibitors are a significant advance in the care of patients with HIV infection, and, in an era of evidence-based medicine, indinavir represents an important component of antiretroviral treatment strategies.

Atherogenic dyslipidemia in HIV-infected individuals treated with protease inhibitors. The Swiss HIV Cohort Study

BACKGROUND

Administration of protease inhibitors (PIs) to HIV-infected individuals has been associated with hyperlipidemia. In this study, we characterized the lipoprotein profile in subjects receiving ritonavir, indinavir, or nelfinavir, alone or in combination with saquinavir.

METHODS AND RESULTS

Plasma lipoprotein levels were quantified in 93 HIV-infected adults receiving PIs. Comparison was done with pretreatment values and with 28 nonPI-treated HIV-infected subjects. An elevation in plasma cholesterol levels was observed in all PI-treated groups but was more pronounced for ritonavir (2.0+/-0.3 mmol/L [mean+/-SEM], n=46, versus 0.1+/-0.2 mmol/L in nonPI treated group, P<0.001) than for indinavir (0.8+/-0.2 mmol/L, n=26, P=0.03) or nelfinavir (1.2+/-0.2 mmol/L, n=21, P=0.01). Administration of ritonavir, but not indinavir or nelfinavir, was associated with a marked elevation in plasma triglyceride levels (1.83+/-0.46 mmol/L, P=0.002). Plasma HDL-cholesterol levels remained unchanged. Combination of ritonavir or nelfinavir with saquinavir did not further elevate plasma lipid levels. A 48% increase in plasma levels of lipoprotein(a) was detected in PI-treated subjects with pretreatment Lp(a) values >20 mg/dL. Similar changes in plasma lipid levels were observed in 6 children receiving ritonavir.

CONCLUSIONS

Administration of PIs to HIV-infected individuals is associated with a marked, compound-specific dyslipidemia. The risk of pancreatitis and premature atherosclerosis due to PI-associated dyslipidemia remains to be established.

Protease inhibitor-induced lipodystrophy

The development of lipodystrophy as evidenced by central obesity, "moon facies," and a "buffalo hump" is a classical feature of Cushing's disease. Recently an association of "lipodystrophy" with the use of protease inhibitors has been reported. We describe a patient with lipodystrophy secondary to protease inhibitor therapy for HIV infection.

Metabolic abnormalities and body fat redistribution in HIV-1 infected patients: the lipodystrophy syndrome

A unique and unexpected syndrome consisting of metabolic abnormalities (hyperlipidaemia and insulin resistance) and body fat redistribution (central adiposity and peripheral fat wasting) has been reported with increasing frequency in HIV-1 infected patients, most of whom are receiving highly active antiretroviral therapies including HIV-1 protease inhibitors. This article reviews the clinical and laboratory characteristics, the pathogenesis, and the management of this syndrome.