Noncirrhotic portal hypertension in HIV-infected patients: unique clinical and pathological findings

Genetic determinants of idiopathic noncirrhotic portal hypertension in HIV-infected patients

BACKGROUND

Noncirrhotic portal hypertension (NCPH) is a rare but potentially life-threatening complication in patients with human immunodeficiency virus (HIV). Cases of NCPH have been reported in HIV-negative individuals as result of treatment with thiopurines for leukemia or inflammatory bowel disease. Exposure to didanosine, which is also a purine analogue, predisposes to NCPH in the HIV setting. However, it is unclear why NCPH only develops in a small subset of didanosine-treated patients.

METHODS

A multicenter, case-control study was conducted to investigate the role of pharmacogenomics in NCPH in HIV patients with prior didanosine exposure. Three controls were chosen for each case, adjusted for sex, age, CD4 counts, plasma HIV-RNA, and site. Tagging 36 single-nucleotide polymorphisms (SNPs) at enzymes involved in the purine metabolism (inosine triphosphatase, 5'-nucleotidase cytosolic-II, purine nucleoside phosphorylase and xanthine oxidase) was performed using SNPlex microarray technology.

RESULTS

Eighty individuals were examined; 22 with NCPH and 58 matched controls. Two SNPs at the 5'-nucleotidase gene were associated with NCPH: rs11191561 (48% CG/GG vs 17% CC; P=.003) and rs11598702 (40% CC/CT vs 9% TT; P=.003). SNPs at another 2 loci at the xanthine oxidase gene were also associated with NCPH: rs1429376 (71% AA vs 23% CC/AC; P=.015) and rs1594160 (71% AA vs 23% CC/AC; P=.015). There was a cumulative risk of NCPH for these 4 SNPs: 7%, 26%, 42%, 50%, and 100%, respectively, for 0, 1, 2, 3, or all SNPs (P=.001).

CONCLUSIONS

SNPs at the 5'-nucleotidase and xanthine oxidase genes influence the risk of NCPH in HIV patients treated with didanosine.

Risk factors and outcome of HIV-associated idiopathic noncirrhotic portal hypertension

BACKGROUND

Idiopathic noncirrhotic portal hypertension (INCPH) has been reported increasingly in patients with HIV infection.

AIM

To evaluate the number of nationwide diagnosed HIV-associated INCPH cases and to assess its clinical features, risk factors and outcome.

METHODS

All HIV centres in the Netherlands were contacted and requested to notify INCPH cases diagnosed in their population. A case–control study was performed to identify the risk factors of INCPH. The cases were group-matched for duration of follow-up after HIV diagnosis to controls. Controls were selected from a database of HIV patients with negative screening for signs of portal hypertension on abdominal ultrasound. Univariate and multivariate conditional logistic regression analyses were performed.

RESULTS

On 1st of July 2011, 18.085 individuals were infected with HIV in the Netherlands. Within this population, sixteen patients with clinically overt INCPH were identified. At the time of INCPH diagnosis, cases had a lower platelet count and a higher ALT level. In univariate and multivariate analyses, didanosine [OR: 1.9 (1.3–2.8)], concomitant didanosine and stavudine treatment [OR: 6.3 (2.1–19.1)] and concomitant didanosine and tenofovir treatment [OR: 5.1 (1.2–22.6)] were independently associated INCPH. During follow-up, 4 patients died [malignancy (n = 3), liver failure (n = 1)]. A significant decline in platelets was observed after didanosine discontinuation (P = 0.003).

CONCLUSIONS

HIV-associated clinically relevant idiopathic noncirrhotic portal hypertension appears to be a rarely diagnosed disease. Long-term exposure to didanosine and short-term combination of didanosine and stavudine or tenofovir exposure are associated with idiopathic noncirrhotic portal hypertension. Mortality in HIV-associated idiopathic noncirrhotic portal hypertension is mainly related to HIV-associated disorders. Portal hypertension continues despite didanosine discontinuation

Antiretroviral drug-related liver mortality among HIV-positive persons in the absence of hepatitis B or C virus coinfection: the data collection on adverse events of anti-HIV drugs study

BACKGROUND

Liver diseases are the leading causes of death in human immunodeficiency virus (HIV)-positive persons since the widespread use of combination antiretroviral treatment (cART). Most of these deaths are due to hepatitis C (HCV) or B (HBV) virus coinfections. Little is known about other causes. Prolonged exposure to some antiretroviral drugs might increase hepatic mortality.

METHODS

All patients in the Data Collection on Adverse Events of Anti-HIV Drugs study without HCV or HBV coinfection were prospectively followed from date of entry until death or last follow-up. In patients with liver-related death, clinical charts were reviewed using a structured questionnaire.

RESULTS

We followed 22 910 participants without hepatitis virus coinfection for 114 478 person-years. There were 12 liver-related deaths (incidence, 0.10/1000 person-years); 7 due to severe alcohol use and 5 due to established ART-related toxicity. The rate of ART-related deaths in treatment-experienced persons was 0.04/1000 person-years (95% confidence interval, .01, .10).

CONCLUSIONS

We found a low incidence of liver-related deaths in HIV-infected persons without HCV or HBV coinfection. Liver-related mortality because of ART-related toxicity was rare.

Splenomegaly and variceal bleeding in a ten-year-old HIV-infected girl with noncirrhotic portal hypertension

Noncirrhotic portal hypertension is an uncommon liver disease of unknown origin, increasingly described in HIV-infected adults. Prolonged antiretroviral exposure, in particular to didanosine, and thrombophilic predisposition have been suggested as potential pathogenic factors. Data are limited in children. We describe a 10-year-old HIV-infected girl with noncirrhotic portal hypertension who presented with progressive spleen enlargement and variceal bleeding.

Non-cirrhotic portal hypertension in HIV mono-infected patients

BACKGROUND AND AIM

Unexplained liver injury including fibrosis and portal hypertension has rarely been reported among patients with HIV in the absence of co-infection with hepatitis B (HBV) or hepatitis C (HCV). We describe a series of HIV mono-infected patients with evidence of non-cirrhotic portal hypertension.

METHODS

HIV-infected patients with evidence of portal hypertension who were anti-HBV and anti-HCV negative and HBV and HCV RNA polymerase chain reaction (PCR) negative were identified from patients managed by the Victorian statewide HIV referral service located at The Alfred Hospital, Melbourne. Portal hypertension was defined as either radiological or endoscopic evidence of varices, portal vein flow obstruction, or elevated hepatic venous pressure gradient (HPVG).

RESULTS

Five patients were found to have portal hypertension. These patients were male, aged 41 to 65 years, with known duration of HIV infection between 11 to 25 years. All had been treated with antiretroviral therapy, including didanosine. Tests for metabolic, autoimmune, and hereditary causes of liver disease failed to establish an etiology for the liver injury. All had radiological or endoscopic findings of varices, and four patients had radiological features of portal vein obstruction or flow reversal. Only one patient underwent HPVG measurement, which was elevated. Non-invasive fibrosis assessment revealed increased liver stiffness in three (out of four) patients, and no cirrhotic features were found on those who underwent liver biopsy.

CONCLUSIONS

To our knowledge, this is the largest published series of non-cirrhotic portal hypertension in HIV mono-infected patients in Australia. Further research is needed to understand what relationship, if any, HIV or its treatments might have on liver injury over time.

Management of hepatic vascular diseases

Primary damage to hepatic vessels is rare. (i) Hepatic arterial disorders, related mostly to iatrogenic injury and occasionally to systemic diseases, lead to ischemic cholangiopathy. (ii) Hepatic vein or inferior vena cava thrombosis, causing primary Budd-Chiari syndrome, is related typically to a combination of underlying prothrombotic conditions, particularly myeloproliferative neoplasms, factor V Leiden, and oral contraceptive use. The outcome of Budd-Chiari syndrome has markedly improved with anticoagulation therapy and, when needed, angioplasty, stenting, TIPS, or liver transplantation. (iii) Extrahepatic portal vein thrombosis is related to local causes (advanced cirrhosis, surgery, malignant or inflammatory conditions), or general prothrombotic conditions (mostly myeloproliferative neoplasms or factor II gene mutation), often in combination. Anticoagulation at the early stage prevents thrombus extension and, in 40% of the cases, allows for recanalization. At the late stage, gastrointestinal bleeding related to portal hypertension can be prevented in the same way as in cirrhosis. (iv) Sinusoidal obstruction syndrome (or venoocclusive disease), caused by agents toxic to bone marrow progenitors and to sinusoidal endothelial cells, induces portal hypertension and liver dysfunction. Decreasing the intensity of myeloablative regimens reduces the incidence of sinusoidal toxicity. (v) Obstruction of intrahepatic portal veins (obliterative portal venopathy) can be associated with autoimmune diseases, prothrombotic conditions, or HIV infection. The disease can eventually be complicated with end-stage liver disease. Extrahepatic portal vein obstruction is common. Anticoagulation should be considered. (vi) Nodular regenerative hyperplasia is induced by the uneven perfusion due to obstructed sinusoids, or portal or hepatic venules. It causes pure portal hypertension.

Severe transaminitis after interferon-ribavirin therapy in HIV/HCV-coinfected patients: influence of a sustained HCV response

Chronic hepatitis C is an independent risk factor for severe drug hepatotoxicity. Successful treatment of chronic hepatitis C may modulate drug hepatotoxicity, as it is associated with a decline in hepatic enzyme release and halts fibrosis progression in HIV/HCV-coinfected patients. The aim of this study was to determine biological and/or clinical determinants of alanine aminotransferase and/or aspartate aminotransferase elevation (>five-fold above the upper limit of normal in patients with normal baseline levels or >3.5-fold increase from baseline in those with increased baseline levels) in a large prospective cohort of HIV/HCV-coinfected patients on HAART who had previously been treated for HCV infection. Median follow-up exceeded five years. Cox proportional hazards models were used. At baseline, 248 patients had been receiving antiretroviral therapy for a mean of 6.3 (± 3.2) years. Seventy-one patients (29%) had a sustained HCV viral response (SVR). During follow-up, 66 patients (26.6%) received a second course of HCV therapy and 29 (44%) of them had an SVR. Severe transaminitis occurred in 64 patients (26%). In multivariate analysis, no SVR (HR 33.33, 95% CI 4.54-222, P = 0.001) and stavudine-based therapy (HR 2.11, 95% CI 1.12-3.99, P = 0.018) remained significantly associated with severe transaminitis. A SVR to anti-HCV therapy is thus associated with a markedly reduced risk of severe transaminitis during antiretroviral therapy. Treatment of HCV infection should therefore be a priority in HIV-coinfected patients. Stavudine is associated with an increased risk of severe transaminitis.

Human immunodeficiency virus infection and the liver

Liver disease in human immunodeficiency virus (HIV)-infected individuals encompasses the spectrum from abnormal liver function tests, liver decompensation, with and without evidence of cirrhosis on biopsy, to non-alcoholic liver disease and its more severe form, non-alcoholic steatohepatitis and hepatocellular cancer. HIV can infect multiple cells in the liver, leading to enhanced intrahepatic apoptosis, activation and fibrosis. HIV can also alter gastro-intestinal tract permeability, leading to increased levels of circulating lipopolysaccharide that may have an impact on liver function. This review focuses on recent changes in the epidemiology, pathogenesis and clinical presentation of liver disease in HIV-infected patients, in the absence of co-infection with hepatitis B virus or hepatitis C virus, with a specific focus on issues relevant to low and middle income countries.

Human immunodeficiency virus and liver disease forum 2010: conference proceedings

Liver disease continues to represent a critical mediator of morbidity and mortality in those with human immunodeficiency virus (HIV) infection. The frequent presence and overlap of concomitant injurious processes, including hepatitis C virus and hepatitis B virus infections, hepatoxicity associated with antiretroviral therapeutic agents, alcohol, and other toxins, in the setting of immunosuppression lead to rapid fibrotic progression and early development of end-stage liver disease. This conference summary describes the proceedings of a state-of-the-art gathering of international experts designed to highlight the status of current research in epidemiology, natural history, pathogenesis, and treatment of HIV and liver disease.

Influence of antiretroviral therapy on liver disease

PURPOSE OF REVIEW

Liver disease is a major cause of morbidity and mortality in HIV-infected persons. The long-term beneficial versus potentially harmful influence of antiretroviral therapy (ART) on the liver is debated. We review current data on factors contributing to liver disease in HIV-monoinfected as well as in HIV/viral hepatitis-coinfected patients, highlighting the role of ART, HIV itself, immunodeficiency, patient characteristics, and lifestyle risk factors.

RECENT FINDINGS

New ART-related clinical syndromes, including noncirrhotic portal hypertension and nonalcoholic fatty liver disease, have emerged, and observational data suggest long-term ART-associated liver injury. Recently, there is increasing evidence that HIV itself and immunosuppression are contributing to liver injury in both HIV-coinfected and HIV-monoinfected patients. In HIV-positive persons, ART attenuates progression of chronic viral hepatitis.

SUMMARY

Current expert guidelines recommend earlier treatment of HIV infection in persons coinfected with hepatitis B virus and possibly hepatitis C virus. It is unknown whether an earlier start of ART is beneficial for the liver in HIV-monoinfected patients. Future research should focus on long-term ART-related hepatotoxicity.

Central role of mitochondria in drug-induced liver injury

A frequent mechanism for drug-induced liver injury (DILI) is the formation of reactive metabolites that trigger hepatitis through direct toxicity or immune reactions. Both events cause mitochondrial membrane disruption. Genetic or acquired factors predispose to metabolite-mediated hepatitis by increasing the formation of the reactive metabolite, decreasing its detoxification, or by the presence of critical human leukocyte antigen molecule(s). In other instances, the parent drug itself triggers mitochondrial membrane disruption or inhibits mitochondrial function through different mechanisms. Drugs can sequester coenzyme A or can inhibit mitochondrial β-oxidation enzymes, the transfer of electrons along the respiratory chain, or adenosine triphosphate (ATP) synthase. Drugs can also destroy mitochondrial DNA, inhibit its replication, decrease mitochondrial transcripts, or hamper mitochondrial protein synthesis. Quite often, a single drug has many different effects on mitochondrial function. A severe impairment of oxidative phosphorylation decreases hepatic ATP, leading to cell dysfunction or necrosis; it can also secondarily inhibit ß-oxidation, thus causing steatosis, and can also inhibit pyruvate catabolism, leading to lactic acidosis. A severe impairment of β-oxidation can cause a fatty liver; further, decreased gluconeogenesis and increased utilization of glucose to compensate for the inability to oxidize fatty acids, together with the mitochondrial toxicity of accumulated free fatty acids and lipid peroxidation products, may impair energy production, possibly leading to coma and death. Susceptibility to parent drug-mediated mitochondrial dysfunction can be increased by factors impairing the removal of the toxic parent compound or by the presence of other medical condition(s) impairing mitochondrial function. New drug molecules should be screened for possible mitochondrial effects.

Idiopathic noncirrhotic portal hypertension

Idiopathic noncirrhotic portal hypertension (INCPH) is characterized by an increased portal venous pressure gradient in the absence of a known cause of liver disease and portal vein thrombosis. In contrast to the high prevalence of this disorder in India, INCPH is a rare disease in the Western world. The etiology of INCPH can be divided in five categories: chronic infections, exposure to medication or toxins, thrombophilia, immunological disorders, and genetic disorders. Multifactorial etiology can also be encountered. Chronic abdominal infection is incriminated as the most important etiological factor in Eastern patients and thrombophilia in Western patients. The majority of patients with INCPH initially present with signs or complications of portal hypertension (mainly variceal bleeding and splenomegaly). These patients usually have preserved liver function. Liver function impairment occurs mainly in the context of intercurrent conditions. Patients with INCPH are often clinically and radiologically misdiagnosed as liver cirrhosis, so that a liver biopsy is indispensable to discriminate cirrhosis from INCPH. Histopathological characteristics of INCPH are heterogeneous, demonstrating overlap between several pathological entities (e.g., hepatoportal sclerosis, nodular regenerative hyperplasia, and incomplete septal cirrhosis). Even though hemodynamical changes in INCPH patients are not comparable to those in cirrhotics, prophylaxis and treatment of variceal bleeding are recommended to be similar. Anticoagulation therapy must be considered only in patients who develop portal vein thrombosis. INCPH has been considered a disorder with a relatively benign disease course. However, liver failure, hepatic encephalopathy, and hepatopulmonary syndrome can occur and are considered indications for liver transplantation.

Immunopathogenesis of HIV/hepatitis C virus coinfection

As a result of shared infection routes, approximately 25% of individuals infected with HIV in North America are also infected with hepatitis C virus (HCV). In the setting of HIV coinfection, the course of HCV disease is more aggressive, resulting in higher HCV viral loads and a more rapid progression of liver pathology. With the success of HAART, HCV-related end-stage liver disease has become a leading cause of morbidity and mortality in HIV/HCV-coinfected patients. In this article, we will discuss recent studies examining the immune response during HIV and HCV coinfection, focusing on alterations or dysfunctions in virus-specific T-cell responses that may play a role in the immunopathogenesis of HIV/HCV coinfection. Summarizing the impact of HIV coinfection on HCV-specific T-cell immunity and highlighting some of the proposed mechanisms of T-cell dysfunction in HIV/HCV-coinfected individuals may uncover information that could lead to new treatment strategies for these patients experiencing accelerated liver disease and generally poorer outcomes than their HCV-monoinfected counterparts.

Noncirrhotic portal hypertension in HIV infection

PURPOSE OF REVIEW

Liver disease in the HAART era is one of the leading causes of morbidity and mortality in HIV-infected individuals in Western countries. Even if the majority of cases rely on identifiable causes (viral hepatitis, steatohepatitis, alcohol abuse, drug toxicity, etc.), the cause of liver abnormalities remains unknown for a subset of patients, some of whom present with noncirrhotic portal hypertension (NCPH).

RECENT FINDINGS

In 2006, the first reports of NCPH in HIV-infected patients attracted special attention. Typically, individuals unaware of any underlying liver illness presented with variceal bleeding, occasionally fatal. Interestingly, severe portal hypertension occurred in the absence of liver function impairment in most cases. Liver biopsy revealed a distinctive histological feature characterized by massive absence of portal veins along with focal obliteration of small portal veins. After extensive ruling out of other causes, the role of antiretroviral toxicity (particularly didanosine exposure) emerged as the major contributor to this condition. Other potential factors could be an enhanced microbial translocation from the gut and prothrombotic conditions.

SUMMARY

NCPH is an uncommon condition, although increasingly being reported in HIV-infected individuals. It generally presents as a clinical episode of decompensated portal hypertension, generally with gastrointestinal bleeding. Long-lasting HIV infection and prolonged antiretroviral exposure are universally recognized in these patients. The involvement of didanosine has been highlighted in most series. Removal of this drug and prevention of variceal bleeding episodes are currently the most effective prophylactic and therapeutic interventions.

Increasing burden of liver disease in patients with HIV infection

Introduction of effective combined antiretroviral therapy has made HIV infection a chronic illness. Substantial reductions in the number of AIDS-related deaths have been accompanied by an increase in liver-related morbidity and mortality due to co-infection with chronic hepatitis B and C viruses. Increases in non-alcoholic fatty liver disease and drug-induced hepatotoxicity, together with development of hepatocellular carcinoma, also potentiate the burden of liver disease in individuals with HIV infection. We provide an overview of the key causes, disease mechanisms of pathogenesis, and recommendations for treatment options including the evolving role of liver transplantation.

Nodular regenerative hyperplasia: Evolving concepts on underdiagnosed cause of portal hypertension

Nodular regenerative hyperplasia (NRH) is a rare liver condition characterized by a widespread benign transformation of the hepatic parenchyma into small regenerative nodules. NRH may lead to the development of non-cirrhotic portal hypertension. There are no published systematic population studies on NRH and our current knowledge is limited to case reports and case series. NRH may develop via autoimmune, hematological, infectious, neoplastic, or drug-related causes. The disease is usually asymptomatic, slowly or non-progressive unless complications of portal hypertension develop. Accurate diagnosis is made by histopathology, which demonstrates diffuse micronodular transformation without fibrous septa. Lack of perinuclear collagen tissue distinguishes NRH from typical regenerative nodules in the cirrhotic liver. While the initial treatment is to address the underlying disease, ultimately the therapy is directed to the management of portal hypertension. The prognosis of NRH depends on both the severity of the underlying illness and the prevention of secondary complications of portal hypertension. In this review we detail the epidemiology, pathogenesis, diagnosis, management, and prognosis of NRH.

The role of nucleoside and nucleotide analogues in nodular regenerative hyperplasia in HIV-infected patients: a case control study

BACKGROUND & AIMS

Nodular regenerative hyperplasia (NRH) leading to non-cirrhotic portal hypertension has been described in HIV-infected patients and has been linked to didanosine. The relation between NRH and other antiretrovirals remains unclear.

METHODS

A case-control study was performed in 13 patients with NRH and 78 controls matched for time of inclusion, baseline CD4, and duration of follow-up. Univariate and multivariate conditional logistic regression analyses were performed.

RESULTS

Control patients and patients with NRH were similar at baseline regarding demographics and biological data with the exception of older age for patients with NRH (43.9 vs. 33.5 years, p=0.044). At the time of NRH diagnosis, cases had a lower CD4 count (327 vs. 468/mm(3), p=0.013), a similar CD4 percentage (24 vs. 26.2%, p=0.7), a lower platelet count (169 vs. 228 giga/L, p=0.003) and a higher AST level (33 vs. 26 IU/L, p=0.001) than controls. Univariate analysis demonstrated that patients with NRH had been exposed longer than controls to didanosine, stavudine, tenofovir, didanosine+stavudine, and didanosine+tenofovir. The age at baseline [OR 2.2 (1.0-5.0) per 10 years, p=0.053] and didanosine+stavudine cumulative exposure [OR 3.7 (1.4-10.2) per year, p=0.011] were independently associated with NRH. The age at baseline [OR 2.3 (1.0-5.3) per 10 years, p=0.045], cumulative exposure to didanosine [OR 1.4 (1.1-1.9) per year, p=0.023] and to tenofovir [OR 1.7 (1.0-2.8) per year, p=0.04] were independently associated with NRH when didanosine+stavudine exposure was excluded from the model.

CONCLUSIONS

NRH in HIV-infected patients seems strongly related to age and the cumulative exposure to didanosine+stavudine, didanosine, and stavudine.

Noncirrhotic portal hypertension in HIV-infected patients: a case control evaluation and review of the literature

Idiopathic noncirrhotic portal hypertension (NCPH) is an infrequent but possibly underestimated cryptogenetic liver disease recently described in small series of HIV-infected patients. The exposure to antiretroviral drugs, a direct role of HIV itself, microbial translocation from the gut, or a thrombophilic propensity have been suggested as possible pathogenic mechanisms. In this case control study, we describe 11 HIV-infected patients with idiopathic NCPH and compare the activity of protein C and S, and soluble CD14 levels (a surrogate marker of the translocation of intestinal bacterial products) with 10 age- and gender-matched HIV-infected controls with no liver disease. The clinical presentation of the 11 patients with NCPH was characterised by acute variceal bleeding (2/11), ascites (2/11), portal thrombosis (2/11), and ultrasonographic and endoscopic signs of portal hypertension (11/11), with slightly high alanine transaminase (ALT) and γglutamyl transpeptidase (γ-GT) levels. The FibroScan median liver stiffness was 8.1 kPa, which is inconsistent with significant fibrosis, and nodular regenerative hyperplasia was diagnosed in the 5 patients who underwent liver biopsy. The NCPH patients showed no impairment of hepatic synthesis, but had lower serum albumin levels and a higher international normalized ratio (INR) than the controls (p = 0.01), and lower protein C and S activity, although within the normal range (p = 0.02 and 0.3, respectively). No significant difference in soluble CD14 was seen between the two groups. In conclusion, the etiology of NCHP is not still established, but in order to prevent the dramatic complications of portal hypertension, all HIV-infected patients with unexplained liver enzyme abnormalities or thrombocytopenia should be considered for further investigations by means of thrombophilic screening, Doppler ultrasound evaluation, and in the presence of portal hypertension, endoscopy and liver biopsy.

Clinical syndromes and consequences of antiretroviral-related hepatotoxicity

Highly active antiretroviral therapy (HAART)-related hepatotoxicity complicates the management of patients infected with human immunodeficiency virus (HIV), increases medical costs, alters the prescription patterns, and affects the guideline recommendations. Among the clinical consequences derived from HAART-related liver toxicity, hypersensitivity reactions and lactic acidosis are recognized as acute events with potential to evolve into fatal cases, whereas there seems to be other syndromes not as well characterized but of equal concern as possible long-term liver complications. Belonging to the latter category of syndrome, HAART-related nonalcoholic steatohepatitis, liver fibrosis, portal hypertension, and nodular regenerative hyperplasia are discussed in this review. Updated information on liver toxicity of current antiretroviral drugs, including the most recently licensed, is provided. Management and prevention of liver toxicity among HIV-infected patients treated with HAART are reviewed as well.