Adverse effects of reverse transcriptase inhibitors: mitochondrial toxicity as common pathway

Changes in Mitochondrial Toxicity in Peripheral Blood Mononuclear Cells During Four-Year Administration of Entecavir Monotherapy in Chinese Patients with Chronic Hepatitis B

BACKGROUND

This study aimed to assess whether long-term entecavir monotherapy induces mitochondrial toxicity in patients with chronic hepatitis B (CHB).

MATERIAL AND METHODS

This was a prospective study in 34 antiviral treatment-naïve patients with CHB who received entecavir monotherapy and were followed up for 4 years. Blood samples were collected after 0, 2, 3, and 4 years of entecavir (ETC) monotherapy (ETC0, ETC2, ETC3, and ETC4, respectively). Mitochondrial DNA (mtDNA) contents were determined using real-time quantitative polymerase chain reaction (qRT-PCR) and mtDNA4977 depletions were detected using nested PCR. Levels of hepatitis B virus (HBV) DNA, alanine aminotransferase, alanine aminotransferase, hepatitis B e antigen (HBeAg), creatine kinase, urea nitrogen, and serum creatinine were recorded.

RESULTS

mtDNA contents at ETC0 (9.6±6.3) and ETC4 (10.3±6.2) were markedly higher than at ETC2 (0.8±0.5, P<0.01) and ETC3 (1.3±0.9, P<0.01), but there were no differences between ETC2 and ETC3 or between ETC0 and ETC4. MtDNA4977 depletion appeared in 79.4% cases at ETC2 and in 70.6% at ETC3, which were much higher than at ETC0 (32.4%, P<0.01) and ETC4 (8.8%, P<0.01), but there were no differences in mtDNA4977 depletion ratio between ETC2 and ETC3, or between ETC0 and ETC4. mtDNA content was negatively correlated to mtDNA4977 depletion (partial regression coefficient of -4.555, P<0.001, R2=0.315). mtDNA content was positively correlated with age (partial regression coefficient of 0.131, P=0.045).

CONCLUSIONS

Results suggest that during 4-year entecavir monotherapy for CHB, the mtDNA contents initially decreased and then increased, while the mtDNA4977 depletion rates first increased and then decreased.

Changing utilization of Stavudine (d4T) in HIV-positive people in 2006-2013 in the EuroSIDA study

OBJECTIVES

The long-term side effects of stavudine (d4T) led to recommendations in 2009 to phase out use of this drug. We aimed to describe temporal patterns of d4T use across Europe.

METHODS

Patients taking combination antiretroviral therapy (cART) in EuroSIDA with follow-up after 1 January 2006 were included in the study. cART was defined as d4T-containing [d4T plus at least two other antiretrovirals (ARVs) from any class] or non-d4T-containing (at least three ARVs from any class, excluding d4T). Poisson regression was used to describe temporal changes in the prevalence of d4T use and factors associated with initiating d4T.

RESULTS

A total of 5850 patients receiving cART on 1 January 2006 were included in the current analysis, rising to 7768 patients on January 1 2013. During this time, the prevalence of d4T use fell from 11.2% to 0.7%, with an overall decline of 19% per 6 months [95% confidence interval (CI) 19-20%]. d4T use declined fastest in Northern Europe [26% (95% CI 23-29%) per 6 months], and slowest in Eastern Europe [17% (95% CI 16-19%) per 6 months]. In multivariable Poisson regression models, new d4T initiations decreased by 14% per 6 months [adjusted incidence rate ratio (aIRR) 0.86; 95% CI 0.80-0.91]. Factors associated with initiating d4T were residence in Eastern Europe (aIRR 4.31; 95% CI 2.17-9.98) versus other European regions and HIV RNA > 400 copies/mL (aIRR 3.11; 95% CI 1.60-6.02) versus HIV RNA < 400 copies/mL.

CONCLUSIONS

d4T use has declined sharply since 2006 to low levels in most regions; however, a low but persistent level of d4T use remains in Eastern Europe, where new d4T initiations post 2006 are also more common. The reasons for the regional differences may be multifactorial, but it is important to ensure that all clinicians treating HIV-positive patients are aware of the potential harmful effects associated with d4T.

Caenorhabditis elegans as a Model System for Studying Drug Induced Mitochondrial Toxicity

Today HIV-1 infection is recognized as a chronic disease with obligatory lifelong treatment to keep viral titers below detectable levels. The continuous intake of antiretroviral drugs however, leads to severe and even life-threatening side effects, supposedly by the deleterious impact of nucleoside-analogue type compounds on the functioning of the mitochondrial DNA polymerase. For detailed investigation of the yet partially understood underlying mechanisms, the availability of a versatile model system is crucial. We therefore set out to develop the use of Caenorhabditis elegans to study drug induced mitochondrial toxicity. Using a combination of molecular-biological and functional assays, combined with a quantitative analysis of mitochondrial network morphology, we conclude that anti-retroviral drugs with similar working mechanisms can be classified into distinct groups based on their effects on mitochondrial morphology and biochemistry. Additionally we show that mitochondrial toxicity of antiretroviral drugs cannot be exclusively attributed to interference with the mitochondrial DNA polymerase.

Mitochondrial and apoptotic in vitro modelling of differential HIV-1 progression and antiretroviral toxicity

OBJECTIVES

Ex vivo analysis of mitochondrial function may reveal HIV progression and the impact of ART. We propose a mitochondrial and apoptotic in vitro model using Jurkat T cells incubated with plasma. The objectives of this study were to evaluate mitochondrial and apoptotic lesions in this model in relation to HIV progression, and to assess the effect of >1 year of standard non-thymidine-containing therapy.

METHODS

This was a cross-sectional comparison among three age- and gender-matched groups (n = 19 × 3): healthy non-HIV-infected participants, HIV-infected long-term non-progressors (LTNPs) and standard antiretroviral-naive chronically infected patients [standard progressors (Sps)], longitudinally evaluated before (Sp1) and after (Sp2) >1 year of efavirenz + tenofovir + emtricitabine therapy. We analysed mitochondrial DNA content by RT-PCR, mitochondrial function by spectrophotometry, mitochondrial protein synthesis by western blot analysis, mitochondrial dynamics by western blot analysis (MFN2), apoptotic transition pore formation by western blot analysis (VDAC-1) and mitochondrial membrane potential and annexin V/propidium iodide fluorescence by flow cytometry.

RESULTS

There was a decreasing non-significant trend towards lower mitochondrial parameters for HIV-infected values with respect to uninfected control reference values. HIV progression (LTNP versus Sp1) was associated with decreased mitochondrial genetic, functional and translational parameters, which partially recovered after treatment intervention (Sp2). Mitochondrial fusion showed a trend to decrease non-significantly in Sp patients compared with LTNP patients, especially after therapy. All apoptotic parameters showed a trend to increase in Sp1 with respect to LTNP, followed by recovery in Sp2.

CONCLUSIONS

We proposed an in vitro model for mitochondrial and apoptotic assessment to test the effects of HIV infection and its therapy, resembling in vivo conditions. This model could be useful for clinical research purposes.

On the Molecular Modeling Analyses of Novel HIV-1 Protease Inhibitors Based on Modified Chitosan Dimer

The molecular modeling studies include quantitative structure activity relationship, IR spectra, and docking calculations, occurring for novel inhibitors based on chitosan dimer which were tried as HIV protease. The inhibitors were investigated with molecular modeling calculations at different level of theories. Each compound has phenol with hydroxymethylcarbonyl (HMC) group which added to chitosan in positions 2, 3, 2′, or 3′. The geometry of studied compounds is optimized with semiempirical PM3 method. Quantitative structure activity relationship (QSAR) properties of the suggested compounds are calculated at the same level of theory. Depending on QSAR calculations, the compounds with positions 2 and 2′ are less hydrophilic. The position 2′ compound makes good docking interaction into HIV protease active site. Calculated IR spectra indicate that the interaction through hydrogen bonding through the hydrogen of OH at positions 3 and 3′ gives rise to two OH bands one for chitosan and the other for phenol and HMC group. While at position 3′ CH band starts to appear.

Understanding the etiology and management of HIV-associated peripheral neuropathy

HIV may cause several forms of peripheral neuropathy, the most common of which is distal symmetric polyneuropathy (DSP) characterized by pain and sensory deficits in a stocking-glove distribution. The pathophysiology of DSP remains largely unknown but is thought to be related both to the neurotoxicity of HIV-through indirect immunomodulatory mechanisms-and to the neurotoxic effects of anti-retroviral therapies, most notably the dideoxynucleoside reverse transcription inhibitors or so-called d-drugs. Determining whether symptoms arise from the virus or the treatment poses a challenge to the clinician who must decide if a patient's HAART regimen should be altered. Treatment of symptoms related to HIV-DSP is a difficult task and there is no evidence that the traditional agents used in chronic neuropathic pain are efficacious in the HIV-DSP population. Indeed few pharmacologic agents have proven efficacy in HIV-DSP - these include cannabis and the capsaicin 8 % dermal patch. As such, alternative, non-pharmacologic therapies are being investigated. More research is needed to further elucidate the complex pathophysiology of HIV-DSP which may yield additional therapies for these patients.

Long-Term Effect of Acetyl-L-Carnitine for Antiretroviral Toxic Neuropathy

BACKGROUND

Nucleoside analogue reverse transcriptase inhibitors (NRTIs) used for the treatment of HIV can a cause distal symmetrical peripheral polyneuropathy by disruption of mitochondrial metabolism. Treatment with acetyl-L-carnitine (ALCAR) has shown short-term symptomatic and histological improvement. Long-term effects have not been investigated.

PURPOSE

To assess the subjective and objective degree of antiretroviral toxic neuropathy (ATN) during treatment with ALCAR.

METHOD

A cohort of 21 patients with ATN who commenced treatment with ALCAR between March 1999 and October 2001 was reviewed after a mean of 4.3 years using standardized questionnaires and neurological examination.

RESULTS

Of the 21 patients, 2 had died and 3 were lost to follow-up. 16 patients were assessed. 10 were still on potentially neurotoxic drugs. 13 were still taking ALCAR. 9 were pain free. The most common symptom was numbness (mild, moderate, and severe in 12, 3, and 0 patients, respectively), followed by paraesthesia (8, 2, 2), pain (4, 3, 0), and burning (5, 2, 0). There was mildly reduced sensation in the toes of 8 patients. 13 patients reported that ALCAR had improved their symptoms very much or moderately, 2 reported no change, and 1 reported a moderate worsening.

CONCLUSION

ALCAR led to long-term symptomatic improvement in most patients without the need to discontinue neurotoxic drugs. Although in this study there was no control group, this agent appears to be an effective pathogenesis-based treatment for ATN.

Hydroxyurea plus Didanosine as Maintenance Therapy for HIV-Infected Patients on Long-Term Successful Highly Active Antiretroviral Therapy

BACKGROUND

Toxicity and quality of life issues have moved to delay the initiation of highly active antiretroviral therapy (HAART) and to explore novel treatment strategies for HIV infection. The switch to simpler regimens or treatment discontinuation has been attempted with limited success. The combination of hydroxyurea (HU) plus didanosine (ddI) is a simple regimen that might be able to restrain virus replication for long periods of time and could be an acceptable option as maintenance therapy in patients on prolonged successful HAART.

METHOD

The combination of HU (500 mg bid) plus ddI (400 mg qd) was offered to participants with viral load (VL) <50 HIV RNA copies/mL and CD4 counts >350 cells/microL for more than 6 months under HAART. The prior HAART regimen was resumed if VL rose to >5,000 copies/mL and/or the CD4 count fell to <200 cells/microL after being on HU + ddI maintenance therapy.

RESULTS

A total of 187 participants replaced HAART with HU + ddI. In an intent-to-treat analysis at 48 weeks, 109 (58%) and 77 (41%) patients had VL below 5,000 and 500 HIV RNA copies/mL, respectively. The mean CD4 count dropped from 809 +/- 283 to 573 +/- 270 cells/microL, while 77% of patients remained above 350 cells/microL. The proportion of participants with hypercholesterolemia declined from 70% to 46% (p <.001), while those with hypertriglyceridemia fell from 36% to 21% (p <.05). Significant improvements in lipohypertrophy and lipoatrophy were observed in 52% and 64% of participants, respectively. Grade 3-4 toxicities appeared in 20 patients (11%), including 3 cases of pancreatitis and 1 of peripheral neuropathy. Prior history of VL >5 log, CD4 counts <200 cells/microL, and ddI experience were independently associated with lower response to HU + ddI maintenance therapy.

CONCLUSION

The combination of HU + ddI may be a satisfactory maintenance therapy for more than half of patients on successful HAART who want to alleviate drug-related toxicities and/or pill burden. Patients with metabolic and/or body-shape abnormalities might particularly benefit from switching to this simple regimen.

Mild to Moderate Symptoms Do Not Correlate with Lactate Levels in HIV-Positive Patients on Nucleoside Reverse Transcriptase Inhibitors

PURPOSE

Nucleoside reverse transcriptase inhibitors (NRTIs) are associated with mitochondrial toxicities ranging from asymptomatic hyperlactatemia to fatal lactic acidosis. It is uncertain whether mild clinical symptoms predict hyperlactatemia and the need to consider changes in antiretroviral therapy. This cross-sectional study evaluated whether an association exists between mild symptoms and lactate levels.

METHOD

HIV-positive patients on NRTIs attending routine clinic visits were surveyed about symptoms associated with hyperlactatemia. Symptom severity was quantified using Likert scales, and the sum was converted into a symptom score ranging from 0 to 30. Tourniquet-free blood specimens were collected simultaneously to measure serum lactate. Symptom scores were compared between patients with normal and elevated lactates.

RESULTS

284 individuals were included. The most common NRTIs used included lamivudine (79%), zidovudine (50%), abacavir (39%), and stavudine (24%). Twenty-two patients (8%) had increased lactates (mean = 2.7 mmol/L; range, 2.1-4.5 mmol/L), while 262 patients (92%) had normal lactates (mean = 1.2 mmol/L, range, 0.1-2.0 mmol/L). Median symptom scores were similar between groups (3 vs. 2, p = .23). Spearman's correlation coefficient for lactate and symptom score was 0.07 (p = .22).

CONCLUSIONS

Mild symptoms did not correlate with lactate levels, and symptoms alone should not trigger clinicians to measure serum lactates and stop NRTIs if the levels are elevated.

Chronic liver disease in the human immunodeficiency virus patient

There are an estimated 40 million HIV infected individuals worldwide, with chronic liver disease being the 2nd leading cause of mortality in this population. Elevated liver functions are commonly noted in HIV patients and the etiologies are varied. Viral hepatitis B and C, fatty liver and drug induced liver injury are more common. Treatment options for viral hepatitis C are rapidly evolving and are promising, but treatments are limited for the other conditions and is primarily supportive. Opportunistic infections of the liver are now uncommon. Irrespective of etiology, management requires referral to specialized centers and with due diligence mortality can be reduced.

Low dose versus high dose stavudine for treating people with HIV infection

BACKGROUND

Stavudine remains a component of combination antiretroviral therapy (ART) in resource-constrained countries due to its relatively low cost despite the WHO recommendation for its phasing out as a strategy to reduce stavudine associated toxicities. Where stavudine is still in use, it is recommended at a dose lower than the standard dose in order to reduce stavudine related toxicity.

OBJECTIVES

To compare the safety and virologic efficacy of low dose versus high dose stavudine for treating HIV-1 infection.

SEARCH METHODS

The comprehensive search strategy developed by the Cochrane HIV/AIDS Review Group was used to identify randomised controlled trials that compared the use of low dose versus high dose stavudine. The last search was conducted in February 2014 and the searches covered the period 1996 to 2014.

SELECTION CRITERIA

Randomised controlled trials comparing the use of low dose and high dose stavudine as part of ART combination therapy for treating adults.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected eligible trials, assessed methodological quality of the included studies and completed data extraction and analysis.

MAIN RESULTS

The search identified 3952 abstracts which were scanned for relevance. Three trials met the inclusion criteria (Milinkovic 2007; McComsey 2008; Sanchez-Conde 2005). All three trials were conducted in developed countries, participants were ART experienced and all had sustained virologic suppression at baseline. A total of 157 participants were recruited to the trials. Sample sizes ranged from 24 to 92 and more than 79% of participants were male.The studies were at a high risk of selection, performance/detection and selective outcome reporting biases. Some baseline characteristics differed among the groups, including triglyceride levels in two studies and body mass index in one study. In light of variation in the design and follow-up of the study results, no meta-analysis was performed and the results of single studies are presented. There was no significant difference in virologic suppression in the included studies (Milinkovic 2007; McComsey 2008; Sanchez-Conde 2005); Risk Ratio (RR) 1.09 (95% CI: 0.93 to 1.28), 0.94 (95% CI:0.59 to 1.50) and 1.03 (95% CI: 0.90 to 1.18) respectively. Symptomatic hyperlactatemia was seen in the high dose arm of the Milinkovic 2007 study; RR 0.21 (95% CI: 0.01 to 4.66), in no participants in the McComsey 2008 trial and not reported on in the Sanchez-Conde 2005 trial. McComsey 2008 and Milinkovic 2007 demonstrated a reduction in bone mineral density (BMD), reduction in limb fat and an increase in triglycerides in the high dose arms. The studies did not indicate that any participants discontinued treatment due to adverse events.

AUTHORS' CONCLUSIONS

This systematic review identified only three small trials that evaluated virologic efficacy and safety of high dose versus low dose stavudine. All three trials were conducted in developed countries and none reported from developing countries yet stavudine remains a component of ART combination therapy in many developing countries. It was not possible to perform a meta-analysis on these trails. Individual results from the trials were imprecise and have not identified a clear advantage in virologic efficacy or safety between low and high dose stavudine. Furthermore, enrolled participants were treatment experienced with sustained virologic suppression and so existing data cannot be generalized to settings where stavudine is currently used in ART naive patients with high viral loads. Stavudine dose reduction trials in ART naive patients, in developing countries where stavudine is still being used are warranted as the phasing out of stavudine that is recommended by WHO may not be immediately universally feasible.

Monotherapy with boosted PIs as an ART simplification strategy in clinical practice

BACKGROUND

Data on the efficacy of simplifying therapy using darunavir/ritonavir and lopinavir/ritonavir monotherapy in clinical practice remain limited.

METHODS

A retrospective single-centre study including patients initiating darunavir/ritonavir or lopinavir/ritonavir monotherapy with a plasma HIV-1 viral load (pVL) <50 copies/mL and at least one subsequent follow-up visit. The primary endpoint was the percentage of patients remaining free of virological failure (VF; defined as a confirmed pVL >50 copies/mL or as any change in the regimen after a single determination with a pVL >50 copies/mL) during the follow-up. We also evaluated the percentage of patients remaining free of treatment failure (TF; defined as VF or the early discontinuation of monotherapy for any reason) and compared the effectiveness of the two regimens. Effectiveness was evaluated using cumulative survival analysis (at Weeks 48 and 96). Factors associated with VF and TF were analysed using Cox regression.

RESULTS

A total of 522 patients were included (309 receiving lopinavir/ritonavir and 213 receiving darunavir/ritonavir). The median follow-up was 64.3 (30.5-143.0) weeks. The percentage of patients free of VF and TF was 94% (95% CI 91%-96%) and 79% (95% CI 75%-82%) at 48 weeks, respectively, and 86% (95% CI 81%-89%) and 62% (95% CI 57%-67%) at 96 weeks, respectively. The risk of VF was similar for the two regimens (HR=1.0, 95% CI 0.6-1.8; P=0.962). Lopinavir/ritonavir monotherapy was associated with a 1.5-fold greater risk of TF (95% CI 1.1-2.1; P=0.012) and a 2.3-fold greater risk of discontinuation of therapy due to adverse events (95% CI 1.3-3.9; P=0.003).

CONCLUSIONS

The virological efficacy of darunavir/ritonavir and lopinavir/ritonavir monotherapy is high in clinical practice. Treatment discontinuation due to safety issues is more frequent with lopinavir/ritonavir.

A review of the toxicity of HIV medications

Antiretroviral therapy has changed human immunodeficiency virus (HIV) infection from a near-certainly fatal illness to one that can be managed chronically. More patients are taking antiretroviral drugs (ARVs) for longer periods of time, which naturally results in more observed toxicity. Overdose with ARVs is not commonly reported. The most serious overdose outcomes have been reported in neonates who were inadvertently administered supratherapeutic doses of HIV prophylaxis medications. Typical ARV regimens include a "backbone" of two nucleoside reverse transcriptase inhibitors (NRTI) and a "base" of either a protease inhibitor (PI) or nonnucleoside reverse transcriptase inhibitor. New classes of drugs called entry inhibitors and integrase inhibitors have also emerged. Older NRTIs were associated with mitochondrial toxicity, but this is less common in the newer drugs, emtricitabine, lamivudine, and tenofovir. Mitochondrial toxicity results from NRTI inhibition of a mitochondrial DNA polymerase. Mitochondrial toxicity manifests as myopathy, neuropathy, hepatic failure, and lactic acidosis. Routine lactate assessment in asymptomatic patients is not indicated. Lactate concentration should be obtained in patients taking NRTIs who have fatigue, nausea, vomiting, or vague abdominal pain. Mitochondrial toxicity can be fatal and is treated by supportive care and discontinuing NRTIs. Metabolic cofactors like thiamine, carnitine, and riboflavin may be helpful in managing mitochondrial toxicity. Lipodystrophy describes changes in fat distribution and lipid metabolism that have been attributed to both PIs and NRTIs. Lipodystrophy consists of loss of fat around the face (lipoatrophy), increase in truncal fat, and hypertriglyceridemia. There is no specific treatment of lipodystrophy. Clinicians should be able to recognize effects of chronic toxicity of ARVs, especially mitochondrial toxicity.

Association of circulating cytochrome c with clinical manifestations of antiretroviral-induced toxicity

Diagnosis of antiretroviral therapy (ART) toxicity is complicated. Apoptosis has been implicated in ART toxicity. Cytochrome c (Cyt-C) is a mitochondrial protein found in plasma during pro-apoptotic states. We conducted a study of HIV-infected individuals on ART with (cases, n=21) and without (controls, n=21) clinical evidence of toxicity to determine if elevated plasma Cyt-C is associated with ART toxicity. When corrected for CD4 count, viral load, and duration of HIV infection, cases are 7.86 times more likely than controls to have plasma Cyt-C>0.216 ng/mL. Cyt-C could be a useful clinical tool to guide treatment decisions in this population.

Contemporary review of drug-induced pancreatitis: A different perspective

Although gallstone and alcohol use have been considered the most common causes of acute pancreatitis, hundreds of frequently prescribed medications are associated with this disease state. The true incidence is unknown since there are few population based studies available. The knowledge of drug induced acute pancreatitis is limited by the availability and the quality of the evidence as the majority of data is extrapolated from case reports. Establishing a definitive causal relationship between a drug and acute pancreatitis poses a challenge to clinicians. Several causative agent classification systems are often used to identify the suspected agents. They require regular updates since new drug induced acute pancreatitis cases are reported continuously. In addition, infrequently prescribed medications and herbal medications are often omitted. Furthermore, identification of drug induced acute pancreatitis with new medications often requires accumulation of post market case reports. The unrealistic expectation for a comprehensive list of medications and the multifactorial nature of acute pancreatitis call for a different approach. In this article, we review the potential mechanisms of drug induced acute pancreatitis and provide the perspective of deductive reasoning in order to allow clinicians to identify potential drug induced acute pancreatitis with limited data.

Acquired Fanconi syndrome due to long-term adefovir administration in a patient with IgG-kappa monoclonal gammopathy and kappa Bence-Jones protein

A 77-year-old man was admitted to our hospital for a right femoral neck fracture. He had been prescribed lamivudine for chronic hepatitis B infection for 11 years, and adefovir was added 5 years ago. After hospitalization, a right femoral head prosthesis was performed successfully, but an unknown hypokalemia was revealed. Hypophosphatemia, hypouricemia, glucosuria, and panaminoaciduria were also revealed, and multiple microfractures were detected by bone scintigraphy. We diagnosed him as 'osteomalacia associated with Fanconi syndrome,' which was likely due to the adefovir. Moreover, a monoclonal IgG-kappa and a kappa Bence-Jones protein were detected in his serum and urine, respectively. We switched from adefovir plus lamivudine to entecavir and started calcitriol. His excessive urinary β2-microglobulin excretion and glucosuria had decreased dramatically at 10 weeks after the modification of drugs; those of the phosphate, uric acid and total protein, however, continued. Renal biopsy specimens obtained at 10 weeks after discontinuation of adefovir revealed focal tubular atrophic changes with/without inflammatory cells, which were predominantly observed next to glomeruli. Kappa-dominant staining was not observed in either glomeruli or tubules with immunostaining by the enzyme-labeled antibody method. Electron microscopy revealed neither crystalline structures in the cytoplasm of proximal tubules nor electron-dense deposits. Because of the remarkable proportional reduction of other urinary protein fractions, urinary M-peak appeared 26 weeks after discontinuation of adefovir, but the net amounts of the fraction decreased gradually.

A brief review on human mtDNA mutations and NRTI-associated mtDNA toxicity and mutations

Mitochondrion is a cellular organelle that is present in most of the cells and is responsible for producing energy for the cell. Mitochondria have their own double-stranded DNA genome which is distinct from nuclear genome. The replication, recombination and repair of mtDNA are achieved by DNA polymerase-gamma which is encoded by POLG gene. Mutation in the mtDNA or POLG gene might lead to mitochondrial dysfunction and disease. Several mutations and polymorphisms in these regions have been associated to mitochondrial disorders. Nuceloside and nucelotide reverse transcriptase inhibitors (NRTIs) that form the basis of AIDS therapy have significantly increased the survival rate of HIV-infected individuals predisposing them to other side effects. One of the most common side effects of NRTI usage is mitochondrial toxicity leading to several mitochondrial disorders. Mutations in mtDNA have also been associated to the use of specific NRTIs leading to specific mitochondrial disorders. This review briefly summarizes the advances in mtDNA mutations and NRTI-caused mitochondrial toxicity and mutations.

Zidovudine induces downregulation of mitochondrial deoxynucleoside kinases: implications for mitochondrial toxicity of antiviral nucleoside analogs

Mitochondrial thymidine kinase 2 (TK2) and deoxyguanosine kinase (dGK) catalyze the initial phosphorylation of deoxynucleosides in the synthesis of the DNA precursors required for mitochondrial DNA (mtDNA) replication and are essential for mitochondrial function. Antiviral nucleosides are known to cause toxic mitochondrial side effects. Here, we examined the effects of 3'-azido-2',3'-dideoxythymidine (AZT) (zidovudine) on mitochondrial TK2 and dGK levels and found that AZT treatment led to downregulation of mitochondrial TK2 and dGK in U2OS cells, whereas cytosolic deoxycytidine kinase (dCK) and thymidine kinase 1 (TK1) levels were not affected. The AZT effects on mitochondrial TK2 and dGK were similar to those of oxidants (e.g., hydrogen peroxide); therefore, we examined the oxidative effects of AZT. We found a modest increase in cellular reactive oxygen species (ROS) levels in the AZT-treated cells. The addition of uridine to AZT-treated cells reduced ROS levels and protein oxidation and prevented the degradation of mitochondrial TK2 and dGK. In organello studies indicated that the degradation of mitochondrial TK2 and dGK is a mitochondrial event. These results suggest that downregulation of mitochondrial TK2 and dGK may lead to decreased mitochondrial DNA precursor pools and eventually mtDNA depletion, which has significant implications for the regulation of mitochondrial nucleotide biosynthesis and for antiviral therapy using nucleoside analogs.

HIV-associated lipodystrophy: impact of antiretroviral therapy

In the late 1990s, reports of unusual changes in body fat distribution named 'lipodystrophy' (LD) began to appear in HIV patients mitigating the enormous enthusiasm about improvement of survival and quality of life provided by the combinations of antiretroviral (ARV) drug classes, the so-called highly active antiretroviral therapy (HAART), which had just become available at that time. The objective of this paper is to critically review the literature on LD and to discuss the impact of newer ARV agents, namely atazanavir, darunavir and raltegravir, as well as strategies of the late HAART era, including single-tablet regimens and nucleoside-sparing regimens. Studies in which LD was measured by dual-energy x-ray absorptiometry or by abdominal computed tomography or magnetic resonance imaging scan only, were included. We were unable to identify studies depicting a negative impact of drugs or ARV regimens on limb fat loss. On the contrary, a few studies identified a negative impact of atazanavir/ritonavir or darunavir/ritonavir on trunk fat increase. It should be noted that this anthropometric measure is a poor instrument since it cannot distinguish between subcutaneous and visceral fat. We conclude that presumably the body fat changes currently observed in HIV-infected patients is the net result of competing phenomena: on one side the natural history of lipohypertrophy as a result of HIV and HAART impact, and on the other side the physiological body fat changes observed in the aging population.

Antiretroviral therapy-induced mitochondrial toxicity: potential mechanisms beyond polymerase-γ inhibition

We hypothesized that competition between nucleotide reverse-transcriptase inhibitor triphosphate and endogenous deoxyribonucleotide triphosphate (dNTP) may lead to depletion of dNTP pools and mitochondrial dysfunction independent of polymerase-γ (pol-γ) inhibition. We collected peripheral blood mononuclear cells from 75 adults (25 cases: HIV-infected patients with mitochondrial toxicity, 25 HIV-infected positive controls, and 25 HIV-negative controls). We observed statistically significant individual and group differences in ribonucleotide (RN) and deoxyribonucleotide (dRN) pools. The median values for the RN pools were 10,062 (interquartile range (IQR): 7,090-12,590), 4,360 (IQR: 3,058-6,838), and 2,968 (IQR: 2,538-4,436) pmol/10(6) cells for negative controls, positive controls, and cases, respectively. Cases had significantly higher absolute mitochondrial DNA copy number as compared with negative controls (P < 0.05). Moreover, cases had significantly higher expression levels of pol-γ, nucleotide transporters, cellular kinases, and adenosine triphosphate (ATP)-binding cassette (ABC) proteins as compared with controls. Antiretroviral therapy (ART) perturbs RN and dRN pools. Depletion of RN and dRN pools may be associated with ART-induced mitochondrial toxicity independent of pol-γ inhibition.

Neurological and psychiatric adverse effects of antiretroviral drugs

Antiretroviral drugs are associated with a variety of adverse effects on the central and peripheral nervous systems. The frequency and severity of neuropsychiatric adverse events is highly variable, with differences between the antiretroviral classes and amongst the individual drugs in each class. In the developing world, where the nucleoside reverse transcriptase inhibitor (NRTI) stavudine remains a commonly prescribed antiretroviral, peripheral neuropathy is an important complication of treatment. Importantly, this clinical entity is often difficult to distinguish from human immunodeficiency virus (HIV)-induced peripheral neuropathy. Several clinical trials have addressed the efficacy of various agents in the treatment of NRTI-induced neurotoxicity. NRTI-induced neurotoxicity is caused by inhibition of mitochondrial DNA polymerase. This mechanism is also responsible for the mitochondrial myopathy and lactic acidosis that occur with zidovudine. NRTIs, particularly zidovudine and abacavir, may also cause central nervous system (CNS) manifestations, including mania and psychosis. The non-nucleoside reverse transcriptase inhibitor (NNRTI) efavirenz is perhaps the antiretroviral most commonly associated with CNS toxicity, causing insomnia, irritability and vivid dreams. Recent studies have suggested that the risk of developing these adverse effects is increased in patients with various cytochrome P450 2B6 alleles. Protease inhibitors cause perioral paraesthesias and may indirectly increase the relative risk of stroke by promoting atherogenesis. HIV integrase inhibitors, C-C chemokine receptor type 5 (CCR5) inhibitors and fusion inhibitors rarely cause neuropsychiatric manifestations.

Hyperlactatemia in a group of HIV patients living in Yaounde-Cameroon

Background and aim

Prolonged exposure to highly active antiretroviral therapy (HAART) is associated with adverse effects such as hyperlactatemia. We determined the prevalence and risk factors for developing hyperlactatemia among human immunodeficiency virus (HIV)-infected cameroonians on antiretroviral therapy (ART).

Methods

We conducted a cross-sectional study from January to April 2012 involving 91 HIV-infected patients receiving ART for at least 12 months and 30 HIV-infected patients who have never received ART (ART-naïve patients). Plasma lactate levels were determined after at least 12 hours of overnight fasting and hyperlactatemia defined as lactate concentrations ≥ 3 mmol/L. The prevalence of hyperlactatemia was determined and the risk factors were analyzed by a multivariate logistic regression model.

Results

The mean lactataemia was significantly higher in the group of HIV patients currently taking ART than in the ART-naïve one (2.3 ± 1.3 and 1.7 ± 0.7 mmol/L respectively, p = 0.002). Patients on first line ART regimens had significantly higher lactatemia than those on second line regimens (2.5 ± 1.5 and 1.9 ± 0.7 mmol/L respectively, p = 0.014). The prevalence of hyperlactatemia in HIV patients receiving ART and in ART-naïve HIV patients was respectively 18.7 and 6.7% (p = 0.095). ART-exposure (adjusted odds ratio (aOR) 5.44, 95% confidence interval (CI) 1.06 – 27.84; p = 0.042) and being on a first line regimen (aOR 16.22, 95% CI 1.57 – 167.91; p = 0.019) were independent strong predictors of hyperlactatemia.

Conclusion

Hyperlactatemia was not rare in our study population. Being on a first line regimen constitutes an important risk factor for developing hyperlactatemia. Measurement of plasma lactate may be useful in optimizing the management of HIV-positive persons on ART.

Conformationally constrained nucleoside phosphonic acids – potent inhibitors of human mitochondrial and cytosolic 5′(3′)-nucleotidases

Conformationally constrained nucleoside phosphonic acids – potent inhibitors of human mitochondrial and cytosolic 5′(3′)-deoxynucleotidases.

Rhabdomyolysis in an HIV-infected patient following coronary angiography: case report and literature review

Rhabdomyolysis is a rare, but possible, complication of combination antiretroviral therapy (cART). We report a unique case of an HIV-positive patient on cART who came to our attention for suspected ischaemic heart disease. Coronary angiography was carried out and complicated in the following days by rhabdomyolysis. We discuss the possible links between rhabdomyolysis, iodinated contrast media and HAART.

Zidovudine (AZT) and hepatic lipid accumulation: implication of inflammation, oxidative and endoplasmic reticulum stress mediators

The clinical effectiveness of Zidovudine (AZT) is constrained due to its side-effects including hepatic steatosis and toxicity. However, the mechanism(s) of hepatic lipid accumulation in AZT-treated individuals is unknown. We hypothesized that AZT-mediated oxidative and endoplasmic reticulum (ER) stress may play a role in the AZT-induced hepatic lipid accumulation. AZT treatment of C57BL/6J female mice (400 mg/day/kg body weight, i.p.) for 10 consecutive days significantly increased hepatic triglyceride levels and inflammation. Markers of oxidative stress such as protein oxidation, nitration, glycation and lipid peroxidation were significantly higher in the AZT-treated mice compared to vehicle controls. Further, the levels of ER stress marker proteins like GRP78, p-PERK, and p-eIF2α were significantly elevated in AZT-treated mice. The level of nuclear SREBP-1c, a transcription factor involved in fat synthesis, was increased while significantly decreased protein levels of phospho-acetyl-CoA carboxylase, phospho-AMP kinase and PPARα as well as inactivation of 3-keto-acyl-CoA thiolase in the mitochondrial fatty acid β-oxidation pathway were observed in AZT-exposed mice compared to those in control animals. Collectively, these data suggest that elevated oxidative and ER stress plays a key role, at least partially, in lipid accumulation, inflammation and hepatotoxicity in AZT-treated mice.

Effects of substitutions at the 4' and 2 positions on the bioactivity of 4'-ethynyl-2-fluoro-2'-deoxyadenosine

Nucleos(t)ide reverse transcriptase inhibitors (NRTIs) form the backbone of most anti-HIV therapies. We have shown that 4'-ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) is a highly effective NRTI; however, the reasons for the potent antiviral activity of EFdA are not well understood. Here, we use a combination of structural, computational, and biochemical approaches to examine how substitutions in the sugar or adenine rings affect the incorporation of dA-based NRTIs like EFdA into DNA by HIV RT and their susceptibility to deamination by adenosine deaminase (ADA). Nuclear magnetic resonance (NMR) spectroscopy studies of 4'-substituted NRTIs show that ethynyl or cyano groups stabilize the sugar ring in the C-2'-exo/C-3'-endo (north) conformation. Steady-state kinetic analysis of the incorporation of 4'-substituted NRTIs by RT reveals a correlation between the north conformation of the NRTI sugar ring and efficiency of incorporation into the nascent DNA strand. Structural analysis and the kinetics of deamination by ADA demonstrate that 4'-ethynyl and cyano substitutions decrease the susceptibility of adenosine-based compounds to ADA through steric interactions at the active site. However, the major determinant for decreased susceptibility to ADA is the 2-halo substitution, which alters the pKa of N1 on the adenine base. These results provide insight into how NRTI structural attributes affect their antiviral activities through their interactions with the RT and ADA active sites.

Routine depression screening in an HIV clinic cohort identifies patients with complex psychiatric co-morbidities who show significant response to treatment

This study described characteristics, psychiatric diagnoses and response to treatment among patients in an outpatient HIV clinic who screened positive for depression. Depressed (25 %) were less likely to have private insurance, less likely to have suppressed HIV viral loads, had more anxiety symptoms, and were more likely to report current substance abuse than not depressed. Among depressed, 81.2 % met diagnostic criteria for a depressive disorder; 78 % for an anxiety disorder; 61 % for a substance use disorder; and 30 % for co-morbid anxiety, depression, and substance use disorders. Depressed received significantly more treatment for depression and less HIV primary care than not depressed patients. PHQ-9 total depression scores decreased by 0.63 from baseline to 6-month follow-up for every additional attended depression treatment visit. HIV clinics can routinely screen and treat depressive symptoms, but should consider accurate psychiatric diagnosis as well as co-occurring mental disorders.

Safety of tenofovir during pregnancy for the mother and fetus: a systematic review

Tenofovir disoproxil fumarate (TDF) safety during pregnancy has important public health implications. This review summarizes TDF safety during pregnancy, focusing on pregnancy outcomes, congenital anomaly risk, and other potential toxicities on neonates. Although information is limited, TDF appears to be safe during pregnancy. In 6 studies of human immunodeficiency virus type 1 (and/or hepatitis B virus)-infected women receiving TDF during pregnancy, adverse events were mild to moderate; none were considered to be TDF-related. Five studies that followed in utero TDF-exposed infants showed no increased risk of growth or bone abnormalities. One study showed slightly lower infant height at age 1 year, but the significance is unclear. The Antiretroviral Pregnancy Registry database, with 1800 pregnancies exposed to TDF in the first trimester, does not indicate increased congenital anomaly risk with TDF exposure. More evidence collected prospectively, ideally with bone density measurements and randomized trial design, will be optimal to determine the effects of antenatal TDF exposure on children's health.

An unusual case of hyperlactataemia in a neonate

We report a HIV uninfected neonate born to HIV positive mother, who had tachypnoea at birth. On investigations, he was found to have hyperlactataemia. All the secondary causes for elevated lactate were ruled out. Hyperlactataemia was attributed to the perinatal exposure, to maternal antiretroviral (ARV) drugs, mainly nucleoside analogues. Asymptomatic and symptomatic hyperlactataemia is not uncommon in HIV-exposed infants. Neonates with tachypnoea, who are HIV- and ARV-exposed with no obvious cause, should be screened for raised arterial lactate.

Virological efficacy in cerebrospinal fluid and neurocognitive status in patients with long-term monotherapy based on lopinavir/ritonavir: an exploratory study

BACKGROUND

Data on suppression of HIV replication in the CNS and on the subsequent risk of neurocognitive impairment using monotherapy with boosted protease inhibitors are limited.

METHODS

Ours was an exploratory cross-sectional study in patients on lopinavir/ritonavir-based monotherapy (LPV/r-MT) or standard triple therapy (LPV/r-ART) for at least 96 weeks who maintained a plasma viral load <50 copies/mL. HIV-1 RNA in CSF was determined by HIV-1 SuperLow assay (lower limit of detection, 1 copy/mL). Neurocognitive functioning was assessed using a recommended battery of neuropsychological tests covering 7 areas. Neurocognitive impairment (NCI) was determined and also a global deficit score (GDS) for study comparisons.

RESULTS

Seventeen patients on LPV/r-MT and 17 on LPV/r-ART were included. Fourteen (82.4%) patients on LPV/r-MT and 16 (94.1%) on LPV/r-ART had HIV-1 RNA <1 copy/mL in CSF (p = 0.601). NCI was observed in 7 patients on LPV/r-MT and in 10 on LPV/r-ART (41% vs 59%; p = 0.494). Mean (SD) GDS was 0.22 (0.20) in patients on LPV/r-MT and 0.47 (0.34) in those on LPV/r-ART (p = 0.012).

CONCLUSIONS

Suppression of HIV in CSF is similar in individuals with durable plasma HIV-1 RNA suppression who are receiving LPV/r-MT or LPV/r-ART for at least 96 weeks. Findings for HIV-1 replication in CSF and neurocognitive status indicate that this strategy seems to be safe for CNS functioning.

Does mitochondrial dysfunction during antiretroviral therapy in human immunodeficiency virus infection suggest antioxidant supplementation as a beneficial option?

Over the last few years, a relative decline of the morbidity and mortality of human immunodeficiency virus (HIV) infection in industrialised countries has been observed due to the use of a potent combined therapy known as high active antiretroviral therapies (HAARTs). It has led to a decrease of viral load and a quantitative and qualitative improvement of immune function in patients, especially CD4+ T-lymphocyte count, having as a consequence a decrease of infectious complications and a global clinical improvement. Besides the positive effects of HAARTs on immune and metabolic alterations during HIV infection, it has been reported that the commonly used drugs AZT, ddI, and ddC are toxic to hepatocytes. Recent reports continue to point to the mitochondria as targets for toxicity. The prevalence of these symptoms is continued during acquired immunodeficiency syndrome (AIDS). The effects of oxidative stress occurring as a consequence of mitochondrial toxicity may amplify some of the pathophysiological and phenotypic events during infection. Mitochondrial stabilisation and antioxidative strategies are possible new therapeutic aims since the antiretroviral treatment is prolonged with increased longevity from AIDS, which has become a more manageable chronic illness. The aim of the present review article is to summarize the current knowledge about mitochondrial dysfunction during HAART and its consequence for patients with chronic treatment. Oxidative stress may serve as one pathway for cellular damage in AIDS and its treatment. One important future goal is to prevent or attenuate the side effects of HAART so that improved disease management can be achieved.

Identification of fatigue biomarkers in treated and treatment-naive HIV patients: preliminary results

Objective assessment in human immunodeficiency virus (HIV)-related fatigue has been elusive because the biological mechanisms are not well characterized. We tried to identify low-abundance plasma proteins that correlate with self-reported fatigue intensity in people living with HIV. We used plasma samples from 32 patients with HIV with varying degrees of fatigue who were either treated with nucleoside reverse transcriptase inhibitors or treatment naïve. The plasma samples were enriched for low-abundance proteins and trypsinized. The peptides were analyzed using shotgun proteomics. Five targets correlated with severity of fatigue: apolipoprotein A-1 (ApoA1), apolipoprotein B (ApoB), histine-rich glycoprotein, alpha-1 B glycoprotein, and orosomucoid 2. These targets were selected based on total abundance and spectral count differences, and ApoA1 and ApoB were analyzed via Western blots to verify the mass spectrometry results. ApoA1 levels were higher in untreated patients, while ApoB results suggested a possible positive trend in treated patients. Further analysis is needed to identify additional low-abundance proteins and confirm already-identified proteins as potential fatigue biomarkers.

Maraviroc once-daily nucleoside analog-sparing regimen in treatment-naive patients: randomized, open-label pilot study

OBJECTIVE

This study was performed to evaluate a once-daily dual-therapy regimen, maraviroc (MVC) + atazanavir/ritonavir (ATV/r), in treatment-naive patients.

DESIGN

A phase 2b, randomized, open-label pilot study.

METHODS

In Study A4001078 (NCT00827112), treatment-naive patients with CCR5-tropic HIV-1 (HIV-1 RNA ≥1000 copies/mL; CD4 cell count ≥100 cells/mm) were randomized to receive either MVC 150 mg once daily (n = 60) or tenofovir/emtricitabine (TDF/FTC) 300/200 mg once daily (n = 61) + ATV/r 300/100 mg once daily. Primary endpoint was proportion of patients with HIV-1 RNA <50 copies per milliliter at week 48.

RESULTS

At week 48, 44 (74.6%) and 51 (83.6%) patients in the MVC and TDF/FTC treatment groups, respectively, had plasma HIV-1 RNA <50 copies per milliliter. Median change from baseline in CD4 cell count at week 48 was +173 and +187 cells per cubic millimeter with MVC and TDF/FTC, respectively. Seven patients discontinued from each arm; there were no deaths. The incidence of serious adverse events (AEs) was similar in each group; however, there were more grade 3/4 AEs in the MVC group (18 vs 11), mostly due to hyperbilirubinemia. Three patients in each arm were evaluable for virological analysis at discontinuation or failure (HIV-1 RNA >500 copies/mL); no genotypic resistance, change in tropism, or loss of susceptibility relevant to treatment was observed.

CONCLUSIONS

The virological activity and immunological benefit of once-daily MVC + ATV/r were confirmed. Indirect hyperbilirubinemia and associated signs were the most commonly reported AEs in both study treatment groups and were not associated with significant transaminase increases. No drug resistance occurred.

A Case of Possible Darunavir/Ritonavir-Induced Peripheral Neuropathy

A 65-year-old man, M.S.M., known as being HIV infected for 20 years, presented with muscle ache and progressive weakness 3 months after initiation of darunavir as a part of his antiretroviral therapy (ART). The patient's treatment included darunavir/ritonavir 600/100 mg twice daily, plus a backbone of didanosine and abacavir which were the backbone in his previous regimen for several years according to his drug resistance profile. Three months after initiation of darunavir/ritonavir the patient exhibited clinical symptoms of severe pain and progressive weakness of his lower limbs; he was unable to walk and was totally wheelchair-bound. Severe sensory peripheral polyneuropathy was revealed on electromyogram (EMG). All medications, including ART, were stopped. Within two months, concomitantly with initiation of raltegravir, etravirine and emcitricabine/tenofovir, the patient recovered, gained weight, resumed walking and his CD4 counts rose from 270 to 450 cells/mm3. A second EMG study 3 months after initiation of his new ART regimen showed compete recovery of the previously diagnosed peripheral neuropathy. In this report, we present a case of severe HIV-1-related acute demyelinating polyneuropathy which initiated after new generation PI darunavir/ritonavir was given and resolved after cessation of the drug without the use of immune-based therapies. The variety of HIV-related polyneuropathies will be discussed.

Association of thymidylate synthase polymorphisms with acute pancreatitis and/or peripheral neuropathy in HIV-infected patients on stavudine-based therapy

Background

Low expression thymidylate synthase (TS) polymorphism has been associated with increased stavudine triphosphate intracellular (d4T-TP) levels and the lipodystrophy syndrome. The use of d4T has been associated with acute pancreatitis and peripheral neuropathy. However, no relationship has ever been proved between TS polymorphisms and pancreatitis and/or peripheral neuropathy.

Methods

We performed a case-control study to assess the relationship of TS and methylene-tetrahydrofolate reductase (MTHFR) gene polymorphisms with acute pancreatitis and/or peripheral neuropathy in patients exposed to d4T. Student’s t test, Pearson’s correlations, one-way ANOVA with Bonferroni correction and stepwise logistic regression analyses were done.

Results

Forty-three cases and 129 controls were studied. Eight patients (18.6%) had acute pancreatitis, and 35 (81.4%) had peripheral neuropathy. Prior AIDS was more frequent in cases than in controls (OR = 2.36; 95%CI 1.10–5.07, P = 0.0247). L7ow expression TS and MTHFR genotype associated with increased activity were more frequent in patients with acute pancreatitis and/or peripheral neuropathy than in controls (72.1% vs. 46.5%, OR = 2.97; 95%CI: 1.33–6.90, P = 0.0062, and 79.1% vs. 56.6%, OR = 2.90, 95%CI: 1.23–7.41, P = 0.0142, respectively). Independent positive or negative predictors for the development of d4T-associated pancreatitis and/or peripheral neuropathy were: combined TS and MTHFR genotypes (reference: A+A; P = 0.002; OR_A+B = 0.34 [95%CI: 0.08 to 1.44], OR_B+A = 3.38 [95%CI: 1.33 to 8.57], OR_B+B = 1.13 [95%CI: 0.34 to 3.71]), nadir CD4 cell count >200 cells/mm³ (OR = 0.38; 95%CI: 0.17–0.86, P = 0.021), and HALS (OR = 0.39 95%CI: 0.18–0.85, P = 0.018).

Conclusions

Low expression TS plus a MTHFR genotype associated with increased activity is associated with the development of peripheral neuropathy in d4T-exposed patients.

Premature and accelerated aging: HIV or HAART?

Highly active antiretroviral therapy (HAART) has significantly increased life expectancy of the human immunodeficiency virus (HIV)-positive population. Nevertheless, the average lifespan of HIV-patients remains shorter compared to uninfected individuals. Immunosenescence, a current explanation for this difference invokes heavily on viral stimulus despite HAART efficiency in viral suppression. We propose here that the premature and accelerated aging of HIV-patients can also be caused by adverse effects of antiretroviral drugs, specifically those that affect the mitochondria. The nucleoside reverse transcriptase inhibitor (NRTI) antiretroviral drug class for instance, is known to cause depletion of mitochondrial DNA via inhibition of the mitochondrial specific DNA polymerase-γ. Besides NRTIs, other antiretroviral drug classes such as protease inhibitors also cause severe mitochondrial damage by increasing oxidative stress and diminishing mitochondrial function. We also discuss important areas for future research and argue in favor of the use of Caenorhabditis elegans as a novel model system for studying these effects.

Fatigue-related gene networks identified in CD(14)+ cells isolated from HIV-infected patients: part I: research findings

PURPOSE

Human immunodeficiency virus (HIV)-related fatigue (HRF) is multicausal and potentially related to mitochondrial dysfunction caused by antiretroviral therapy with nucleoside reverse transcriptase inhibitors (NRTIs).

METHODOLOGY

The authors compared gene expression profiles of CD14(+) cells of low versus high fatigued, NRTI-treated HIV patients to healthy controls (n = 5/group). The authors identified 32 genes predictive of low versus high fatigue and 33 genes predictive of healthy versus HIV infection. The authors constructed genetic networks to further elucidate the possible biological pathways in which these genes are involved. RELEVANCE FOR NURSING PRACTICE: Genes including the actin cytoskeletal regulatory proteins Prokineticin 2 and Cofilin 2 along with mitochondrial inner membrane proteins are involved in multiple pathways and were predictors of fatigue status. Previously identified inflammatory and signaling genes were predictive of HIV status, clearly confirming our results and suggesting a possible further connection between mitochondrial function and HIV. Isolated CD14(+) cells are easily accessible cells that could be used for further study of the connection between fatigue and mitochondrial function of HIV patients.

IMPLICATION FOR PRACTICE

The findings from this pilot study take us one step closer to identifying biomarker targets for fatigue status and mitochondrial dysfunction. Specific biomarkers will be pertinent to the development of methodologies to diagnosis, monitor, and treat fatigue and mitochondrial dysfunction.

Impact of age on markers of HIV-1 disease

Aging is a complicated process characterized by a progressive loss of homeostasis, which results in an increased vulnerability to multiple diseases. HIV-1-infected patients demonstrate a premature aging phenotype and develop certain age-related diseases earlier in their lifespan than what is seen in the general population. Age-related comorbidities may include the development of bone disease, metabolic disorders, neurologic impairment and immunosenescence. Age also appears to have an effect on traditional markers of HIV-1 disease progression, including CD4+ T-cell count and viral load. These effects are not only a consequence of HIV-1 infection, but in many cases, are also linked to antiretroviral therapy. This review summarizes the complex interplay between HIV-1 infection and aging, and the impact that aging has on markers of HIV-1 disease.

Treatment strategies using adefovir dipivoxil for individuals with lamivudine-resistant chronic hepatitis B

AIM: To investigate retrospectively the long-term efficacy of various treatment strategies using adefovir dipivoxil (adefovir) in patients with lamivudine-resistant chronic hepatitis B.

METHODS: We included 154 consecutive patients in two treatment groups: the “add-on” group (n = 79), in which adefovir was added to ongoing lamivudine treatment due to lamivudine resistance, and the “switch/combination” group (n = 75), in which lamivudine was first switched to adefovir and then re-added later as needed. The “switch/combination” group was then divided into two subgroups depending on whether participants followed (group A, n = 30) or violated (group B, n = 45) a proposed treatment strategy that determined whether to add lamivudine based on the serum hepatitis B virus (HBV) DNA levels (< 60 IU/mL or not) after 6 mo of treatment (roadmap concept).

RESULTS: The cumulative probability of virologic response (HBV DNA < 60 IU/mL) was higher in group A than in the “add-on” group and in group B (P < 0.001). In contrast, the cumulative probability of virologic breakthrough was lower in the “add-on” group than in group B (P = 0.002). Furthermore, the risk of virologic breakthrough in the multivariate analysis was significantly lower in the “add-on” group than in group A (hazard ratio = 0.096; 95%CI, 0.015-0.629; P = 0.015).

CONCLUSION: The selective combination of adefovir with lamivudine based upon early treatment responses increased the odds of virologic breakthrough relative to the use of uniform combination therapy from the beginning of treatment.