Mitochondrial Toxicity in the Era of HAART: Evaluating Venous Lactate and Peripheral Blood Mitochondrial DNA in HIV-Infected Patients Taking Antiretroviral Therapy

Raman-based metabonomics unravels metabolic changes related to a first-line tenofovir-based treatment in a small cohort of South African HIV-infected patients

In addition to immunological disorders, human immunodeficiency virus (HIV) also causes metabolic abnormalities. Though successful in viral suppression and immune restoration, continued use of antiretroviral therapy (ART) has also been linked to the development of several metabolic ailments. Currently, the only clinical markers used to manage and monitor the development of HIV-induced metabolic disorders, disease progression as well as observing individual's response to antiviral treatment are CD4 count, viral loads and several other single variable colometric assays. Despite the common use of these clinical markers, these markers remain unreliable and limited in the ability to monitor the development of metabolic disorders as well as monitor treatment response. Given these limitations, it is imperative to discover and develop reliable biological markers for overall HIV disease management. Here, Raman spectroscopy was used to profile metabolic changes in the plasma of 22 HIV⁺ receiving a first-line tenofovir-based combination antiretroviral therapy compared to their 8 HIV⁺ ART^- and 10 HIV^- counterparts. Multivariate statistical analysis was performed in order to classify the samples into their respective groups and to identify significantly altered metabolites between the control and experimental groups. Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) discriminant analysis identified significant differences (p < 0.05) in 9 different metabolites. Alterations were identified in spectral regions associated with glucose (1124 cm^-1), lipids/phospholipids (1116 cm^-1, 1098 cm^-1, 1077 cm^-1), proteins (1120 cm^-1), nucleic acids (1081 cm^-1) and phenylalanine (1103 cm^-1). Pathway analysis also revealed 3 significantly altered pathways. This study presented the reproducible nature of Raman spectroscopy in distinguishing between HIV-infected (treated and untreated) and uninfected blood plasma and allowed for the detection and identification of treatment induced metabolite changes. The results obtained in the study may, therefore, give insights into understanding the metabolic effect of HIV therapy.

Mitochondrial toxicity and body shape changes during nucleos(t)ide analogues administration in patients with chronic hepatitis B

Our study purpose was to evaluate mitochondrial (mt)DNA and RNA in peripheral blood mononuclear cells (PBMCs) and body shape changes (BSC) in HBV-infected patients. mtDNA and mtRNA were measured in PBMCs. The presence of BSC was evaluated through a questionnaire and clinical evaluation. A total of 157 subjects were enrolled, of these 107 were HBV-infected patients, 54 receiving nucleoside analogues (NAs, Group A), 53 naive to antivirals (Group B) and 50 age-sex matched controls (Group C). All HBV-treated patients had negative HBV–DNA. Twenty (37,0%) received lamivudine + adefovir, 20 (37.0%) tenofovir, 2 (3.7%) lamivudine and 12 (22.2%) entecavir. Therapy median duration was 38 months (IQR 20–60) in NA-treated patients. Group A showed significantly higher mtDNA/nuclear (n) DNA ratio (p = 0.000008) compared to Group C and Group B (p = 0.002). Group B showed significantly higher mtDNA/nDNA ratio compared to Group C (p = 0.017). Group A and B had significantly lower mtRNA/nRNA ratio compared to Group C (p = 0.00003 and p = 0.00006, respectively). Tenofovir and entecavir showed less impact compared to lamivudine + adefovir. mtDNA/nDNA ratio positively (Rho = 0.34, p < 0.05) and mtRNA/nRNA ratio negatively (Rho = −0.34, p < 0.05) correlated with therapy duration. BSC were significantly more frequent in Group A [10/54 (18.5%)] compared to Group B [3/53 (5.6%, p = 0.04)] and Group C [0/50, (p = 0.0009)]. In conclusion, long-term NA therapy was associated both to mitochondrial toxicity and BSC, showing significant differences in mtDNA and mtRNA levels. Tenofovir and entecavir showed lower impact on alterations, compared to 1^st generation NA.

Peripheral Blood Mitochondrial DNA Copy Number Obtained From Genome-Wide Genotype Data Is Associated With Neurocognitive Impairment in Persons With Chronic HIV Infection

BACKGROUND

Mitochondrial DNA (mtDNA) copy number varies by cell type and energy demands. Blood mtDNA copy number has been associated with neurocognitive function in persons without HIV. Low mtDNA copy number may indicate disordered mtDNA replication; high copy number may reflect a response to mitochondrial dysfunction. We hypothesized that blood mtDNA copy number estimated from genome-wide genotyping data is related to neurocognitive impairment (NCI) in persons with HIV.

METHODS

In the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) study, peripheral blood mtDNA copy number was obtained from genome-wide genotyping data as a ratio of mtDNA single-nucleotide polymorphism probe intensities relative to nuclear DNA single-nucleotide polymorphisms. In a multivariable regression model, associations between mtDNA copy number and demographics, blood cell counts, and HIV disease and treatment characteristics were tested. Associations of mtDNA copy number with the global deficit score (GDS), GDS-defined NCI (GDS ≥ 0.5), and HIV-associated neurocognitive disorder (HAND) diagnosis were tested by logistic regression, adjusting for potential confounders.

RESULTS

Among 1010 CHARTER participants, lower mtDNA copy number was associated with longer antiretroviral therapy duration (P < 0.001), but not with d-drug exposure (P = 0.85). mtDNA copy number was also associated with GDS (P = 0.007), GDS-defined NCI (P < 0.001), and HAND (P = 0.002). In all analyses, higher mtDNA copy number was associated with poorer cognitive performance.

CONCLUSIONS

Higher mtDNA copy number estimated from peripheral blood genotyping was associated with worse neurocognitive performance in adults with HIV. These results suggest a connection between peripheral blood mtDNA and NCI, and may represent increased mtDNA replication in response to mitochondrial dysfunction.

Acute hepatitis and acute liver failure: Pathologic diagnosis and differential diagnosis

Acute hepatitis and acute liver failure are severe medical conditions that require early clinical intervention. Histopathologic findings on a liver biopsy or a liver explant may help identify the underlying etiology or provide an important direction for further clinical, laboratory and radiographical investigation. This review is divided into two main portions. The first portion concentrates on various etiologies and discusses unique histologic features that can be associated with specific etiologies. The second portion describes the general morphologic features based on which the diagnosis of acute hepatitis and acute liver failure are made. Histopathologic distinction between collapse and cirrhosis and limitations of histopathologic assessment for underlying etiologies are addressed in this portion. Another focus of this review is non-necrotic acute liver failure, which typically features diffuse microvesicular steatosis secondary to various etiologies causing mitochondrial dysfunction. Molecular testing serves an increasingly important role in the diagnosis and management of this group of disorders.

Mitochondrial DNA content of peripheral blood mononuclear cells in ART untreated & stavudine/zidovudine treated HIV-1-infected patients

Background & objectives:

Nucleoside reverse transcriptase inhibitors (NRTIs) are known to cause mitochondrial toxicity. This study was done to estimate mitochondrial DNA (mtDNA) content of peripheral blood mononuclear cells (PBMCs) among human immunodeficiency virus (HIV) infected, NRTI treated and antiretroviral therapy (ART)-naïve patients and evaluate the utility of mtDNA content as a biomarker of mitochondrial toxicity.

Methods:

mtDNA content in PBMCs of 57 HIV-infected ART untreated and 30 ART treated with stavudine (d4T) or zidovudine (AZT) containing regimen were compared against 24 low-risk healthy controls (LoRHC).

Results:

There was a significant (P=0.01) reduction in mtDNA content among HIV-infected (104; 80-135) compared to LoRHC (127; 110-167), and it was the same in both the treated (104.8; 88-130) and untreated patients (104.7; 78-142). mtDNA significantly (P=0.014) declined in ART treated patients symptomatic for toxicity (97; 74-111) than the asymptomatic patients (128; 103- 153).

Interpretation & conclusions:

mtDNA depletion in PBMCs was evident among HIV-infected individuals on ART. Moreover, as mtDNA content was reduced among the patients symptomatic for toxicity than the asymptomatic in both the HIV-infected groups, the current study supports mtDNA content of PBMCs to serve as a biomarker of mitochondrial dysfunction induced by NRTI and HIV. Longitudinal studies with a large sample need to be done to confirm these findings.

Hemochromatosis (HFE) Gene Variants Are Associated with Increased Mitochondrial DNA Levels During HIV-1 Infection and Antiretroviral Therapy

Some HIV-associated complications involve mitochondrial dysfunction and may be less common in individuals with iron-loading HFE (hemochromatosis gene) variants. We evaluated HFE 845A and 187G alleles in relation to mitochondrial DNA (mtDNA) levels in peripheral blood mononuclear cells from 85 individuals with HIV infection on uninterrupted antiretroviral therapy (ART) for 15 or more consecutive weeks. Carriers of HFE gene variants (N = 24) had significantly higher mtDNA levels than noncarriers (N = 61), after adjusting for age, race, sex, and type of ART [adjusted β-coefficient 297, p-value < .001 for at least one HFE variant], but mtDNA declined among all individuals on study during 48 weeks on ART. Increased cellular mtDNA content may represent a compensatory response to mitochondrial stress that is influenced by iron-loading HFE variants.

Blood Mitochondrial DNA Content in HIV-Exposed Uninfected Children with Autism Spectrum Disorder

Long-term outcomes of perinatal exposure to maternal antiretroviral therapy in HIV-exposed uninfected (HEU) children are unknown. However, both HIV antiretroviral therapy and autism spectrum disorder (ASD) have been associated with mitochondrial alterations. Leukocyte mitochondrial DNA (mtDNA) content can serve as a marker for mitochondrial dysfunction. In this cross-sectional, nested case-control study, HEU children with ASD were matched approximately 1:3 on age, sex, and ethnicity to HEU children without ASD, HIV-unexposed uninfected (HUU) controls, and HUU children with ASD. Leukocyte mtDNA content was measured using quantitative PCR. Among 299 HEU in this study, 14 (4.7%) were diagnosed with ASD, which is higher than the general population prevalence estimates. HEU children without ASD and HUU children with ASD had higher mtDNA content than HUU controls. HEU children with ASD had significantly higher mtDNA content than all other study groups. Our results suggest a clear association between elevated leukocyte mtDNA content and both HEU and ASD status. This may implicate mitochondrial dysfunction as a contributor to the high ASD prevalence observed in our cohort.

Low Plasma Zinc Is Associated with Higher Mitochondrial Oxidative Stress and Faster Liver Fibrosis Development in the Miami Adult Studies in HIV Cohort

Background: Oxidative stress and reduced antioxidants may be a trigger for liver fibrogenesis. Reducing oxidative stress through higher antioxidant concentration may be a potential antifibrotic target.Objective: We aimed to investigate longitudinally whether plasma zinc, an antioxidant, is related to mitochondrial oxidative stress and the progression of liver fibrosis in the Miami Adult Studies in HIV (MASH) cohort.Methods: A prospective observational cohort study was conducted in 487 predominantly African American HIV-monoinfected and HIV/hepatitis C virus (HCV)-coinfected adults with a mean ± SD age of 47.08 ± 7.67 y from the MASH cohort and followed for a median of 34 mo. Blood was collected for plasma zinc and measures were used to calculate the fibrosis-4 (FIB-4) score (aspartate amino transferase, alanine aminotransferase, and platelets). Plasma zinc deficiency was defined as <0.75 mg/L. Total DNA was extracted from peripheral blood mononuclear cells and mitochondrial DNA (mtDNA) 8-hydroxyguanosine (8-oxo-dG) was determined. Adjusted mixed models were used to assess the relations between zinc, stage of liver disease, and oxidative stress over time and compared between HIV and HIV/HCV groups.Results: Zinc concentrations (β: -0.368, SE = 0.172; P = 0.033) and deficiency were associated with lower FIB-4 scores over time (β: 0.381, SE = 0.118; P = 0.001). Compared with those who were not zinc deficient, zinc-deficient participants had an increased risk of having more-progressed liver disease (OR: 1.91; 95% CI: 1.15, 3.16; P = 0.012). Higher mtDNA 8-oxo-dG was associated with zinc deficiency (β: 0.049, SE = 0.024; P = 0.044) and higher FIB-4 scores over time (β: 0.597, SE = 0.168, P < 0.001).Conclusions: Lower plasma zinc concentrations were associated with liver fibrosis progression and mitochondrial oxidative stress in the HIV and HIV/HCV groups. Zinc may play a role in the impact of liver disease outcomes.

Antiretroviral exposure during pregnancy and adverse outcomes in HIV-exposed uninfected infants and children using a trigger-based design

OBJECTIVE

To evaluate the safety of in-utero antiretroviral exposure in children born to mothers with HIV, using a trigger-based design.

DESIGN

The Surveillance Monitoring of ART Toxicities Study is a prospective cohort study conducted at 22 US sites to evaluate safety of in-utero antiretroviral drug exposure in HIV-uninfected children born to HIV-infected mothers. Children meeting predefined clinical or laboratory thresholds have more intensive evaluations to determine whether they meet criteria for adverse events.

METHODS

Adverse event "cases" were defined for the following domains: growth, hearing, language, neurology, neurodevelopment, metabolic, hematologic/clinical chemistry and blood lactate. We used adjusted log-binomial models to calculate relative risks (RR) of case status overall and within individual domains for various antiretroviral exposures during pregnancy.

RESULTS

Among 2680 youth enrolled between 2007 and 2012 (48% female, 66% black, 33% Hispanic), 48% met a trigger and 25% were defined as a case in at least one domain. Language (13.2%) and metabolic (11.4%) cases were most common. After adjustment for birth cohort and other factors, there was no association of any antiretroviral regimen, drug class, or individual drug with meeting overall case criteria (case in any domain). Within individual domains, zidovudine (74% exposed) was associated with increased risk of metabolic case [RR = 1.69, 95%confidence interval (CI) 1.08-2.64] and didanosine plus stavudine (<1% exposed) with increased risk of both neurodevelopmental (RR = 12.40, 95%CI 5.29-29.08) and language (RR = 4.84, 95%CI 1.14-20.51) cases.

CONCLUSION

Our findings support current recommendations for combination antiretroviral therapy during pregnancy, although higher risk of metabolic disorder with zidovudine exposure warrants further study.

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.

Serious adverse events are uncommon with combination neonatal antiretroviral prophylaxis: a retrospective case review

Six weeks of zidovudine (ZDV) is recommended for postnatal prophylaxis of HIV-exposed infants, but combination antiretrovirals are indicated if HIV transmission risk is increased. We investigated the frequency and severity of adverse events (AE) in infants receiving multiple drug prophylaxis compared to ZDV alone. In this retrospective review of 148 HIV-exposed uninfected infants born between 1997–2009, we determined clinical and laboratory AE that occurred between days of life 8–42. Thirty-six infants received combination prophylaxis; among those, a three-drug regimen containing ZDV, lamivudine, and nevirapine was most common (53%). Rates of laboratory AE grade ≥1 were as follows for the combination prophylaxis and ZDV alone groups, respectively: neutropenia 55% and 39%; anemia 50% and 39%; thrombocytopenia 0 and 3%; elevated aspartate aminotransferase 3% and 3%; elevated alanine aminotransferase 0 and 1%; hyperbilirubinemia 19% and 42%. Anemia occurred more frequently in infants who received three-drug prophylaxis compared to infants who received ZDV alone (63% vs. 39%, p = 0.04); all anemia AE were grade 1 or 2 in the three-drug prophylaxis group. Overall, 75% of infants on combination prophylaxis and 66% of infants on ZDV alone developed grade ≥1 AE (p = 0.32), and 17% of infants in either group developed grade ≥3 AE. Stavudine was substituted for ZDV in 23 infants due to anemia or neutropenia. After this antiretroviral change, 50% of evaluable infants demonstrated improvement in AE grade, and 25% had no change. In conclusion, low grade anemia, neutropenia, and hyperbilirubinemia occurred frequently regardless of the prophylactic regimen, but serious AE were uncommon. Although most AE were typical of ZDV toxicity, the combination of ZDV with lamivudine and nevirapine resulted in an increased frequency of low-grade anemia. Further studies are needed to identify prophylactic regimens with less toxicity for infants born to HIV-infected mothers.

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.

Portable lactate analyzer for measuring lactate in cerebrospinal fluid (CSF) and plasma - method-comparison evaluations

Increased plasma lactate levels can indicate the presence of metabolic disorders in HIV infected individuals.

OBJECTIVE

To determine whether a portable analyzer is valid for measuring cerebrospinal fluid (CSF) and plasma lactate levels in HIV infected individuals.

METHOD

CSF and plasma were collected from 178 subjects. Samples tested by the Accutrend portable analyzer were compared to those tested by a reference device (SYNCHRON LX 20).

RESULTS

The portable analyzer had in plasma sensitivity of 0.95 and specificity 0.87. For CSF the specificity was 0.95; the sensitivity 0.33; the negative predictive value was 95% and the positive predictive value 33%.

CONCLUSIONS

These findings support the validity of the portable analyzer in measuring lactate concentrations in CSF that fall within the normal range. The relatively poor positive predictive value indicates that a result above the reference range may represent a "false positive test", and should be confirmed by the reference device before concluding abnormality.

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.

Alterations in the levels of vesicular trafficking proteins involved in HIV replication in the brains and CSF of patients with HIV-associated neurocognitive disorders

Human immunodeficiency virus (HIV) associated neurocognitive disorders (HAND) remain prevalent despite improved antiretroviral therapies. A HAND-specific biomarker indicative of neuropsychological impairment (NPI) would give insight into disease progression and aid clinicians in designing therapy. Endosomal sorting complex required for transport (ESCRT) proteins such as tumor susceptibility gene (TSG)-101, vacuolar protein sorting (VPS)-4 and LIP-5 are important for HIV replication and recently antiviral interferon stimulated gene (ISG)-15 was proposed as a biomarker for CNS injury. Here, we analyzed a well-characterized cohort of HIV+ cerebral spinal fluid (CSF) and postmortem brain specimens for multiple vesicular trafficking proteins and a related innate immune protein, ISG-15, TSG-101, VPS-4 and LIP-5. All protein levels trended higher with increased NPI and neuropathology. ISG-15 CSF levels were increased in HIV encephalitis (HIVE) compared to normal cases, and three quarters of HIVE samples had above average CSF ISG-15 levels. VPS-4 CSF levels were increased in NPI/NPI-O compared to normal patients. VPS-4 CSF levels in HIV-associated dementia were equivalent to that of normal patients. LIP-5 CSF levels positively correlate with ISG-15 levels, and higher than average ISG-15 levels indicate elevated viral load. Immunoblot and immunohistochemical analyses show increased expression of ISG-15, VPS-4 and LIP-5 in neuronal cell bodies and astroglial cells. ESCRT protein CSF levels analyzed in conjunction with viral load may be indicative of NPI stage, and may aid in the diagnosis and design of therapies for HIV patients. Further studies on the ESCRT protein expression during HIV infection may lead to a promising biomarker for predicting progression of NPI.

Elevated serum fibroblast growth factor 21 levels correlate with immune recovery but not mitochondrial dysfunction in HIV infection

Background

Anti-retroviral treated HIV-infected patients are at risk of mitochondrial toxicity, but non-invasive markers are lacking. Serum FGF-21 (fibroblast growth factor 21) levels correlate strongly with muscle biopsy findings in inherited mitochondrial disorders. We therefore aimed to determine whether serum FGF-21 levels correlate with muscle mitochondrial dysfunction in HIV-infected patients.

Findings

We performed a cross-sectional study of anti-retroviral treated HIV-infected subjects (aged 29 – 71 years, n = 32). Serum FGF-21 levels were determined by quantitative ELISA. Cellular mitochondrial dysfunction was assessed by COX (cytochrome c oxidase) histochemistry of lower limb skeletal muscle biopsy. Serum FGF-21 levels were elevated in 66% of subjects. Levels correlated significantly with current CD4 lymphocyte count (p = 0.042) and with total CD4 count gain since initiation of anti-retroviral therapy (p = 0.016), but not with the nature or duration of past or current anti-retroviral treatment. There was no correlation between serum FGF-21 levels and severity of the muscle mitochondrial (COX) defect.

Conclusions

Serum FGF-21 levels are a poor predictor of muscle mitochondrial dysfunction in contemporary anti-retroviral treated patients. Serum FGF-21 levels are nevertheless commonly elevated, in association with the degree of immune recovery, suggesting a non-mitochondrial metabolic disturbance with potential implications for future comorbidity.

Factors influencing liver fibrosis and necroinflammation in HIV/HCV coinfection and HCV monoinfection

OBJECTIVES

To define differences in liver histology between HIV/HCV coinfection and HCV monoinfection, and to investigate possible causative factors.

METHODS

Liver biopsies (LBs) from 440 consecutive HIV/HCV-coinfected patients (Group HIV/HCV) and 374 consecutive HCV-monoinfected patients (Group HCV) were evaluated for necroinflammation and fibrosis (Ishak) by a pathologist unaware of the clinical and laboratory data. All patients were HBsAg-negative, with no history of alcohol abuse and naïve to anti-HCV treatment. At LB, 78.4% of patients in Group HIV/HCV were on an antiretroviral regimen.

RESULTS

HIV/HCV-coinfected patients compared to the HCV-monoinfected patients were younger (p < 0.0001), more frequently males (p < 0.0001), and had HCV genotype 3 (p < 0.0001); they showed a good immunological condition (CD4+ cell count: 518 ± 166 cells/mm(3)). Patients in Group HIV/HCV more frequently showed a fibrosis score ≥4 (27.5 vs. 20.6%, p < 0.05) and a necroinflammation score ≥9 (25.9 vs. 13.4%; p < 0.0001). The prevalence of patients with fibrosis score ≥4 was significantly higher in older age classes in both Group HIV/HCV (p < 0.005) and Group HCV (p < 0.05). A necroinflammation score ≥9 was significantly higher in older age classes only in Group HIV/HCV (p < 0.05). A multivariate analysis for Group HIV/HCV revealed that the patient age and nadir of CD4+ cell count were independently associated to higher degrees of fibrosis, the patient age and antiretroviral treatment were associated to higher degrees of necroinflammation, and HCV genotype 3 was associated to higher degrees of steatosis.

CONCLUSION

The data suggest a need for early anti-HCV treatment in both HCV-monoinfected and HIV/HCV-coinfected patients.

Performance of Clinical Criteria for Screening of Possible Antiretroviral Related Mitochondrial Toxicity in HIV-Infected Children in Accra

Mitochondrial damage is implicated in highly active antiretroviral therapy (HAART) toxicity. HIV infection also causes mitochondrial toxicity (MT). Differentiating between the two is critical for HIV management. Our objective was to test the utility of the Mitochondrial Disease Criteria (MDC) and the Enquête Périnatale Française (EPF) to screen for possible HAART related MT in HIV-infected children in Ghana. The EPF and MDC are compilations of clinical symptoms, or criteria, of MT: a (+) score indicates possible MT. We applied these criteria retrospectively to 403 charts of HIV-infected children. Of those studied, 331/403 received HAART. Comparing HAART exposed and HAART naïve children, the difference in EPF score, but not MDC, approached significance (P = 0.1). Young age at HIV diagnosis or at HAART initiation was associated with (+) EPF (P ≤ 0.01). Adherence to HAART trended toward an association with (+) EPF (P = 0.09). Exposure to nevirapine, abacavir, or didanosine increased risk of (+) EPF (OR = 3.55 (CI = 1.99-6.33), 4.76 (2.39-9.43), 4.93 (1.29-18.87)). Neither EPF nor MDC identified a significant difference between HAART exposed or naïve children regarding possible MT. However, as indicators of HAART exposure are associated with (+) EPF, it may be a candidate for prospective study of possible HAART related MT in resource-poor settings.

Quantification of mitochondrial toxicity in HIV-infected individuals by quantitative PCR compared to flow cytometry

BACKGROUND

Non-invasive diagnostic assays to evaluate mitochondrial toxicity could have significant clinical utility for HIV-infected individuals on antiretroviral therapy (ART).

METHODS

This study compared the ratio of mitochondrial to nuclear DNA determined by quantitative polymerase chain reaction (qPCR) to the ratio of mitochondrial to nuclear-encoded proteins by flow cytometry, in peripheral blood mononuclear cells from 73 HIV-infected individuals with and without risk factors for mitochondrial toxicity.

RESULTS

PCR detected similar mitochondrial/nuclear DNA in HIV-infected individuals without a history of ART, and those receiving ART with lipodystrophy, lipoatrophy, or a history of suspected lactic acidosis. However, the ratio was significantly greater in ART-untreated compared to those receiving either stavudine or didanosine. In contrast, flow cytometry did not detect any differences in mitochondrial/nuclear protein (Lin et al., Cytometry B 2009;76B:181-190). There was no correlation between the assays (rho = -0.05, P = 0.65).

CONCLUSIONS

Assessment of the mitochondrial/nuclear DNA ratio by qPCR performed better than the mitochondrial/nuclear-encoded protein ratio by flow cytometry to detect adverse effects of nucleoside analogs on mitochondria.

Hyperlactatemia and in utero exposure to antiretrovirals: is the control group the clue?

Perinatal antiretroviral (ARV) exposure has been related to hyperlactatemia and lactic acidosis in infants born to HIV-infected mothers. Our objective was to determine the incidence of these conditions during the first year of life in uninfected infants born to HIV-infected mothers and compare the data with infants born to mothers with hepatitis C virus (HCV) infection. We investigated the relationships between hyperlactatemia and neurological and neurodevelopmental disorders by conducting a prospective, comparative cohort study (October 2004 to October 2007) consecutively including children of HIV- and HCV-infected mothers. Liver enzymes, pH, lactic acid, and plasma amino acids were determined at 1.5, 3, 6, and 12 months of life. Pathological hyperlactatemia was defined as lactate >2.1 mmol/liter together with alanine >475 μmol/liter. Seventy-nine patients (39 HIV-exposed patients and 40 unexposed patients) were included. Baseline maternal characteristics in the two groups were similar. Almost 90% of HIV-infected mothers received HAART during gestation, while 10.3% were given AZT monotherapy. Eight newborns received combined therapy and 31 received AZT-based monotherapy. Twelve patients (five exposed and seven nonexposed) had some neurological disorder, and four other patients (one vs. three) showed signs of neurodevelopmental delay, with no significant differences between the groups (p=0.34). Pathological hyperlactatemia was detected in 56.4% (95% CI 39.6-72.2) and 57.5% (95% CI 40.9-73.0) of patients, respectively (p=0.92), and this condition was more frequent in preterm children (p<0.05). ARV use during pregnancy and the neonatal period was not associated with pathological hyperlactatemia. The presence of hyperlactatemia was not associated with neurological or neurodevelopmental disorders. No association was established between the use of ARV agents and the development of hyperlactatemia or neurological disorders in HIV-exposed children during their first year of life.

HIV-1 infection and first line ART induced differential responses in mitochondria from blood lymphocytes and monocytes: the ANRS EP45 "Aging" study

BACKGROUND

The ANRS EP45 "Aging" study investigates the cellular mechanisms involved in the accelerated aging of HIV-1 infected and treated patients. The data reported focus on mitochondria, organelles known to be involved in cell senescence.

METHODS

49 HIV-1 infected patients untreated with antiretroviral therapy, together with 49 seronegative age- and sex-matched control subjects and 81 HIV-1 infected and treated patients, were recruited by 3 AIDS centres (Marseille, Montpellier, Nice; France; http://clinicaltrials.gov/, NCT01038999). In more than 88% of treated patients, the viral load was <40 copies/ml and the CD4+ cell count was >500/mm(3). ROS (reactive oxygen species) production and ΔΨm (inner membrane potential) were measured by flow cytometry in blood lymphocytes and monocytes (functional parameters). Three mitochondrial network quantitative morphological parameters were computed using confocal microscopy and image analysis. Three PBMC mitochondrial proteins (porin and subunits 2 and 4 of cytochrome C oxidase encoded by mtDNA or nuclear DNA, respectively) were analysed by western blotting.

RESULTS

Quantitative changes in PBMC mitochondrial proteins were not induced by either HIV-1 infection or ART. Discriminant analysis integrating functional (ROS production and ΔΨm) or morphological (network volume density, fragmentation and branching) parameters revealed HIV-1 infection and ART differential effects according to cell type. First line ART tended to rescue lymphocyte mitochondrial parameters altered by viral infection, but induced slight changes in monocytes. No statistical difference was found between the effects of three ART regimens on mitochondrial parameters. Correlations between functional parameters and viral load confirmed the damaging effects of HIV-1 in lymphocyte mitochondria.

CONCLUSIONS

In patients considered to be clinically stable, mitochondria exhibited functional and morphological modifications in PBMCs resulting from either direct or indirect effects of HIV-1 infection (lymphocytes), or from first line ART (monocytes). Together with other tissue impairments, these changes may contribute to global aging.

A trigger-based design for evaluating the safety of in utero antiretroviral exposure in uninfected children of human immunodeficiency virus-infected mothers

The Pediatric HIV/AIDS Cohort Study's Surveillance Monitoring of ART Toxicities Study is a prospective cohort study conducted at 22 US sites between 2007 and 2011 that was designed to evaluate the safety of in utero antiretroviral drug exposure in children not infected with human immunodeficiency virus who were born to mothers who were infected. This ongoing study uses a "trigger-based" design; that is, initial assessments are conducted on all children, and only those meeting certain thresholds or "triggers" undergo more intensive evaluations to determine whether they have had an adverse event (AE). The authors present the estimated rates of AEs for each domain of interest in the Surveillance Monitoring of ART Toxicities Study. They also evaluated the efficiency of this trigger-based design for estimating AE rates and for testing associations between in utero exposures to antiretroviral drugs and AEs. The authors demonstrate that estimated AE rates from the trigger-based design are unbiased after correction for the sensitivity of the trigger for identifying AEs. Even without correcting for bias based on trigger sensitivity, the trigger approach is generally more efficient for estimating AE rates than is evaluating a random sample of the same size. Minor losses in efficiency when comparing AE rates between persons exposed and unexposed in utero to particular antiretroviral drugs or drug classes were observed under most scenarios.

Point-of-care capillary blood lactate measurements in human immunodeficiency virus-uninfected children with in utero exposure to human immunodeficiency virus and antiretroviral medications

OBJECTIVES

To estimate the prevalence of elevated point-of-care (POC) capillary blood lactate concentrations in human immunodeficiency virus (HIV)-exposed, uninfected children (HEU) and to determine if POC lactate varies with in utero antiretroviral (ARV) exposure.

METHODS

The Surveillance Monitoring for Antiretroviral Therapy Toxicities protocol of the Pediatric HIV/AIDS Cohort Study enrolled 1934 children between 2007 and 2009, 0 to 12 years of age, born to HIV-infected mothers. POC lactate was measured annually on capillary blood using the Lactate Pro device. Associations of POC lactate with in utero ARV exposure and other characteristics were evaluated using logistic regression models, adjusting for maternal characteristics and other confounders.

RESULTS

Of 1641 children with POC measurements (median age, 3.0 years), 3.4% had POC lactate >3 mmol/L. Median POC lactate level decreased with age (1.9 mmol/L, 1.7 mmol/L, and 1.6 mmol/L for children 0-<6 months [99% ≤6 weeks of life], 6-<24 months, and ≥24 months of age, respectively; P < 0.001). Prevalence of elevated POC lactate did not differ by in utero ARV exposure drug class, but was significantly higher in children exposed in utero to emtricitabine or efavirenz, cocaine or opiates, and those of white race.

CONCLUSIONS

POC lactate testing is a useful rapid laboratory screening assay for HEU children with ARV exposure. ARV use during pregnancy has resulted in a dramatic decrease in mother-to-child transmission of HIV, and the risk of elevated lactate in HEU children is low. However, as new ARVs and more complex regimens are used during pregnancy by HIV-infected women, continued monitoring for infant toxicities is essential.

[Anaesthesia for HIV-infected patients]

France is one of main countries affected by the HIV-outbreak in Europe with more than 120,000 cases, among which 34,600 patients having developed an AIDS. The antiretroviral combination therapies (combined antiretroviral therapy [cART]) reduced by half the mortality. A low compliance to cART alters the virologic control and increases the morbimortality. If required, the therapeutic break should be the shortest possible, including the whole treatment (to limit the risk of viral resistance). The perioperative care should take into account the underlying conditions. During the preoperative period, the clinical picture could combine various complications: 1: respiratory impairment; 2: impairment of neuronal functions (related to viral factors, host response and environmental factors such as alcohol, drug addiction, HCV co-infection) inducing a cognitive dysfunction or a peripheral neuropathy; 3: lipodystrophy, dyslipidemia and insulin resistance are the main metabolic cART-related side effects, responsible for atherosclerosis and coronaropathy; 4: major nutritional impairment. Anesthesia for HIV patients is almost the same than usual, without HIV-related contraindication to regional anesthesia. Anesthetic drugs can be associated to cART. The main restriction belongs to the protease inhibitors, which could affect the metabolic pathways of opioids, NSAIDs and benzodiazepines (over dosage risks). During the postoperative period, the follow-up should include the thromboembolism prevention (increased risk compared to main people), the cardiovascular side effects, the nutritional status and the continuation of the treatment. Moreover, the psychological status related and a close collaboration with the corresponding physician is critical.

Antiretroviral therapy-associated acute motor and sensory axonal neuropathy

Guillain-Barré syndrome (GBS) has been reported in HIV-infected patients in association with the immune reconstitution syndrome whose symptoms can be mimicked by highly active antiretroviral therapy (HAART)-mediated mitochondrial toxicity. We report a case of a 17-year-old, HIV-infected patient on HAART with a normal CD4 count and undetectable viral load, presenting with acute lower extremity weakness associated with lactatemia. Electromyography/nerve conduction studies revealed absent sensory potentials and decreased compound muscle action potentials, consistent with a diagnosis of acute motor and sensory axonal neuropathy. Lactatemia resolved following cessation of HAART; however, neurological deficits minimally improved over several months in spite of immune modulatory therapy. This case highlights the potential association between HAART, mitochondrial toxicity and acute axonal neuropathies in HIV-infected patients, distinct from the immune reconstitution syndrome.

Persistent organic pollutants, mitochondrial dysfunction, and metabolic syndrome

The number of individuals with metabolic syndrome is increasing worldwide, constituting a major social problem in many countries. Recently, epidemiological and experimental studies have associated insulin resistance or type 2 diabetes with elevated body burdens of persistent organic pollutants (POPs). It has been proposed that mitochondrial dysfunction plays a key role in this association. Mitochondrial DNA abnormalities are known to cause pancreas beta cell damage, insulin resistance, and diabetes mellitus. Recently, much evidence has emerged showing that environmental toxins, including POPs, affect mitochondrial function and subsequently induce insulin resistance. In this review, we present a novel concept in which metabolic syndrome is the result of mitochondrial dysfunction, which in turn is caused by exposure to POPs. The potential mechanism including POPs for mitochondrial dysfunction on metabolic syndrome is also discussed. We propose that the mitochondrial paradigm for the etiology of metabolic syndrome will facilitate the prevention and treatment of this major health problem.

Mitochondrial dysfunction in CD4+ lymphocytes from stavudine-treated HIV patients

HIV therapy with nucleoside analogue reverse transcriptase inhibitors (NRTI) such as stavudine remains in widespread use in resource-limited nations due to potent efficacy, convenience of formulation and lack of practical alternatives. However, it remains unclear whether adverse side effects with NRTI include reduced mitochondrial respiratory function, particularly in peripheral blood lymphocytes (PBLs). The aim of this study was to determine whether stavudine-based highly active antiretroviral therapy (HAART) is associated with impaired mitochondrial respiratory transport chain function in patient derived CD4+PBLs. CD4+PBLs were isolated from asymptomatic HIV-infected patients treated with stavudine-HAART for 3 months (n=10), HIV-infected patients not on treatment (n=9) and uninfected controls (n=18). The basal mitochondrial oxygen consumption of CD4+PBLs from stavudine-treated patients was reduced relative to that of untreated HIV-infected patients and controls (stavudine treated group, 4.22 (25% 2.16, 75% 8.84); control uninfected, 11.2 (25% 3.95, 75% 16.6); untreated 18.1 (25% 11.8, 75% 37.9)ng oxygen atoms/min/ml). Maximal oxygen consumption (stimulated with the proton ionophore FCCP) in cells from stavudine treated patients was also reduced relative to that of untreated patients and controls (stavudine treated, 24.4+/-10.5; control uninfected, 50.6+/-39.5; untreated, 68.8+/-41.1 ng oxygen atoms/min/ml). Citrate synthase activities, relative mitochondrial volume (by electron microscopy) and mtDNA copy numbers per cell were not different between groups. Therapy with stavudine results in impaired mitochondrial function in CD4+PBLs that does not appear to be due to reduced mitochondrial volume or DNA content and cannot be attributed to infection with HIV.

LIPODYSTROPHY SYNDROME IN HIV-INFECTED CHILDREN ON HAART

Lipodystrophy syndrome (LD) is common in HIV-infected children, particularly those taking didanosine, stavudine or zidovudine. Lipo-atrophy in particular causes major stigmatisation and interferes with adherence. In addition, LD may have significant long-term health consequences, particularly cardiovascular. Since the stigmatising fat distribution changes of LD are largely permanent, the focus of management remains on early detection and arresting progression. Practical guidelines for surveillance and avoidance of LD in routine clinical practice are presented. The diagnosis of LD is described and therapeutic options are reviewed. The most important therapeutic intervention is to switch the most likely offending antiretroviral to a non-LD-inducing agent as soon as LD is recognised. Typically, when lipoatrophy or lipohypertrophy is diagnosed the thymidine nucleoside reverse transcriptase inhibitor (NRTI) is switched to a non-thymidine agent such as abacavir (or tenofovir in adults). Where dyslipidaemia is predominant, a dietician review is helpful, and the clinician may consider switching to a protease inhibitor-sparing regimen or to atazanavir.

Assessment of mitochondrial toxicity by analysis of mitochondrial protein expression in mononuclear cells

BACKGROUND

Real-time PCR has quantified decreased mitochondrial DNA levels in association with nucleoside reverse transcriptase inhibitor (NRTI) therapy of HIV-infected populations. However, real-time PCR is best suited to distinguish log differences in an analyte. In an effort to monitor individuals in more detail, we developed a flow cytometric assay to gauge mitochondrial function.

METHODS

Flow cytometric quantification of a mitochondrial DNA-encoded mitochondrial protein (cytochrome c oxidase subunit I (COX-I)) and a nuclear DNA-encoded mitochondrial protein [ATP synthase subunit D (Sub-D)] was optimized and validated.

RESULTS

Intra-assay and interassay variability was low using peripheral blood mononuclear cells (PBMCs) (CV of 6.15% for COX-I and 7.11% Sub-D, and 9.38% and 9.83% for COX-I and Sub-D, respectively). Mitochondrial protein depletion was evident with in vitro treatment of cells with ethidium bromide (EtBr) and zalcitabine (ddC). Mitochondrial protein expression in 40 healthy adults clustered tightly. Depletion of mitochondrial protein, however, was neither detected in cryopreserved PBMC from NRTI-treated children (n = 9) nor in adults with a history of symptoms consistent with mitochondrial toxicity or ongoing treatment with didanosine (ddI) or stavudine (d4T) (n = 51).

CONCLUSIONS

A validated flow cytometric assay allows simultaneous detection of mitochondrial DNA and nuclear DNA encoded proteins at the single cell level, offering a method to monitor for mitochondrial function. Prospective studies are required to evaluate whether mitochondrial protein loss is observed in at-risk patients prior to the onset of symptoms from mitochondrial dysfunction.

Pharmacogenetic information derived from analysis of HLA alleles

A large amount of pharmacogenetic information has, in particular, accumulated on the association between human leukocyte antigen (HLA) alleles and hypersensitivity to certain drugs. Prospective HLA typing has dramatically reduced the risk of abacavir hypersensitivity because of its strong association with HLA-B*5701. Significant predisposition to nevirapine hypersensitivity has been reported in Caucasian Australians harboring HLA-DRB1*0101 with high CD4+ T-cell counts, and Sardinians and Japanese harboring HLA-Cw8. A strong association between carbamazepine hypersensitivity and HLA-B*1502 has been reported in Han Chinese. Most Han Chinese individuals with allopurinol-induced severe cutaneous adverse reactions are positive for HLA-B*5801. HLA typing can stratify risk of hypersensitivity to certain drugs and allow personalized treatment, although the patients should be monitored closely even if they are negative for HLA alleles associated with hypersensitivity.

Estimating the impact of alcohol consumption on survival for HIV+ individuals

Alcohol consumption is associated with decreased antiretroviral adherence, and decreased adherence results in poorer outcomes. However the magnitude of alcohol's impact on survival is unknown. Our objective was to use a calibrated and validated simulation of HIV disease to estimate the impact of alcohol on survival. We incorporated clinical data describing the temporal and dose-response relationships between alcohol consumption and adherence in a large observational cohort (N=2,702). Individuals were categorized as nondrinkers (no alcohol consumption), hazardous drinkers (consume > or =5 standard drinks on drinking days), and nonhazardous drinkers (consume <5 standard drinks on drinking days). Our results showed that nonhazardous alcohol consumption decreased survival by more than 1 year if the frequency of consumption was once per week or greater, and by 3.3 years (from 21.7 years to 18.4 years) with daily consumption. Hazardous alcohol consumption decreased overall survival by more than 3 years if frequency of consumption was once per week or greater, and by 6.4 years (From 16.1 years to 9.7 years) with daily consumption. Our results suggest that alcohol is an underappreciated yet modifiable risk factor for poor survival among individuals with HIV.

Monitoring oxygen transport and tissue oxygenation

PURPOSE OF REVIEW

To review recent publications in the field of oxygen delivery and tissue oxygenation. With few exceptions, we restricted our selection to clinical studies published in the English literature.

RECENT FINDINGS

No major breakthroughs have occurred in the past decade in the diagnosis or treatment of tissue hypoxia. There is renewed interest in goal-directed resuscitation when applied early in the course of treatment. Monitoring metabolic markers of tissue hypoxia continues to hold great clinical interest, in particular, tissue PCO2, near infrared spectroscopy, base deficit and blood lactate concentration. Technical issues, however, seem to restrict the widespread use of many of these techniques.

SUMMARY

There is an urgent need to develop methods to accurately and rapidly identify patients with tissue hypoxia. Perhaps the combination of gastric tonometry, near-infrared spectroscopy, urinary PO2 and continuous measures of mixed (or central) venous O2 saturation may provide the answer. An even more formidable task is that of developing effective therapy to correct tissue hypoxia while avoiding harm to the patient.

A brief overview of mechanisms of mitochondrial toxicity from NRTIs

Nucleoside reverse transcriptase inhibitors (NRTIs) in combinations with other antiretrovirals (highly active antiretroviral therapy, HAART) are the cornerstones of AIDS therapy, turning HIV infection into a manageable clinical entity. Despite the initial positive impact of NRTIs, therapeutic experience revealed serious side effects that appeared to originate in the mitochondria and which ultimately manifested as dysfunction of that organelle. It may be reasonable to consider that as the AIDS epidemic continues and as survival with HIV infection is prolonged by treatment with HAART, long-term side effects of NRTIs may become increasingly common. This consideration may be underscored in children who are born to HIV-infected mothers who received NRTI therapy in utero during gestation. The long-term effect of that NRTI exposure in utero is not clear yet. This review examines some proposed mechanisms of NRTI mitochondrial toxicity, including genetic predisposition, defects in mitochondria DNA replication, the encompassing "DNA pol-gamma hypothesis," the relationship between mitochondrial nucleotide and NRTI pools, mitochondrial DNA mutation and dysfunction, and oxidative stresses related to HIV infection and NRTIs. Mechanisms of mitochondrial toxicity are reviewed with respect to key cell biological, pathological, and pharmacological events.

Constant mitochondrial DNA levels in blood leukocytes of patients enrolled in a NRTI-free therapeutic trial (BIKS-2 study)

OBJECTIVES

Determine if a nucleoside reverse transcriptase inhibitors (NRTI)-free regimen affected mitochondrial DNA (mtDNA) levels in peripheral blood mononuclear cells (PBMCs) of patients enrolled in BIKS-2 trial.

METHODS

Antiretroviral (ARV) naïve (N=13) and NRTI experienced (N=7) patients, received lopinavir/ritonavir, a boosted protease inhibitor, and efavirenz, a non-nucleoside reverse transcriptase inhibitor from Month (M) 0 to M12 (1-year BIKS trial) and from M12 to M36 (2-year BIKS-2 trial). MtDNA was quantified at M12, M24 and M36 via real-time PCR assay.

RESULTS

From M12 to M36, the 20 patients have maintained undetectable plasma HIV-1 RNA, gained CD4 cells and had no side effects attributable to these drugs. Median mtDNA contents were constant: 478.6 at M12, 478.6 at M24 and 324.4 copies/cell at M36 (pM12-M36=0.5). Because M0 data is missing, these results were compared to those of two groups of age matched individuals: healthy donors and HIV-infected patients before and after exposure to NRTIs. Healthy donors have higher contents (871), followed by patients never treated (602), than by BIKS patients where 7 had toxic NRTIs (478.6) and at last by patients exposed for six months to the most toxic combination (ddI-d4T) (85 copies/cell).

CONCLUSION

Lopinavir/ritonavir+efavirenz did not affect mtDNA contents in PBMCs.

Hepatic steatosis is associated with fibrosis, nucleoside analogue use, and hepatitis C virus genotype 3 infection in HIV-seropositive patients

BACKGROUND

We conducted a study to determine the prevalence and factors associated with hepatic steatosis in human immunodeficiency virus (HIV)-seropositive patients with hepatitis C and to investigate whether steatosis is associated with liver fibrosis.

METHODS

Retrospective chart reviews were conducted in 4 hospitals that serve community-based and incarcerated HIV-infected patients who had undergone a liver biopsy for evaluation of hepatitis C virus (HCV) infection during the period of 2000-2003. Demographic characteristics and medication and laboratory data were collected from the time of the biopsy. A pathologist blinded to all clinical data evaluated the specimens. The primary outcome was presence or absence of steatosis.

RESULTS

Of 260 HIV-HCV-coinfected patients, 183 met inclusion criteria and had a biopsy specimen adequate for review. Steatosis was present in 69% of patients (graded as minimal in 31%, mild in 27%, moderate in 18%, and severe in 1%). Factors associated with steatosis included use of dideoxynucleoside analogues, such as didanosine and stavudine (odds ratio [OR], 4.63; 95% confidence interval [CI], 1.55-13.82). There was a trend toward presence of steatosis and use of other nucleoside analogues or infection with HCV genotype 3 (OR, 2.65 [95% CI, 0.95-7.41] and 3.38 [95% CI, 0.86-13.28], respectively). The presence of steatosis was associated with fibrosis (OR, 1.37; 95% CI, 1.03-1.81).

CONCLUSIONS

In this multiracial population of HIV-HCV-coinfected patients, steatosis was prevalent and was associated with severity of liver fibrosis. Use of nucleoside analogues (particularly didanosine and stavudine) and HCV genotype 3 infection were associated with hepatic steatosis. The development of steatosis is multifactorial in nature and may play a contributory role in the progression of liver disease in HIV-infected patients.

Real-Time Nucleic Acid Sequence–Based Amplification Assay to Quantify Changes in Mitochondrial DNA Concentrations in Cell Cultures and Blood Cells from HIV-Infected Patients Receiving Antiviral Therapy

Background: To study the clinical relevance of changes in mitochondrial DNA (mtDNA) in peripheral blood mononuclear cells (PBMCs) attributable to HIV infection and/or combination antiretroviral therapy (cART), a high-throughput molecular assay to quantify mtDNA is required.

Methods: We developed a quantitative real-time duplex nucleic acid sequence–based amplification assay in which both mtDNA and nuclear DNA are simultaneously amplified in 1 tube. The assay could accurately quantify mtDNA in a range of 15–1500 copies of mtDNA per 2 genomic copies with an intrarun variation of 11% and an interrun variation of 16%. We compared this real-time assay with the lactate/pyruvate ratios in fibroblasts incubated with glucose and exposed to zalcitabine. Additionally, we studied the effects of platelet contamination and the in vivo effects of cART on mtDNA in PBMCs from a small group of patients.

Results: Decreases in mtDNA preceded the increase in lactate/pyruvate ratios and vice versa when zalcitabine was eliminated from the culture. Platelets affected the mtDNA in PBMCs if &gt;5 platelets per PBMC were present. Within 12 weeks, mtDNA increased and remained increased in PBMCs from patients on continuous treatment with zidovudine/lamivudine/indinavir therapy (P = 0.03), but increased if patients were switched to stavudine/didanosine therapy (P = 0.008).

Conclusion: After drug exposure, the mtDNA assay can detect changes in mtDNA concentrations in cell lines and PBMCs, when properly controlled for platelet effects, earlier than traditional assays.

Risk Factors for and Outcome of Hyperlactatemia in HIV-Infected Persons: Is There a Need for Routine Lactate Monitoring?

BACKGROUND

Lactic acidosis is a rare but life-threatening complication of combination antiretroviral therapy (CART). Asymptomatic or mildly symptomatic episodes of hyperlactatemia are more frequent, but their clinical relevance is unknown.

METHODS

The incidences of, risk factors for, and courses of hyperlactatemia and lactic acidosis were prospectively assessed in the following 3 groups at the Zurich center of the Swiss HIV Cohort Study: persons already receiving CART at baseline, treatment-naive persons who initiated CART during the observation period, and persons who received no CART before or during the observation period.

RESULTS

During 4788 person-years of follow-up, a total of 22,678 lactate assessments were performed for 1566 persons; 662 (42.3%) had at least 1 lactate level measurement of > 2.4 mmol/L, and 49 (3.1%) had severe hyperlactatemia (lactate level of > 5.0 mmol/L). The incidence of hyperlactatemia was 227 cases (95% confidence interval [CI], 210-245) and 59 cases (95% CI, 38-93) per 1000 person-years of follow-up among persons with and persons without CART, respectively. During the observation period, the incidence decreased from 459 cases (95% CI, 415-508) to 85 cases (95% CI, 76-107) per 1000 person-years of follow-up, respectively, because of changing CART prescription patterns. Severe hyperlactatemia occurred in treated persons only. In multivariable Cox proportional hazards models, significant risk factors for severe hyperlactatemia were regimens containing stavudine and didanosine (hazard ratio [HR], 6.65; 95% CI, 2.70-16.3) and regimens containing efavirenz (HR, 2.85; 95% CI, 1.31-6.21). Lactic acidosis was diagnosed in 4 of 1566 persons, all of whom were receiving stavudine and didanosine.

CONCLUSIONS

Hyperlactatemia was frequently observed in all 3 groups, but severe hyperlactatemia and lactic acidosis were rarely observed among persons who received CART. Lactate monitoring appears to be indicated primarily for persons receiving stavudine and didanosine and for persons who are symptomatic. Long-term follow-up is needed to investigate the risk of novel treatment regimens for hyperlactatemia.

Hepatic steatosis and antiretroviral drug use among adults coinfected with HIV and hepatitis C virus

OBJECTIVE

To ascertain the prevalence and severity of hepatic steatosis among patients coinfected with HIV and hepatitis C virus (HCV) who had been taking antiretroviral therapy (ART); to investigate if steatosis is associated with more advanced liver disease, and to identify factors that might contribute to the process.

METHODS

Steatosis was assessed among a randomly selected subset of HIV-HCV-coinfected patients who had received at least 2 years of ART in a cohort study at the Johns Hopkins University HIV clinic. Liver histology was evaluated by a single pathologist. The primary outcome measure was the hepatic steatosis grade, which was classified on a 5 point scale: 0, none; 1, steatosis involving < 5% of hepatocytes; 2, 5-29%; 3, 30-60%; 4 > 60%.

RESULTS

Liver histology was assessed in 112 patients, 74% of whom were taking ART at the time of biopsy. The median cumulative exposure to nucleoside reverse transcriptase inhibitors and protease inhibitors was 5.8 and 3.7 years, respectively. No steatosis was detected in 60%; grades 2-4 steatosis was recognized in 18%. In multivariate analysis, steatosis was independently associated with Caucasian race, weight > 86 kg, hyperglycemia, and stavudine use. Patients with steatosis also were more likely to have greater hepatic fibrosis (P = 0.02) and necroinflammatory activity (P = 0.005).

CONCLUSIONS

Steatosis was observed in 40% of HIV-HCV-coinfected patients with extensive ART exposure and was associated with more severe HCV-related liver disease. Metabolic abnormalities (excess weight and hyperglycemia) and stavudine use were modifiable risk factors for steatosis in this population.

Immune activation and oxidative damage in HIV-positive and HIV-negative adolescents

In a cross-sectional study involving subjects from the Reaching for Excellence in Adolescent Health cohort, we examined the associations between HIV status, disease severity, immune activation, and oxidative damage. Subjects (265 HIV-positive and 127 HIV-negative) were young (range: 14-23 years of age) and primarily female (75%) and black (67%). Many subjects, particularly female subjects, were overweight or obese. Relatively few HIV-positive subjects had advanced HIV disease (13%), and 54% were taking antiretroviral therapy (ART). The 2 markers of oxidative damage used in this study (plasma malondialdehyde and protein carbonyl concentrations) did not correlate with each other, and neither was higher in HIV-positive subjects than in HIV-negative controls. Increased oxidative damage was seen in association with male gender, cigarette smoking, marijuana use, immune activation (as indicated by activated CD8 T-cell counts and plasma C-reactive protein concentration), and use of ART, however. Plasma ceruloplasmin was associated with decreased oxidative damage in HIV-positive subjects, although this association was not seen in those taking ART.

Body Composition and Metabolic Changes in Antiretroviral-Naive Patients Randomized to Didanosine and Stavudine vs. Abacavir and Lamivudine

Comparisons of body composition and metabolic changes among antiretroviral-naive patients randomly assigned to didanosine and stavudine- (ddI+d4T) vs. abacavir and lamivudine- (ABC+3TC) containing regimens were assessed in a nested substudy of an ongoing multicenter randomized trial. At baseline and every 4 months, body cell mass and total body fat were calculated, anthropometric measurements were performed, and fasting metabolic parameters were obtained. The rates of change (unit/mo) estimated using the slopes of regression lines and overall mean changes from baseline were compared by study assignment. Among 96 patients enrolled, 46 received ddI+d4T- and 50 received ABC+3TC-containing regimens with a median follow-up of 32.4 months. For both study arms, an overall increase in the rates of change was seen for body cell mass. For ddI+d4T, after an initial increase, the rates of change declined for regional fat and total body fat compared with an increase for ABC+3TC, with the 2 arms being significantly different (P<0.05). For high-density lipoprotein cholesterol rates of change, ddI+d4T decreased, while ABC+3TC increased. For both arms, low-density lipoprotein cholesterol decreased, while triglycerides increased. Early and sustained increases in insulin and insulin resistance were seen only for ddI+d4T. In this prospective study, metabolic and body composition changes varied according to whether subjects received ddI+d4T or ABC+3TC.

Isofurans: novel products of lipid peroxidation that define the occurrence of oxidant injury in settings of elevated oxygen tension

We recently reported the discovery of isofurans, novel products of free radical-induced peroxidation of arachidonic acid that exhibit favored formation with increasing oxygen concentrations. In this review, the biochemistry of isofuran formation is compared with that of isoprostanes, with an emphasis on the mechanistic basis for the favored formation of isofurans at elevated oxygen tensions. In addition, the formation of isofurans in various disease states in vivo is also discussed. Parkinson's disease is presented as a disease model involving mitochondrial dysfunction, a situation in which quantification of isofurans can provide a uniquely sensitive indicator of oxidant injury. Measurement of isofurans has also provided unexpected insights into the earliest events in hyperoxic lung injury, an important clinical problem in which measurement of isofurans might prove to be uniquely valuable in the evaluation of approaches to limit this injury. These two settings are then used as models to suggest a variety of other pathological settings in which measurement of isofurans together with isoprostanes could provide a complete and robust picture of oxidative stress status in ongoing and future investigations.

Mitochondrial Abnormalities in HIV-Infected Lipoatrophic Patients Treated With Antiretroviral Agents

BACKGROUND

Lipodystrophy is now widely described in HIV infected patients under antiretroviral regimen with important psychological impact. But physiopathology of loss of fat mass is still debated and the role of mitochondrial impairment is not clearly defined.

OBJECTIVE

To correlate clinical lipoatrophy (LA) in HIV patients with long-term treatment by nucleoside reverse transcriptase inhibitors (NRTIs) and muscular impairment related to mitochondrial dysfunction.

METHODS

Ten consecutive patients with clinical LA and 10 nonlipodystrophic (NLD) individuals on antiretroviral therapy were included. Patients underwent the following investigations: dual-energy x-ray absorptiometry (DEXA) scanning and lactate kinetics during standardized exercise. The mitochondrial respiratory complex activity (III and IV) and histoenzymatic abnormalities (classified as none, mild, or severe) were evaluated on muscle tissue obtained by biopsy in deltoid muscle.

RESULTS

Mean NRTI exposure was longer in the LA group than in the NLD group (81 +/- 30 months vs. 59 +/- 15 months), but mean protease inhibitor exposure was identical in both groups. Mean fat mass distribution for leg in the LA and NLD groups was 860 +/- 381 g versus 1895 +/- 999 g, respectively. The lactic acidosis threshold during exercise was reached in the LA group at lower workloads (mean: 45 +/- 17 W in the LA group vs. 68 +/- 11 W in the NLD group), and maximum power output exercise was restricted in LA patients (mean: 115 +/- 30 W vs. 153 +/- 28 W). Total complex activities in muscular tissue were lower in LA patients: the median (range) for complex III was 67 (1-128) versus 112 (28-143), and the median (range) for complex IV was 28 (1-70) versus 42 (1-75). Six patients had severe histoenzymatic abnormalities in the LA group versus none in the NLD group.

CONCLUSION

Clinical LA, confirmed by DEXA, in long-term NRTI-treated patients was associated with muscular mitochondrial dysfunction as shown by rapid lactic acidemia increase, impairment of respiratory chain activity for complexes III and IV, and mitochondrial histoenzymatic abnormalities.

Special considerations in the initiation and management of antiretroviral therapy in individuals coinfected with HIV and hepatitis C

BACKGROUND

Although hepatitis C (HCV) treatment efficacy has improved in recent years, the majority of HIV/HCV-coinfected individuals may not enjoy the full benefits of these treatments and appropriate HIV management is crucial. Evidence is accumulating regarding the impact of HIV/HCV coinfection on the response to, and safety and tolerability of, antiretroviral therapy (ART) in this population.

METHODS

Computerized, English-language literature searches of MEDLINE and PubMed databases (January 1985 to May 2004) for studies of HIV and HCV infection in humans to examine critically (a) the impact of HCV on the HIV virologic and immunologic response to ART; (b) the safety and tolerability of ART in coinfected individuals; and (c) the relationship between immune suppression and immune restoration on hepatic injury.

RESULTS

Three key messages emerged regarding the use of ART in HIV/HCV-coinfected individuals: (a) although HCV appeared to have no impact on HIV virologic response, the data are equivocal regarding immunologic response; (b) morbidities associated with HCV infection, such as insulin resistance, diabetes, mitochondrial dysfunction, and liver inflammation, are also associated toxicities of ART, and (c) both immune suppression and restoration can contribute to the onset and acceleration of HCV-related liver disease.

CONCLUSIONS

The CD4 cell count threshold for initiating ART in HIV/HCV-coinfected patients may be higher because of the impact of immune suppression and restoration on the onset of HCV-associated liver disease and the possibility of a blunted immune response to ART at lower CD4 cell counts. Further, overlapping morbidity between HCV-related mitochondrial and metabolic disease manifestations and ART toxicities warrant careful attention by clinicians.

Prospective evaluation of blood concentration of mitochondrial DNA as a marker of toxicity in 157 consecutively recruited untreated or HAART-treated HIV-positive patients

Highly active antiretroviral therapy (HAART) can cause mitochondrial toxicity. The concentration of mitochondrial DNA (mtDNA) in peripheral blood cells has been reported to be a marker of this toxicity. However, these observations are controversial and were drawn from small series. Thus, we analysed the value of blood mtDNA as a marker of mitochondrial toxicity in a large cohort of human immunodeficiency virus (HIV)-infected out-patients during routine clinical evaluations. Real-time quantitative PCR was used to determine the mtDNA to nuclear DNA (nDNA) ratio in peripheral blood mononuclear cells from 157 consecutive HIV-1-infected patients (13 naive, 144 receiving HAART) and 30 HIV-1-uninfected patients. The mtDNA to nDNA ratio was significantly lower in both groups of HIV-infected patients than in the control group. No significant difference was observed between treated and naive HIV-infected patients. Lactataemia was significantly lower in controls than in the group of HIV-treated patients. None of the treated patients had lactataemia >5 mmol/l or bicarbonates <20 mmol/l. Triglyceride levels were significantly higher in the HAART-treated patients than in the nontreated patients. Clinical symptoms of lipodystrophy were observed in 62 HAART-treated patients. These symptoms were not associated with an abnormal mtDNA to nDNA ratio or plasma triglyceride concentration. The mtDNA to nDNA ratio was lower in DDI/D4T-treated patients than in AZT/3TC-treated patients. In conclusion, there are no obvious links between the mtDNA to nDNA ratio in peripheral mononuclear cells and any clinical symptoms or lactate level. Thus, the mtDNA to nDNA ratio in leukocytes does not seem to be an accurate marker of mild and/or long-term mitochondrial toxicity.