High-density lipoprotein concentrations relate to the clinical course of HIV viral load in patients undergoing antiretroviral therapy

Factors affecting high-density lipoprotein cholesterol in HIV-infected patients on nevirapine-based antiretroviral therapy

Background & objectives:

Cardiovascular disease (CVD) risk with low high-density lipoprotein cholesterol (HDL-C) and high triglycerides is common in the general population in India. As nevirapine (NVP)-based antiretroviral therapy (ART) tends to increase HDL-C, gene polymorphisms associated with HDL-C metabolism in HIV-infected adults on stable NVP-based ART were studied.

Methods:

A cross-sectional study was conducted between January 2013 and July 2014 among adults receiving NVP-based ART for 12-15 months. Blood lipids were estimated and gene polymorphisms in apolipoprotein C3 (APOC3), cholesteryl ester transfer protein (CETP) and lipoprotein lipase (LPL) genes were analyzed by real-time polymerase chain reaction. Framingham's 10-yr CVD risk score was estimated. Logistic regression was done to show factors related to low HDL-C levels.

Results:

Of the 300 patients included (mean age: 38.6±8.7 yr; mean CD4 count 449±210 cell/μl), total cholesterol (TC) >200 mg/dl was observed in 116 (39%) patients. Thirty nine per cent males and 47 per cent females had HDL-C levels below normal while 32 per cent males and 37 per cent females had TC/HDL ratio of 4.5 and 4.0, respectively. Body mass index [adjusted odds ratio (aOR)=1.70, 95% confidence interval (CI) 1.01-2.84, P=0.04] and viral load (aOR=3.39, 95% CI: 1.52-7.52, P=0.003) were negatively associated with serum HDL-C levels. The 10-yr risk score of developing CVD was 11-20 per cent in 3 per cent patients. Allelic variants of APOC3 showed a trend towards low HDL-C.

Interpretation & conclusions:

High-risk lipid profiles for atherosclerosis and cardiovascular disease were common among HIV-infected individuals, even after 12 months of NVP-based ART. Targeted interventions to address these factors should be recommended in the national ART programmes.

Liver Transcriptome and miRNA Analysis of Silver Carp (Hypophthalmichthys molitrix) Intraperitoneally Injected With Microcystin-LR

Next-generation sequencing was used to analyze the effects of toxic microcystin-LR (MC-LR) on silver carp (Hypophthalmichthys molitrix). Silver carps were intraperitoneally injected with MC-LR, and RNA-seq and miRNA-seq in the liver were analyzed at 0.25, 0.5, and 1 h. The expression of glutathione S-transferase (GST), which acts as a marker gene for MC-LR, was tested to determine the earliest time point at which GST transcription was initiated in the liver tissues of the MC-LR-treated silver carps. Hepatic RNA-seq/miRNA-seq analysis and data integration analysis were conducted with reference to the identified time point. Quantitative PCR (qPCR) was performed to detect the expression of the following genes at the three time points: heme oxygenase 1 (HO-1), interleukin-10 receptor 1 (IL-10R1), apolipoprotein A-I (apoA-I), and heme binding protein 2 (HBP2). Results showed that the liver GST expression was remarkably decreased at 0.25 h (P < 0.05). RNA-seq at this time point revealed that the liver tissue contained 97,505 unigenes, including 184 significantly different unigenes and 75 unknown genes. Gene Ontology (GO) term enrichment analysis suggested that 35 of the 145 enriched GO terms were significantly enriched and mainly related to the immune system regulation network. KEGG pathway enrichment analysis showed that 18 of the 189 pathways were significantly enriched, and the most significant was a ribosome pathway containing 77 differentially expressed genes. miRNA-seq analysis indicated that the longest miRNA had 22 nucleotides (nt), followed by 21 and 23 nt. A total of 286 known miRNAs, 332 known miRNA precursor sequences, and 438 new miRNAs were predicted. A total of 1,048,575 mRNA–miRNA interaction sites were obtained, and 21,252 and 21,241 target genes were respectively predicted in known and new miRNAs. qPCR revealed that HO-1, IL-10R1, apoA-I, and HBP2 were significantly differentially expressed and might play important roles in the toxicity and liver detoxification of MC-LR in fish. These results were consistent with those of high-throughput sequencing, thereby verifying the accuracy of our sequencing data. RNA-seq and miRNA-seq analyses of silver carp liver injected with MC-LR provided valuable and new insights into the toxic effects of MC-LR and the antitoxic mechanisms of MC-LR in fish.

The RNA/miRNA data are available from the NCBI database Registration No. : SRP075165.

Paraoxonases and infectious diseases

The paraoxonases (PON1, PON2 and PON3) are an enzyme family with a high structural homology. All of them have lactonase activity and degrade lipid peroxides in lipoproteins and cells. As such, they play a role in protection against oxidation and inflammation. Infectious diseases are often associated with oxidative stress and an inflammatory response. Infection and inflammation trigger a cascade of reactions in the host, known as the acute-phase response. This response is associated with dramatic changes in serum proteins and lipoproteins, including a decrease in serum PON1 activity. These alterations have clinical consequences for the infected patient, including an increased risk for cardiovascular diseases, and an impaired protection against the formation of antibiotic-resistant bacterial biofilms. Several studies have investigated the value of serum PON1 measurement as a biomarker of the infection process. Low serum PON1 activities are associated with poor survival in patients with severe sepsis. In addition, preliminary studies suggest that serum PON1 concentration and/or enzyme activity may be useful as markers of acute concomitant infection in patients with an indwelling central venous catheter. Investigating the associations between paraoxonases and infectious diseases is a recent, and productive, line of research.

Apolipoprotein A-I in Labeo rohita: Cloning and functional characterisation reveal its broad spectrum antimicrobial property, and indicate significant role during ectoparasitic infection

Apolipoprotein A-I (ApoA-I) is the most abundant and multifunctional high-density lipoprotein (HDL) having a major role in lipid transport and potent antimicrobial activity against a wide range of microbes. In this study, a complete CDS of 771 bp of Labeo rohita (rohu) ApoA-I (LrApoA-I) encoding a protein of 256 amino acids was amplified, cloned and sequenced. Tissue specific transcription analysis of LrApoA-I revealed its expression in a wide range of tissues, with a very high level of expression in liver and spleen. Ontogenic study of LrApoA-I expression showed presence of transcripts in milt and 3 h post-fertilization onwards in the larvae. The expression kinetics of LrApoA-I was studied upon infection with three different types of pathogens to elucidate its functional significance. Its expression was found to be up-regulated in the anterior kidney of L. rohita post-infection with Aeromonas hydrophila. Similarly following poly I:C (poly inosinic:cytidylic) stimulation, the transcript levels increased in both the anterior kidney and liver tissues. Significant up-regulation of LrApoA-I expression was observed in skin, mucous, liver and anterior kidney of the fish challenged with the ectoparasite Argulus siamensis. Immunomodulatory effect of recombinant LrApoA-I (rApoA-I) produced in Escherichia coli was demonstrated against A. hydrophila challenge in vivo. L. rohita administered with rApoA-I at a dose of 100 μg exhibited significantly higher protection (∼55%) upon challenge with A. hydrophila 12 h post-administration of the protein, in comparison to that observed in control group, along with higher level of expression of immune-related genes. The heightened expression of ApoA-I observed post-infection reflected its involvement in immune responses against a wide range of infections including bacterial, viral as well as parasitic pathogens. Our results also suggest the possibility of using rApoA-I as an immunostimulant, particularly rendering protection against A. hydrophila.

HIV viral load: a concept analysis and critique

In this article, we examine the concept of HIV viral load and how it has evolved over time (1995-2013) in the field of HIV/AIDS. Although the term viral load is used extensively in this field, few efforts have been directed toward the conceptualization of HIV viral load, which is often left unquestioned, undertheorized, and portrayed as a neutral and objective laboratory value that has remained relatively stable over time--with the exception of progressive advancements in technology, techniques, and sensitivity. The purpose of this article is to apply the evolutionary concept analysis method developed by Rodgers (1989, 2000a) to the concept of HIV viral load. To set the stage, we establish the need for a concept analysis of HIV viral load and provide an overview of the evolutionary view. Then, drawing on the steps proposed by Rodgers (2000a), we outline the process of data collection, management, and analysis. We then offer an in-depth discussion of the findings (attributes, antecedents, and consequences) informed by Wuest's (2000) critical approach to concept analysis. We conclude by highlighting the implications of this analysis for clinical practice, research, and theory.

Isolation and function analysis of apolipoprotein A-I gene response to virus infection in grouper

Apolipoproteins, synthesized mainly in liver and intestine and bounded to lipids, play important roles in lipid transport and uptake through the circulation system. In this study, an apolipoprotein A-I gene homologue was cloned from orange-spotted grouper Epinephelus coioides (designed as Ec-ApoA-I) by rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA of Ec-ApoA-I was comprised of 1278 bp with a 792 bp open reading frame (ORF) that encodes a putative protein of 264 amino acids. Quantitative real-time PCR (qPCR) analysis revealed that Ec-ApoA-I was abundant in liver and intestine, and the expression in liver was significantly (P < 0.01) up-regulated after the stimulation of LPS, Poly(I:C), Vibrio alginolyticus, and Singapore grouper iridovirus (SGIV). Recombinant Ec-ApoA-I (rEc-ApoA-I) was produced in Escherichia coli BL21 (DE3) expression system exhibited bacteriolyticactivity against Microcococcus lysodeikticus and Aeromonas hydrophila. Intracellular localization revealed that Ec-ApoA-I distributed in both cytoplasm and nucleus, and predominantly in the cytoplasm. Overexpression of Ec-ApoA-I in grouper Brain (GB) cells could inhibit the replication of SGIV. These results together indicated that Ec-ApoA-I perhaps is involved in the responses to bacterial and viral challenge.

Human paraoxonase-1 activity is related to the number of CD4+ T-cells and is restored by antiretroviral therapy in HIV-1-infected individuals

Background. Paraoxonase-1 (PON1) activity is suggested to be altered in individuals infected with human immunodeficiency virus type-1 (HIV-1). We investigated PON1 activity in individuals receiving different regimens of highly active antiretroviral therapy (HAART). Methods. PON1 activity was evaluated in 91 HIV-1 seronegative and 624 HIV-1 infected individuals (115 were not undergoing therapy (ART-naïve), and 509 were receiving HAART). HIV-1 infected individuals were treated with the following: efavirenz (EFV; n = 195) or nevirapine (NVP; n = 95) or lopinavir/ritonavir (LOP/r; n = 219). Serum levels of total cholesterol (TC), HDL, and low-density lipoprotein (LDL) fractions and the atherogenic indices (AI, TC : HDL, and LDL : HDL ratios) were determined. Results. PON1 activity (U/L) was lower in the ART-naïve group compared with the other groups. PON1 activity correlated with CD4+ T-cell number of ART-naïve group (r = 0,121; P = 0,014). The LOP/r group showed a reduction in HDL and an increase in AI (TC : HDL ratio) in comparison with other groups. Conclusion. PON1 activity was reduced in untreated individuals, but not in individuals receiving HAART. PON1 activity correlated with the number of CD4+ T-cells. The findings suggest that the activity of PON1 is associated with the immune status of HIV-1 infected individuals.

The deleterious influence of tenofovir-based therapies on the progression of atherosclerosis in HIV-infected patients

We investigated the potential differential effects of antiretroviral therapies on unbalanced chemokine homeostasis and on the progression of atherosclerosis in HIV-infected patients. A two-year prospective study was performed in 67 consecutive HIV-infected patients initiating antiretroviral therapy with abacavir/lamivudine or tenofovir/emtricitabine. Circulating levels of inflammatory biomarkers, progression of subclinical atherosclerosis and expression levels of selected chemokines genes in circulating leukocytes were assessed. Control subjects showed significantly lower plasma concentrations of CRP, tPA, IL-6, and MCP-1 than HIV-infected patients at a baseline. After two years of followup, the observed decreases in plasma inflammatory biomarker levels were only significant for MCP-1, tPA, and IL-6. The decrease in plasma MCP-1 concentration was associated with the progression of atherosclerosis, and this effect was negligible only in patients receiving TDF-based therapy. Multivariate analysis confirmed that treatment with TDF was positively and significantly associated with a higher likelihood of subclinical atherosclerosis progression. However, the expression levels of selected genes in blood cells only showed associations with the viral load and total and HDL-cholesterol levels. Current antiretroviral treatments may partially attenuate the influence of HIV infection on certain inflammatory pathways, though patients receiving TDF therapy must be carefully monitored with respect to the presence and/or progression of atherosclerosis.

Serum paraoxonase-3 concentration in HIV-infected patients. Evidence for a protective role against oxidation

We investigated the influence of the HIV infection on serum paraoxonase-3 (PON3) concentration and assessed the relationships with lipoprotein-associated abnormalities, immunological response, and accelerated atherosclerosis. We studied 207 HIV-infected patients and 385 healthy volunteers. Serum PON3 was determined by in-house ELISA, and PON3 distribution in lipoproteins was investigated by fast-performance liquid chromatography (FPLC). Polymorphisms of the PON3 promoter were analyzed by the Iplex Gold MassArray(TM) method. PON3 concentrations were increased (about three times) in HIV-infected patients with respect to controls (P < 0.001) and were inversely correlated with oxidized LDL levels (P = 0.038). Long-term use of nonnucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral therapy was associated with a decrease of PON3 concentrations. In a multivariate linear regression analysis, these relationships were still strong when the main confounding covariates were considered. PON3 was mainly found in HDL in HIV-infected patients, but a substantial amount of the protein was detected in LDL particles. This study reports for the first time an important increase in serum PON3 concentrations in HIV-infected patients that is associated with their oxidative status and their treatment with NNRTI. Long-term, prospective studies are needed to confirm the possible influence of this enzyme on the course of this disease and its possible utility as an analytical biomarker.

Metabolic and anthropometric parameters contribute to ART-mediated CD4+ T cell recovery in HIV-1-infected individuals: an observational study

BACKGROUND

The degree of immune reconstitution achieved in response to suppressive ART is associated with baseline individual characteristics, such as pre-treatment CD4 count, levels of viral replication, cellular activation, choice of treatment regimen and gender. However, the combined effect of these variables on long-term CD4 recovery remains elusive, and no single variable predicts treatment response. We sought to determine if adiposity and molecules associated with lipid metabolism may affect the response to ART and the degree of subsequent immune reconstitution, and to assess their ability to predict CD4 recovery.

METHODS

We studied a cohort of 69 (48 females and 21 males) HIV-infected, treatment-naïve South African subjects initiating antiretroviral treatment (d4T, 3Tc and lopinavir/ritonavir). We collected information at baseline and six months after viral suppression, assessing anthropometric parameters, dual energy X-ray absorptiometry and magnetic resonance imaging scans, serum-based clinical laboratory tests and whole blood-based flow cytometry, and determined their role in predicting the increase in CD4 count in response to ART.

RESULTS

We present evidence that baseline CD4+ T cell count, viral load, CD8+ T cell activation (CD95 expression) and metabolic and anthropometric parameters linked to adiposity (LDL/HDL cholesterol ratio and waist/hip ratio) significantly contribute to variability in the extent of CD4 reconstitution (ΔCD4) after six months of continuous ART.

CONCLUSIONS

Our final model accounts for 44% of the variability in CD4+ T cell recovery in virally suppressed individuals, representing a workable predictive model of immune reconstitution.

The inverse association of serum HBV DNA level with HDL and adiponectin in chronic hepatitis B infection

BACKGROUND

The natural history of hepatitis B virus (HBV) is complex and influenced by the level of viral replication and host factors. The hepatoprotective role of high density lipoproteins (HDL) and adiponectin as host factors on HBV persistence is less well understood.

METHODS

To investigate correlation between HBV DNA level with clinical parameters in patients with chronic hepatitis B, 92 male subjects with HBV infection without any risk factors for diabetes were enrolled in this study. Age and BMI of the study population were matched and HBV DNA, ALT, tumor necrosis factor alpha (TNF-α), adiponectin and lipid levels was measured.

RESULTS

Serum HBV DNA correlated inversely with serum HDL level (r = -0.23; P = 0.014). The median of log copies/ml for HBV DNA (3.67) was considered as cut off point. Patients with HBV DNA level higher than cut off point had lower adiponectin (8.7 ± 5.3 vs 10.7 ± 4.9 μg/ml p = 0.05). Also, adiponectin had a negative correlation with TNF-α (r = -0.21, P = 0.04) and positive correlations with HDL (r = 0.18, P = 0.043). Multivariate regression models show that serum HDL level is an independent factor to predict serum HBV DNA.

CONCLUSION

Our findings showed that higher HBV DNA levels are associated with lower HDL and adiponectin but induced TNF-alpha values.

Effect of efavirenz on high-density lipoprotein antioxidant properties in HIV-infected patients

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

* In previous work, we showed a long-term and concentration-dependent beneficial effect of the non-nucleoside reverse transcriptase inhibitor efavirenz (EFV) on high-density lipoproteins (HDL) in human immunodeficiency virus (HIV)-infected patients. * Furthermore, it has been suggested that instead of the current practice of only measuring HDL-chelesterol values, the evaluation of HDL function, namely its antioxidant properties, might be an improved tool for identifying subjects at increased risk for cardiovascular events. * Paraoxonase-1 (PON-1) is an enzyme associated with HDL that is responsible for HDL antioxidant function.

WHAT THIS STUDY ADDS

* In the present work, we studied the effect of EFV on the activity of PON-1 and showed, for the first time, that EFV-based antiretroviral therapy is associated with a better antioxidant function, i.e. with a higher PON-1 activity.

AIMS

A long-term and concentration-dependent beneficial effect of efavirenz (EFV) on cholesterol associated with high-density lipoprotein (HDL-c) in human immunodeficiency virus (HIV)-infected patients has been documented. Furthermore, it has been suggested that, instead of the current practice of only measuring HDL-c values, the evaluation of HDL quality might be an improved tool for identifying subjects at increased risk of cardiovascular events. Paraoxonase-1 (PON-1) is an enzyme associated with HDL that is involved in the onset of cardiovascular disease and responsible for HDL antioxidant function. The aim of the present study was to investigate the effect of EFV on the circulating activity of PON-1 in HIV-infected patients.

METHODS

The patients included were adults with a documented HIV-1 infection, nontreated or treated with antiretroviral regimens including EFV 600 mg once daily as first therapeutic regimen for at least 3 months. The influence of treatment with EFV, HDL-c and CD4 cell count on PON-1 activity was analysed.

RESULTS

HIV-infected White patients treated with EFV had higher PON-1 activity [77.35 U l(-1) (65.66, 89.04)] (P < 0.05) and higher PON-1 activity : HDL-c ratio [1.88 (1.49, 2.28)] (P < 0.01) than untreated patients. PON-1 activity was higher in Black patients (P < 0.001) and in patients with a CD4 cell count >500 cells ml(-1) (P= 0.0120).

CONCLUSIONS

EFV-based antiretroviral regimens are associated with HDL particles with a better antioxidant function, i.e. with a higher PON-1 activity. The PON-1 activity of Black patients is higher than that found in Whites regardless of treatment. Ethnicity should be taken into consideration when studying drug effects on PON-1 activity.

Low cholesterol? Don't brag yet ... hypocholesterolemia blunts HAART effectiveness: a longitudinal study

BACKGROUND

In vitro studies suggest that reducing cholesterol inhibits HIV replication. However, this effect may not hold in vivo, where other factors, such as cholesterol's immunomodulatory properties, may interact.

METHODS

Fasting blood samples were obtained on 165 people living with HIV at baseline and after 24 weeks on highly active antiretroviral therapy (HAART). Participants were classified as hypocholesterolemic (HypoCHL; <150 mg/dl) or non-HypoCHL (>150 mg/dl) and were compared on viro-immune outcomes.

RESULTS

At baseline, participants with HypoCHL (40%) exhibited lower CD4 (197 +/- 181 vs. 295 +/- 191 cells/mm3, p = 0.02) and CD8 (823 +/- 448 vs. 1194 +/- 598 cells/mm3, p = 0.001) counts and were more likely to have detectable viral loads (OR = 3.5, p = 0.01) than non-HypoCHL controls. After HAART, participants with HypoCHL were twice as likely to experience a virological failure >400 copies (95% CI 1-2.6, p = 0.05) and to exhibit <200 CD4 (95% CI 1.03-2.9, p = 0.04) compared with non-HypoCHL. Low thymic output was related to poorer CD4 cell response in HypoCHL subjects. Analyses suggest a dose-response relationship with every increase of 50 mg/dl in cholesterol related to a parallel rise of 50 CD4 cells.

CONCLUSIONS

The study implicates, for the first time, HypoCHL with impaired HAART effectiveness, including limited CD4 repletion by the thymus and suboptimal viral clearance.

Pitfalls in measuring high-density lipoprotein cholesterol concentrations in HIV-infected patients

OBJECTIVES

HIV infection and its treatment are associated with dyslipidaemia and increased risk of cardiovascular disease. Accurate high-density lipoprotein (HDL) cholesterol values are necessary for the management of these abnormalities, but current methods have not been properly assessed in these patients. The aim of this study was to assess in HIV-infected patients the consistency and accuracy of a synthetic polymer/detergent homogeneous assay used to measure HDL cholesterol concentrations and to evaluate the impact of storage.

METHODS

HDL cholesterol was measured using a synthetic polymer/detergent homogeneous method in samples from HIV-infected patients and healthy subjects for each of the storage regimens: baseline, after 1 week at 4 degrees C, and after 12 months at -80 degrees C. The ultracentrifugation and precipitation assays were used for comparison.

RESULTS

Three out of every 20 samples from HIV-infected patients had discrepant HDL cholesterol values with respect to the ultracentrifugation method. Overestimation was associated with high C-reactive protein concentrations and underestimation with plasma gamma-globulin concentrations, an effect that was amplified by any of the storage conditions tested.

CONCLUSIONS

Caution is needed when using the synthetic polymer/detergent homogeneous method for direct measurement of HDL cholesterol concentrations in HIV-infected patients. This assay is of limited use in clinical trials in which frozen samples are analysed.

The paraoxonases: role in human diseases and methodological difficulties in measurement

Research into the paraoxonase (PON) gene family has flourished over the past few years. In the 1970s and 1980s, only PON1 was known, and the investigations were conducted, essentially, by toxicologists focusing on protection against organophosphate poisoning. Since then, two new members of the family, PON2 and PON3, have been identified, both being shown to play antioxidant and anti-inflammatory roles. Evidence exists indicating that the PON family is central to a wide variety of human illnesses such as cardiovascular disease, diabetes mellitus, metabolic syndrome, obesity, non-alcoholic steatohepatitis, and several mental disorders. However, research is hampered considerably by the methods currently available to measure the activity of these enzymes. In this review, we summarize the state of knowledge on PON biochemistry and function, the influence of genetic variations, and the involvement of PON in several diseases. The problems associated with PON measurement, such as sample acquisition, lack of reference methods, and variety of substrates, will be presented. Also, we cover some of the present lines of research and propose some others for future progress in this field.

HIV replication enhances production of free fatty acids, low density lipoproteins and many key proteins involved in lipid metabolism: a proteomics study

Background

HIV-infected patients develop multiple metabolic abnormalities including insulin resistance, lipodystrophy and dyslipidemia. Although progression of these disorders has been associated with the use of various protease inhibitors and other antiretroviral drugs, HIV-infected individuals who have not received these treatments also develop lipid abnormalities albeit to a lesser extent. How HIV alters lipid metabolism in an infected cell and what molecular changes are affected through protein interaction pathways are not well-understood.

Results

Since many genetic, epigenetic, dietary and other factors influence lipid metabolism in vivo, we have chosen to study genome-wide changes in the proteomes of a human T-cell line before and after HIV infection in order to circumvent computational problems associated with multiple variables. Four separate experiments were conducted including one that compared 14 different time points over a period of >3 months. By subtractive analyses of protein profiles overtime, several hundred differentially expressed proteins were identified in HIV-infected cells by mass spectrometry and each protein was scrutinized for its biological functions by using various bioinformatics programs. Herein, we report 18 HIV-modulated proteins and their interaction pathways that enhance fatty acid synthesis, increase low density lipoproteins (triglycerides), dysregulate lipid transport, oxidize lipids, and alter cellular lipid metabolism.

Conclusions

We conclude that HIV replication alone (i.e. without any influence of antiviral drugs, or other human genetic factors), can induce novel cellular enzymes and proteins that are significantly associated with biologically relevant processes involved in lipid synthesis, transport and metabolism (p = <0.0002–0.01). Translational and clinical studies on the newly discovered proteins may now shed light on how some of these proteins may be useful for early diagnosis of individuals who might be at high risk for developing lipid-related disorders. The target proteins could then be used for future studies in the development of inhibitors for preventing lipid-metabolic anomalies. This is the first direct evidence that HIV-modulates production of proteins that are significantly involved in disrupting the normal lipid-metabolic pathways.

High-density lipoprotein cholesterol in HIV-infected patients: evidence for an association with HIV-1 viral load, antiretroviral therapy status, and regimen composition

Low high-density lipoprotein-cholesterol (HDL-C) levels have been associated with cardiovascular risk in non-HIV populations. Limited information exists on the prevalence of low HDL-C in HIV- infected patients and related factors remain largely unknown. The aims of this study were to estimate the prevalence and characteristics of low HDL-C levels in HIV-infected patients. A cross-sectional study was performed in consecutive HIV-infected patients cared for in an outpatient HIV clinic on the Mediterranean coast of Spain during a 2-month period (September 15, 2003 to November 15, 2003). HDL-C levels below 40 mg/dL were considered low. We analyzed data from 219 patients, 167 of whom were on antiretroviral therapy. The majority (45.20 %) were on non-nucleoside reverse transcriptase inhibitors (NNRTI); 22.83 % were on treatment with protease inhibitors. The prevalence of low HDL-C levels was 44.74 % (98 of 219 patients). In multivariate analysis, hypertriglyceridemia (triglycerides >150 mg/dL; odds ratio [OR], 5.65; 95% confidence interval [CI], 2.85-11.23; p = 0.0001), HIV-1 RNA viral load greater than 50 copies per milliliter (OR, 3.15; 95% CI, 1.63-6.109; p = 0.001) and antiretroviral therapy with regimens other than NNRTIs-based regimens (OR, 2.17; 95% CI, 1.12-4.16; p = 0.021) were associated with low HDL-C levels. These data indicate that prevalence of low HDL-C among HIV-infected patients from this cohort was very high. Low HDL-C was related to triglyceride levels, HIV-1 RNA viral load and antiretroviral therapy composition. Undetectable viral load and treatment with NNRTIs are protective factors, whereas hypertriglyceridemia is directly associated with low HDL-C levels.

Apolipoprotein A-I from striped bass (Morone saxatilis) demonstrates antibacterial activity in vitro

HDL and apolipoprotein A-I from teleostean fishes demonstrate in vitro activity against gram-positive and gram-negative bacteria. In this study, we purified ApoA-1 from striped bass (Morone saxatilis) plasma and examined its in vitro antibacterial activity against Streptococcus sp., Escherichia coli, and Mycobacterium marinum. In addition, we obtained sequence for a putative striped bass ApoA-1 gene, which when translated contained the identical sequence generated from N-terminal sequencing of the purified ApoA-1. The predicted secondary and tertiary structures contained the characteristic proline residues and high alpha-helical content conserved between mammals and fishes. Purified ApoA-1 exhibited antibacterial activity against the bacteria assayed. Concentrations of 125 microg/mL for E. coli, 250 microg/mL for Streptococcus sp., and 250 microg/mL for M. marinum, inhibited bacterial growth by 50% compared to control. ApoA-1 plasma concentrations in experimental and wild fish ranged from undetectable levels to greater than 5 mg/mL, indicating that striped bass ApoA-1 is an effective antibacterial agent at concentrations below the range of physiological concentrations in striped bass plasma. We therefore conclude that ApoA-1 could play a role in innate defense against bacterial pathogens in striped bass.

Different isoforms of apolipoprotein AI present heterologous post-translational expression in HIV infected patients

Human immunodeficiency virus (HIV) is rapidly becoming a global health concern. Proteomics technology was employed to examine HIV infected plasma samples in an attempt to identify disease-associated proteins. By comparison with normal and HIV positive plasma samples, at least eight proteins were significantly changed in HIV infected plasma. In particular, apolipoprotein AI presents a heterogeneous change in expression level with different isoforms. Apolipoprotein AI could be a useful biomarker for HIV diagnosis.

Prevalencia de factores de riesgo cardiovascular en pacientes con infección por el VIH

INTRODUCTION

To determine the prevalence of cardiovascular risk factors in human immunodeficiency virus (HIV)-infected patients.

PATIENTS AND METHOD

A cross-sectional study was performed with HIV-infected patients aged 20 or over managed at the outpatient Infectious Disease Unit during 2003. Clinical and epidemiological characteristics of HIV infection and cardiovascular risk factors were evaluated.

RESULTS

The final 760 patients included in the study had a mean of 1.5 cardiovascular risk factors, with smoking being the most prevalent (66.8%; CI 95%: 63.4-70.2). The cardiovascular risk factor of age and gender was present in 26.4% (CI 95%: 23.3-29.7) of patients and family history of premature coronary heart disease in 14.3% (CI 95%: 11.8-16.9). The prevalence of hypertension and diabetes mellitus was 13.2% (CI 95%: 10.8-15.8) and 4.3% (CI 95%: 3.0-6.0), respectively. High density lipoprotein (HDL) cholesterol concentration under 40 mg/dl was found in 29.3% (CI 95%: 26.1-32.7) and above 60 mg/dl in 16.3% (CI 95%: 13.8-19.1). Twenty-five patients (3.3%; CI 95%: 2.1-4.8) had suffered overt cardiovascular disease.

CONCLUSION

Smoking and HDL cholesterol were the main cardiovascular risk factors in this HIV-infected cohort.

Serum paraoxonase-1 activity and concentration are influenced by human immunodeficiency virus infection

BACKGROUND

Higher high-density lipoprotein concentrations are associated with a better disease course in HIV-infected patients. Paraoxonase-1, an enzyme contained within high-density lipoproteins, is thought to hydrolyse oxidised lipids. The aim of the present study was to investigate the relationships between HIV infection and the circulating activity and concentration of paraoxonase-1, and the concentration of high-density lipoproteins, apolipoprotein A-I and oxidised low-density lipoproteins.

METHODS

We studied patients with HIV infection (n=212) and healthy subjects (n=409). In all the participants we measured the relevant biochemical and genetic variables. The statistical associations between these variables and paraoxonase-1 activity and concentration were assessed using multiple linear regression analysis.

RESULTS

Serum paraoxonase-1 activity was decreased (P<0.001) and its concentration was increased (P=0.017) in HIV-patients compared to the controls. HIV infected patients had lower HDL-cholesterol and apolipoprotein A-I concentrations. Multivariate regression analysis showed that serum paraoxonase-1 activity was associated with the CD4+ T lymphocyte count (P<0.05), apolipoprotein A-I (P<0.001), and paraoxonase-1 genetic polymorphisms (P<0.001). Paraoxonase-1 concentration was associated with that of serum beta-2-microglobulin (P<0.001).

CONCLUSIONS

Both, paraoxonase-1 activity and concentration were influenced by HIV-infection and these were related to alterations in HDL composition and the immunological status of the patients.

HIV infection and high-density lipoprotein: the effect of the disease vs the effect of treatment

HIV infection is commonly associated with hypoalphalipoproteinemia. It is not clear how much the HIV infection and/or treatment contribute to the changes in high-density lipoprotein (HDL) levels. Blood lipids of HIV-positive males were assessed in a retrospective study. The following groups of patients were studied: (1) untreated for at least 6 months; (2) treatment with highly active antiretroviral therapy (HAART) without protease inhibitor (PI); (3) treatment with a HAART regimen that includes a PI (HAART/PI); (4) treatment with HAART that includes low-dose ritonavir and a PI (HAART/PI/boost). Lipoprotein levels were compared with those of age-matched HIV-negative healthy subjects. Compared with the control group, HDL-cholesterol (HDL-C) levels were 22%, 11%, 14%, and 11% lower for currently untreated HIV, HAART, HAART/PI, and HAART/PI/boost groups, respectively. Negative correlations were found among HDL-C level, peak and current viral load, and duration of the disease and the treatment. A positive correlation was found between HDL-C and current and nadir CD4 cell count and CD4 percentage. When patients were divided into subgroups based on duration of antiretroviral therapy, patients treated with HAART and HAART/PI for 3 to 6 years were significantly less likely to have high HDL-C levels compared with the control group and patients treated for 1 to 3 years. A 5-fold decrease in the proportion of subjects with high HDL-C and a 3-fold increase in those with low HDL-C were found in the group treated with HAART/PI/boost. These data suggest that hypoalphalipoproteinemia in patients with HIV is likely to be secondary to HIV infection itself.

High density lipoproteins in the intersection of diabetes mellitus, inflammation and cardiovascular disease

PURPOSE OF REVIEW

Low HDL-cholesterol, diabetes mellitus and elevated C-reactive protein as well as various inflammatory diseases are risk factors for coronary heart disease. Both diabetes mellitus and inflammation decrease HDL-cholesterol. We summarize recent findings on the mechanisms underlying low HDL-cholesterol in diabetes and inflammation, as well as on novel functions of HDL that may protect not only from atherosclerosis but also from diabetes mellitus and inflammation-induced organ damage.

RECENT FINDINGS

Elevated levels of non-esterified fatty acids and disturbed insulin action contribute to low HDL-cholesterol in diabetes mellitus by modifying lipolysis, apolipoprotein A-I production, as well as the activities of adenosine triphosphate-binding cassette transporter A1 and lipid transfer. Inflammation causes low HDL-cholesterol by increasing the activities of endothelial lipase and soluble phospholipase A2 and by replacing apolipoprotein A-I in HDL with serum amyloid A. HDL and lysosphingolipids therein have been identified as activators of the protein kinase Akt, which in turn is a regulator of apoptosis in beta-cells, endothelial cells, and smooth muscle cells, as well as a regulator of nitric oxide production and adhesion molecule expression in endothelial cells.

SUMMARY

The protective properties of HDL in cytokine production, lipid oxidation, cholesterol efflux and reverse cholesterol transport make HDL a protective agent in inflammation-induced organ damage including diabetes mellitus. However, inflammation and diabetes cause a decrease in HDL-cholesterol concentrations and impair HDL function, placing HDL into the centre of a vicious cycle that may escalate into diabetes mellitus, inflammation-induced organ damage and atherosclerosis.