Iron metabolism and HIV infection: reciprocal interactions with potentially harmful consequences?

Anemia, iron, and HIV: decoding the interconnected pathways: A review

This review delves into the intricate relationship between anemia, iron metabolism, and human immunodeficiency virus (HIV), aiming to unravel the interconnected pathways that contribute to the complex interplay between these 3 entities. A systematic exploration of relevant literature was conducted, encompassing studies examining the association between anemia, iron status, and HIV infection. Both clinical and preclinical investigations were analyzed to elucidate the underlying mechanisms linking these components. Chronic inflammation, a hallmark of HIV infection, disrupts iron homeostasis, impacting erythropoiesis and contributing to anemia. Direct viral effects on bone marrow function further compound red blood cell deficiencies. Antiretroviral therapy, while essential for managing HIV, introduces potential complications, including medication-induced anemia. Dysregulation of iron levels in different tissues adds complexity to the intricate network of interactions. Effective management of anemia in HIV necessitates a multifaceted approach. Optimization of antiretroviral therapy, treatment of opportunistic infections, and targeted nutritional interventions, including iron supplementation, are integral components. However, challenges persist in understanding the specific molecular mechanisms governing these interconnected pathways. Decoding the interconnected pathways of anemia, iron metabolism, and HIV is imperative for enhancing the holistic care of individuals with HIV/AIDS. A nuanced understanding of these relationships will inform the development of more precise interventions, optimizing the management of anemia in this population. Future research endeavors should focus on elucidating the intricate molecular mechanisms, paving the way for innovative therapeutic strategies in the context of HIV-associated anemia.

A Novel Vision of Reinforcing Nanofibrous Masks with Metal Nanoparticles: Antiviral Mechanisms Investigation

Prevention of spreading viral respiratory disease, especially in case of a pandemic such as coronavirus disease of 2019 (COVID-19), has been proved impossible without considering obligatory face mask-wearing protocols for both healthy and contaminated populations. The widespread application of face masks for long hours and almost everywhere increases the risks of bacterial growth in the warm and humid environment inside the mask. On the other hand, in the absence of antiviral agents on the surface of the mask, the virus may have a chance to stay alive and be carried to different places or even put the wearers at risk of contamination when touching or disposing the masks. In this article, the antiviral activity and mechanism of action of some of the potent metal and metal oxide nanoparticles in the role of promising virucidal agents have been reviewed, and incorporation of them in an electrospun nanofibrous structure has been considered an applicable method for the fabrication of innovative respiratory protecting materials with upgraded safety levels.

Graphical Abstract

HIV-1 Tat-mediated microglial ferroptosis involves the miR-204–ACSL4 signaling axis

This study was focused on exploring the role of the HIV-1 Tat protein in mediating microglial ferroptosis. Exposure of mouse primary microglial cells (mPMs) to HIV-1 Tat protein resulted in induction of ferroptosis, which was characterized by increased expression of Acyl-CoA synthetase long-chain family member 4 (ACSL4), in turn, leading to increased generation of oxidized phosphatidylethanolamine, elevated levels of lipid peroxidation, upregulated labile iron pool (LIP) and ferritin heavy chain-1 (FTH1), decreased glutathione peroxidase-4 and mitochondrial outer membrane rupture. Also, inhibition of ferroptosis by ferrostatin-1 (Fer-1) or deferoxamine (DFO) treatment suppressed ferroptosis-related changes in mPMs. Similarly, the knockdown of ACSL4 by gene silencing also inhibited ferroptosis induced by HIV-1 Tat. Furthermore, increased lipid peroxidation resulted in increased release of proinflammatory cytokines, such as TNFα, IL6, and IL1β and microglial activation. Pretreatment of mPMs with Fer-1 or DFO further blocked HIV-1 Tat-mediated microglial activation in vitro and reduced the expression and release of proinflammatory cytokines. We identified miR-204 as an upstream modulator of ACSL4, which was downregulated in mPMs exposed to HIV-1 Tat. Transient transfection of mPMs with miR-204 mimics reduced the expression of ACSL4 while inhibiting HIV-1 Tat-mediated ferroptosis and the release of proinflammatory cytokines. These in vitro findings were further validated in HIV-1 transgenic rats as well as HIV + ve human brain samples. Overall, this study underscores a novel mechanism(s) underlying HIV-1 Tat-mediated ferroptosis and microglial activation involving miR-204-ACSL4 signaling.

Glycolysis downregulation is a hallmark of HIV-1 latency and sensitizes infected cells to oxidative stress

HIV-1 infects lymphoid and myeloid cells, which can harbor a latent proviral reservoir responsible for maintaining lifelong infection. Glycolytic metabolism has been identified as a determinant of susceptibility to HIV-1 infection, but its role in the development and maintenance of HIV-1 latency has not been elucidated. By combining transcriptomic, proteomic, and metabolomic analyses, we here show that transition to latent HIV-1 infection downregulates glycolysis, while viral reactivation by conventional stimuli reverts this effect. Decreased glycolytic output in latently infected cells is associated with downregulation of NAD+ /NADH. Consequently, infected cells rely on the parallel pentose phosphate pathway and its main product, NADPH, fueling antioxidant pathways maintaining HIV-1 latency. Of note, blocking NADPH downstream effectors, thioredoxin and glutathione, favors HIV-1 reactivation from latency in lymphoid and myeloid cellular models. This provides a "shock and kill effect" decreasing proviral DNA in cells from people living with HIV/AIDS. Overall, our data show that downmodulation of glycolysis is a metabolic signature of HIV-1 latency that can be exploited to target latently infected cells with eradication strategies.

Toxic Metals and Non-Communicable Diseases in HIV Population: A Systematic Review

Background and Objectives: HIV has been a serious global health concern since its discovery, with about 37.9 million people living with HIV worldwide as of 2018. Sub-Saharan Africa (SSA) accounts for 68% of the infection and contributed 74% of the 1.5 million deaths in 2013 despite having only 12% of the total world population residing in the region. This systematic review has attempted to determine the association between heavy metal toxicity and the occurrence of non-communicable diseases in the HIV/AIDS population. Materials and Methods: Three databases were systematically searched: PubMed, Scopus, and Google Scholar for studies written in English and published between 1 April 2000 and 12 April 2020. Studies were excluded if the main outcomes were not measured or did not meet the inclusion criteria. Results: All the six included studies are cross-sectional in design, and therefore were evaluated using the STROBE checklist. The data extraction was done using an extraction table; the ratio of female to male participants included in the study was 1.09:1. Qualitative analysis was used due to the heterogeneity in the heavy metal biomarkers and the outcome measured by the included studies. Two studies compared the concentration of heavy metals in HIV-positive and HIV-negative participants while one compared the levels between HAART-naïve and HAART-treated participants, and three determined the association between heavy metal toxicity and non-communicable diseases (liver fibrosis, anaemia, and reproductive parameters, respectively) in HIV-positive patients. Conclusions: Blood lead, cadmium, and mercury levels were higher in HIV-seropositive than -seronegative subjects, whereas serum zinc level was lower in HIV-seropositive than -seronegative subjects, but the causal association between heavy metals and non-communicable diseases in HIV subjects is largely unknown. Interdisciplinary research between nutrition, toxicology, and human health is envisaged for primary and secondary prevention and treatment.

Effect of Human Immunodeficiency Virus on Trace Elements in the Brain

Comorbidities of human immunodeficiency virus (HIV) include HIV-associated neurocognitive disorder (HAND). Changes in the brain due to HIV include atrophy, hyperintensities, and diffusion changes. However, no research has focused on trace elements concentration changes in the brain due to HIV, as seen in other neurodegenerative diseases. Therefore, the aim of this study was to determine the concentration of several trace elements in the brains of individuals with and without HIV infection. Prior to formalin embalming, blood was drawn and tested in triplicate with Determine HIV-1/2 rapid tests and confirmed with a SD HIV Device 1/2 3.0 rapid HIV Kit. After embalming, tissue was sampled from the caudate nucleus and analyzed using inductively coupled plasma mass spectrometry. A Kruskal-Wallis test was used to determine statistically significant differences between the two groups (p < 0.05). Fifteen HIV-positive and 14 HIV-negative male cadavers were included (mean age 44, range 22 to 61). Cadmium was marginally decreased, possibly due to malnutrition or utilization by the HIV nucleocapsid. Nickel was marginally increased, perhaps due to a reduced capability to remove metals from the body. In conclusion, this article provides the first information on trace element levels in the brains from HIV-infected individuals and postulates that cadmium and nickel may play a role in the pathophysiology of HAND. This information can contribute to finding a treatment for HAND, other than the use of antiretroviral drugs. Future studies should asses the levels of cadmium and nickel in a larger cohort of HIV-infected individuals.

Iron Pathways and Iron Chelation Approaches in Viral, Microbial, and Fungal Infections

Iron is an essential element required to support the health of organisms. This element is critical for regulating the activities of cellular enzymes including those involved in cellular metabolism and DNA replication. Mechanisms that underlie the tight control of iron levels are crucial in mediating the interaction between microorganisms and their host and hence, the spread of infection. Microorganisms including viruses, bacteria, and fungi have differing iron acquisition/utilization mechanisms to support their ability to acquire/use iron (e.g., from free iron and heme). These pathways of iron uptake are associated with promoting their growth and virulence and consequently, their pathogenicity. Thus, controlling microorganismal survival by limiting iron availability may prove feasible through the use of agents targeting their iron uptake pathways and/or use of iron chelators as a means to hinder development of infections. This review will serve to assimilate findings regarding iron and the pathogenicity of specific microorganisms, and furthermore, find whether treating infections mediated by such organisms via iron chelation approaches may have potential clinical benefit.

Iron intake is positively associated with viral load in antiretroviral naïve Brazilian men living with HIV

BACKGROUND

Iron homeostasis contribute for the human immunodeficiency virus (HIV) pathogenesis.

OBJECTIVES

We assessed the iron intake pattern in antiretroviral naïve Brazilian men living with HIV correlating with clinical and nutritional parameters.

METHODS

The iron consumption mean was estimated according to a food frequency questionnaire (FFQ), and a 3-day food record (3dFR) submitted to the patients. HIV viral load, CD4+ T cell counts, serum iron, haematological and anthropometrics parameters were recorded.

FINDINGS

Fifty-one HIV-infected adult men naïve for antiretroviral therapy (ART) were enrolled. The mean age of participants was 35 (SEM ± 1.28) years old, with mean time of HIV-1 infection of 1.78 (0-16.36, min-max) years. Majority (41.18%) had complete secondary, and 21.57% had tertiary educational level. The income was around 1x (54.90%) to 2x (41.18%) minimum wage. Fifty-four percent showed normal weight, while 40% were overweight. The patients showed normal mean values of haematological parameters, and mean serum iron was 14.40 µM (SEM ± 0.83). The FFQ showed moderate correlation with the 3dFR (ρ = 0.5436, p = 0.0009), and the mean values of iron intake were 10.55(± 0.92) mg/day, recorded by FFQ, and 15.75(± 1.51) mg/day, recorded by 3dFR. The iron intake, recorded by FFQ, negatively correlated with serum iron (ρ = -0.3448, p = 0.0132), and did not have influence in the CD4+ T cell counts [e.B 0.99 (0.97-1.01, 95% confidence interval (CI), p = 0.2]. However, the iron intake showed a positive effect in HIV viral load [e.B 1.12 (1.02-1.25, 95%CI), p < 0.01].

MAIN CONCLUSIONS

This study draws attention for the importance of iron intake nutritional counseling in people living with HIV. However, more studies are required to clarify the association between high iron intake and HIV infection and outcome.

Isolation of ferritin and its interaction with BmNPV in the silkworm, Bombyx mori

Ferritin is a ubiquitous iron storage protein that plays an important role in host defence against pathogen infections. In the present study, native ferritin was isolated from the hemolymph of Bombyx mori using native-polyacrylamide gel electrophoresis (native-PAGE) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results revealed that ferritin consisted of two subunits, designated as BmFerHCH and BmFerLCH. Previously integrated previous transcriptome and iTRAQ data showed that the two subunits were down-regulated in resistant silkworm strain BC9 and there was no obvious change in the expression levels of the subunits in susceptible silkworm strain P50 after BmNPV infection. Virus overlay assays revealed that B. mori ferritin as the form of heteropolymer had an interaction with B. mori nucleopolyhedrovirus (BmNPV), but it can't interact with BmNPV after depolymerisation. What's more, reverse transcription quantitative PCR (RT-qPCR) analysis suggested that BmFerHCH and BmFerLCH could be induced by bacteria, virus and iron. This is the first study to extract B. mori ferritin successfully and confirms their roles in the process of BmNPV infection. All these results will lay a foundation for further research the function of B. mori ferritin.

Serum iron, Folate, Ferritin and CD4 Count in HIV Seropositive Women

HIV infects cluster of differentiation 4 (CD4) T-lymphocytes, monocytes and macrophages resulting in decreased number and function of CD4 cells, changes that affect both cell mediated and humoral immunity. Hematological abnormalities are a common complication of human immune virus (HIV) infection and these abnormalities increase as the disease advances. Anemia is the most common haematological abnormality in HIV seropositive patients and its incidence is strongly associated with the progression of the disease. The aim of present study was to assess the haematological profile of HIV seropositive women and compare them with CD4 count. Two hundred seropositive females (age 18-25 years) attending antiretroviral therapy clinic were selected. Routine gynaecological and haematological investigations were carried out, study samples were drawn and serum iron, folate and ferritin were analysed by chemiluminiscence and CD4 count was determined by using flow-cytometry. Anemia was prevalent in seropositive women especially in those with low CD4 levels. Serum folate and ferritin levels were significantly lower in females with lower CD4 levels. Serum iron levels were higher at low CD4 levels. The mean CD4 count in HIV seropositive anaemic women were lower as compared to non anaemics suggesting that anaemia improves with higher CD4 cell counts. Plasma folate and ferritin levels are sensitive predictor of anaemia in early HIV infections and these patients should have a regular monitoring of their folate and ferritin levels especially with lower CD4 levels.

Anaemia and Iron Homeostasis in a Cohort of HIV-Infected Patients: A Cross-Sectional Study in Ghana

Aim. We determined the prevalence of anaemia and evaluated markers of iron homeostasis in a cohort of HIV patients. Methods. A comparative cross-sectional study on 319 participants was carried out at the Tamale Teaching Hospital from July 2013 to December 2013, 219 patients on HAART (designated On-HAART) and 100 HAART-naive patients. Data gathered include sociodemography, clinical history, and selected laboratory assays. Results. Prevalence of anaemia was 23.8%. On-HAART participants had higher CD4/CD3 lymphocyte counts, Hb, HCT/PCV, MCV, MCH, iron, ferritin, and TSAT (P < 0.05). Hb, iron, ferritin, and TSAT decreased from grade 1 to grade 3 anaemia and CD4/CD3 lymphocyte count was lowest in grade 3 anaemia (P < 0.05). Iron (P = 0.0072) decreased with disease severity whilst transferrin (P = 0.0143) and TIBC (P = 0.0143) increased with disease severity. Seventy-six (23.8%) participants fulfilled the criteria for anaemia, 86 (26.9%) for iron deficiency, 41 (12.8%) for iron deficiency anaemia, and 17 (5.3%) for iron overload. The frequency of anaemia was higher amongst participants not on HAART (OR 2.6 for grade 1 anaemia; OR 3.0 for grade 3 anaemia). Conclusion. In this study population, HIV-associated anaemia is common and is related to HAART status and disease progression. HIV itself is the most important cause of anaemia and treatment of HIV should be a priority compared to iron supplementation.

Minimal impact of an iron-fortified lipid-based nutrient supplement on Hb and iron status: a randomised controlled trial in malnourished HIV-positive African adults starting antiretroviral therapy

Anaemia, redistribution of Fe, malnutrition and heightened systemic inflammation during HIV infection confer an increased risk of morbidity and mortality in HIV patients. We analysed information on Fe status and inflammation from a randomised, double blind, controlled phase-III clinical trial in Lusaka, Zambia and Mwanza, Tanzania. Malnourished patients (n 1815) were recruited at referral to antiretroviral therapy (ART) into a two-stage nutritional rehabilitation programme, randomised to receive a lipid-based nutrient supplement with or without added micronutrients. Fe was included in the intervention arm during the second stage, given from 2 to 6 weeks post-ART. Hb, serum C-reactive protein (CRP), serum ferritin and soluble transferrin receptor (sTfR) were measured at recruitment and 6 weeks post-ART. Multivariable linear regression models were used to assess the impact of the intervention, and the effect of reducing inflammation from recruitment to week 6 on Hb and Fe status. There was no effect of the intervention on Hb, serum ferritin, sTfR or serum CRP. A one-log decrease of serum CRP from recruitment to week 6 was associated with a 1.81 g/l increase in Hb (95% CI 0.85, 2.76; P< 0.001), and a 0.11 log decrease in serum ferritin (95% CI - 0.22, 0.03; P= 0.012) from recruitment to week 6. There was no association between the change in serum CRP and the change in sTfR over the same time period (P= 0.78). In malnourished, HIV-infected adults receiving dietary Fe, a reduction in inflammation in the early ART treatment period appears to be a precondition for recovery from anaemia.

Prolonged-acting, multi-targeting gallium nanoparticles potently inhibit growth of both HIV and mycobacteria in co-infected human macrophages

Human immunodeficiency virus (HIV) infection and Mycobacterium tuberculosis (TB) are responsible for two of the major global human infectious diseases that result in significant morbidity, mortality and socioeconomic impact. Furthermore, severity and disease prevention of both infections is enhanced by co-infection. Parallel limitations also exist in access to effective drug therapy and the emergence of resistance. Furthermore, drug-drug interactions have proven problematic during treatment of co-incident HIV and TB infections. Thus, improvements in drug access and simplified treatment regimens are needed immediately. One of the key host cells infected by both HIV and TB is the mononuclear phagocyte (MP; monocyte, macrophage and dendritic cell). Therefore, we hypothesized that one way this can be achieved is through drug-targeting by a nanoformulated drug that ideally would be active against both HIV and TB. Accordingly, we validated macrophage targeted long acting (sustained drug release) gallium (Ga) nanoformulation against HIV-mycobacterium co-infection. The multi-targeted Ga nanoparticle agent inhibited growth of both HIV and TB in the macrophage. The Ga nanoparticles reduced the growth of mycobacterium and HIV for up to 15 days following single drug loading. These results provide a potential new approach to treat HIV-TB co-infection that could eventually lead to improved clinical outcomes.

Prevalence and related factors of anemia in HAART-naive HIV positive patients at Gondar University Hospital, Northwest Ethiopia

BACKGROUND

Anaemia is a common complication of infection with the human immunodeficiency virus (HIV) and may have various causes. The aim of this study was to determine the prevalence and related factors of anemia in HAART-naive HIV positive Patients.

METHODS

A retrospective study was conducted on HAART naive HIV positive patients at the Gondar University Hospital between September 2011 and August 2012. Socio-demographic and immunohematological (hemoglobin and CD4+ T cells) data were collected carefully from the existing ART logbook and patient follow up cards. Anaemia was defined according to the WHO criteria.

RESULTS

The overall prevalence of anaemia was 138 (35%). Female HAART naive HIV positive patients had significantly (P < 0.05) higher prevalence of anaemia than males (62% Vs 38%). The prevalence of anaemia at different CD4 level was; 6 (4%) with CD4 count greater than 500 cells/μL, 18 (13%) with a CD4 count of 350-500 cells/μL, 37 (27%) with a CD4 count of 200-349 cells/μL, 44 (32%) with a CD4 count of 100-199 cells/μL, 14 (10%) with a CD4 count of 50-99 and 19 (14%) with CD4 count of less than 50 cells/μL.

CONCLUSIONS

Our findings showed that one-third of HAART naïve HIV positive patients were anaemic and the increase in prevalence of anaemia with decreased CD4 cell count was statistically significant. Therefore, early diagnosis and treatment of anaemia in these patients are essential.

Positive association between dietary iron intake and iron status in HIV-infected children in Johannesburg, South Africa

Anemia is a common complication of pediatric HIV infection and is associated with suboptimal cognitive performance and growth failure. Routine iron supplementation is not provided to South African HIV-infected children. We hypothesized that dietary iron intake without supplementation is sufficient to protect against iron deficiency (ID) in HIV-infected children receiving highly active antiretroviral therapy. In this prospective study, the difference between dietary intakes of iron-deficient children (soluble transferrin receptor >9.4 mg/L) and iron-sufficient children after 18 months on highly active antiretroviral therapy was examined. The association between iron intake and hemoglobin (Hb) concentration was also assessed. Longitudinal data collected for 18 months from 58 HIV-infected African children were assessed by generalized estimation equations, with adjustment for demographic information, dietary intakes, growth parameters, and CD4%. After adjustment for covariates, the longitudinal association between dietary iron intake and Hb concentration remained significant. This association shows that for every 1-mg increase in iron intake per day, Hb increases by 1.1 g/L (P < .001). Mean Hb increased significantly after 18 months of follow-up (106 ± 14 to 129 ± 14 g/L, P < .01), but soluble transferrin receptor also increased (7.7 ± 2.7 to 8.9 ± 3.0 mg/L, P < .01). The incidence of ID increased from 15.2% at baseline to 37.2% after 18 months. Children with animal protein intakes greater than >20 g/d had significantly lower odds for ID at 18 months than did children with lower intakes (odds ratio, 0.40; 95% confidence interval, 0.21-0.77). Dietary iron intake was insufficient to protect against ID, pointing to a need for low-dose iron supplementation for iron-deficient HIV-infected children and interventions to increase the consumption of animal protein.

Iron status in HIV-1 infection: implications in disease pathology

BACKGROUND

There had been conflicting reports with levels of markers of iron metabolism in HIV infection. This study was therefore aimed at investigating iron status and its possible mediation of severity of HIV- 1 infection and pathogenesis.

METHOD

Eighty (80) anti-retroviral naive HIV-1 positive and 50 sero-negative controls were recruited for the study. Concentrations of serum total iron, transferrin, total iron binding capacity (TIBC), CD4+ T -lymphocytes, vitamin C, zinc, selenium and transferrin saturation were estimated.

RESULTS

The mean CD4+ T-lymphocyte cell counts, serum iron, TIBC, transferrin saturation for the tests and controls were 319 ± 22, 952 ± 57 cells/μl (P < 0.001), 35 ± 0.8, 11.8 ± 0.9 μmol/l (P < 0.001), 58.5 ± 2.2, 45.2 ± 2.4 μmol/l (P < 0.005) and 68.8 ± 3.3, 27.7 ± 2.2%, (P <0.001), respectively, while mean concentrations of vitamin C, zinc and selenium were 0.03 ± 0.01, 0.3 ± 0.04 (P < 0.001), 0.6 ± 0.05, 11.9 ± 0.26 μmol/l (P < 0.001) and 0.1 ± 0.01, 1.2 ± 0.12 μmol/l (P < 0.001) respectively. Furthermore, CD4+ T-lymphocyte cell count had a positive correlation with levels of vitamin C (r = 0.497, P < 0.001), zinc (r = 0.737, P < 0.001), selenium (r = 0.639, P < 0.001) and a negative correlation with serum iron levels (r = -0.572, P < 0.001).

CONCLUSION

It could be inferred that derangement in iron metabolism, in addition to oxidative stress, might have contributed to the depletion of CD4+ T cell population in our subjects and this may result in poor prognosis of the disease.

An LC-MS/MS method for concurrent determination of nicotine metabolites and the role of CYP2A6 in nicotine metabolite-mediated oxidative stress in SVGA astrocytes

BACKGROUND

Nicotine is known to generate oxidative stress through cytochrome P450 2A6 (CYP2A6)-mediated metabolism in the liver and other organs, including macrophages. This study has been designed to examine the role of CYP2A6 in nicotine metabolism and oxidative stress in SVGA cells, an immortalized human astrocyte cell line.

METHODS

SVGA astrocytes were treated with 1 μM nicotine, followed by determination of mRNA and protein levels of several CYPs using quantitative RT-PCR and western blot analyses, respectively. Quantitation of nicotine and the nicotine metabolites, cotinine and nicotine-derived nitrosamine ketones (NNK), was performed using an LC-MS/MS method. The generation of reactive oxygen species (ROS) was measured using flow cytometry.

RESULTS

Nicotine significantly upregulated mRNA and protein expression of the most abundantly expressed CYPs in SVGA astrocytes, CYP2A6 and CYP1A1. To characterize the metabolism of nicotine in astrocytes, a highly sensitive LC-MS/MS method was developed which is capable of quantifying very low concentrations of nicotine (0.3 ng/mL), cotinine and NNK (0.11 ng/mL). The LC-MS/MS results showed that nicotine is steadily metabolized to cotinine and NNK from 0.5 to 4h. Finally, we showed that nicotine initially causes an increase in ROS formation which is then gradually decreased, perhaps due to the increase in superoxide dismutase level. Nicotine metabolism and ROS formation by CYP2A6 were further confirmed by using tryptamine, a selective inhibitor of CYP2A6, which significantly lowered the levels of cotinine and NNK and inhibited ROS formation.

CONCLUSIONS

CYP2A6 plays a key role in nicotine metabolism and oxidative stress in astrocytes, and this has implications in nicotine-associated brain toxicity.

Modulatory effects of low-dose hydrogen peroxide on the function of human plasmacytoid dendritic cells

Under normal conditions, plasmacytoid dendritic cells (pDCs) are located in peripheral lymphoid organs or circulate in the blood, from where they can migrate to sites of infection or inflammation. In inflamed tissues, pDCs can be exposed to elevated levels of reactive oxygen species produced by inflammatory cells and we presume that oxidative stress could affect the cellular responses of pDCs to microenvironmental stimuli. To explore this possibility, human pDCs isolated from peripheral blood of healthy donors were treated with H(2)O(2) and R837 (a Toll-like receptor 7 ligand), separately and in combination. Our results demonstrate that treatment with a low concentration (0.01 μM) of H(2)O(2) resulted in only slight changes in the expression of CD40, CD80, CD86, and CD83; however, low-dose H(2)O(2) markedly decreased the expression of HLA-DQ on pDCs. Exposure to H(2)O(2) did not trigger the release of IL-6, TNF-α, IL-8, or IFN-α from pDCs. Although addition of H(2)O(2) did not modify the capacity of pDCs to activate allogeneic IL-17- or IFN-γ-producing T cells, it significantly increased the ability of pDCs to stimulate IL-4-secreting T cells. Exposure of pDCs to H(2)O(2) before cocultivation with naïve autologous T cells significantly lowered IL-10 production by T cells, but did not affect IL-17 release. It was also observed that H(2)O(2)-exposed pDCs provided stronger stimuli for Th2 than for Th1 differentiation upon autologous activation, compared to untreated pDCs, possibly because of elevated surface expression of OX40-L. Most importantly, when pDCs were stimulated with R837 in the presence of H(2)O(2), decreased phenotypic activation, decreased chemokine and cytokine release, and impaired allo- and autostimulatory functions of pDCs were detected, indicating that pDCs exposed to oxidative stress in vivo may have an anti-inflammatory or tolerogenic role in regulating adaptive immune responses.

Iron deficiency and anemia predict mortality in patients with tuberculosis

Many studies have documented a high prevalence of anemia among tuberculosis (TB) patients and anemia at TB diagnosis has been associated with an increased risk of death. However, little is known about the factors contributing to the development of TB-associated anemia and their importance in TB disease progression. Data from a randomized clinical trial of micronutrient supplementation in patients with pulmonary TB in Tanzania were analyzed. Repeated measures of anemia with iron deficiency, anemia without iron deficiency, and iron deficiency without anemia were assessed as risk factors for treatment failure, TB recurrence, and mortality. The prevalence of anemia (hemoglobin < 110 g/L) at baseline was 64%, more than one-half of which was related to iron deficiency (mean corpuscular volume , 80 fL). We found no evidence of an association between anemia (with or without iron deficiency) or iron deficiency without anemia at baseline and the risk of treatment failure at 1 mo after initiation. Anemia without iron deficiency was associated with an independent, 4-fold increased risk of TB recurrence [adjusted RR = 4.10 (95% CI = 1.88, 8.91); P < 0.001]. Iron deficiency and anemia (with and without iron deficiency) were associated with a 2- to nearly 3-fold independent increase in the risk of death [adjusted RR for iron deficiency without anemia = 2.89 (95% CI = 1.53, 5.47); P = 0.001; anemia without iron deficiency = 2.72 (95% CI = 1.50, 4.93); P = 0.001; iron deficiency anemia = 2.13 (95% CI = 1.10, 4.11); P = 0.02]. Efforts to identify and address the conditions contributing to TB-associated anemia, including iron deficiency, could play an important role in reducing morbidity and mortality in areas heavily affected by TB.

Anemia and iron homeostasis in a cohort of HIV-infected patients in Indonesia

Background

Anemia is a common clinical finding in HIV-infected patients and iron deficiency or redistribution may contribute to the development of low hemoglobin levels. Iron overload is associated with a poor prognosis in HIV and Hepatitis C virus infections. Iron redistribution may be caused by inflammation but possibly also by hepatitis C co-infection. We examined the prevalence of anemia and its relation to mortality in a cohort of HIV patients in a setting where injecting drug use (IDU) is a main mode of HIV transmission, and measured serum ferritin and sTfR, in relation to anemia, inflammation, stage of HIV disease, ART and HCV infection.

Methods

Patient characteristics, ART history and iron parameters were recorded from adult HIV patients presenting between September 2007 and August 2009 in the referral hospital for West Java, Indonesia. Kaplan-Meier estimates and Cox's regression were used to assess factors affecting survival. Logistic regression was used to identity parameters associated with high ferritin concentrations.

Results

Anemia was found in 49.6% of 611 ART-naïve patients, with mild (Hb 10.5 - 12.99 g/dL for men; and 10.5 - 11.99 g/dL for women) anemia in 62.0%, and moderate to severe anemia (Hb < 10.5 g/dL) in 38.0%. Anemia remained an independent factor associated with death, also after adjustment for CD4 count and ART (p = 0.008). Seroprevalence of HCV did not differ in patients with (56.9%) or without anemia (59.6%). Serum ferritin concentrations were elevated, especially in patients with anemia (p = 0.07) and/or low CD4 counts (p < 0.001), and were not related to hsCRP or HCV infection. Soluble TfR concentrations were low and not related to Hb, CD4, hsCRP or ART.

Conclusion

HIV-associated anemia is common among HIV-infected patients in Indonesia and strongly related to mortality. High ferritin with low sTfR levels suggest that iron redistribution and low erythropoietic activity, rather than iron deficiency, contribute to anemia. Serum ferritin and sTfR should be used cautiously to assess iron status in patients with advanced HIV infection.

A LC-MS/MS method for concurrent determination of nicotine metabolites and role of CYP2A6 in nicotine metabolism in U937 macrophages: implications in oxidative stress in HIV + smokers

Nicotine, the major constituent of tobacco, is predominantly metabolized by liver CYP2A6 into cotinine and many other compounds, including nicotine-derived nitrosamine ketone (NNK), which is known to cause oxidative stress. We have recently shown that CYP2A6 is highly expressed in U937 monocyte-derived macrophages. In this study we investigated the role of CYP2A6 in nicotine metabolism and oxidative stress in U937 macrophages. To study nicotine metabolism, we developed a highly sensitive LC-MS/MS method for simultaneous quantitative determination of nicotine, cotinine, and NNK. The LC-MS/MS analysis was carried out by multiple reaction monitoring mass transitions with m/z of 163.2/130.1, 177.4/98.3, and 208.4/122.1 for nicotine, cotinine, and NNK, respectively. The calibration curves were linear within 3.3-1028.1 ng/ml for nicotine and 0.3-652.6 ng/ml for cotinine and NNK. This novel method was then applied to quantify nicotine metabolites, cotinine and NNK, in nicotine-treated U937 macrophages. Cotinine and NNK initially formed at 30 min, followed by a peak at 2-3 h. The role of CYP2A6 in nicotine metabolism in U937 macrophages was further confirmed by using CYP2A6-selective inhibitor, tryptamine, which significantly decreased cotinine (70%) and completely inhibited NNK formations. Finally, we showed that nicotine-treated macrophages increase the formation of oxidant at 30-60 min, which is consistent with the initial formation of cotinine and NNK. In conclusion, we have developed a new LCMS/MS method for concurrent determination of nicotine metabolites and analyzed the role of CYP2A6 in nicotine metabolism and oxidative stress in U937 macrophages, which may have implications in viral replication among HIV + smokers.

Towards a unifying, systems biology understanding of large-scale cellular death and destruction caused by poorly liganded iron: Parkinson's, Huntington's, Alzheimer's, prions, bactericides, chemical toxicology and others as examples

Exposure to a variety of toxins and/or infectious agents leads to disease, degeneration and death, often characterised by circumstances in which cells or tissues do not merely die and cease to function but may be more or less entirely obliterated. It is then legitimate to ask the question as to whether, despite the many kinds of agent involved, there may be at least some unifying mechanisms of such cell death and destruction. I summarise the evidence that in a great many cases, one underlying mechanism, providing major stresses of this type, entails continuing and autocatalytic production (based on positive feedback mechanisms) of hydroxyl radicals via Fenton chemistry involving poorly liganded iron, leading to cell death via apoptosis (probably including via pathways induced by changes in the NF-κB system). While every pathway is in some sense connected to every other one, I highlight the literature evidence suggesting that the degenerative effects of many diseases and toxicological insults converge on iron dysregulation. This highlights specifically the role of iron metabolism, and the detailed speciation of iron, in chemical and other toxicology, and has significant implications for the use of iron chelating substances (probably in partnership with appropriate anti-oxidants) as nutritional or therapeutic agents in inhibiting both the progression of these mainly degenerative diseases and the sequelae of both chronic and acute toxin exposure. The complexity of biochemical networks, especially those involving autocatalytic behaviour and positive feedbacks, means that multiple interventions (e.g. of iron chelators plus antioxidants) are likely to prove most effective. A variety of systems biology approaches, that I summarise, can predict both the mechanisms involved in these cell death pathways and the optimal sites of action for nutritional or pharmacological interventions.

Syntenic relationships among legumes revealed using a gene-based genetic linkage map of common bean (Phaseolus vulgaris L.)

Molecular linkage maps are an important tool for gene discovery and cloning, crop improvement, further genetic studies, studies on diversity and evolutionary history, and cross-species comparisons. Linkage maps differ in both the type of marker and type of population used. In this study, gene-based markers were used for mapping in a recombinant inbred (RI) population of Phaseolus vulgaris L. P. vulgaris, common dry bean, is an important food source, economic product, and model organism for the legumes. Gene-based markers were developed that corresponded to genes controlling mutant phenotypes in Arabidopsis thaliana, genes undergoing selection during domestication in maize, and genes that function in a biochemical pathway in A. thaliana. Sequence information, including introns and 3' UTR, was generated for over 550 genes in the two genotypes of P. vulgaris. Over 1,800 single nucleotide polymorphisms and indels were found, 300 of which were screened in the RI population. The resulting LOD 2.0 map is 1,545 cM in length and consists of 275 gene-based and previously mapped core markers. An additional 153 markers that mapped at LOD <1.0 were placed in genetic bins. By screening the parents of other mapping populations, it was determined that the markers were useful for other common Mesoamerican × Andean mapping populations. The location of the mapped genes relative to their homologs in Arabidopsis thaliana (At), Medicago truncatula (Mt), and Lotus japonicus (Lj) were determine by using a tblastx analysis with the current psedouchromosome builds for each of the species. While only short blocks of synteny were observed with At, large-scale macrosyntenic blocks were observed with Mt and Lj. By using Mt and Lj as bridging species, the syntenic relationship between the common bean and peanut was inferred.

Micronutrients and HIV infection

The immune system requires several essential micronutrients to maintain an effective immune response. HIV infection destroys the immune system and promotes nutritional deficiencies, which further impair immunity. This article reviews the role of several micronutrients (vitamins A, C, E and D, the B vitamins, and minerals, selenium, iron and zinc) that are relevant for maintaining immune function. In addition, the deficiencies of these micronutrients have been associated with faster progression of HIV-1 disease. This review examines the evidence from observational studies of an association between micronutrient status and HIV disease, as well as the effectiveness of micronutrient supplementation on HIV-disease progression, pregnancy outcomes and nutritional status, among others, utilizing randomized clinical trials. Each micronutrient is introduced with a summary of its functions in human physiology, followed by the presentation of studies conducted in HIV-infected patients in relation to this specific micronutrient. Overall findings and recommendations are then summarized.

"Shock and kill" effects of class I-selective histone deacetylase inhibitors in combination with the glutathione synthesis inhibitor buthionine sulfoximine in cell line models for HIV-1 quiescence

Latently infected, resting memory CD4+ T cells and macrophages represent a major obstacle to the eradication of HIV-1. For this purpose, "shock and kill" strategies have been proposed (activation of HIV-1 followed by stimuli leading to cell death). Histone deacetylase inhibitors (HDACIs) induce HIV-1 activation from quiescence, yet class/isoform-selective HDACIs are needed to specifically target HIV-1 latency. We tested 32 small molecule HDACIs for their ability to induce HIV-1 activation in the ACH-2 and U1 cell line models. In general, potent activators of HIV-1 replication were found among non-class selective and class I-selective HDACIs. However, class I selectivity did not reduce the toxicity of most of the molecules for uninfected cells, which is a major concern for possible HDACI-based therapies. To overcome this problem, complementary strategies using lower HDACI concentrations have been explored. We added to class I HDACIs the glutathione-synthesis inhibitor buthionine sulfoximine (BSO), in an attempt to create an intracellular environment that would facilitate HIV-1 activation. The basis for this strategy was that HIV-1 replication decreases the intracellular levels of reduced glutathione, creating a pro-oxidant environment which in turn stimulates HIV-1 transcription. We found that BSO increased the ability of class I HDACIs to activate HIV-1. This interaction allowed the use of both types of drugs at concentrations that were non-toxic for uninfected cells, whereas the infected cell cultures succumbed more readily to the drug combination. These effects were associated with BSO-induced recruitment of HDACI-insensitive cells into the responding cell population, as shown in Jurkat cell models for HIV-1 quiescence. The results of the present study may contribute to the future design of class I HDACIs for treating HIV-1. Moreover, the combined effects of class I-selective HDACIs and the glutathione synthesis inhibitor BSO suggest the existence of an Achilles' heel that could be manipulated in order to facilitate the "kill" phase of experimental HIV-1 eradication strategies.

AZT-induced oxidative cardiovascular toxicity: attenuation by Mg-supplementation

Cardiovascular effects of chronic AZT treatment on SD male rats (185 g) fed either a normal Mg diet (0.1% MgO) or a high Mg diet (0.6% MgO) were examined. AZT treatment (1 mg/ml drinking water) for 3 weeks led to a 5.5-fold (0.88 +/- 0.11 nmol/min/10(6) cells, P < 0.05) elevation in neutrophil basal activity of O2(-) production versus controls (0.16 +/- 0.03 nmol/min, assayed ex vivo as SOD-inhibitable cytochrome c reduction). Concomitantly, plasma 8-isoprostane and PGE(2) levels rose 2.1-fold and 3-fold (both P < 0.05), respectively, compared to control; however, RBC GSH decreased 28% (P < 0.02) with GSSG content increased 3-fold, indicative of systemic oxidative stress. High Mg diet substantially attenuated the AZT-induced neutrophil activation by 70% (0.26 +/- 0.05 nmol/min, P < 0.05); reduced plasma 8-isoprostane and PGE(2) to levels comparable to normal; and RBC GSH was restored back to 92% of control. AZT alone caused moderate, but significant vascular inflammatory lesions in the heart (assessed by H&E staining). Immunohistochemical staining revealed significantly higher (about 4-fold) infiltration of CD11b positive cells (WBC surface marker) in the atria and ventricles of AZT-treated rats. However, these inflammatory pathological markers were minimal in samples of rats treated with AZT plus high Mg diet. Moreover, AZT alone significantly (P < 0.02) decreased rat weight gain by 21% at 3 weeks; Mg-supplementation completely prevented (P < 0.05) the weight gain loss due to AZT intake. It is concluded that high dietary Mg may provide beneficial effects against AZT toxicity due to its systemic antioxidative/anti-inflammatory properties.

Iron-related proteins: candidate urine biomarkers in childhood HIV-associated renal diseases

BACKGROUND

Because of the risk of performing renal biopsies in children with co-morbid conditions, we carried out this study to identify candidate protein biomarkers in the urine of HIV-infected children with renal disease.

DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS

Urine samples from HIV-infected children with biopsy proven HIV-nephropathy (HIVAN; n = 4), HIV-associated Hemolytic Uremic Syndrome (HIV-HUS; n = 2), or no renal disease (n = 3) were analyzed by two-dimensional electrophoresis (2-DE) and proteomic methods. Positive findings were confirmed in HIV-infected children with (n = 20) and without (n = 10) proteinuria using commercially available assays.

RESULTS

By 2-DE analysis, a single urine marker was not sufficient to distinguish children with HIVAN from the others. High urine levels of beta(2)-microglobulin and retinol-binding protein (RBP) suggested the presence of tubular injury. In addition, we found elevated urine levels of iron and the iron-related proteins, transferrin, hemopexin, haptoglobin, lactoferrin, and neutrophil gelatinase-associated lipocalin (NGAL), in children with HIVAN and HIV-HUS. Furthermore, we detected a significant accumulation of iron in the urine and kidneys of HIV-transgenic (Tg) rats with renal disease.

CONCLUSION

These findings suggest that iron and iron-related proteins might be promising candidate urine biomarkers to identify HIV-infected children at risk of developing HIVAN and HIV-HUS. Moreover, based on the results of previous studies, we speculate that the release or accumulation of iron in the kidney of HIV-infected children may contribute to the rapid progression of their renal disease, and could become a new therapeutic target against HIVAN and HIV-HUS.

Iron supplementation for reducing morbidity and mortality in children with HIV

BACKGROUND

The most prevalent haematologic disturbance associated with HIV in children (apart from CD4 lymphocytopenia) is anaemia. Anaemia associated with HIV arises from multiple mechanisms, including the direct inhibitory effect of HIV on red cell precursors, other locally prevalent and/or opportunistic infections, micronutrient deficiency, anaemia of chronic disease, and as a consequence of medicines given for HIV and/or other concurrent illnesses. Iron deficiency is the most common cause of nutritional anaemia globally. There is significant geographical overlap of areas of the world where iron deficiency anaemia (IDA) and paediatric HIV are distributed. Given the high prevalence of IDA, it is likely that many HIV-infected children also are iron deficient. The contribution of iron deficiency to anaemia in HIV-infected children has been described but is incompletely understood. Currently, iron supplementation for anaemic infants and children is routinely practiced without any obvious effect in most developing countries, which bear most of the burden of global paediatric HIV infections.Because iron deficiency and IDA are common in HIV-infected children in high-prevalence areas and because there are concerns about possible deleterious effects of iron, this review aims to assess the evidence for iron supplementation for reducing morbidity and mortality in HIV-infected children.

OBJECTIVES

To determine whether iron supplementation improves clinical, immunologic, and virologic outcomes in children infected with HIV SEARCH STRATEGY: We used the comprehensive search strategy developed specifically by the Cochrane HIV/AIDS Review Group to identify HIV/AIDS randomised controlled trials, and searched the following electronic databases: MEDLINE (searched November 2007); Embase (searched December 2007); and CENTRAL (December 2007). This search was supplemented with a search of AIDSearch (searched December 2007) and NLM Gateway (searched December 2007) to identify relevant conference abstracts, as well as a search of the reference lists of all eligible articles. The search was not limited by language or publication status.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of iron supplementation in any form and dose in HIV-infected children aged 12 years and younger.

DATA COLLECTION AND ANALYSIS

We independently screened the results of the search to select potentially relevant studies and to retrieve the full articles. We independently applied the inclusion criteria to the potentially relevant studies. No studies were identified that fulfilled the selection criteria.

MAIN RESULTS

No RCTs of iron supplementation in HIV-infected children were found.

IMPLICATIONS FOR CLINICAL PRACTICE

The current clinical practice of iron supplementation in HIV-infected children is based on weak evidence comprising observational studies and expert opinions.

IMPLICATIONS FOR RESEARCH

High-quality RCTs of iron supplementation are urgently required, especially in areas with significant overlap of high prevalence of HIV, iron deficiency anaemia, and malaria. Policy makers should prioritise funding for these trials.

Elevated iron stores are associated with HIV disease severity and mortality among postpartum women in Zimbabwe

OBJECTIVES

The relationship between Fe status and HIV infection is complex and poorly understood. While anaemia is a major complication of HIV infection, higher Fe stores may be associated with disease progression. There is limited and conflicting data available from Africa.

DESIGN

Cross-sectional and prospective cohort study. SETTING, SUBJECTS AND METHODS: We examined the association between postpartum Fe status (Hb, serum ferritin (SF) and transferrin receptor (TfR)) and viral load (VL) and HIV-related mortality in 643 HIV-positive Zimbabwean women over a period of 12 months.

RESULTS

In non-anaemic women a log10 increase in SF was associated with a 2.3-fold increase in VL (P = 0.019); this association was absent in anaemic women. In prospective analyses, a log10 increase in SF was associated with a 4-fold increase in mortality by 12 months (P = 0.002). Hb was negatively associated with VL (P = 0.001) and mortality (P = 0.047). The adverse associations between SF and both VL and mortality were found at SF concentrations > 45 microg/l (P < 0.05). Controlling for alpha1 acid glycoprotein, a marker of inflammation, attenuated the association between both SF and VL and mortality, but these remained significant.

CONCLUSIONS

These results are consistent with the hypothesis that high Fe stores have adverse consequences in HIV infection. If adverse consequences are real, our data suggest that they occur at SF concentrations exceeding those consistent with adequate Fe nutriture.

Association between consumption of black tea and iron status in adult Africans in the North West Province: the THUSA study

The association between black tea consumption and iron status was investigated in a sample of African adults participating in the cross-sectional THUSA (Transition and Health during Urbanization of South Africans) study in the North West Province, South Africa. Data were analysed from 1605 apparently healthy adults aged 15–65 years by demographic and FFQ, anthropometric measurements and biochemical analyses. The main outcome measures were Hb and serum ferritin concentrations. No associations were seen between black tea consumption and concentrations of serum ferritin (menP = 0·059; womenP = 0·49) or Hb (menP = 0·33; womenP = 0·49). Logistic regression showed that tea consumption did not significantly increase risk for iron deficiency (men: OR 1·36; 95 % CI 0·99, 1·87; women: OR 0·98; 95 % CI 0·84, 1·13) nor for iron deficiency anaemia (men: OR 1·28; 95 % CI 0·84, 1·96; women: OR 0·93; 95 % CI 0·78, 1·11). Prevalence of iron deficiency and iron deficiency anaemia was especially high in women: 21·6 and 14·6 %, respectively. However, the likelihood of iron deficiency and iron deficiency anaemia was not significantly explained by tea consumption in sub-populations which were assumed to be at risk for iron deficiency. Regression of serum ferritin levels on tea consumption in women ≤ 40 years, adults with a daily iron intake ≤ 5·80 mg and adults with ferritin levels ≤ 26·60 μg/l, respectively, showedPvalues in the range of 0·28–0·88. Our findings demonstrate that iron deficiency and iron deficiency anaemia is not significantly explained by black tea consumption in a black adult population in South Africa. Tea intake was also not shown to be related to iron status in several sub-populations at risk for iron deficiency.

HIV-1-infected astrocytes and the microglial proteome

The human immunodeficiency virus (HIV) invades the central nervous system early after viral exposure but causes progressive cognitive, behavior, and motor impairments years later with the onset of immune deficiency. Although in the brain, HIV preferentially replicates productively in cells of mononuclear phagocyte (MP; blood borne macrophage and microglia), astrocytes also can be infected, at low and variable frequency, particularly in patients with encephalitis. Among their many functions, astrocytes network with microglia to provide the first line of defense against microbial infection; however, very little is known about astrocytes' consequences on MP. Here, we addressed this question using co-culture systems of HIV-infected mouse astrocytes and microglia. Pseudotyped vesicular stomatis virus/HIV was used to circumvent the absence of viral receptors and ensure cell genotypic uniformity for studies of intercellular communication. The study demonstrated that infected astrocytes show modest changes in protein elements compared to uninfected cells. In contrast, infected astrocytes induce robust changes in the proteome of HIV-1-infected microglia. Accelerated cell death and redox proteins, among others, were produced in abundance. The observations confirmed the potential of astrocytes to influence the neuropathogenesis of HIV-1 infection by specifically altering the neurotoxic potential of infected microglia and regulating viral maturation.

Predictors of mortality in HIV-infected patients starting antiretroviral therapy in a rural hospital in Tanzania

BACKGROUND

Studies of antiretroviral therapy (ART) programs in Africa have shown high initial mortality. Factors contributing to this high mortality are poorly described. The aim of the present study was to assess mortality and to identify predictors of mortality in HIV-infected patients starting ART in a rural hospital in Tanzania.

METHODS

This was a cohort study of 320 treatment-naïve adults who started ART between October 2003 and November 2006. Reliable CD4 cell counts were not available, thus ART initiation was based on clinical criteria in accordance with WHO and Tanzanian guidelines. Kaplan-Meier models were used to estimate mortality and Cox proportional hazards models to identify predictors of mortality.

RESULTS

Patients were followed for a median of 10.9 months (IQR 2.9-19.5). Overall, 95 patients died, among whom 59 died within 3 months of starting ART. Estimated mortality was 19.2, 29.0 and 40.7% at 3, 12 and 36 months, respectively. Independent predictors of mortality were severe anemia (hemoglobin <8 g/dL; adjusted hazard ratio [AHR] 9.20; 95% CI 2.05-41.3), moderate anemia (hemoglobin 8-9.9 g/dL; AHR 7.50; 95% CI 1.77-31.9), thrombocytopenia (platelet count <150 x 109/L; AHR 2.30; 95% CI 1.33-3.99) and severe malnutrition (body mass index <16 kg/m2; AHR 2.12; 95% CI 1.06-4.24). Estimated one year mortality was 55.2% in patients with severe anemia, compared to 3.7% in patients without anemia (P < 0.001).

CONCLUSION

Mortality was found to be high, with the majority of deaths occurring within 3 months of starting ART. Anemia, thrombocytopenia and severe malnutrition were strong independent predictors of mortality. A prognostic model based on hemoglobin level appears to be a useful tool for initial risk assessment in resource-limited settings.

Interpreting indicators of iron status during an acute phase response--lessons from malaria and human immunodeficiency virus

Iron status is influenced by inflammation when the normal control of iron metabolism is reorganized by the primary mediators of the acute phase response, tumour necrosis factor-alpha and interleukin-1. The objective of this review is to show how indices of iron status, particularly haemoglobin, serum ferritin and soluble transferrin receptor concentrations relate to changes in the acute phase proteins during inflammation. The pattern of acute phase response after elective surgery, not preceded by infection, is used to demonstrate the time course of stimulation of the acute phase proteins. The changes in the concentrations of serum acute phase protein and markers of iron status during treatment for infection are used to demonstrate inter-relationships between the indicators. In many developing countries, asymptomatic malaria and human immunodeficiency virus (HIV) are common and may affect the interpretation of iron indicators during population assessments. Malaria produces an acute phase response and relationships between acute phase protein and indices of iron status indicate an influence of inflammation in both symptomatic and asymptomatic malaria, except when the parasitaemia is less than 1000/microL of blood when ferritin appears to be unaffected. HIV-1 impacts on haemopoiesis and anaemia. Anaemia increases in severity as the disease progresses and it is often a negative prognostic indicator. However, in individuals infected with HIV there may be an atypical acute phase response in the absence of opportunistic infections. Tentative conclusions are drawn concerning the inter-relationships between ferritin and the acute phase proteins, C-reactive protein and alpha-1-acid glycoprotein during an acute phase response.

Anaemia in acute HIV-1 subtype C infection

BACKGROUND

The high prevalence of anaemia and the increased morbidity and mortality associated with anaemia during AIDS has been well described yet there has been little information about anaemia and changes in haemoglobin levels during acute and early HIV-1 infection.

METHODS

HIV-negative women (n = 245) were enrolled into an observational cohort as part of the Centre for the AIDS Programme of Research in South Africa (CAPRISA) Acute Infection Study. Acute infection was diagnosed following a positive HIV RNA PCR in the absence of antibodies, or detection of HIV-1 antibodies within 3 months of a previously negative antibody test. Haemotologic parameters were assessed before infection and at regular intervals in the first twelve months of HIV infection.

RESULTS

Fifty-seven participants with acute HIV infection were identified at a median of 14.5 days post-infection (range 10-81) and were enrolled in the CAPRISA Acute Infection cohort at a median of 41 days post-infection (range 15-104). Mean haemoglobin prior to HIV-1 infection was 12.7 g/dL, with a mean decline of 0.46 g/dL following infection. The prevalence of anaemia increased from 25.0% prior to HIV-1 infection to 52.6% at 3 months post-infection, 61.1% at 6 months post-infection, and 51.4% at 12 months post-infection.

CONCLUSIONS

Haematologic derangements and anaemia with a trend towards iron deficiency are common with acute HIV-1 subtype C infection in this small cohort. The negative impact of anaemia concurrent with established HIV infection upon morbidity and mortality has been well documented but the prognostic potential and long-term effects of anaemia during acute HIV-1 infection remain unknown.

Ferritin levels during structured treatment interruption of highly active antiretroviral therapy

OBJECTIVE

The aim of the study was to investigate the influence of highly active antiretroviral therapy (HAART) on iron status and, conversely, the influence of iron status on the response to HAART.

METHODS

Ferritin levels were retrospectively determined in stored plasma from 138 HAART-naïve, moderately immunosuppressed HIV-infected Thai patients participating in a structured treatment interruption trial. Ferritin levels were determined at three predefined time-points: (1) HAART initiation; (2) HAART discontinuation; and (3) HAART resumption.

RESULTS

At baseline, 31% and 16% of the HIV-infected patients included in the study had high (>200 ng/mL) and low (<30 ng/mL) ferritin levels, respectively. Ninety-five per cent of patients with low ferritin levels were female. Ferritin decreased significantly during the interruption phase of HAART (-8.8 ng/mL; P=0.0005) but remained elevated in 62% of the patients with high baseline levels. A low baseline ferritin level was associated with a shorter time (P=0.041) to reach the CD4 cell target for HAART interruption (350 cells/microL), compared with a normal or high baseline ferritin level. Moreover, in a multivariate model, the relative risk (RR) of arriving at this CD4 cell target was significantly higher [RR 1.81; 95% confidence interval (CI) 1.05-3.14] in patients with low baseline ferritin. It is unlikely that inflammation affected ferritin in our patients, as mean levels of C-reactive protein were not elevated in patients with either high or low ferritin levels.

CONCLUSIONS

Both high and low ferritin levels were highly prevalent in moderately immunosuppressed HIV-positive Thai patients. Structured treatment interruption of HAART resulted in a significant decrease in overall ferritin levels. Furthermore, subjects with low baseline ferritin levels had a faster and greater CD4 response to HAART, suggesting a potential beneficial effect of iron deficiency on immunological recovery after initiation of HAART.

Ferritin and ferritin isoforms II: protection against uncontrolled cellular proliferation, oxidative damage and inflammatory processes

Ferritin is a major iron storage protein involved in the regulation of iron availability. Each ferritin molecule comprises 24 subunits. Various combinations of H-subunits and L-subunits make up the 24-subunit protein structure and these ferritin isoforms differ in their H-subunit to L-subunit ratio, as well as in their metabolic properties. Ferritin is an acute-phase protein and its expression is up-regulated in conditions such as uncontrolled cellular proliferation, in any condition marked by excessive production of toxic oxygen radicals, and by infectious and inflammatory processes. Under such conditions ferritin up-regulation is predominantly stimulated by increased reactive oxygen radical production and by cytokines. The major function of ferritin in these conditions is to reduce the bio-availability of iron in order to stem uncontrolled cellular proliferation and excessive production of reactive oxygen radicals. Ferritin is not, however, indiscriminately up-regulated in these conditions as a marked shift towards a predominance in H-subunit rich ferritins occurs. Preliminary indications are that, while the L-subunit primarily fulfils the conventional iron storage role, the H-subunit functions primarily as rapid regulator of iron availability, and perhaps indirectly as regulator of other cellular processes. It is suggested that the optimum differential expression of the two subunits differ for different cells and under different conditions and that the expression of appropriate isoferritins offers protection against uncontrolled cellular proliferation, oxidative stress and against side effects of infectious and inflammatory conditions.

Iron and infection: effects of host iron status and the iron-regulatory genes haptoglobin and NRAMP1 (SLC11A1) on host-pathogen interactions in tuberculosis and HIV

There are many lines of evidence illustrating that iron plays a pivotal role in modulating the battle for survival between mammalian hosts and their pathogens. Each displays considerable genetic investment in a wide range of mechanisms for acquiring and maintaining iron. These competitive mechanisms are highly complex, existing within an interacting matrix of absorption, transport, storage and detoxification systems, each of which are iron-responsive and thus able to adapt to the different phases of infection. Considerable genetic polymorphism in some of these systems, with signals of geographic selection in the hosts, and niche selection in the pathogens, indicates that they are critical for species survival. In this review we briefly summarize the role of iron in host immune function before reviewing the available evidence that iron modulates susceptibility and disease outcomes in HIV and TB (tuberculosis). We then examine the putative role of iron-related host genes by focussing on two candidate genes, haptoglobin and NRAMP1, for which there are common polymorphic variants in humans with strong evidence of functionally distinct biochemical phenotypes that would be predicted to influence the course of HIV and TB infections. Finally, we examine the limited evidence so far available that nutrient-gene interactions are likely to influence the way in which gene variants can protect against infection. We conclude that there is a wealth of evidence associating alterations in iron balance and in iron-regulatory systems with disease progression, but that many issues related to the direction of causality, mechanisms of action and sensitivity to pharmacological intervention remain to be elucidated. Since iron is probably the most widely prescribed compound throughout the world, used in both preventative and treatment regimens, a deeper understanding of the host-pathogen interactions relating to iron constitutes an important area for both basic and clinical research.

Anemia is an independent predictor of mortality and immunologic progression of disease among women with HIV in Tanzania

OBJECTIVES

To examine the association of anemia with mortality and disease progression among a cohort of women with HIV in Dar es Salaam, Tanzania.

METHODS

Time to all-cause death, AIDS-related death, and a 50% decrease in CD4 cell count among 1078 HIV-positive pregnant women enrolled in a clinical trial of vitamin supplementation from 1995-2003.

RESULTS

Adjusted models showed that anemia was associated with an increased risk of all-cause mortality (relative hazard [RH]: 2.06, 95% CI: 1.52 to 2.79 for moderate anemia and RH: 3.19, 95% CI: 2.23 to 4.56 for severe anemia) and AIDS-related mortality (RH: 2.21, 95% CI: 1.53 to 3.19 for moderate anemia and RH: 3.47, 95% CI: 2.25 to 5.33 for severe anemia), independent of CD4 cell count, World Health Organization clinical stage, age, pregnancy, vitamin supplementation, and body mass index. Anemia was also associated with a more rapid decline in CD4 counts, measured as time to a 50% drop in CD4 cell count from baseline. Erythrocyte characteristics suggestive of iron deficiency were also associated with all-cause and AIDS-related death and a 50% decline in CD4 cell count.

CONCLUSIONS

Anemia is an independent predictor of mortality and disease progression in this cohort. Screening for anemia, coupled with prevention and treatment efforts, should be included in HIV care initiatives, particularly those that target women.

Role of Lymphocyte Multidrug Resistance Protein 1 in HIV Infection

The multidrug resistance protein 1 (MRP1) is a drug transporter that protects cells from oxidative stress, which increases HIV-1 replication. The aim of this study was to characterize the expression, function, and role of lymphocyte MRP1 in HIV-1 infection and its modulation by antiretroviral drugs such as the protease inhibitors (PIs). Peripheral blood mononuclear cells (PBMCs) from HIV-positive individuals do not show significant alterations of MRP1 expression despite highly active antiretroviral therapy and HIV plasma viral load levels; however, they exhibit different intracellular MRP1 expression as compared with healthy subjects. By contrast, MRP efflux function is increased in subjects with primary HIV infection and becomes defective in later stages of the infection. PI- and probenecid (PBCD)-mediated inhibition of MRP lowers the in vitro stress-induced response of lymphoid cells by reducing the level of the specific reactive oxygen species superoxide anion and hydrogen peroxide. Finally, the blockade of MRP by PBCD and PIs down-modulates HIV-1 replication by a mechanism independent of inhibition of the HIV-1 protease. Our results are consistent with a model wherein HIV replication is favored by the MRP1-related oxidative stress and inhibition of MRP1 may contribute to the antiviral activity of PIs.

Regulatory networks affected by iron availability in Candida albicans

Iron, an essential element for almost every organism, serves as a regulatory signal for the expression of virulence determinants in many prokaryotic and eukaryotic pathogens. Using a custom Affymetrix GeneChip representing the entire Candida albicans genome, we examined the changes in genome-wide gene expression in this opportunistic pathogen as a function of alterations in environmental concentrations of iron. A total of 526 open reading frame (ORF) transcripts are more highly expressed when the levels of available iron are low, while 626 ORF transcripts are more highly expressed in high-iron conditions. The transcripts dominantly affected by iron concentration range from those associated with cell-surface properties to others which affect mitochondrial function, iron transport and virulence-related secreted hydrolases. Moreover gene expression as assayed in DNA microarrays confirms and extends reports of alterations in cell-surface antigens and drug sensitivity correlated with iron availability. To understand how these genes and pathways might be regulated, we isolated a gene designated SFU1 that encodes a homologue of the Ustilago maydis URBS1, a transcriptional repressor of siderophore uptake/biosynthesis. Comparisons between wild-type and SFU1-null mutant strains revealed 139 potential target genes of Sfu1p; many of which are iron-responsive. Together, these results not only expand our understanding of global iron regulation in C. albicans, but also provide insights into the potential role of iron availability in C. albicans virulence.

The effect of iron overload on in vitro HIV-1 infection

BACKGROUND

It has been shown that Fe is required by HIV-infected cells for production of viral particles. Excess iron in the cell is detrimental to the host but beneficial to the pathogen.

OBJECTIVES

Here, we investigated the effect of excess Fe (overload) and chelation of the metal on in vitro HIV infection by assessing host cell responses (viability/death, stress protein expression and cytokine production) as well as virus replication (core protein content and enzyme activity).

RESULTS AND CONCLUSION

Excess iron decreased viability (21%, P<0.01) of HIV-infected cells, increased p24 levels by 8.6% (P=0.32) and elevated reverse transcriptase (RT) activity (81.7%, P<0.01). The stimulation of viral replication was decreased when Fe was first complexed to desferrioxamine (DFO). DFO alone (in the absence of excess Fe), lowered cell viability (35%, P=0.039) and in the presence of virus lowered both p24 levels (66%, P=0.054) and RT activity (43%, P<0.01) and unexpectedly increased cell viability (25%, P=0.01047). Interleukin-2 (IL-2) production of infected cells was completely inhibited by DFO and excess iron while stress protein (Hsp70) levels were lowered in the presence of HIV in combination with excess iron (37%, P<0.01) or DFO (47.2%, P<0.01) when compared to untreated cells. According to flow cytometric data, HIV infection caused a two-fold increase in the numbers of necrotic (P=0.006) and decreased apoptotic cells (28.5%, P=0.15) cells. These findings indicate that Fe overload associated with HIV infection is detrimental to host cell responses against viral infection and that chelation can prevent and/or reverse this effect.

Position of the American Dietetic Association and Dietitians of Canada: nutrition intervention in the care of persons with human immunodeficiency virus infection

Infection with the human immunodeficiency virus (HIV) and the development of acquired immunodeficiency syndrome (AIDS) have had a significant impact on domestic and global health, social, political, and economic outcomes. Prevention and treatment efforts to control HIV infection are more demanding than in previous decades. Achieving food and nutrition security, and managing nutrition-related complications of HIV infection and the multiple aspects of disease initiated by or surrounding HIV infection, referred to as HIV disease, remain challenges for patients and for those involved with HIV/AIDS prevention, care, and treatment efforts. Confounding clinical issues include medication interactions, coinfection with other infections and diseases, wasting, lipodystrophy, and others. Dietetics professionals, other health care professionals, and people infected with HIV will need to understand and address multiple complex aspects of HIV infection and treatment to improve survival, body functions, and overall quality of life. Individualized nutrition care plans will be an essential feature of the medical management of persons with HIV infection and AIDS.

Dialyzing a patient with human immunodeficiency virus infection: what a nephrologist needs to know

The percentage of dialysis centers that have reported dialyzing human immunodeficiency virus (HIV)-infected patients increased from 11% in 1985 to 37% in 2000. Being primary care physicians for the dialysis patients, nephrologists are frequently confronted with the management of HIV-infected dialysis patients especially in urban centers. The aims of the present review are to discuss issues that are unique to HIV infection and end-stage renal disease, and to provide dialysis caretakers with sufficient information to help them optimize care and improve outcomes of these patients. Issues related to the choice of renal replacement therapy, vascular access, management of anemia, vaccination, and antiretroviral therapies are discussed in detail.

A single viral protein HCMV US2 affects antigen presentation and intracellular iron homeostasis by degradation of classical HLA class I and HFE molecules

HFE is a nonclassical class I molecule that associates with beta 2-microglobulin (beta 2m) and with the transferrin receptor. HFE accumulates in transferrin-containing endosomes, and its overexpression in human cell lines correlates with decreased transferrin receptor (TFR)-mediated iron uptake and decreased intracellular iron pools. A mutation that interferes with proper folding and assembly of HFE complexes results in a severe iron-overload disease hereditary hemochromatosis. We previously suggested that viruses could also interfere with iron metabolism through the production of proteins that inactivate HFE, similarly to classical class I proteins. In particular, we demonstrated in a transient expression system that human cytomegalovirus (HCMV) US2 targeted HFE for proteasomal degradation. Here we demonstrate that the stable expression of HCMV US2 in HEK 293 cells constitutively expressing HFE leads to loss of HFE expression both intracellularly and on the cell surface, and the significant reduction of classical class I expression. Both HFE and classical class I molecules are targeted to degradation via a similar pathway. This HCMV US2-mediated degradation of HFE leads to increased intracellular iron pools as indicated by reduced synthesis of TfR and increased ferritin synthesis. Whether this interference with regulation of iron metabolism potentiates viral replication and/or promotes damage of HCMV-infected tissues remains to be determined. Nevertheless, the deleterious effect of US2 on the expression of HFE and classical class I major histo-compatibility complexes (MHC) provides HCMV with an efficient tool for altering cellular metabolic functions, as well as supporting the escape of virus-infected cells from cytotoxic T lymphocyte (CTL)-mediated immune responses.

Cellular gene expression upon human immunodeficiency virus type 1 infection of CD4(+)-T-cell lines

The expression levels of approximately 4,600 cellular RNA transcripts were assessed in CD4(+)-T-cell lines at different times after infection with human immunodeficiency virus type 1 strain BRU (HIV-1(BRU)) using DNA microarrays. We found that several classes of genes were inhibited by HIV-1(BRU) infection, consistent with the G(2) arrest of HIV-1-infected cells induced by Vpr. These included genes involved in cell division and transcription, a family of DEAD-box proteins (RNA helicases), and all genes involved in translation and splicing. However, the overall level of cell activation and signaling was increased in infected cells, consistent with strong virus production. These included a subgroup of transcription factors, including EGR1 and JUN, suggesting they play a specific role in the HIV-1 life cycle. Some regulatory changes were cell line specific; however, the majority, including enzymes involved in cholesterol biosynthesis, of changes were regulated in most infected cell lines. Compendium analysis comparing gene expression profiles of our HIV-1 infection experiments to those of cells exposed to heat shock, interferon, or influenza A virus indicated that HIV-1 infection largely induced specific changes rather than simply activating stress response or cytokine response pathways. Thus, microarray analysis confirmed several known HIV-1 host cell interactions and permitted identification of specific cellular pathways not previously implicated in HIV-1 infection. Continuing analyses are expected to suggest strategies for impacting HIV-1 replication in vivo by targeting these pathways.

Human immunodeficiency virus-related anemia of chronic disease: relationship to hematologic, immune, and iron metabolism parameters, and lack of association with serum interferon-gamma levels

Anemia of chronic disease (ACD) is frequent in patients with human immunodeficiency virus (HIV) and its etiology is multifactorial. In a group of 111 patients with HIV, 19 were diagnosed with ACD. Parameters related to iron metabolism, such as serum iron (SI), serum ferritin (SF), and soluble transferrin receptor (sTfR) were correlated to levels of interferon-gamma (IFN-gamma) and results compared to a group of 42 nonanemic patients with HIV. Measurements of erythropoietin (EPO), CD4/CD8 T-cell ratio, and reticulocyte count (RTC) were determined to verify aspects related to severity of disease and bone marrow response. The results showed higher SF concentrations in ACD patients and normal or slightly increased sTfR measurements in both groups. There was no correlation between IFN-gamma and SF and between IFN-gamma and sTfR determinations. Lower CD4/CD8 values were obtained in ACD, and an inverse correlation was observed between IFN-gamma and CD4/CD8 in groups with and without anemia. RTC counts and EPO concentrations were similar in both groups: immature RTC were increased in patients with anemia, indicating an apparent attempt of marrow response to compensate the increased demand. Our data showed no correlation between IFN-gamma levels and iron disturbances in ACD, but results reinforced the observation of enhanced immunologic system deterioration in patients with HIV and ACD.