Iron status and the severity of HIV infection in pregnant women

Development of a sensitive HPLC method to measure in vitro permeability of E- and Z-isomeric forms of thiosemicarbazones in Caco-2 monolayers

In the current study, we developed a HPLC method to quantitatively measure the permeability of the BpT-based chelators, 2-benzoylpyridine 4-ethyl-3-thiosemicarbazone (Bp4eT) and 2-benzoylpyridine 4-allyl-3-thiosemicarbazone (Bp4aT), across human colorectal adenocarcinoma (Caco-2) monolayers as a model of gut absorption. In aqueous solution, Bp4eT and Bp4aT formed inter-convertible Z and E isomers that were resolved by HPLC. Peak area was linear with respect to chelator concentration. Acceptable within-day and between-day precision (<22%) and accuracy (85-115% of true values) were obtained over a range of 1.0-100μM for Bp4eT and 1.5-300μM for Bp4aT. Limits of detection were 0.3μM and 1μM for Bp4eT and Bp4aT, respectively, while corresponding limits of quantification were 1μM and 5μM. Both chelators showed significant ability to chelate iron in THP-1 cells using a calcein-based assay and no apparent cytotoxicity was observed within 24h. Ratios of the apical to basolateral and basolateral to apical transport for Bp4eT were 1.10 and 0.89 at 100μM and 300μM respectively, indicating equal bi-directional movement of the compounds. Similarly, ratios were 0.77 and 0.92 for Bp4aT, respectively. This study demonstrates that Bp4eT and Bp4aT can be efficiently transported through Caco-2 cells and can potentially be formulated for oral delivery.

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.

Iron status is an important cause of anemia in HIV-infected Tanzanian women but is not related to accelerated HIV disease progression

In HIV-infected populations from developing countries, it is unclear what proportion of anemia is attributable to iron deficiency (ID) and whether high body iron stores worsen HIV disease progression. We therefore evaluated these research questions in 584 HIV-infected Tanzanian women. Hemoglobin (Hb), serum ferritin (SF), serum transferrin receptor (sTfR), and C-reactive protein (CRP) concentrations were evaluated between 13 and 43 wk after women gave birth. ID was defined as SF or sTfR outside normal ranges, and ID anemia (IDA) as ID plus low Hb. In multivariate Cox regression models, the association between SF and HIV disease progression was assessed. Participants received iron + folate supplements during pregnancy. Hb (r = -0.159; P = 0.0001), SF (r = 0.355; P < 0.0001), and sTfR/log SF index (r = -0.119; P = 0.004) were related to CRP, whereas sTfR (r = 0.029; P = 0.48) was not. Prevalence estimates were 39.7% for ID and 23.6% for IDA. ID was associated with 48.9% of anemia cases. Categories of SF were not significantly associated with HIV-related mortality or progression to stage 4. Nevertheless, SF > 150.0 microg/L was related to a nonsignificantly elevated risk of progression to stage 4 (rate ratio = 1.78; 95% CI = 0.68-4.64; P = 0.24) compared with SF < 12.0 microg/L. In HIV-infected, parous women from sub-Saharan Africa, ID is of moderately high prevalence and is an important underlying cause of anemia. High storage iron does not appear to be related to HIV disease progression in this population, but more research on the role of iron during HIV disease is needed.

Host nutritional status: the neglected virulence factor

The emergence of new infectious diseases and old diseases with new pathogenic properties is a burgeoning worldwide problem. Severe acute respiratory syndrome (SARS) and acquired immune deficiency syndrome (AIDS) are just two of the most widely reported recent emerging infectious diseases. What are the factors that contribute to the rapid evolution of viral species? Various hypotheses have been proposed, all involving opportunities for virus spread (for example, agricultural practices, climate changes, rainforest clearing or air travel). However, the nutritional status of the host, until recently, has not been considered a contributing factor to the emergence of infectious disease. In this review, we show that host nutritional status can influence not only the host response to the pathogen, but can also influence the genetic make-up of the viral genome. This latter finding markedly changes our concept of host–pathogen interactions and creates a new paradigm for the study of such phenomena.

Iron, haptoglobin phenotype, and HIV-1 viral load: a cross-sectional study among pregnant Zimbabwean women

BACKGROUND

Viral load is a determinant of HIV-1 progression and transmission. Iron status and the phenotype of haptoglobin, a heme-binding acute phase reactant, may be determinants of viral load. We aimed to describe the effect of iron status, haptoglobin phenotype (Hp), and other predictors on HIV-1 viral load.

METHODS

Based on a cross-sectional study among 1669 antenatal care attenders (22-35 weeks) in Zimbabwe, 526 (31.5%) were found to be HIV infected. The role of season, age, gravidity, gestational age, malaria parasitemia, Hp, and elevated serum alpha(1)-antichymotrypsin (ACT) as well as serum ferritin, folate, retinol, and beta-carotene on HIV viral load among the 526 HIV-infected women was assessed using multiple linear regression analysis.

RESULTS

The distribution of Hp 1-1 (32%), Hp 2-1 (48%), and Hp 2-2 (20%) was not different from that of 53 uninfected women. Mean viral load was 3.85 log(10) (95% CI: 3.77-3.93) genome equivalents (geq)/mL, ranging from 3.77 (95% CI: 3.64-3.90) geq/mL in women with Hp 1-1 to 4.05 (95% CI: 3.81-4.21) geq/mL in women with Hp 2-2. With elevated serum ACT controlled for, women with Hp 2-2 had viral loads twice (95% CI: 1.4-4.0, p =.002) that of women with Hp 1-1, whereas those with serum ferritin <6 micro g/L had viral loads less than one third (95% CI: 0.13-0.53, p =.013) that of women with serum ferritin >24 micro g/L. Viral loads were also higher in women enrolled in the early rainy season compared with the dry season, in gravidae 4+ compared with gravidae 1 through 3, and in those with moderately elevated compared with low serum alpha(1)-antichymotrypsin, but neither age, gestational age, serum folate, serum retinol, nor serum beta-carotene were predictors.

CONCLUSION

Storage iron, Hp 2-2, and elevated ACT are independent positive predictors of HIV-1 viral load. The positive relationship between serum ferritin and viral load was not the result of an acute phase response or iron accumulation with advanced HIV infection. A possible detrimental role of iron in HIV infection would have serious public health implications.