Lower survival in AIDS patients receiving dapsone compared with aerosolized pentamidine for secondary prophylaxis of Pneumocystis carinii pneumonia. Study Group

Comparative efficacy and safety of Pneumocystis jirovecii pneumonia prophylaxis regimens for people living with HIV: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Pneumocystis jirovecii pneumonia (PCP) is a common opportunistic infection among people living with HIV (PWH), particularly among new and untreated cases. Several regimens are available for the prophylaxis of PCP, including trimethoprim-sulfamethoxazole (TMP-SMX), dapsone-based regimens (DBRs), aerosolized pentamidine (AP), and atovaquone.

OBJECTIVES

To compare the efficacy and safety of PCP prophylaxis regimens in PWH by network meta-analysis.

METHODS

DATA SOURCES: Embase, MEDLINE, and CENTRAL from inception to June 21, 2023.

STUDY ELIGIBILITY CRITERIA

Comparative randomized controlled trials (RCTs).

PARTICIPANTS

PWH.

INTERVENTIONS

Regimens for PCP prophylaxis either compared head-to-head or versus no treatment/placebo.

ASSESSMENT OF RISK OF BIAS

Cochrane risk-of-bias tool for RCTs 2.

METHODS OF DATA SYNTHESIS

Title or abstract and full-text screening and data extraction were performed in duplicate by two independent reviewers. Data on PCP incidence, all-cause mortality, and discontinuation due to toxicity were pooled and ranked by network meta-analysis. Subgroup analyses of primary versus secondary prophylaxis, by year, and by dosage were performed.

RESULTS

A total of 26 RCTs, comprising 55 treatment arms involving 7516 PWH were included. For the prevention of PCP, TMP-SMX was ranked the most favourable agent and was superior to DBRs (risk ratio [RR] = 0.54; 95% CI, 0.36-0.83) and AP (RR = 0.53; 95% CI, 0.36-0.77). TMP-SMX was also the only agent with a mortality benefit compared with no treatment/placebo (RR = 0.79; 95% CI, 0.64-0.98). However, TMP-SMX was also ranked as the most toxic agent with a greater risk of discontinuation than DBRs (RR = 1.25; 95% CI, 1.01-1.54) and AP (7.20; 95% CI, 5.37-9.66). No significant differences in PCP prevention or mortality were detected among the other regimens. The findings remained consistent within subgroups.

CONCLUSIONS

TMP-SMX is the most effective agent for PCP prophylaxis in PWH and the only agent to confer a mortality benefit; consequently, it should continue to be recommended as the first-line agent. Further studies are necessary to determine the optimal dosing of TMP-SMX to maximize efficacy and minimize toxicity.

4,4'-Diaminodiphenyl Sulfone (DDS) as an Inflammasome Competitor

The aim of this study is to examine the use of an inflammasome competitor as a preventative agent. Coronaviruses have zoonotic potential due to the adaptability of their S protein to bind receptors of other species, most notably demonstrated by SARS-CoV. The binding of SARS-CoV-2 to TLR (Toll-like receptor) causes the release of pro-IL-1β, which is cleaved by caspase-1, followed by the formation and activation of the inflammasome, which is a mediator of lung inflammation, fever, and fibrosis. The NLRP3 (NACHT, LRR and PYD domains-containing protein 3) inflammasome is implicated in a variety of human diseases including Alzheimer’s disease (AD), prion diseases, type 2 diabetes, and numerous infectious diseases. By examining the use of 4,4′-diaminodiphenyl sulfone (DDS) in the treatment of patients with Hansen’s disease, also diagnosed as Alzheimer’s disease, this study demonstrates the diverse mechanisms involved in the activation of inflammasomes. TLRs, due to genetic polymorphisms, can alter the immune response to a wide variety of microbial ligands, including viruses. In particular, TLR2Arg⁶⁷⁷Trp was reported to be exclusively present in Korean patients with lepromatous leprosy (LL). Previously, mutation of the intracellular domain of TLR2 has demonstrated its role in determining the susceptibility to LL, though LL was successfully treated using a combination of DDS with rifampicin and clofazimine. Of the three tested antibiotics, DDS was effective in the molecular regulation of NLRP3 inflammasome activators that are important in mild cognitive impairment (MCI), Parkinson’s disease (PD), and AD. The specific targeting of NLRP3 itself or up-/downstream factors of the NLRP3 inflammasome by DDS may be responsible for its observed preventive effects, functioning as a competitor.

Treatment of Pneumocystis jirovecii pneumonia in HIV-infected patients: a review

INTRODUCTION

Pneumocystis pneumonia is a potentially life-threatening pulmonary infection that occurs in immunocompromised individuals and HIV-infected patients with a low CD4 cell count. Trimethoprim-sulfamethoxazole has been used as the first-line agent for treatment, but mutations within dihydropteroate synthase gene render potential resistance to sulfamide. Despite advances of combination antiretroviral therapy (cART), Pneumocystis pneumonia continues to occur in HIV-infected patients with late presentation for cART or virological and immunological failure after receiving cART. Areas covered: This review summarizes the diagnosis and first-line and alternative treatment and prophylaxis for Pneumocystis pneumonia in HIV-infected patients. Articles for this review were identified through searching PubMed. Search terms included: 'Pneumocystis pneumonia', 'Pneumocystis jirovecii pneumonia', 'Pneumocystis carinii pneumonia', 'trimethoprim-sulfamethoxazole', 'primaquine', 'trimetrexate', 'dapsone', 'pentamidine', 'atovaquone', 'echinocandins', 'human immunodeficiency virus infection', 'acquired immunodeficiency syndrome', 'resistance to sulfamide' and combinations of these terms. We limited the search to English language papers that were published between 1981 and March 2017. We screened all identified articles and cross-referenced studies from retrieved articles. Expert commentary: Trimethoprim-sulfamethoxazole will continue to be the first-line agent for Pneumocystis pneumonia given its cost, availability of both oral and parenteral formulations, and effectiveness or efficacy in both treatment and prophylaxis. Whether resistance due to mutations within dihydropteroate synthase gene compromises treatment effectiveness remains controversial. Continued search for effective alternatives with better safety profiles for Pneumocystis pneumonia is warranted.

Lentiviral Nef suppresses iron uptake in a strain specific manner through inhibition of Transferrin endocytosis

BACKGROUND

Increased cellular iron levels are associated with high mortality in HIV-1 infection. Moreover iron is an important cofactor for viral replication, raising the question whether highly divergent lentiviruses actively modulate iron homeostasis. Here, we evaluated the effect on cellular iron uptake upon expression of the accessory protein Nef from different lentiviral strains.

RESULTS

Surface Transferrin receptor (TfR) levels are unaffected by Nef proteins of HIV-1 and its simian precursors but elevated in cells expressing Nefs from most other primate lentiviruses due to reduced TfR internalization. The SIV Nef-mediated reduction of TfR endocytosis is dependent on an N-terminal AP2 binding motif that is not required for downmodulation of CD4, CD28, CD3 or MHCI. Importantly, SIV Nef-induced inhibition of TfR endocytosis leads to the reduction of Transferrin uptake and intracellular iron concentration and is accompanied by attenuated lentiviral replication in macrophages.

CONCLUSION

Inhibition of Transferrin and thereby iron uptake by SIV Nef might limit viral replication in myeloid cells. Furthermore, this new SIV Nef function could represent a virus-host adaptation that evolved in natural SIV-infected monkeys.

Post-natal anaemia and iron deficiency in HIV-infected women and the health and survival of their children

Prenatal iron supplementation may improve pregnancy outcomes and decrease the risk of child mortality. However, little is known about the importance of post-natal maternal iron status for child health and survival, particularly in the context of HIV infection. We examined the association of maternal anaemia and hypochromic microcytosis, an erythrocyte morphology consistent with iron deficiency, with child health and survival in the first two to five years of life. Repeated measures of maternal anaemia and hypochromic microcytosis from 840 HIV-positive women enrolled in a clinical trial of vitamin supplementation were prospectively related to child mortality, HIV infection and CD4 T-cell count. Median duration of follow-up for the endpoints of child mortality, HIV infection and CD4 cell count was 58, 17 and 23 months, respectively. Maternal anaemia and hypochromic microcytosis were associated with greater risk of child mortality [hazard ratio (HR) for severe anaemia = 2.58, 95% confidence interval (CI): 1.66-4.01, P trend < 0.0001; HR for severe hypochromic microcytosis = 2.36, 95% CI: 1.27-4.38, P trend = 0.001]. Maternal anaemia was not significantly associated with greater risk of child HIV infection (HR for severe anaemia = 1.46, 95% CI: 0.91, 2.33, P trend = 0.08) but predicted lower CD4 T-cell counts among HIV-uninfected children (difference in CD4 T-cell count/µL for severe anaemia: -93, 95% CI: -204-17, P trend = 0.02). The potential child health risks associated with maternal anaemia and iron deficiency may not be limited to the prenatal period. Efforts to reduce maternal anaemia and iron deficiency during pregnancy may need to be expanded to include the post-partum period.

Micronutrients, N-acetyl cysteine, probiotics and prebiotics, a review of effectiveness in reducing HIV progression

Low serum concentrations of micronutrients, intestinal abnormalities, and an inflammatory state have been associated with HIV progression. These may be ameliorated by micronutrients, N-acetyl cysteine, probiotics, and prebiotics. This review aims to integrate the evidence from clinical trials of these interventions on the progression of HIV. Vitamin B, C, E, and folic acid have been shown to delay the progression of HIV. Supplementation with selenium, N-acetyl cysteine, probiotics, and prebiotics has considerable potential, but the evidence needs to be further substantiated. Vitamin A, iron, and zinc have been associated with adverse effects and caution is warranted for their use.

Anemia and growth failure among HIV-infected children in India: a retrospective analysis

Background

Anemia and poor nutrition have been previously described as independent risk factors for death among HIV-infected children. We sought to describe nutritional status, anemia burden and HIV disease correlates among infected children in India.

Methods

We analyzed retrospective data from 248 HIV-infected children aged 1–12 years attending three outpatient clinics in South India (2004–2006). Standard WHO definitions were used for anemia, HIV staging and growth parameters. Statistical analysis included chi square, t tests, univariate and multivariate logistic regression analyses.

Results

The overall prevalence of anemia (defined as hemoglobin < 11 gm/dL) was 66%, and 8% had severe anemia (Hb < 7 gm/dL). The proportion of underweight and stunted children in the population was 55% and 46% respectively. Independent risk factors of anemia by multivariate analysis included the pre-school age group (age younger than 6 years) (OR: 2.87; 95% CI: 1.45, 5.70; p < 0.01), rural residence (OR: 12.04; 95% CI: 5.64, 26.00; p < 0.01), advanced HIV disease stage (OR: 6.95; 95% CI: 3.06, 15.79; p < 0.01) and presence of stunting (Height-for-age Z Score < -2) (OR: 3.24; 95% CI: 1.65, 6.35; p < 0.01). Use of iron/multivitamin supplementation was protective against risk of anemia (OR: 0.44; 95% CI: 0.22, 0.90; p = 0.03). Pulmonary tuberculosis was an independent risk factor in multivariate analysis (OR: 3.36; 95% CI: 1.43, 7.89; p < 0.01) when correlated variables such as HIV disease stage and severe immunodeficiency, and nutritional supplement use were not included. Use of antiretroviral therapy (ART) was associated with a reduced risk of anemia (OR: 0.29; 95% CI: 0.16, 0.53; p < 0.01). No significant association was found between anemia and gender, cotrimoxazole, or ART type (zidovudine versus stavudine).

Conclusion

The high prevalence and strong interrelationship of anemia and poor nutrition among HIV-infected children in India, particularly those living in rural areas underscores the need for incorporating targeted nutritional interventions during national scale up of care, support and treatment among HIV-infected children.

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.

Viral infection and iron metabolism

Fundamental cellular operations, including DNA synthesis and the generation of ATP, require iron. Viruses hijack cells in order to replicate, and efficient replication needs an iron-replete host. Some viruses selectively infect iron-acquiring cells by binding to transferrin receptor 1 during cell entry. Other viruses alter the expression of proteins involved in iron homeostasis, such as HFE and hepcidin. In HIV-1 and hepatitis C virus infections, iron overload is associated with poor prognosis and could be partly caused by the viruses themselves. Understanding how iron metabolism and viral infection interact might suggest new methods to control disease.

Elevated iron status strongly predicts mortality in West African adults with HIV infection

OBJECTIVE

To comprehensively assess iron status and determine whether elevated iron status, like anemia, predicts mortality.

METHODS

We followed 1362 Gambian adults (53% female) in an HIV-seroprevalent clinic-based cohort over 11.5 years to ascertain all-cause mortality. Baseline iron status (iron, soluble transferrin receptor [sTfR], transferrin, ferritin, transferrin saturation, log [transferrin receptor: ferritin]), age, gender, ethnicity, hemoglobin, body mass index, HIV type, absolute CD4 count, malaria status, and [alpha]-(1)-antichymotrypsin were measured.

RESULTS

The mortality rate was 25.9/100 person-years. Elevated iron universally predicted greater mortality compared to normal iron status for all iron status indices, with the exception of sTfR in unadjusted models. In fully adjusted models, transferrin (elevated vs. normal, hazard ratio [HR]: 1.77; 95% confidence interval [CI]: 1.30 to 2.42; P < 0.001), ferritin (elevated vs. normal, HR: 1.40; 95% CI: 1.07 to 1.83; P = 0.014), and the combined iron status index (highly elevated vs. normal, HR: 2.20; 95% CI: 1.16 to 4.18; P = 0.016) remained significant predictors. As expected, hemoglobin (Hb) concentration and absolute CD4 counts were each inversely associated with mortality.

CONCLUSIONS

Elevated iron status predicts mortality in HIV infection, even after adjustment for immunosuppression and other confounders. This finding has implications in the clinical monitoring of disease progression and for iron-supplementation practices in areas of high HIV prevalence.

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.

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.

Effect of micronutrients and iron supplementation on hemoglobin, iron status, and plasma hepatitis C and HIV RNA levels in female injection drug users: a controlled clinical trial

BACKGROUND

Iron deficiency is common among female injection drug users, but it is unclear whether iron supplementation can reduce anemia and improve iron status without increasing plasma hepatitis C virus (HCV) or HIV RNA levels.

METHODS

We conducted a phase 3, double-blind, randomized, controlled clinical trial of daily micronutrients with 18 mg of iron (iron group) versus micronutrients without iron (control group) for 12 months among hepatitis C-positive female injection drug users in Baltimore, Maryland. The main outcome measures were hemoglobin, markers of iron status, plasma HCV RNA, plasma HIV RNA, and liver enzymes at 6 and 12 months of follow-up.

RESULTS

Four hundred fifty-eight women (320 HIV-negative and 138 HIV-positive) enrolled in the trial. There were no significant differences in the proportion of women with anemia, ferritin<30 ng/mL, log10 plasma HCV RNA, or log10 plasma HIV RNA between treatment groups at enrollment. The proportion with anemia in the iron and control groups, respectively, was 20.7% versus 31.3% (P=0.026) at 6 months and 26.2% versus 30.4% (P=0.5) at 12 months; with ferritin<30 ng/mL, the proportion was 29.2% versus 55.5% (P<0.0001) at 6 months and 26.2% versus 46.9% (P=0.0018) at 12 months. In the iron and control groups, respectively, mean log10 plasma HCV RNA (IU/mL) was 5.2 versus 5.2 (P=0.86) at 6 months and 5.4 versus 5.3 (P=0.6) at 12 months. Among HIV-positive subjects, mean log10 plasma RNA (copies/mL) in the iron and placebo groups, respectively, was 3.8 versus 3.7 (P=0.75) at 6 months and 3.7 versus 4.1 (P=0.19) at 12 months. There were no significant differences in liver enzyme levels between the treatment groups at enrollment, 6 months, and 12 months.

CONCLUSIONS

A daily micronutrient supplement with iron can reduce anemia and improve iron status in female injection drug users without increasing plasma HCV or HIV RNA levels or altering liver enzymes.

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.

Micronutrient supplementation in children and adults with HIV infection

BACKGROUND

The scale and impact of the HIV/AIDS pandemic has made the search for simple, affordable, safe, and effective public health interventions all the more urgent. Micronutrient supplements hold the promise of meeting these criteria, but their widespread use needs to be based on sound scientific evidence of effectiveness and safety.

OBJECTIVES

To assess whether micronutrient supplements are effective in reducing morbidity and mortality in adults and children with HIV infection.

SEARCH STRATEGY

The Cochrane Library (CENTRAL), EMBASE, MEDLINE, AIDSearch, CINAHL, and conference proceedings were searched, and pharmaceutical manufacturers and researchers in the field were contacted to locate any ongoing or unpublished trials.

SELECTION CRITERIA

Randomised controlled trials comparing the effects of micronutrient supplements (vitamins, trace elements, and combinations of these) with placebo or no treatment on mortality and morbidity in HIV-infected individuals.

DATA COLLECTION AND ANALYSIS

Two reviewers independently appraised trial quality and extracted data. Study authors were contacted for additional data where necessary. A meta-analysis was not deemed appropriate due to significant heterogeneity between trials.

MAIN RESULTS

Fifteen trials were included. Six trials comparing vitamin A/beta-carotene with placebo in adults failed to show any effects on mortality, morbidity, CD4 and CD8 counts, or on viral load. Four trials of other micronutrients in adults did not affect overall mortality, although there was a reduction in mortality in a low CD4 subgroup. In a large Tanzanian trial in pregnant and lactating women, daily multivitamin supplementation was associated with a number of benefits to both mothers and children: a reduction in maternal mortality from AIDS-related causes; a reduced risk of progression to stage four disease; fewer adverse pregnancy outcomes; less diarrhoeal morbidity; and a reduction in early-child mortality among immunologically- and nutritionally-compromised women. Vitamin A alone reduced all-cause mortality and improved growth in a small sub-group of HIV-infected children in one hospital-based trial, and reduced diarrhoea-associated morbidity in a small HIV-infected sub-group of infants in another trial.

AUTHORS' CONCLUSIONS

There is no conclusive evidence at present to show that micronutrient supplementation effectively reduces morbidity and mortality among HIV-infected adults. It is reasonable to support the current WHO recommendations to promote and support adequate dietary intake of micronutrients at RDA levels wherever possible. There is evidence of benefit of vitamin A supplementation in children. The long-term clinical benefits, adverse effects, and optimal formulation of micronutrient supplements require further investigation.

Prevention of infection due to Pneumocystis spp. in human immunodeficiency virus-negative immunocompromised patients

Pneumocystis infection in humans was originally described in 1942. The organism was initially thought to be a protozoan, but more recent data suggest that it is more closely related to the fungi. Patients with cellular immune deficiencies are at risk for the development of symptomatic Pneumocystis infection. Populations at risk also include patients with hematologic and nonhematologic malignancies, hematopoietic stem cell transplant recipients, solid-organ recipients, and patients receiving immunosuppressive therapies for connective tissue disorders and vasculitides. Trimethoprim-sulfamethoxazole is the agent of choice for prophylaxis against Pneumocystis unless a clear contraindication is identified. Other options include pentamidine, dapsone, dapsone-pyrimethamine, and atovaquone. The risk for PCP varies based on individual immune defects, regional differences, and immunosuppressive regimens. Prophylactic strategies must be linked to an ongoing assessment of the patient's risk for disease.

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.

Iron supplementation during human immunodeficiency virus infection: a double-edged sword?

Although iron supplementation is considered beneficial for groups at risk for anemia, concern has been raised that it could be harmful during human immunodeficiency virus (HIV) infection. Studies suggest: (1) faster HIV disease progression in thalassemia major patients receiving inadequate doses of iron-chelating drug; (2) higher mortality among patients receiving iron supplementation with dapsone compared with aerosolized pentamidine for prophylaxis against Pneumocytis carinii pneumonia; (3) higher iron stores and mortality among patients with haptoglobin Hp 2-2 phenotype; and (4) shorter survival among patients with high bone marrow iron deposition. These studies largely involved men in developed countries. Among HIV-infected pregnant women in Africa with a high prevalence of iron deficiency, no relationship was found between indicators of iron status and HIV disease severity. The available data do not contraindicate the current practice of iron supplementation in developing countries where there is a high prevalence of both HIV infection and iron deficiency.

HIV and other predictors of serum folate, serum ferritin, and hemoglobin in pregnancy: a cross-sectional study in Zimbabwe

BACKGROUND

Folate and iron status and hemoglobin concentrations are important to maternal and infant health.

OBJECTIVE

Our goal was to identify predictors of serum folate, serum ferritin, and hemoglobin.

DESIGN

This was a cross-sectional study of 1669 pregnant women (22-35 wk of gestation) in Harare, Zimbabwe, who were receiving prenatal care. The statistical effects of age, season, gestational age, gravidity, HIV-1 infection, malaria parasitemia, and serum alpha1-antichymotrypsin (ACT) on serum folate, serum ferritin (log10 transformed), and hemoglobin were estimated by using multiple linear regression analyses.

RESULTS

Serum folate (x: 11.4 micromol/L) was 0.52-nmol/L (95% CI: 0.04, 1.0) lower in HIV-infected women than in uninfected women and 0.65-nmol/L (0.014, 1.28) lower in weeks 25-35 than in weeks 22-25. Serum ferritin (geometric x: 11.6 microg/L) was 0.93 times (0.86, 0.99) lower in HIV-infected women and 2.25 times (1.41, 3.61) higher in women with malaria parasitemia than in uninfected women. Similarly, serum ferritin was 0.71 times (0.63, 0.79) higher in weeks 32-35 than in weeks 22-25 and 1.21 times (1.12, 1.29) higher in gravida > or =3 than in gravida 1. Elevated serum ACT was a strong predictor of serum folate, serum ferritin, and hemoglobin. HIV infection was associated with a 12.9-g/L (8.9, 16.8) lower hemoglobin concentration in women with nondepleted iron stores but low serum retinol and a 7-8-g/L lower hemoglobin concentration in women with other combinations of serum ferritin and retinol (P for interaction = 0.038). Season, age, gestational age, and gravidity were not significant predictors of hemoglobin. Low serum folate, ferritin, and retinol were associated with low hemoglobin.

CONCLUSIONS

HIV was associated with lower serum folate, serum ferritin, and hemoglobin. HIV infection was also associated with lower hemoglobin, particularly in women with stored iron and low serum retinol. Low serum folate, ferritin, and retinol were associated with low hemoglobin.

Iron status and indicators of human immunodeficiency virus disease severity among pregnant women in Malawi

The relationships among hemoglobin, ferritin, and transferrin receptor levels and 2 markers of human immunodeficiency virus (HIV) disease severity--HIV load and CD4(+) lymphocyte count--were characterized among 483 pregnant women in Malawi, Africa. The only significant correlation was an inverse correlation between hemoglobin level and plasma HIV load (r=-.104; P<.03). The prevalence of iron deficiency anemia was not significantly different across quartiles of HIV load or CD4(+) lymphocyte count. In contrast to previous studies, these data suggest that iron status is not related to markers of HIV disease severity in pregnant women in Africa.

Iron status and the outcome of HIV infection: an overview

BACKGROUND

Theoretical considerations and experiments in the laboratory suggest that excessive iron stores may have an adverse effect on immunity. If so, high iron stores might be especially a problem in patients with human immunodeficiency virus (HIV) infection.

OBJECTIVE AND STUDY DESIGN

Review published clinical studies that provide information regarding the effect of iron status on the outcome of HIV infection.

RESULTS

Four clinical observations have provided some perspective on the effect of iron status on the outcome of HIV-1 infection. First, in a retrospective study of HIV-positive thalassemia major patients, the rate of progression of HIV disease was significantly faster in patients with lower doses of desferrioxamine and higher serum ferritin concentrations. Second, the inadvertent simultaneous administration of low doses of oral iron with dapsone for the prophylaxis of Pneumocystis carinii pneumonia in HIV-positive patients may have been associated with excess mortality. Third, a study of haptoglobin polymorphisms in HIV-positive subjects indicated that the haptoglobin 2-2 polymorphism is associated with higher iron stores and shortened survival as compared with the haptoglobin 1-1 or 2-1 phenotypes. Fourth, a retrospective study of bone marrow macrophage iron in HIV-positive patients suggested that survival is shorter with high iron stores.

CONCLUSION

These four observations raise the possibility that high iron status may adversely influence the outcome of HIV-1 infection.

Effects of MS-8209, an amphotericin B derivative, on tumor necrosis factor alpha synthesis and human immunodeficiency virus replication in macrophages

Amphotericin B derivatives, such as MS-8209, have been evaluated as a therapeutic approach to human immunodeficiency virus (HIV) infection. We show that MS-8209, like amphotericin B, increases tumor necrosis factor alpha (TNF-alpha) mRNA expression and TNF-alpha production and consequently HIV replication in human macrophages. These effects confirm the pharmacological risk associated with the administration of amphotericin B or its derivatives to HIV-infected patients.

Toxicity and efficacy of daily vs. weekly dapsone for prevention of Pneumocystis carinii pneumonia in children infected with human immunodeficiency virus. ACTG 179 Study Team. AIDS Clinical Trials Group

BACKGROUND

Dapsone is an alternative drug for Pneumocystis carinii pneumonia (PCP) prophylaxis in individuals intolerant to trimethoprim-sulfamethoxazole (T/S). There are, however, few data on the pharmacokinetics, toxicity or efficacy of dapsone in children. Design. Randomized, multicenter trial comparing daily (1 or 2 mg/kg) with weekly (4 mg/kg) dapsone regimens in 94 HIV-infected children intolerant to T/S.

METHODS

Hematologic and hepatic toxicity was monitored, as well as the occurrence of skin rash, PCP or death.

RESULTS

Initial pharmacokinetic data indicated that adequate serum dapsone concentrations were not achieved with the daily 1-mg/kg regimen; the daily dose was then increased to 2 mg/kg. Both short and long term hematologic toxicities were marginally greater in children receiving the daily 2 mg/kg compared with the weekly regimen. Allergic skin rashes were similar in children receiving the daily and weekly regimens (17% in both) and were not associated with prior history of rash with T/S. PCP occurred most frequently with the daily 1-mg/kg regimen (22.0 cases/100 patient years), least frequently with the daily 2-mg/kg regimen (0 case/100 patient years) and at intermediate frequency with the weekly regimen (9.5 cases/100 patient years). More deaths were observed in patients receiving the daily than the weekly regimen (8 vs. 2, respectively), although the deaths were not directly attributable to dapsone treatment.

CONCLUSION

Although a weekly dapsone regimen of 4 mg/kg produced less hematologic toxicity than a daily regimen of 2 mg/kg, this advantage was offset by a trend toward higher breakthrough rates of PCP.

Pathogenesis and pathophysiology of anemia in HIV infection

Anemia is common in human immunodeficiency virus infection, particularly in patients with acquired immunodeficiency syndrome. Anemia is multifactorial. HIV infection itself causes anemia, probably as a consequence of HIV infection of stromal cells rather than HIV infection of hematopoietic stem cells. Other common causes of anemia in AIDS are anemia of chronic disease consequent on opportunistic infections, bone marrow suppression by antiretroviral therapy, and hemolytic anemia induced by oxidant drugs. Thrombotic microangiopathy is a significant complication of HIV infection and may respond to plasmapheresis.

Bone marrow macrophage iron grade and survival of HIV-seropositive patients

OBJECTIVE

Increased iron stores predispose to certain microbial infections. This association might be especially important in patients whose immune system is impaired by HIV. This study examined the relationship between iron stores and the survival times of patients with HIV infection.

DESIGN

Retrospective analysis of iron stores, as determined directly in bone marrow aspirates, and of hospital records.

SETTING

The George Washington University Hospital, an urban academic tertiary care institution.

PATIENTS

Three hundred and forty-eight HIV-seropositive adults who had diagnostic bone marrow aspirates between January 1985 and June 1996.

MEASUREMENTS

Bone marrow macrophage iron stores were graded on a scale of 0 to 5. For analysis of the influence of iron stores on survival, we compared patients with grades 4-5 iron stores (markedly or massively increased; n = 188) to those with grades 0-2 iron stores (normal or decreased; n = 130).

RESULTS

Infections caused by Candida spp., Pneumocystis carinii, and Mycobacterium spp. were more common in patients with high macrophage iron grades than in patients with low or normal iron grades (P < or = 0.006). The adjusted estimated rate of death (hazards ratio) was higher in patients with high iron stores compared with patients with low or normal iron stores, both from the time of the bone marrow study (ratio of 2.1; 95% confidence interval 1.3-3.5; P = 0.003) and the determination of HIV-seropositivity (ratio of 2.8; 95% confidence interval 1.4-4.9; P = 0.001).

CONCLUSION

High iron stores, as determined by bone marrow macrophage iron grade, may be associated with shorter survival times in patients with HIV infection.

Atovaquone compared with dapsone for the prevention of Pneumocystis carinii pneumonia in patients with HIV infection who cannot tolerate trimethoprim, sulfonamides, or both. Community Program for Clinical Research on AIDS and the AIDS Clinical Trials Group

BACKGROUND

Although trimethoprim-sulfamethoxazole is the drug of choice for the prevention of Pneumocystis carinii pneumonia, many patients cannot tolerate it and must switch to an alternative agent.

METHODS

We conducted a multicenter, open-label, randomized trial comparing daily atovaquone (1500-mg suspension) with daily dapsone (100 mg) for the prevention of P. carinii pneumonia among patients infected with the human immunodeficiency virus who could not tolerate trimethoprim-sulfamethoxazole. The median follow-up period was 27 months.

RESULTS

Of 1057 patients enrolled, 298 had a history of P. carinii pneumonia. P. carinii pneumonia developed in 122 of 536 patients assigned to atovaquone (15.7 cases per 100 person-years), as compared with 135 of 521 in the dapsone group (18.4 cases per 100 person-years; relative risk for atovaquone vs. dapsone, 0.85; 95 percent confidence interval, 0.67 to 1.09; P=0.20). The relative risk of death was 1.07 (95 percent confidence interval, 0.89 to 1.30; P=0.45), and the relative risk of discontinuation of the assigned medication because of adverse events was 0.94 (95 percent confidence interval, 0.74 to 1.19; P=0.59). Among the 546 patients who were receiving dapsone at base line, the relative risk of discontinuation because of adverse events was 3.78 for atovaquone as compared with dapsone (95 percent confidence interval, 2.37 to 6.01; P<0.001); among those not receiving dapsone at base line, it was 0.42 (95 percent confidence interval, 0.30 to 0.58; P<0.001).

CONCLUSIONS

Among patients who cannot tolerate trimethoprim-sulfamethoxazole, atovaquone and dapsone are similarly effective for the prevention of P. carinii pneumonia. Our results support the continuation of dapsone prophylaxis among patients who are already receiving it. However, among those not receiving dapsone, atovaquone is better tolerated and may be the preferred choice for prophylaxis against P. carinii pneumonia.

Human immunodeficiency virus infection, Part I

Initially recognized in 1982, acquired immunodeficiency syndrome (AIDS) has been the leading cause of death among young adults in the United States for much of this decade, and it has had a devastating impact on people in the developing world. It is estimated that 42 million people worldwide have been infected with human immunodeficiency virus (HIV), the virus that causes AIDS, and that almost 12 million people have died from AIDS-related diseases through 1997. Among these 12 million are 3 million children. Two thirds of the more than 30 million people with HIV or AIDS reside in sub-Saharan Africa. In the United States, 641,086 patients have been diagnosed with AIDS through 1997, and at least 385,000 have died. However, for the first time, new highly active antiretroviral therapies that include multiple drugs that attack the virus at several sites have slowed the progression from HIV to AIDS and from AIDS to death for those infected with HIV. The cumulative effect of these changes has been a reduction in both AIDS incident cases and AIDS deaths. Recent epidemiologic trends indicate that the proportion of AIDS incident cases and new HIV infections are increasing among women, African-Americans, and Hispanics, and the infections are more likely to be acquired through heterosexual transmission. The clinical management of HIV infection and AIDS has become increasingly complex in recent years. In addition to complete medical and social histories and physical examinations, hematologic, biochemical, serologic, and immunologic laboratory tests are required to predict the likelihood that patients will develop opportunistic infections and other complications related to HIV infection. Among the most important laboratory tests are measurements of HIV in plasma (viral load) in conjunction with peripheral blood CD4+ helper T lymphocyte counts. These tests are potent predictors of disease progression and their results have become markers for clinical response to therapy. The development of highly active antiretroviral therapy has had a profound impact on the epidemiology of AIDS and on the lives of individual patients. Through combinations of antiretroviral drugs, especially protease inhibitors, viral suppression can be achieved. However, adherence to these complex medical regimens and drug interactions have been problems for many patients. In addition, numerous questions remain unanswered, most importantly those regarding the timing of the initiation of treatment, the durability of viral suppression and clinical response, and the optimal "salvage" regimens for patients failing therapy either clinically or virologically.

Serum ferritin, desferrioxamine, and evolution of HIV-1 infection in thalassemic patients

To study the respective roles of mean serum ferritin level and the mean desferrioxamine (DFX) dose on progression of HIV-1 infection, data from 49 HIV-seropositive thalassemic patients were analyzed using a Cox proportional hazards model including known confounding variables. Nine years after seroconversion, 10% of those who had been prescribed >40 mg/kg of DFX daily had entered stage IV versus 39% of those who had been prescribed a lower dose. Patients with ferritin level >1935 g/L entered stage IV more rapidly than those with a lower level (31% versus 16%). In multivariate analysis, the ferritin level was found to be an independent predictor of progression of HIV disease, whereas the mean daily dose of DFX was not. Similar results were obtained when death was the endpoint. Our results support a hypothesis that was recently expressed, that iron overload could be associated with a more rapid progression of HIV-1 infection.

The impact of high-risk patients on the results of clinical trials

The results of clinical trials may not reflect equally the experiences of all their individual participants. By modeling populations where patients have very diverse baseline risks of suffering an event of interest, it can be seen that very sick patients of high risk become the major determinants of how many events occur in the whole population, even though they may represent only a small minority. Human immunodeficiency virus-related trials and trials of magnesium in acute myocardial infarction are analyzed. When the benefit or toxicity from a treatment varies with the baseline risk of each patient, the treatment effect may be markedly different in populations with a different representation of high- and low-risk patients. The results of small clinical trials studying heterogeneous populations with binary outcomes depend on the sampling and outcomes of very few high risk participants. Conversely, mega-trials studying homogeneous populations would miss subgroups or individuals with diverse treatment responses. In both cases, aggregate trial results may be misleading for the care of many individuals.

Meta-analysis of prophylactic treatments against Pneumocystis carinii pneumonia and toxoplasma encephalitis in HIV-infected patients

In a meta-analysis, we examined the efficacy of aerosolized pentamidine, trimethoprim-sulfamethoxazole, and dapsone or dapsone/pyrimethamine for the prevention of Pneumocystis carinii pneumonia and toxoplasma encephalitis in patients with HIV infection. Of 22 trials, 13 compared trimethoprim-sulfamethoxazole with aerosolized pentamidine, nine compared dapsone alone or in combination with pyrimethamine with aerosolized pentamidine, and eight compared trimethoprim-sulfamethoxazole with dapsone/pyrimethamine. In total, 1484 patients were treated with trimethoprim-sulfamethoxazole, 1548 patients with dapsone/pyrimethamine or dapsone, and 1800 patients with aerosolized pentamidine. For dapsone/pyrimethamine versus aerosolized pentamidine, the risk ratio for P. carinii pneumonia was 0.90 (95% confidence interval [CI], 0.71-1.15), and for toxoplasma encephalitis it was 0.72 (95% CI, 0.54-0.97). For trimethoprim-sulfamethoxazole versus aerosolized pentamidine, the risk ratio of P. carinii pneumonia was 0.59 (95% CI, 0.45-0.76), and for toxoplasma encephalitis it was 0.78 (95% CI, 0.55-1.11). For trimethoprim-sulfamethoxazole versus dapsone/pyrimethamine, the risk ratio of P. carinii pneumonia was 0.49 (95% CI, 0.26-0.92), and for toxoplasma encephalitis it was 1.17 (95% CI, 0.68-2.04). Although current evidence does not allow a definitive recommendation, administration of trimethoprim-sulfamethoxazole for prophylaxis of P. carinii pneumonia and toxoplasmosis in patients with HIV infection is consistent with the available data.

Drug treatment of HIV-related opportunistic infections

The AIDS epidemic has led to the emergence of several disease entities which in the pre-AIDS era were rare or seemingly innocuous. Experience of treating these diseases varies. In some instances, such as Pneumocystis carinii pneumonia, there is an abundance of published literature to direct our course of action. However, for many of these newly recognised diseases our treatment experience is limited. Furthermore, in many instances, well controlled trials evaluating treatment modalities in the AIDS population are lacking. We have identified 13 disease entities (P. carinii pneumonia, toxoplasmosis, cryptococcosis, histoplasmosis, Mycobacterium tuberculosis, Mycobacterium avium complex, cytomegalovirus, coccidioidomycosis, isosporiasis, candidosis, Kaposi's sarcoma, herpes simplex virus, and varicella zoster virus) and have reviewed the current literature with regard to their treatment.