Mortality risk in selenium-deficient HIV-positive children

The oxidative stress-induced niacin sink (OSINS) model for HIV pathogenesis

Although several specific micronutrient deficiencies are associated with disease progression and increased mortality risk in HIV/AIDS, and even a simple multivitamin/mineral supplement can prolong survival, this is typically viewed merely as nutritional support of the immune system, and only necessary if there are deficiencies to be rectified. However, the reality is more complex. Several striking nutrient-related metabolic abnormalities have been consistently documented in HIV infection. One is chronic oxidative stress, including a drastic depletion of cysteine from the glutathione pool, and a progressive decline of serum selenium that is correlated with disease progression and mortality. Another is decreased blood levels of tryptophan, with an associated intracellular niacin deficiency. Tryptophan depletion or "deletion" by induction of indoleamine-2,3-dioxygenase (IDO), the first step in oxidative tryptophan metabolism, is a known mechanism for immune suppression that is of critical importance in cancer and pregnancy, and, potentially, in HIV/AIDS. Existing evidence supports the hypothesis that these nutrient-related metabolic abnormalities in HIV infection regarding antioxidants, selenium, sulfur, tryptophan and niacin are interrelated, because HIV-associated oxidative stress can induce niacin/NAD+ depletion via activation of poly(ADP-ribose) polymerase (PARP), which could lead to tryptophan oxidation for compensatory de novo niacin synthesis, thereby contributing to immune tolerance and T-cell loss via tryptophan deletion and PARP-induced cell death. This "oxidative stress-induced niacin sink" (OSINS) model provides a mechanism whereby the oxidative stress associated with HIV infection can contribute to immunosuppression via tryptophan deletion. This model is directly supported by evidence that antioxidants can counteract indoleamine-2,3-dioxygenase (IDO), providing the critical link between oxidative stress and tryptophan metabolism proposed here. The OSINS model can be used to guide the design of nutraceutical regimens that can effectively complement antiretroviral therapy for HIV/AIDS.

How to use the world's scarce selenium resources efficiently to increase the selenium concentration in food

The world's rare selenium resources need to be managed carefully. Selenium is extracted as a by-product of copper mining and there are no deposits that can be mined for selenium alone. Selenium has unique properties as a semi-conductor, making it of special value to industry, but it is also an essential nutrient for humans and animals and may promote plant growth and quality. Selenium deficiency is regarded as a major health problem for 0.5 to 1 billion people worldwide, while an even larger number may consume less selenium than required for optimal protection against cancer, cardiovascular diseases and severe infectious diseases including HIV disease. Efficient recycling of selenium is difficult. Selenium is added in some commercial fertilizers, but only a small proportion is taken up by plants and much of the remainder is lost for future utilization. Large biofortification programmes with selenium added to commercial fertilizers may therefore be a fortification method that is too wasteful to be applied to large areas of our planet. Direct addition of selenium compounds to food (process fortification) can be undertaken by the food industry. If selenomethionine is added directly to food, however, oxidation due to heat processing needs to be avoided. New ways to biofortify food products are needed, and it is generally observed that there is less wastage if selenium is added late in the production chain rather than early. On these bases we have proposed adding selenium-enriched, sprouted cereal grain during food processing as an efficient way to introduce this nutrient into deficient diets. Selenium is a non-renewable resource. There is now an enormous wastage of selenium associated with large-scale mining and industrial processing. We recommend that this must be changed and that much of the selenium that is extracted should be stockpiled for use as a nutrient by future generations.

The effect of selenium supplementation on DTH skin responses in healthy North American men

The trace element selenium (Se) is essential for immune system development and function in animals. However, the exact functions of Se in the human immune system and the achievable health benefits from Se supplementation remain unclear. To test whether an increased intake of dietary Se affects immune function, we conducted a randomized, controlled trial of Se supplementation in healthy free-living men. Forty-two men were administered 300microg of Se a day as high-Se Baker's yeast, or low-Se yeast for 48 weeks. Serum immunoglobulins, differential complete blood counts and lymphocyte sub-populations were measured every 6 weeks. Tests of delayed-type hypersensitivity (DTH) skin responses to mumps, candida, trychophyton, tuberculin-purified protein, and tetanus were performed at baseline and at the end of 48 weeks of treatment. Supplementation increased blood Se concentration by 50%. Surprisingly, consumption of the low-Se yeast induced anergy in DTH skin responses and increased counts of natural killer (NK) cells and T lymphocytes expressing both subunits of the high affinity interleukin-2 receptor (IL2R). DTH skin responses and IL2R+ cells did not change in the high-Se group, suggesting Se supplementation blocked induction of DTH anergy. There were no differences between groups in quality of life indicators, number of days sick, other leukocyte phenotypes, serum immunoglobulins, or complement factors. These results suggest that Se plays a role in immunotolerization, a cell-mediated process involved in many aspects of immune function.

Viral RNA kinetics is associated with changes in trace elements in target organs of Coxsackie virus B3 infection

Trace elements are pivotal for the host defense, as well as potentially important for viral replication and virulence. Studies of sequential changes in viral replication in target organs of infection are sparse and a possible association with changes in specific trace elements is unknown. In this study Balb/c mice were infected with Coxsackie virus B3 (CVB3). Results indicated that sequential changes in viral replication (RT-PCR) were related to changes in trace element (arsenic, copper, iron, selenium and zinc) concentrations (as determined by ICP-MS) on days 3, 5 and 7 of the infection in serum, heart, lung, liver, pancreas, kidney, spleen, intestine and brain. After an initial viral peak on day 3, viral load drastically decreased in all organs, i.e. by >99% (serum), 97% (lung), 98% (liver), 60% (pancreas), 95% (kidney) and 93% (spleen), except in the heart, intestine and brain in which viral load increased after day 3. Selenium decreased in all organs except the heart while arsenic decreased in all organs except the kidney, spleen and brain. Moreover, selenium was negatively correlated to viral load in serum, liver, pancreas and intestine. To conclude, these findings give evidence that trace elements are directly involved in the replication of CVB3.

Food-chain selenium and human health: emphasis on intake

Following the publication of the landmark trial of Clark et al. in 1996 that appeared to show that Se could reduce the risk of cancer, awareness of the importance of Se to human health has markedly increased. As a result, there is now much more aggressive marketing of Se supplements and functional foods, even in situations where additional consumption of Se is inappropriate. The present review addresses how Se gets into the food chain, the wide variability in Se content of foods and the very different levels of intake between countries and regions. Though it is clear that there are adverse consequences for health of both deficient and excessive intake, health effects at intermediate levels of intake are less certain. Thus it is difficult to define optimal intake which depends on a large number of factors, such as which functions of Se are most relevant to a particular disease state, which species of Se is most prominent in the Se source, which health condition is being considered, the adequacy or otherwise of intake of other nutrients, the presence of additional stressors, and lastly whether the ability to make selenoproteins may be compromised. These complexities need to be understood, particularly by policy makers, in order to make informed judgments. Potential solutions for increasing Se intake, where required, include agronomic biofortification and genetic biofortification or, for individuals, increased intake of naturally Se-rich foods, functional foods or supplements. The difficulties of balancing the risks and benefits in relation to Se intake are highlighted.

Randomized, double-blind, placebo-controlled trial of selenium supplements among HIV-infected pregnant women in Tanzania: effects on maternal and child outcomes

BACKGROUND

In observational studies, adequate selenium status has been associated with better pregnancy outcomes and slowed HIV disease progression.

OBJECTIVE

We investigated the effects of daily selenium supplements on CD4 cell counts, viral load, pregnancy outcomes, and maternal and infant mortality among 913 HIV-infected pregnant women.

DESIGN

In this randomized, double-blind, placebo-controlled trial, eligible women between 12 and 27 wk of gestation were given daily selenium (200 mug as selenomethionine) or placebo as supplements from recruitment until 6 mo after delivery. All women received prenatal iron, folic acid, and multivitamin supplements irrespective of experimental assignment.

RESULTS

The selenium regimen had no significant effect on maternal CD4 cell counts or viral load. Selenium was marginally associated with a reduced risk of low birth weight [relative risk (RR) = 0.71; 95% CI: 0.49, 1.05; P = 0.09] and increased risk of fetal death (RR = 1.58; 95% CI = 0.95, 2.63; P = 0.08), but had no effect on risk of prematurity or small-for-gestational age birth. The regimen had no significant effect on maternal mortality (RR = 1.02; 95% CI = 0.51, 2.04; P = 0.96). There was no significant effect on neonatal or overall child mortality, but selenium reduced the risk of child mortality after 6 wk (RR = 0.43; 95% CI = 0.19, 0.99; P = 0.048).

CONCLUSION

Among HIV-infected women from Dar es Salaam, Tanzania, selenium supplements given during and after pregnancy did not improve HIV disease progression or pregnancy outcomes, but may improve child survival. This trial was registered at clinicaltrials.gov as NCT00197561.

Micronutrients and T-cell subsets: a comparison between HIV-infected and uninfected, severely malnourished Rwandan children

OBJECTIVE

To determine the levels of CD4+ cells and micronutrients in HIV-infected and uninfected severely malnourished children.

DESIGN

Cross-sectional study in two centres.

SETTING

Children admitted to the malnutrition units in Kigali and Butare, Rwanda.

PATIENTS

A total of 112 children aged 2 months to 5 years presenting with severe malnutrition (weight for height Z- score -3 SD +/- oedema). Fifty-two (46.4%) were HIV-infected.

METHODS

CD4+ counts, selenium, zinc and copper levels were measured. The percentage of CD4 cells was calculated as a proportion of total lymphocyte count.

RESULTS

The mean age of the 52 HIV-infected children (18 months) was lower than of the 60 uninfected children (26 months) (p=0.01). Six (11.5%) of the HIV-infected had oedematous malnutrition compared with 50% of the uninfected group. The mean (SD) CD4+ count was 1054 (780) in the HIV-infected and 1579 (721) in the uninfected group (p=0.001). The CD4+ count was also significantly lower in the HIV-infected group than in the uninfected group for the ages <12 mths (p=0.09), 12-24 mths (p=0.045) and >36 mths (p=0.001). In HIV-infected children, 17% had severe immunosuppression (<15% CD4+ cells), 33% moderate (15-24%) and 50% had none (>25%) compared with 9%, 12% and 80% in the HIV-uninfected group, respectively (p<0.001). Approximately one-third in both groups had low levels of selenium and zinc and 77% had raised levels of copper. In multivariate analysis there was significant correlation between selenium and CD4+ (r=0.36, p<0.001) in HIV-infected children and no correlation of zinc and copper to CD4+ %. In HIV uninfected children, CD4+ % was related to selenium (r=0.282, p=0.03) and to zinc (r=0.264, p=0.047) but not to copper.

CONCLUSIONS

In severely malnourished children with HIV infection, low CD4+ levels are associated mainly with HIV infection. There was no significant difference in levels of selenium, zinc and copper between HIV-infected and uninfected children.

Micronutrients in HIV-positive persons receiving highly active antiretroviral therapy

In HIV-infected persons, low serum concentrations of vitamins and minerals, termed micronutrients, are associated with an increased risk of HIV disease progression and mortality. Micronutrient supplements can delay HIV disease progression and reduce mortality in HIV-positive persons not receiving highly active antiretroviral therapy (HAART). With the transition to more universal access to HAART, a better understanding of micronutrient deficiencies and the role of micronutrient supplements in HIV-positive persons receiving HAART has become a priority. The provision of simple, inexpensive micronutrient supplements as an adjunct to HAART may have several cellular and clinical benefits, such as a reduction in mitochondrial toxicity and oxidative stress and an improvement in immune reconstitution. We reviewed observational and trial evidence on micronutrients in HIV-positive persons receiving HAART to summarize the current literature and suggest future research priorities. A small number of observational studies have suggested that some, but not all, micronutrients may become replete after HAART initiation, and few intervention studies have found that certain micronutrients may be a beneficial adjunct to HAART. However, most of these studies had some major limitations, including a small sample size, a short duration of follow-up, a lack of adjustment for inflammatory markers, and an inadequate assessment of HIV-related outcomes. Therefore, few data are available to determine whether HAART ameliorates micronutrient deficiencies or to recommend or refute the benefit of providing micronutrient supplements to HIV-positive persons receiving HAART. Because micronutrient supplementation may cause harm, randomized placebo-controlled trials are needed. Future research should determine whether HAART initiation restores micronutrient concentrations, independent of inflammatory markers, and whether micronutrient supplements affect HIV-related outcomes in HIV-positive persons receiving HAART.

Micronutrient levels and HIV disease status in HIV-infected patients on highly active antiretroviral therapy in the Nutrition for Healthy Living cohort

BACKGROUND

Low serum micronutrient levels were common before widespread use of highly active antiretroviral therapy (HAART) and were associated with adverse outcomes. Few data are available on micronutrient levels in subjects taking HAART.

OBJECTIVE

To determine the prevalence of low serum retinol, alpha-tocopherol, zinc, and selenium in HIV-infected subjects taking HAART and to assess the association of micronutrient levels with HIV disease status.

DESIGN

Cross-sectional.

SETTING

Nutrition for Healthy Living (NFHL) study.

PARTICIPANTS

HIV-infected subjects on HAART.

METHODS

Retinol, alpha-tocopherol, zinc, and selenium were determined in frozen serum samples from 171 men and 117 women. Low serum levels were defined as retinol <30 microg/dL, selenium <85 microg/L, alpha-tocopherol <500 microg/dL, and zinc <670 microg/L. Association of micronutrient quartiles with CD4 cell count, CD4 count <200 cells/mm, HIV viral load (VL), and undetectable VL was assessed using adjusted multivariate regression.

RESULTS

Five percent of men and 14% of women had low retinol, 8% of men and 3% of women had low selenium, and 7% of men and no women had low alpha-tocopherol. Forty percent of men and 36% of women had low zinc, however. Subjects in the upper quartiles of zinc had lower log VL levels than those in the lowest quartile (significant for women). Subjects in the upper quartiles of selenium also tended to have lower VL levels compared with those in the lowest quartile. Surprisingly, women in the upper quartiles of retinol had higher log VLs than those in the lowest quartile. There was no significant association of any micronutrient with CD4 cell count or likelihood of CD4 count <200 cells/mm. The level of CD4 cell count influenced the association of retinol with log VL in men, however. In men with CD4 counts >350 cells/mm, those with higher retinol had higher log VLs compared with the lowest quartile, whereas in men with CD4 counts <350, those with higher retinol levels had lower log VLs compared with the lowest quartile.

CONCLUSIONS

Low retinol, alpha-tocopherol, and selenium are uncommon in HIV-infected subjects on HAART. Zinc deficiency remains common, however. Decreased retinol levels in women and in men with CD4 counts >350 cells/mm and increased zinc and selenium levels in both genders may be associated with improved virologic control.

Factors contributing to spontaneous Enterocytozoon bieneusi infection in simian immunodeficiency virus-infected macaques

BACKGROUND

A cohort of SIV-infected macaques had been used to investigate the effect of dietary supplement, immune status, SIV/AIDS disease progression and serum micronutrients levels on spontaneous acquisition of Enterocytozoon bieneusi infection in SIV-infected macaques.

METHODS

Twenty-four SIV-infected macaques were randomized into 2 groups. One group received a vitamin/mineral supplementation and a second group received a placebo. Both groups were examined for E. bieneusi infection.

RESULTS

SIV-infected macaques were more prone to acquire E. bieneusi with the progression of SIV/AIDS, and the increased shedding of infectious spores was directly associated with decreased CD4 lymphocyte and increased circulating SIV, in both supplemented and unsupplemented groups of animals. Dietary supplementation, body composition factors and serum micronutrients levels however had no association with the acquisition of E. bieneusi infection in these animals.

CONCLUSIONS

Acquisition of E. bieneusi infection is related to SIV disease progression, CD4 counts and viral load but independent of changes in body composition and serum micronutrient levels.

Oxidative stress and therapeutic approaches in HIV dementia

Despite the rapidly increasing incidence of HIV infection worldwide and the increasing prevalence of HIVassociated cognitive impairment, even in patients adequately treated with antiretroviral therapy, currently no effective treatment exists for HIV dementia. A broad range of studies using either brain or cerebrospinal fluid (CSF) tissues from well-characterized patients with HIV dementia, animal models, and in vitro studies from several laboratories using HIV-infected cells or HIV proteins provide overwhelming evidence for oxidative stress in mediating neuronal injury in this patient population. These studies also suggest that patients with apolipoprotein E (ApoE) 4 allele are more susceptible to such oxidative damage. In this review, we provide a critical analysis of these studies, including the few clinical trials that have used antioxidants to treat HIV dementia. We also discuss several novel agents with potent antioxidative properties and provide a rationale for combination antioxidant and neuroprotective therapy.

Low serum albumin and the acute phase response predict low serum selenium in HIV-1 infected women

Background

Low serum selenium has been associated with lower CD4 counts and greater mortality among HIV-1-seropositive individuals, but most studies have not controlled for serum albumin and the presence of an acute phase response.

Methods

A cross-sectional study was conducted to evaluate relationships between serum selenium concentrations and CD4 count, plasma viral load, serum albumin, and acute phase response markers among 400 HIV-1-seropositive women.

Results

In univariate analyses, lower CD4 count, higher plasma viral load, lower albumin, and the presence of an acute phase response were each significantly associated with lower serum selenium concentrations. In multivariate analyses including all four of these covariates, only albumin remained significantly associated with serum selenium. For each 0.1 g/dl increase in serum albumin, serum selenium increased by 0.8 μg/l (p < 0.001). Women with an acute phase response also had lower serum selenium (by 5.6 μg/l, p = 0.06).

Conclusion

Serum selenium was independently associated with serum albumin, but not with CD4 count or plasma viral load, in HIV-1-seropositive women. Our findings suggest that associations between lower serum selenium, lower CD4 count, and higher plasma viral load may be related to the frequent occurrence of low serum albumin and the acute phase response among individuals with more advanced HIV-1 infection.

Selenium levels in relation to morbidity and mortality among children born to HIV-infected mothers

OBJECTIVE

To examine the relation between selenium status and child mortality and morbidity among children born to HIV-infected mothers.

DESIGN

Prospective cohort study.

METHODS

Study participants were originally part of a trial to study the effect of maternal vitamin supplements on maternal and child health outcomes. Morbidity information was collected during monthly clinic visits until the child reached 24 months of age. Out of 984 livebirths, 806 had morbidity information, and 610 also had data on plasma selenium levels available.

SETTING

A study clinic at Muhimbili National Hospital, Dar es Salaam, Tanzania, a tertiary-care hospital.

RESULTS

The median age at baseline was 10.5 weeks. A total of 117 (19%) of the 610 study children died during follow-up. In a multivariate model, child plasma selenium levels were inversely associated with risk of all-cause mortality (P-value, test for trend=0.05). Plasma selenium levels were not significantly associated with risk of diarrhea or respiratory outcomes.

CONCLUSIONS

Among infants born to HIV-infected women in sub-Saharan Africa, selenium status may be important to prevent child mortality. These preliminary findings warrant future reexamination.

Low serum selenium and total carotenoids predict mortality among older women living in the community: the women's health and aging studies

Selenium and the carotenoids play an important role in antioxidant defenses and in the redox regulation involved in inflammation. We tested the hypothesis that low selenium and carotenoids predict mortality in older women living in the community. Women who were enrolled in the Women's Health and Aging Studies I and II in Baltimore, MD (n = 632; 70-79 y old) had serum selenium and carotenoids measured at baseline and were followed for mortality over 60 mo. Median (minimum, maximum) serum selenium and carotenoids were 1.53 (0.73, 2.51) micromol/L and 1.67 (0.13, 9.10) micromol/L; 14.1% of the women died. The 5 major causes of death were heart disease (32.6%), cancer (18.0%), stroke (9.0%), infection (6.7%), and chronic obstructive pulmonary disease (5.6%). Adjusting for age, education, smoking, BMI, poor appetite, and chronic diseases, higher serum selenium [hazard ratio (HR) 0.71, 95% CI 0.56-0.90/1 SD increase in log(e) selenium; P = 0.005] and higher serum total carotenoids (HR 0.77, 95% CI 0.64-0.84/1 SD increase in log(e) total carotenoids; P = 0.009) were associated with a lower risk of mortality. Women living in the community who have higher serum selenium and carotenoids are at a lower risk of death.

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.

Studies of vitamins and minerals and HIV transmission and disease progression

HIV-1 infection is having a devastating impact on people in developing countries. Poor nutrition and HIV-related adverse health outcomes contribute to a vicious cycle that may be slowed down by using nutritional interventions, including vitamins and minerals. Among children, periodic supplementation with vitamin A starting at 6 mo of age has been shown to be beneficial in reducing mortality and morbidity among both HIV-infected and uninfected children. Limited data exist on the role of other nutrient supplements among children. Among HIV-infected adults, the safety and the efficacy of vitamin A supplements need further study, although adequate dietary intake of this essential nutrient is recommended. Multivitamin supplements were efficacious in reducing adverse pregnancy outcomes and early childhood infections, and is currently provided to pregnant HIV-infected pregnant women in many programs. The efficacy of such supplements among HIV-negative pregnant women needs further study. Daily multivitamin supplements were found to reduce HIV disease progression among men and women in several observational studies and randomized trials, and to provide an important low-cost intervention that could be provided to adults in early stages of HIV disease to prolong the time before antiretroviral therapy is recommended. Next, research priorities include examining the roles of minerals, including selenium, in HIV infection, as well as determining the safety and the efficacy of micronutrient supplements among individuals who are advanced in their disease and who are receiving antiretroviral therapy.

How HIV-1 causes AIDS: implications for prevention and treatment

HIV-1 encodes for one of the human glutathione peroxidases. As a consequence, as it is replicated, its genetic needs cause it to deprive HIV-1 seropositive individuals not only of glutathione peroxidase, but also of the four basic components of this selenoenzyme, namely selenium, cysteine, glutamine, and tryptophan. Eventually this depletion process causes severe deficiencies of all these substances. These, in turn, are responsible for the major symptoms of AIDS which include immune system collapse, greater susceptibility to cancer and myocardial infarction, muscle wasting, depression, diarrhea, psychosis and dementia. As the immune system fails, associated pathogenic cofactors become responsible for a variety of their own unique symptoms. Any treatment for HIV/AIDS must, therefore, include normalization of body levels of glutathione, glutathione peroxidase, selenium, cysteine, glutamine, and tryptophan. Although various clinical trials have improved the health of AIDS patients by correcting one or more of these nutritional deficiencies, they have not, until the present, been addressed together. Physicians involved in a selenium and amino-acid field trial in Botswana, however, are reporting that this nutritional protocol reverses AIDS in 99% of patients receiving it, usually within three weeks.

Oxidative stress in viral hepatitis and AIDS

Dominant types of viral hepatitis are presently A, B, and C with prophylactic immunization available only for A and B. Hepatitis B and C and human immunodeficiency virus (HIV) infection constitute a worldwide scourge and treatment is far from satisfactory. Each produces severe oxidative stress (OS) and secondary cellular damage of varying severity and, as in toxic hepatitis, progression and regression are dependent on redox balance between oxidation and antioxidation. Experimental and clinical studies suggest that xenobiotics and co-infections exert cumulative, detrimental effects on their pathogeneses and further deplete antioxidants. It is proposed therefore that in the clinical management of these infections and especially in their early stages, considerable benefit should accrue from antioxidant repletion at dosages substantially above recommended daily allowances (RDAs) in conjunction with a nutritious high protein diet. Because plasma zinc and selenium concentrations are very low, their replenishment by high dosages is urgent and mandatory particularly in advanced HIV infections bordering on acrodermatitis enteropathica. Also recommended is their long-term continuance at high normal levels.

Selenium status is associated with accelerated HIV disease progression among HIV-1-infected pregnant women in Tanzania

Selenium deficiency has been implicated in accelerated disease progression and poorer survival among populations infected with HIV in developed countries, yet these associations remain unexamined in developing countries. Among 949 HIV-1-infected Tanzanian women who were pregnant, we prospectively examined the association between plasma selenium levels and survival and CD4 counts over time. Over the 5.7-y median follow-up time, 306 of 949 women died. In a Cox multivariate model, lower plasma selenium levels were significantly associated with an increased risk of mortality (P-value, test for trend = 0.01). Each 0.1 micromol/L increase in plasma selenium levels was related to a 5% (95% CI = 0%-9%) decreased risk of mortality. Plasma selenium levels were not associated with time to progression to CD4 cell count < 200 cells/mm(3) but were weakly and positively related to CD4 cell count in the first years of follow up. Selenium status may be important for clinical outcomes related to HIV disease in sub-Saharan Africa.

Selenoproteins, Cholesterol-Lowering Drugs, and the Consequences Revisiting of the Mevalonate Pathway

3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) and peroxisome proliferator-activated receptor alpha activators (fibrates) are the backbone of pharmacologic hypercholesterolemia and dyslipidemia treatment. Many of their clinical effects, however, are still enigmatic. This article describes how a side road of the mevalonate pathway, characterized in recent years, can rationalize a major fraction of these unexplained observations. This side road is the enzymatic isopentenylation of selenocysteine-tRNA([Ser]Sec) (Sec-tRNA), the singular tRNA to decode the unusual amino acid selenocysteine. The functionally indispensable isopentenylation of Sec-tRNA requires a unique intermediate from the mevalonate pathway, isopentenyl pyrophosphate, which concomitantly constitutes the central building block for cholesterol biosynthesis, and whose formation is suppressed by statins and fibrates. The resultant inhibition of Sec-tRNA isopentenylation profoundly decreases selenoprotein expression. This effect might seamlessly explain the immunosuppressive, redox, endothelial, sympatholytic, and thyroidal effects of statins and fibrates as well as their common side effects and drug interactions.

HIV-infected children with moderate/severe immune-suppression: changes in the immune system after highly active antiretroviral therapy

The objective of this study was to monitor the changes in the immune system of HIV-infected children with moderate or severe immunodeficiency after highly active antiretroviral therapy (HAART), comprising a follow-up study in 14 HIV-infected children on HAART at two time points separated approximately by 11.8 +/- 0.4 (9.9; 15.4) months. HIV-infected children had significantly lower TREC levels than the control group, but 1 year after HAART the levels increased significantly (P < 0.05). In contrast, viral load (VL) did not change significantly. A positive correlation between T cell receptor excision circle (TREC) levels and both CD4(+) T cell absolute counts (r = 0.558; P = 0.05) and percentages (r = 0.625; P = 0.030) was found. During follow-up on HAART, the percentages and absolute counts of naive CD4(+) and CD8(+) T cell subsets were increased significantly (P < 0.05). CD4(+) CD45RA(hi+) CD62L(+), CD4(+) CD45RA(+) and CD4(+) CD38(+) percentages, and the CD8(+) CD45RA(hi+) CD62L(+) counts reached similar values to the control group. Also, CD8(+) CD45RO(+) CD38(+) and CD8(+) CD45RO(+) percentages, and CD8(+) CD45RO(+) CD38(+) absolute counts (P < 0.05) decreased with respect to the baseline. Lymphoproliferative responses to pokeweed mitogen (PWM) before HAART were lower in HIV-infected children than the control group, but they recovered to normal levels after a year on HAART. Tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma production by PHA-activated peripheral blood mononuclear cells (PBMC) was lower before HAART (P < 0.001), but reached similar levels to the control group 1 year after HAART. In HIV-infected children IgG, IgG(1) and IgG(3) plasma levels decreased significantly after HAART. The immune system reconstitution induced by HAART in HIV-infected children seems to be the consequence of decreased immune system activation and naive T cell reconstitution, mainly of thymic origin.

Assessment of requirements for selenium and adequacy of selenium status: a review

OBJECTIVE

The intent of this review is to evaluate the scientific evidence for the assessment of adequacy of selenium status and of the requirements for selenium. From this evidence, attempts have been made to define levels of plasma selenium and dietary selenium intake, which could be used for the assessment of deficiency or adequacy of selenium status.

METHOD

The first section briefly reviews the methods for assessment of selenium status. The second section outlines the requirements for selenium based on a number of criteria, and how these have been translated into recommended intakes of selenium. In the final section, levels of plasma selenium and dietary intake based on different criteria of adequacy have been proposed.

RESULTS AND CONCLUSION

The minimum requirement for selenium is that which prevents the deficiency disease, Keshan disease. The recommended intakes of selenium have been calculated from the requirement for optimum plasma glutathione peroxidase (GPx) activity that must, because of the hierarchy of selenoproteins, also take account of the amounts needed for normal levels of other biologically necessary selenium compounds. Whether optimal health depends upon maximization of GPx or other selenoproteins, however, has yet to be resolved, and the consequences of less-than-maximal GPx activities or mRNA levels need investigation. Intakes, higher than recommended intakes, and plasma selenium concentrations that might be protective for cancer or result in other additional health benefits have been proposed. There is an urgent need for more large-scale trials to assess any such beneficial effects and to provide further data on which to base more reliable estimates for intakes and plasma selenium levels that are protective.

A clinical review of micronutrients in HIV infection

This article reviews current literature on the role of micronutrients in human immunodeficiency virus (HIV) infection. Deficiencies of micronutrients are common in HIV-infected persons. They occur due to malabsorption, altered metabolism, gut infection, and altered gut barrier function. There is a compelling association of deficiencies of micronutrients in HIV-infection with immune deficiency, rapid disease progression, and mortality. Also, there is increased risk of vertical HIV transmission from mother to child with deficiency of vitamin A, and of neurological impairment with vitamin B12. The last five years have been exciting in micronutrient research, and there is promise that some micronutrients may be key factors in maintaining health in HIV immunodeficiency, and in reducing mortality. Selenium appears important in reducing virulence of HIV and slowing disease progression. Vitamin A supplementation in pregnant women with HIV may reduce maternal mortality and improve birth outcomes. Supplementation in children with HIV may accelerate growth. Carotenoid supplementation is being evaluated. Vitamin B12 may slow HIV immune deficiency disease progression, and reverse neurological compromise. Clinical benefit of supplementation with some micronutrients may be measurable in the presence of pre-existing deficiency. Apart from improved general nutrition, the impact of micronutrient supplements on health and their optimal use in HIV infection is controversial because there are so few controlled clinical trials. Further research is needed to elucidate the role of micronutrient deficiencies on the course of HIV infection, and the preventive and therapeutic role of supplementation in its clinical management. Nevertheless, current knowledge supports the use of routine multivitamin and trace element supplementation as adjuvant to conventional antiretroviral drug treatment as a relatively low-cost intervention.

Viral Load and CD4+ T Lymphocyte Response to Highly Active Antiretroviral Therapy in Human Immunodeficiency Virus Type 1-Infected Children: An Observational Study

An observational study was performed involving 95 children with vertically transmitted human immunodeficiency virus type 1 infection to assess the sustainability of undetectable viral loads (VLs) and increased CD4+ T lymphocyte percentages after 48 months of highly active antiretroviral therapy (HAART). The median time to achieve a 10% increase in the CD4+ T lymphocyte percentage was 11.01 months. The median time to achieve an undetectable VL was 6.4 months. At the end of the study, 64.2% of the children had achieved an undetectable VL. Of the patients with an initial VL of >3.6 log10 copies/mL, 74.7% had a decrease in the VL of 1 log10 copies/mL. By contrast, of the patients who presented with an initial VL of >4.6 log10 copies/mL, 37.9% had a decrease of >2 log10 copies/mL. Higher VL at baseline, antiretroviral therapy regimens received before HAART, and multiple drug switches while receiving antiretroviral therapy were all inversely associated with an undetectable VL. A CD4+ T lymphocyte percentage of >25% was directly associated with undetectable VL during the follow-up period. In conclusion, first-line HAART induces beneficial virological and immunological outcome responses in children.

Skeletal muscle disorders associated with selenium deficiency in humans

Skeletal muscle disorders manifested by muscle pain, fatigue, proximal weakness, and serum creatine kinase (CK) elevation have been reported in patients with selenium deficiency. The object of this report was to review the conditions in which selenium deficiency is associated with human skeletal muscle disorders and to evaluate the importance of mitochondrial alterations in these disorders. A systematic literature review using the Medline database and Cochrane Library provided 38 relevant articles. The main conditions associated with selenium deficiency fell into three categories: (1) insufficient selenium intake in low soil-selenium areas; (2) parenteral or enteral nutrition, or malabsorption; and (3) chronic conditions associated with oxidative stress, such as chronic alcohol abuse and human immunodeficiency virus (HIV) infection. In low soil-selenium areas, reversibility of muscle symptoms was similar after selenium supplementation and placebo administration, suggesting a role for other factors in the development of disease. In parenteral or enteral nutrition, or malabsorption, muscle symptoms improved after selenium supplementation in 18 of 19 patients (median delay: 4 weeks). The reason that only a minority of selenium-deficient patients present with skeletal muscle disorders is unclear and is possibly related to cofactors, such as viral infections and drugs. Prospective studies of selenium-deficient myopathies would be useful in critically ill patients, alcohol abusers, and HIV-infected patients.

Pattern and predictors of weight gain during pregnancy among HIV-1-infected women from Tanzania

Progression of HIV disease is often accompanied by weight loss and wasting. Gestational weight gain is a strong determinant of maternal and neonatal outcomes; however, the pattern and predictors of weight gain during pregnancy among HIV-positive women are unknown. We obtained monthly anthropometric measurements in a cohort of 957 pregnant women from Tanzania who were HIV infected. We estimated the weekly rate of weight gain at various points during the second and third trimesters of pregnancy and computed rate differences between levels of sociodemographic, nutritional, immunologic, and parasitic variables at the first prenatal visit. The change in mid-upper arm circumference (MUAC) from baseline to delivery was also examined. The rate of weight gain decreased progressively during pregnancy. There was an average decline of 1 cm in MUAC between weeks 12 and 38. Lower level of education and helminthic infections at first visit were associated with decreased adjusted rates of weight gain during the third trimester. High baseline MUAC, not contributing to household income, lower serum retinol and selenium concentrations, advanced clinical stage of HIV disease, and malaria infection were related to decreased rates of weight gain during the second trimester. Low baseline CD4 T-cell counts were related to a poorer pattern of weight gain throughout pregnancy. Prevention and treatment of parasitic infections and improvement of nutritional status are likely to enhance the pattern of gestational weight gain among HIV-infected women.

Assessment of nutritional status, body composition, and human immunodeficiency virus-associated morphologic changes

Nutritional status should be assessed at regular intervals as part of management of human immunodeficiency virus (HIV) infection. The simplest approach to assessment is serial weight measurement. A comprehensive nutritional assessment includes (1) anthropometric measurements of body composition; (2) biochemical measurements of serum protein, micronutrients, and metabolic parameters; (3) clinical assessment of altered nutritional requirements and social or psychological issues that may preclude adequate intake; and (4) measurement of dietary intake. Techniques for measuring body composition of fat and lean body mass include anthropometry and bioelectric impedance analysis. Other techniques, including dual X-ray absorptiometry (DXA), hydrodensitometry, total body potassium measurement, and cross-sectional computed tomography or magnetic resonance imaging are available in research centers. Anthropometry, including waist-hip ratios, regional DXA, and cross-sectional imaging, is best for detecting morphologic changes associated with fat redistribution syndrome. Nutritional assessment and intervention in children with HIV can help to prevent stunted growth and development.

General nutrition management in patients infected with human immunodeficiency virus

Nutritional management is integral to the care of all patients infected with human immunodeficiency virus (HIV). HIV infection results in complicated nutritional issues for patients, and there is growing evidence that nutritional interventions influence health outcomes in HIV-infected patients. We define levels of nutritional care, and we discuss when patients should be referred to providers (i.e., registered dietitians) with nutritional and HIV expertise.

Impact of a selenium chemoprevention clinical trial on hospital admissions of HIV-infected participants

PURPOSE

To evaluate the impact of selenium chemoprevention (200 microg/day) on hospitalizations in HIV-positive individuals.

METHOD

Data were obtained from 186 HIV+ men and women participating in a randomized, double-blind, placebo-controlled selenium clinical trial (1998-2000). Supplements were dispensed monthly, and clinical evaluations were conducted every 6 months. Inpatient hospitalizations, hospitalization costs, and rates of hospitalization were determined 2 years before and during the trial.

RESULTS

At enrollment, no significant differences in CD4 cell counts or viral burden were observed between the two study arms. Fewer placebo-treated participants were using antiretrovirals (p <.05). The total number of hospitalizations declined from 157 before the trial to 103 during the 2 year study. A marked decrease in total admission rates (RR = 0.38; p =.002) and percent of hospitalizations due to infection/100 patients for those receiving selenium was observed (p =.01). As a result, the cost for hospitalization decreased 58% in the selenium group, compared to a 30% decrease in the placebo group (p =.001). In the final analyses, selenium therapy continued to be a significant independent factor associated with lower risk of hospitalization (p =.001).

CONCLUSION

Selenium supplementation appears to be a beneficial adjuvant treatment to decrease hospitalizations as well as the cost of caring for HIV-1-infected patients.

The argument for increasing selenium intake

The essential trace mineral, Se, is of fundamental importance to human health. As a constituent of selenoproteins it plays both structural and enzymic roles, in the latter context being best known as an antioxidant and catalyst for the production of active thyroid hormone. While Se-deficiency diseases have been recognised for some time, evidence is mounting that less-overt deficiency can also cause adverse health effects and furthermore, that supra-nutritional levels of Se may give additional protection from disease. In the context of these effects, low or diminishing Se status in some parts of the world, notably in some European countries such as the UK, is giving cause for concern. While deficiency has an adverse effect on immunocompetence, Se supplementation appears to enhance the immune response. Se appears to be a key nutrient in counteracting certain viral infections; thus, in a Se-deficient host the benign coxsackie virus becomes virulent, causing heart damage, the influenza virus causes more serious lung pathology and HIV infection progresses more rapidly to AIDS. Long recognised as essential for successful animal reproduction, Se is required for human sperm maturation and sperm motility and may reduce the risk of miscarriage. Deficiency has been linked to adverse mood states. Findings have been equivocal in linking Se to cardiovascular disease risk, although other conditions involving oxidative stress and inflammation have shown some association with Se status. There is growing evidence that higher Se intakes are associated with reduced cancer risk. While persuasive evidence already exists to suggest that additional Se would be beneficial in some health conditions, results from intervention trials underway or planned have the potential to reinforce or refute the argument for increasing Se intake.

The role of nutrition in pediatric HIV/AIDS: a review of micronutrient research

It is becoming increasingly evident that nutrition is not only an important component of health but also that levels of specific nutrients can affect disease expression. This is particularly apparent in the realm of HIV disease. Despite this knowledge, research in this area, especially pertaining to the pediatric population, has been limited. This report presents a narrative review and critique of the work that has been conducted in the area of micronutrients including descriptive, correlational, and intervention studies. Gaps in knowledge, recommendations for future research, and nursing implications are highlighted. Current information suggests a role for micronutrients in the treatment of HIV disease, and further research will help develop these adjunct therapies that can affect the overall outcomes and quality of life of these patients.

Selenium deficiency is associated with shedding of HIV-1--infected cells in the female genital tract

OBJECTIVE

To assess the relation between selenium deficiency and vaginal or cervical shedding of HIV-1-infected cells.

DESIGN

Cross-sectional study of 318 HIV-1 seropositive women in Mombasa, Kenya.

METHODS

Vaginal and cervical swab specimens were tested for the presence of HIV-1 DNA by polymerase chain reaction. Multivariate logistic regression models, adjusting for CD4 count and vitamin A deficiency, were used.

RESULTS

Selenium deficiency (defined as levels <85 microg/L) was observed in 11% of the study population. In unstratified multivariate analyses, there was no significant association between selenium deficiency and vaginal or cervical shedding. In stratified analyses, however, significant associations became apparent after excluding women with predictors of shedding with strong local effects on the genital tract mucosa. Among women who did not use oral contraceptives and who did not have vaginal candidiasis, selenium deficiency was significantly associated with vaginal shedding (adjusted odds ratio [AOR] 2.9, 95% confidence interval [CI] 1.0--8.8, p =.05). Effect modification was also observed in the relation between selenium deficiency and cervical shedding, with a significant association seen among those women who were not using oral contraceptive pills or depot medroxyprogesterone acetate and who did not have Neisseria gonorrhoeae infection (AOR 2.8, 95% CI 1.1--7.0, p =.02).

CONCLUSIONS

We found selenium deficiency to be associated with a nearly threefold higher likelihood of genital mucosal shedding of HIV-1--infected cells, suggesting that deficiency may increase the infectiousness of women with HIV-1. Nutritional interventions to prevent HIV-1 transmission warrant investigation.

Role of micronutrients in HIV-infected intravenous drug users

Nutritional deficiencies are widespread among HIV-1-seropositive male and female drug abusers (injecting drug users, or IDUs), among men who have sex with men (MSM), and among children, although the prevalence of nutritional alterations varies among the groups. Low levels of vitamin A, vitamin B12, zinc, and selenium are common and have been demonstrated to be associated with disease progression and HIV-1 related mortality, independent of CD4 count <200 cells/mm3 at baseline and CD4 count over time. When all nutrient factors that are associated with survival are considered together, only selenium deficiency is a significant predictor of mortality. The profound effect of selenium on disease progression may reflect selenium's action in antioxidant defense systems, as well as gene regulation.

HIV-1-Associated Cognitive-Motor Disorders: A Research-Based Approach to Diagnosis and Treatment

The diagnosis of human immunodeficiency virus type 1 (HIV-1)-associated cognitive-motor disorder--either minor cognitive-motor disorder (MCMD) or HIV-1-associated dementia (HAD)--is fraught with potential pitfalls for the clinician. Before making such a diagnosis, clinicians should exclude other etiologies by using neuroimaging, lumbar puncture, and serum chemistries to screen for opportunistic and non-opportunistic infections of the brain and meninges. Clinicians should also consider psychoneurotoxicity (caused from the use of psychoactive substances and prescribed medications) and psychopathology, such as mood, anxiety, and other disorders. In addition, a thorough medical history and physical examination, including a complete neurologic and neuropsychiatric mental status examination, are necessary for an accurate diagnosis. There is also a need for standardized neuropsychological and functional status tests, since the diagnostic criteria for these disorders are partly based on these criteria. Treatment targets should include subclinical cognitive-motor impairment and neuroprotection, as well as MCMD and HAD. Currently, zidovudine remains the best proven treatment for these disorders, but other nucleoside reverse transcriptase inhibitors, as well as nonnucleoside reverse transcriptase inhibitors and protease inhibitors, show promise, and selected agents from these classes are being tested in clinical trials. Other areas that should be investigated are the modulation of inflammatory mediators (such as tumor necrosis factor alpha), neurotransmitter manipulation (especially of dopamine), and nutritional interventions.

The importance of selenium to human health

The essential trace mineral, selenium, is of fundamental importance to human health. As a constituent of selenoproteins, selenium has structural and enzymic roles, in the latter context being best-known as an antioxidant and catalyst for the production of active thyroid hormone. Selenium is needed for the proper functioning of the immune system, and appears to be a key nutrient in counteracting the development of virulence and inhibiting HIV progression to AIDS. It is required for sperm motility and may reduce the risk of miscarriage. Deficiency has been linked to adverse mood states. Findings have been equivocal in linking selenium to cardiovascular disease risk although other conditions involving oxidative stress and inflammation have shown benefits of a higher selenium status. An elevated selenium intake may be associated with reduced cancer risk. Large clinical trials are now planned to confirm or refute this hypothesis. In the context of these health effects, low or diminishing selenium status in some parts of the world, notably in some European countries, is giving cause for concern.

Nutritional Contributions to the CNS Pathophysiology of HIV-1 Infection and Implications for Treatment

Nutritional deficiencies are commonplace in patients with human immunodeficiency virus type 1 (HIV-1) infection, and recent research has indicated that nutritional factors may play an important role in the pathogenesis of HIV-1 disease. Although nutritional deficiencies are unlikely to be the primary causative factor in disease progression, they may contribute to cognitive dysfunction, neurologic abnormalities, mood disturbance, and immune dysregulation associated with HIV-1 infection. Furthermore, deficiencies of specific micronutrients have been associated with increased risk of HIV-1-associated mortality. This article will briefly summarize the role of macronutrient deficiency, the interactions of specific micronutrient deficiencies with neuropsychiatric functioning, and the role of these factors in HIV-1 disease progression. Since recent research has shown that normalization of many nutritional deficits and supplementation beyond normal levels are associated with improvements in neuropsychiatric functioning, potential treatment implications will also be discussed.