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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To study the determinants of CD4% and CD4 counts among HIV-negative Ethiopians, and to identify factors susceptible to explain the low CD4 counts observed among Ethiopian subjects. Cohort studies among factory workers in Akaki and Wonji, Ethiopia. Clinical and laboratory examinations, including determination of HIV serological status and T-cell subsets, were performed during follow-up visits every six months. In addition, micronutrients (retinol, carotenoids, tocopherol, transferrin receptor, and selenium) plasma concentrations were determined in a subset of 38 HIV-positive and 121 HIV-negative participants. HIV-negative participants with at least one CD4 count measurement were 157 females in Akaki, 203 males in Akaki, and 712 males in Wonji. CD4 counts were independently and positively associated with body mass index (through an increase in lymphocyte counts), female gender (through an increase in CD4%), cigarette smoking (through an increase in CD4%), khat chewing (through an increase in both lymphocyte counts and CD4%), and Akaki study site (through a large increase in lymphocyte counts compensating a decrease in CD4%). Intestinal parasitic infections were not associated with CD4% or CD4 counts. Retinol, carotenoids, and alpha-tocopherol plasma concentrations decreased with HIV infection and advancing immunosuppression, but were not associated with CD4 counts among HIV-negative subjects. Low body mass index among Ethiopians may have contributed to their overall low CD4 counts. Other factors remain to be elucidated.
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PMID:Determinants of CD4 counts among HIV-negative Ethiopians: role of body mass index, gender, cigarette smoking, khat (Catha Edulis) chewing, and possibly altitude? 1582 89

BACKGROUND: Observational studies have suggested that low serum vitamin levels are associated with increased mother-to-child transmission (MTCT) of HIV and increased preterm delivery. We aimed to determine the efficacy of vitamins on the prevention of MTCT and preterm delivery by systematically reviewing the available randomized controlled trials [RCTs]. We conducted systematic searches of 7 electronic databases. We extracted data from the RCTs independently, in duplicate. RESULTS: We included 4 trials in our review. Of the three trials on Vitamin A, two suggested no difference in MTCT, while the third and largest trial (n = 1078) suggested an increased risk of MTCT (Relative Risk 1.35, 95% Confidence Interval [CI], 1.11-1.66, P = 0.009). Two of the vitamin A trials addressed the impact of supplementation on pre-term delivery; one suggested a benefit (RR 0.65, 95% CI, 0.44-0.94) and the other no difference. All three vitamin A trials found no significant effect on infant mortality at 1 year. Of the two trials that looked at multivitamin use, only one addressed the prevention of MTCT, and found a non-significant RR of 1.04 (95% CI, 0.82-1.32). Two of the multivitamin trials found no significant effects on pre-term delivery. The single multivitamin trial examining children's mortality at 1 year yielded a non-significant RR of 0.91 (95% CI, 0.17-1.17). CONCLUSION: Randomized trials of vitamins to prevent MTCT have yielded conflicting results without strong evidence of benefit and have failed to exclude the possibility of harm.
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PMID:Vitamin supplementation for prevention of mother-to-child transmission of HIV and pre-term delivery: a systematic review of randomized trial including more than 2800 women. 1587 18

An estimated 25 million lives have been lost to acquired immune-deficiency syndrome (AIDS) since the immunodeficiency syndrome was first described in 1981. The progress made in the field of treatment in the form of antiretroviral therapy (ART) for HIV disease/AIDS has prolonged as well as improved the quality of life of HIV-infected individuals. However, access to such treatment remains a major concern in most parts of the world, especially in the developing countries. Hence, there is a constant need to find low-cost interventions to complement the role of ART in prevention of HIV infection and slowing clinical disease progression. Nutritional interventions, particularly vitamin supplementation, have the potential to be a low-cost method for being such an intervention by virtue of their modulation of the immune system. Among all the vitamins, the role of vitamin A has been studied most extensively; most observational studies have found that low vitamin A levels are associated with increased risk of transmission of HIV from mother to child. This finding has not been supported by large randomized trials of vitamin A supplementation; on the contrary, these trials have found that vitamin A supplementation increases the risk of mother-to-child transmission (MTCT). There are a number of potential mechanisms that might explain these contradictory findings. One is the issue of reverse causality in observational studies-for instance, advanced HIV disease may suppress release of vitamin A from the liver. This would lead to low levels of vitamin A in the plasma despite the body having enough vitamin A liver stores. Further, advanced HIV disease is likely to increase the risk of MTCT, and hence it would appear that low serum vitamin A levels are associated with increased MTCT. The HIV genome also has a retinoic acid receptor element-hence, vitamin A may increase HIV replication via interacting with this element, thus increasing risk of MTCT. Finally, vitamin A is known to increase lymphoid cell differentiation, which leads to an increase in CCR5 receptors. These receptors are essential for attachment of HIV to the lymphocytes and therefore, an increase in their number is likely to increase HIV replication. Vitamin A supplementation in HIV-infected children, on the other hand, has been associated with protective effects against mortality and morbidity, similar to that seen in HIV-negative children. The risk for lower respiratory tract infection and severe watery diarrhea has been shown to be lower in HIV-infected children supplemented with vitamin A. All-cause mortality and AIDS-related deaths have also been found to be lower in vitamin A-supplemented HIV-infected children. The benefits of multivitamin supplementation, particularly vitamins B, C, and E, have been more consistent across studies. Multivitamin supplementation in HIV-infected pregnant mothers has been shown to reduce the incidence of adverse pregnancy outcomes such as fetal loss and low birth weight. It also has been shown to decrease rates of MTCT among women who have poor nutritional or immunologic status. Further, multivitamin supplementation reduces the rate of HIV disease progression among patients in early stage of disease, thus delaying the need for ART by prolonging the pre-ART stage. In brief, there is no evidence to recommend vitamin A supplementation of HIV-infected pregnant women; however, periodic vitamin A supplementation of HIV-infected infants and children is beneficial in reducing all-cause mortality and morbidity and is recommended. Similarly, multivitamin supplementation of people infected with HIV, particularly pregnant women, is strongly suggested.
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PMID:Effects of vitamins, including vitamin A, on HIV/AIDS patients. 1736 22

Vitamin A deficiency has been commonly observed in patients with tuberculosis. Low serum retinol levels return to normal after antituberculosis treatment even when no supplements are provided. The deficiency of vitamin A observed in patients with tuberculosis might have contributed to the development of tuberculous disease in them. Alternatively, deficiency could be the result of loss of appetite, poor intestinal absorption, increased urinary loss of vitamin A or acute phase reaction in TB. Vitamin A deficiency lowers immunity while vitamin A supplementation reduces morbidity and mortality, particularly from measles and diarrhoea. Vitamin A supplementation also decreases the mortality rate in HIV-infected children and delays the progression of HIV disease in infected subjects. A higher incidence of lung cancer and increased mortality have been observed in smokers after beta-carotene supplementation. Zinc deficiency is also common in tuberculosis, which may impose a secondary vitamin A deficiency. Clinical trials have shown conflicting results regarding the effect of supplementation of vitamin A, alone or with other micronutrients, on time taken to sputum conversion in patients with pulmonary tuberculosis. Supplementation with multiple micronutrients (including zinc) rather than vitamin A alone may be more beneficial in patients with tuberculosis, but clinical trials on such a combination are lacking.
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PMID:Role of vitamin A supplementation in the treatment of tuberculosis. 1755 17

Humans have evolved complex immune systems to protect against infection by pathogens. However, pathogens possess a remarkable genetic versatility that allows them to gain new vigour and so escape such population immunity. Conflicting pathogen-host objectives, therefore, lead to the evolutionary equivalent of an "arms race". Typically, in this struggle, pathogens attempt to deplete their host of specific nutrients that are essential for immune system function. After infection, the resulting deficiency of nutrient(s) may cause many of the disease symptoms and sequela. In malaria, Plasmodium falciparum, for example, depletes its host of Vitamin A, possibly resulting in blindness in some cases. However, 200,000 International Units of Vitamin A, given to children every three months can reduce significantly their susceptibility to malaria. This would seem to be a minimum child dosage for the treatment of the disease. In contrast, the Coxsackie B virus causes a selenium deficiency that may result in myocardial infarction or Keshan disease. However, table salt fortified with 15ppm anhydrous sodium selenite can cause dramatic drops in the incidence of Keshan disease, while selenium supplementation also reduces re-infarction rates. HIV-1 depletes its host of four nutrients: selenium, cysteine, glutamine and tryptophan, resulting in symptoms known as AIDS. Open and closed clinical trials in South Africa, Zambia and Uganda, involving daily adult doses of 600mcg l-selenomethione, and some 500mg l-glutamine, hydroxytryptophan and N-acetyl cysteine, however, have shown that such supplementation can reverse the symptoms of AIDS and prevent HIV-1 infected patients declining into this disease. It is obvious, therefore, that supplementation of diet with specific nutrients can reduce infection by particular pathogens. In addition, if infection still occurs, their use as a treatment may prevent many of the symptoms and sequela commonly associated with diseases such as malaria, myocardial infarction and AIDS.
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PMID:Host-pathogen evolution: Implications for the prevention and treatment of malaria, myocardial infarction and AIDS. 1759 May 22

The aim of this article was to collect the results of systematic reviews and meta-analyses that evaluated the effect of vitamin A supplementation on child growth and maternal, fetal, and child morbidity and mortality. A detailed search was performed in PubMed, Cochrane Library, LILACS, PAHO, CAPES, USP Digital Thesis Library, and UNIFESP Collection Database. A total of 14 studies published from 1993 to 2006 were included in the review. There is evidence that vitamin A supplementation in children is associated with a reduction of 23% to 30% in mortality risk and attenuation in the severity of measles and diarrhea. There is no evidence of the intervention's impact on pneumonia incidence or mortality in children without measles. Vitamin A also appears to be protective in children and pregnant women with HIV/AIDS, with a positive effect on child morbidity and mortality and birth weight. There is no evidence that supplementation in pregnant and lactating women reduces infant morbidity and mortality, but there is an indication that vitamin A protects against maternal morbidity.
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PMID:[Evidence of the impact of vitamin A supplementation on maternal and child health]. 1795 49

Vitamin A supplementation starting at 6 months of age is an important child survival intervention; however, not much is known about the association between vitamin A status before 6 months and mortality among children born to HIV-infected women. Plasma concentrations of vitamins A and B-12 were available at 6 weeks of age (n = 576 and 529, respectively) for children born to HIV-infected women and they were followed up for morbidity and survival status until 24 months after birth. Children in the highest quartile of vitamin A had a 49% lower risk of death by 24 months of age compared to the lowest quartile (HR: 0.51, 95% CI: 0.29-0.90; P-value for trend = 0.01). Higher vitamin A levels were protective in the sub-groups of HIV-infected and un-infected children but this was statistically significant only in the HIV-uninfected subgroup. Higher vitamin A concentrations in plasma are protective against mortality in children born to HIV-infected women.
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PMID:Vitamin A and vitamin B-12 concentrations in relation to mortality and morbidity among children born to HIV-infected women. 1950 99

The human immunodeficiency virus type 1 (HIV-1) transgenic (Tg) rat model incorporates a noninfectious viral genome that is under similar regulatory control mechanisms in vivo as those that exist with natural infection in humans. Vitamin A (VA) deficiency in humans has been associated with progressive systemic HIV disease and with impaired cognition in rodent models. The effects on of VA deficiency on the development of behavioral abnormalities with HIV infection have not been previously described. In these studies, wild-type (Wt) and Tg rats maintained on either a normal (VA+) or a VA-deficient (VA-) diet were examined for activity in an open field (horizontal activity, total distance, vertical activity, and rearing) and on rotarod testing. On both open field and rotarod testing, the Tg rats performed worse than the Wt rats, with the most severe deficits noted in the TgVA- animals. Analysis of the specific effects of the presence of the HIV transgene and the diet on the performance on the open field tests showed a dominant effect from the transgene on all of the tests, with an effect from the diet on only the number of rearings. On rotarod testing, effects form both the diet and the transgene were observed at lower speeds, at the highest speeds, and on the accelerating rotarod. These studies therefore demonstrate that behavioral and motor abnormalities can be detected in this model and are likely due to similar mechanisms by which humans infected with HIV might develop cognitive-motor impairment in association with VA deficiency.
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PMID:Vitamin A deficiency and behavioral and motor deficits in the human immunodeficiency virus type 1 transgenic rat. 1999 29

Vitamin A (VA) deficiency in human immunodeficiency virus (HIV) infection has been associated with more progressive HIV disease, which may be enhanced by opioid use. In these studies, we examined the effects of VA deficiency and morphine on frontal cortex neuronal numbers in the HIV-1 transgenic (Tg) rat. These studies showed that total numbers of neurons were similar for rats on the VA-deficient diet as for rats on the normal diet and these numbers were not affected by treatment with morphine. In contrast, numbers of neurons that expressed the calcium-binding protein parvalbumin, which is a marker interneurons that express the inhibitory neurotransmitter gamma-aminobutyric acid (GABAergic neurons) were decreased for wild-type (Wt) rats on the VA-deficient diet and for Wt rats treated with morphine. In addition, parvalbumin+ neurons were also decreased for Tg rats on a normal diet but increased to normal levels when these animals were placed on the VA-deficient diet and treated with morphine. Analysis of expression of the genes that code for the HIV regulatory proteins vif, vpr, nef, and tat in frontal cortex and adjacent subcortical white matter showed that tat expression was increased in the morphine-treated Tg rat on the VA-deficient diet as compared to untreated Tg rats on the normal diet and untreated VA-deficient rats. These studies therefore suggest that VA deficiency, opioid exposure, and HIV infection alone and in combination may potentially alter neuronal metabolic activity and induce cellular stress, resulting in the observed changes in levels of parvalbumin expression. The specific mechanisms that underlie these effects require further study.
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PMID:Quantitation of parvalbumin+ neurons and human immunodeficiency virus type 1 (HIV-1) regulatory gene expression in the HIV-1 transgenic rat: effects of vitamin A deficiency and morphine. 2011 93

We examined whether there are sex differences in the effect of vitamin supplements on birth outcomes, mortality and morbidity by 2 years of age among children born to HIV-infected women in Tanzania. A randomised placebo-controlled trial was conducted among 959 mother-infant pairs. HIV-infected pregnant women were randomly assigned to receive a daily oral dose of one of four regimens: multivitamins (vitamins B-complex, C and E), vitamin A plus beta-carotene, multivitamins including vitamin A plus beta-carotene or placebo. Supplements were administered during pregnancy and continued after delivery. The beneficial effect of multivitamins on decreasing the risk of low birth weight was stronger among girls (relative risks (RR) = 0.39, 95 % CI 0.22, 0.67) than among boys (RR = 0.81, 95 % CI 0.44, 1.49; P for interaction = 0.08). Maternal multivitamin supplements resulted in 32 % reduction in mortality among girls (RR = 0.68, 95 % CI 0.47, 0.97), whereas no effect was found among boys (RR = 1.20, 95 % CI 0.80, 1.78; P for interaction = 0.04). Multivitamins had beneficial effects on the overall risks of diarrhoea that did not differ by sex. Vitamin A plus beta-carotene alone increased the risk of HIV transmission, but had no effects on mortality, and we found no sex differences in these effects. Sex differential effects of multivitamins on mortality may be due to sex-related differences in the immunological or genetic factors. More research is warranted to examine the effect of vitamins by sex and better understand biological mechanisms mediating such effects.
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PMID:Sex differences in the effects of maternal vitamin supplements on mortality and morbidity among children born to HIV-infected women in Tanzania. 2021 Oct 40


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