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

The responsibility of HIV in the occurrence of AIDS is definitely established, but "cofactors" are strongly suspected to intervene, which would explain the difference courses followed by the disease in one patient or the other. Some of these cofactors are related to the host or result from his behaviour. Thus, age at the time of HIV acquisition and the patient's HLA group are associated with differences in the speed of progression towards AIDS. Attitudes that lead to reexposure to the virus by the sexual or intravenous routes shorten the duration of the asymptomatic phase. Other cofactors are environmental in nature. Among the infectious agents, cytomegalovirus and some mycoplasmas have been the object of the most through studies. The responsibility of some physicochemical substances, such as cocaine, vitamin D and corticosteroids, acting as cofactors of increasing severity, mostly rests on data obtained in vitro and need clinical confirmation in man. However, the study of cofactors already seems to be a promising line of research aimed at understanding AIDS and hence its therapeutic approach.
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PMID:[HIV cofactors in the course of AIDS]. 133 99

We report the case of a 28-year-old homosexual man with advanced HIV disease (CDC classification group IV A) who developed erythrodermic psoriasis which responded to calcipotriol, a topical vitamin D analogue. We believe this to be the first reported case of HIV-related psoriasis responsive to this form of treatment. Systemic therapy for HIV-related psoriasis is limited because of immunosuppressive effects. We suggest that calcipotriol may prove to be a useful therapeutic option in these patients.
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PMID:The use of calcipotriol in HIV-related psoriasis. 145 40

The literature is briefly summarized as to how several nutrients affect immune function, susceptibility to infection, and cancer susceptibility or progression. Nutritional deficiencies can impair immunity and so influence susceptibility to infectious agents, including ones that are common and relatively virulent in acquired immune deficiency syndrome (AIDS) patients. A variety of nutrients affect several of the immune functions that are defective in human immunodeficiency virus (HIV)-infected individuals. For example, beta-carotene increased the number of CD4+ cells; vitamin E decreased the number of CD8+ cells and increased the CD4+/CD8+ ratio; vitamin D decreased the CD4+/CD8+ ratio; and iron increased the number of peripheral lymphocytes in humans receiving supplementation. Furthermore, nutritional deficiencies can influence gastrointestinal function, while infectious diseases can influence nutrient requirements by altering the efficiency of absorption and the rate of tissue metabolism. Malnutrition, depressed serum zinc levels, and intestinal nutrient malabsorption have been found in AIDS patients. The above findings suggest that dietary manipulations might diminish the immune defects in HIV infection and enhance resistance to opportunistic infections. However, dietary alterations in immune defects are generally not well quantified and may be small relative to the magnitude of the defects observed in AIDS patients. Because conflicting or adverse effects have been reported for some nutrients, recommendations for dietary supplementation in HIV-infected individuals are premature and possibly hazardous. Further studies are much needed to relate dietary nutrient intakes to clinical outcomes.
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PMID:The potential role of nutritional factors in the induction of immunologic abnormalities in HIV-positive homosexual men. 265 89

Pneumocystis carinii infection is commonly seen in patients infected with HIV, and there is evidence of macrophage involvement in the disease process. Macrophage dysfunction can result in abnormal vitamin D metabolism as is often seen in a granulomatous disease such as sarcoidosis. This article describes a patient with AIDS who had P. carinii pneumonia and hypercalcemia and had elevated 1,25-dihydroxyvitamin D levels, the first such reported case in the literature. There was no other evidence of a granulomatous disease such as sarcoidosis or tuberculosis to account for this. It is suggested that the increase in 1,25-dihydroxyvitamin D level was secondary to P. carinii induced macrophage dysfunction. As the patient's P. carinii pneumonia resolved, his 1,25 dihydroxyvitamin D level normalized along with the resolution of hypercalcemia.
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PMID:Case report: hypercalcemia in a patient with AIDS and Pneumocystis carinii pneumonia. 823 87

The active metabolite of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D), has been shown to induce monocyte-to-macrophage maturation in vitro as well as monocytic differentiation of bone marrow precursors and monocytic leukaemic cell lines. In this study we assessed whether 1,25D could improve the maturation defect we have previously demonstrated in monocytes from AIDS patients. In vitro growth and maturation of monocytes from 10 controls, 15 asymptomatic HIV positives (CDC group II or III) and 13 symptomatic HIV positives (CDC group IV) was examined by assessing cellular morphology, differentiation, adherence and protein content. Cells were cultured for 10 days with or without addition of 1,25D at a concentration of 100 pg/ml. In addition, patients were monitored clinically and by immunological parameters and HIV p24 antigen in serum. The present study showed that addition of 1,25D significantly improved the growth and maturation in both patient and control groups. There was a significant negative correlation between response to 1,25D and CD4+ lymphocyte count in blood in HIV-infected patients. A greater response to 1,25D was seen in monocytes from patients with advanced immunodeficiency and symptomatic disease than in monocytes from asymptomatic patients. However, in the most advanced cases of HIV infection with serious ongoing opportunistic infections the response to 1,25D was very poor, possibly reflecting profound and incorrigible dysfunction of monocytes.
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PMID:The effect of 1,25-vitamin D3 on maturation of monocytes from HIV-infected patients varies with degree of immunodeficiency. 892 Aug 7

Twin and adoptee studies have indicated that host genetic factors are major determinants of susceptibility to infectious disease in humans. Twin studies have also found high heritabilities for many humoral and cellular immune responses to pathogen antigens, with most of the genetic component mapping outside of the major histocompatibility complex. Candidate gene studies have implicated several immunogenetic polymorphisms in human infectious diseases. HLA variation has been associated with susceptibility or resistance to malaria, tuberculosis, leprosy, AIDS, and hepatitis virus persistence. Variation in the tumor necrosis factor gene promoter has also been associated with several infectious diseases. Chemokine receptor polymorphism affects both susceptibility ot HIV-1 infection and the rate of progression to AIDS. Inactivating mutations of the gamma-interferon receptor lead to increased susceptibility to typical mycobacteria and disseminated BCG infection in homozygous children. The active form of vitamin D has immunomodulatory effects, and allelic variants of the vitamin D receptor appear to be associated with differential susceptibility to several infectious diseases. NRAMP1, a macrophage gene identified by positional cloning of its murine homologue, has been implicated in susceptibility to tuberculosis in Africans. Whole genome linkage analysis of multi-case families is now being used to map and identify new loci affecting susceptibility to infectious diseases. It is likely that susceptibility to most microorganisms is determined by a large number of polymorphic genes, and identification of these should provide insights into protective and pathogenic mechanisms in infectious diseases.
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PMID:The immunogenetics of human infectious diseases. 959 43

Mycobacterium avium complex (MAC) is the most common cause of disseminated bacterial infection in patients with acquired immune deficiency syndrome (AIDS) and macrophage dysfunction is important both in the pathogenesis of AIDS- and MAC-infection. 1,25-Dihydroxyvitamin D3 (1,25D), the active metabolite of vitamin D, has a number of effects on cell types of the immune system including monocytes/macrophages. The present study was designed to investigate whether 1,25D supplementation in vitro could modulate MAC replication in macrophages from HIV-infected patients. It was therefore of particular interest to examine whether the effect of 1,25D differs between cells from HIV-infected patients and healthy control subjects. After 3 and 7 days of infection, 1,25D supplementation increased numbers of bacteria in cells from control subjects. In contrast, there was no change or even a decrease in numbers of bacteria in cells from HIV-infected patients. These findings suggest that HIV infection may significantly modulate the macrophage response to 1,25D stimulation, and that 1,25D may have inhibitory effects on MAC replication in macrophages from HIV-infected patients.
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PMID:Different effect of 1,25-dihydroxyvitamin D3 on replication of Mycobacterium avium in monocyte-derived macrophages from human immunodeficiency virus-infected subjects and healthy controls. 976 72

The serum level of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D], the biologically most potent metabolite of vitamin D, is tightly regulated within narrow limits in human healthy adults. 1,25-(OH)2D deficiency is rare and is associated with disturbances in calcium and bone metabolism. We have previously reported a marked decrease in serum levels of 1,25-(OH)2D in human immunodeficiency virus (HIV)-infected patients. The present study was designed to further examine the causes and consequences of severe 1,25-(OH)2D deficiency in these patients. The design was a prospective cohort study. Fifty-four HIV-infected patients clinically classified according to the revised criteria from Centers for Disease Control and Prevention and healthy controls were studied. Parameters related to vitamin D and calcium metabolism as well as immunological and nutritional status were determined. Twenty-nine of the patients (54%) had serum levels of 1,25-(OH)2D below the lower reference limit, and 18 of these had undetectable levels. In contrast, HIV-infected patients had normal serum levels of 25-hydroxyvitamin D and vitamin D-binding protein. HIV-infected patients as a group had modestly depressed serum calcium and PTH levels. There were, however, no correlations between these parameters and serum levels of 1,25-(OH)2D. There were no differences in serum calcium or PTH levels or nutritional status when patients with severe 1,25-(OH)2D deficiency were compared to other patients, but patients with undetectable 1,25-(OH)2D had significantly elevated serum phosphate levels. Furthermore, patients with undetectable 1,25-(OH)2D levels were characterized by advanced clinical HIV infection, low CD4+ lymphocyte counts, and high serum levels of tumor necrosis factor-alpha (TNFalpha). We conclude that inadequate 1alpha-hydroxylation of 25-hydroxyvitamin D seems to be the most likely cause of 1,25-(OH)2D deficiency in HIV-infected patients, possibly induced by an inhibitory effect of TNFalpha. The low 1,25-(OH)2D and high TNFalpha levels observed may impair the immune response in HIV-infected patients both independently and in combination and may represent an important feature of the pathogenesis of HIV-related immunodeficiency. Markedly depressed 1,25-(OH)2D serum levels are also present in certain other disorders characterized by immunological hyperactivity. Thus, the findings in the present study may not only represent a previously unrecognized immune-mediated mechanism for induction of 1,25-(OH)2D deficiency in human disease, but may also reflect the importance of adequate serum levels of 1,25-(OH)2D for satisfactory performance of the immune system in man.
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PMID:Severe deficiency of 1,25-dihydroxyvitamin D3 in human immunodeficiency virus infection: association with immunological hyperactivity and only minor changes in calcium homeostasis. 981 54

In 4 of our patients on chronic dialysis, we were intrigued by the association of hypercalcemia +/- hyperphosphatemia and normal intact PTH, with anicteric cholestasis without cytolysis. This picture occurred in 2 patients after they resumed dialysis because of a transplant rejection and in a third one after discontinuation of corticosteroids, prescribed for an idiopathic thrombocytopenia. No patient was under calcitriol, CaCO3 therapy, and their hypercalcemia persisted on a low calcium dialyzate (1.25 mmol/l). Obvious etiologies of hypercalcemia were not found: vitamin D or A intoxication, hyperparathyroidism, aluminum intoxication, hemopathy, HIV infection. The hypothesis of a granulomatous disease was made and a liver biopsy was performed showing granulomas with giant epitheloid cells. In one case foreign material (silicon ?) was present in the macrophages. Extensive investigations for sarcoidosis, tuberculosis and mycosis were negative. In 2 cases the so-called "dialysis" granulomatosis actually occurred in transplanted patients, suggesting the role of a transplantation related factor (toxic or virus). In the last case HCV seroconversion was present. In the 4 cases, corticotherapy led to the disappearance of hypercalcemia and to an increase of PTH. Our patients had the biological pattern of low bone turnover disease (hypercalcemia and normal intact PTH) and bone biopsy performed in 2 showed osteomalacia or ABD without aluminum. The association of this pattern with cholestasis should evoke liver granulomatosis, which should be confirmed by a liver biopsy and lead to a treatment by corticosteroids. The masking effect of previous corticoid therapy for transplantation should be pointed out. In 2 cases serial monitoring of plasma calcitriol showed a relation between decreasing high normal calcitriol with prednisone and normalization of calcemia, suggesting the role of inappropriate synthesis of calcitriol by the granuloma. In conclusion, liver granulomatosis should be looked for in dialysis patients on the association of unexplained hypercalcemia and normal PTH with anicteric cholestasis, and confirmed by a liver biopsy. Although still of unknown etiology, its evolution is favourable under corticotherapy.
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PMID:Liver granulomatosis is not an exceptional cause of hypercalcemia with hypoparathyroidism in dialysis patients. 1062 31

Data on the bone metabolism of human immunodeficiency virus (HIV)-infected patients are still extremely rare. To investigate the influence of HIV infection on the calciotropic hormones and markers of bone metabolism, we therefore performed a cross-sectional study on 100 patients (65 males and 35 females) with proven HIV infection. The following criteria were used for exclusion from the study: age less than 20/more than 50 years, confinement to bed, wasting symptoms, treatment with agents containing ketoconazole, renal or hepatic insufficiency, clinical or echographic signs of liver cirrhosis, endocrine diseases, or treatment with medications known to influence bone metabolism. Bone mineral content (BMC) was determined by single-photon absorptiometry on the left forearm. Reduced BMC was found among the male and female HIV-infected patients. Additional long-term use of heroin resulted in a severe loss of mineralization in the respective females. The markers of bone metabolism were determined in urine and serum samples. Significantly lower osteocalcin concentrations were found, indicating a reduced bone formation rate whose severity showed a significant correlation with the progressive loss of CD4 helper cells and was independent of low vitamin D3 levels (1,25-dihydroxycholecalciferol) and alterations of protein metabolism. Increased urinary excretion of cross-links as an expression of enhanced bone resorption was likewise significantly correlated with the loss of CD4 helper cells and independent of the vitamin D concentration and protein metabolism. It is therefore concluded that the changes in bone metabolism are mainly due to mechanisms of the impaired immune defense of HIV-infected patients.
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PMID:Changes in calciotropic hormones and biochemical markers of bone metabolism in patients with human immunodeficiency virus infection. 1101 93


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