Altered iron metabolism and the anemia of chronic disease: a role of immune activation.
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Biomedical subjects
Publications and source records attributed to D Fuchs.
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We compared the serum concentrations of soluble CD8 with the immune activation markers neopterin, interferon-gamma, tumour necrosis factor-alpha, soluble CD4, and with CD4+ and CD8+ T-cell counts in patients with human immunodeficiency virus (HIV) infection. The majority of patients had increased concentrations of soluble CD8, interferon-gamma and neopterin, and various significant correlations existed between them. Our results support the view that enhanced soluble CD8 levels indicate activated CD8+ T cells in patients with HIV infection.
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In order to examine the efficiency of an AIDS vaccine potentially acceptable for human use we have investigated a split vaccine. Since such vaccines are safe and efficient, they have been in use for many years to protect man against enveloped RNA viruses, e.g., influenza and measles. Seven rhesus monkeys were immunized at Week 0, 4, 8, and 16 by im injection of 2 ml of vaccine containing 140 micrograms of Tween-ether-disrupted SIVmac251/32H adsorbed onto aluminum hydroxide. The immunized animals and three nonvaccinated control monkeys were challenged 2 weeks after the last immunization by iv injection of 10 to 50 minimal monkey infectious doses of SIVmac251/32H. Four of seven immunized animals did not show any signs of virus replication and therefore appeared to be protected. Nonvaccinated control animals and the vaccine failures showed a rise in their urinary neopterin concentrations 1 to 2 weeks after infection. At the end of the second week and thereafter, cocultures and polymerase chain reaction of their peripheral blood lymphocytes were positive. After the challenge, control animals and infected vaccinees showed a primary or secondary antibody response while antibody titers declined in virus-negative animals. Specific cytotoxic T-lymphocytes were not present prior to challenge, but were present in some animals thereafter. Therefore, these seem to reflect a response to viral replication rather than to immunization. Prior to challenge the CD4-positive lymphocytes of the peripheral blood of the four virus-negative animals only proliferated after exposure to the immunizing antigen. Thus, this reaction appears to predict protection.
This longitudinal study analyzed how the activation of cell-mediated immunity (CMI) was related to the severity of symptomatology in 25 acute schizophrenic inpatients (DSM-III-R, 295.31). Neopterin, which was used to monitor the activation of T-cells and macrophages, was found to be within the normal range, but the lowest neopterin concentrations were measured on day 0. By day 3, a significant increase of neopterin was observed. Compared with healthy controls, patients had significantly lower neopterin levels at baseline. The highest scores on the Clinical Global Impressions Scale and the Brief Psychiatric Rating Scale occurred on day 0 and decreased significantly over the observation period. In general, the increase of neopterin was accompanied by a decrease in psychopathological symptoms. These results' indicate that at study entry, when patients are acutely ill, activation of the CMI is reduced rather than increased. Possible pathophysiological mechanisms are discussed.
Serum kynurenine and neopterin concentrations were determined in patients with hypertrophic (n = 22) and dilated (n = 23) cardiomyopathy. Significantly increased kynurenine and neopterin levels have been observed in cases of dilated cardiomyopathy. In these patients we found a positive correlation between serum kynurenine and neopterin levels (RS = 0.52, P less than 0.001). There existed several associations between the laboratory parameters neopterin and kynurenine and clinical findings, such as left ventricle (LV) systolic volume and LV circumferential fiber shortening velocity in patients with dilated cardiomyopathy (all P less than 0.05). In vitro, interferon-gamma induces the formation of neopterin in human monocytes/macrophages. Also the degradation of tryptophan via the kynurenine pathway is induced by interferon-gamma. Our data show that increased kynurenine as well as neopterin accumulation in serum are associated with severity of dilated cardiomyopathy. Thus, the data point to a role of immune activation in the pathogenesis of the disease.
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Cytokines (IL-1, sIL-2R, IL-3, IL-6, TNF-alpha, IFN-gamma, GM-CSF and neopterin) were measured in sera of 37 patients with hypertensive disorders of pregnancy, 10 healthy pregnant and 10 healthy non-pregnant controls. With the exception of neopterin (p = 0.004) there were no statistically significant differences in cytokine concentrations between healthy pregnant and non-pregnant controls. No statistically relevant differences between healthy pregnant women and hypertensive patients could be found in cytokines of T-lymphocytic origin except GM-CSF in patients with HELLP syndrome (p = 0.02). Elevated levels of IL-6, TNF-alpha and neopterin were observed in hypertensive women. Differences to healthy pregnant controls were statistically significant for IL-6 (p = 0.008), TNF-alpha (p = 0.009) and neopterin (p = 0.04) and were more pronounced in severe forms of the disease. These 3 parameters of monocytic origin showed significant positive correlations amongst each other. A participation of cell-mediated immunity (especially monocytes/macrophages) in the pathomechanism of hypertensive disorders of pregnancy can thus be assumed.
Two vaccine trials were conducted with low- and high-dose purified Twen-ether-treated SIVmac adsorbed onto aluminum hydroxide using rhesus macaques. In the first experiment 7 macaques were immunized with a total amount of 560 micrograms protein and 3 animals served as controls. After the immunization period the vaccinees exhibited ELISA titers up to 1:1280 and 5 immunized animals showed an antigen-specific proliferative response. After the virus challenge the 3 control animals and 3 vaccinees became infected. Four of the infected animals developed a cytotoxic T-cell response beginning 8 weeks postchallenge. The 4 protected animals were rechallenged 16 weeks later and all became infected. For the high-dose experiment 5 immunized animals receiving 2 mg of antigen and 2 control animals were used. The ELISA titers of the vaccinees reached 1:20480 and 4 animals exhibited an antigen-specific proliferative response. In response to virus challenge the 2 control and 1 immunized animal became infected. From these data it can be concluded that the high-dose immunization scheme elicited higher antibody titers and increased the fraction of protected animals.
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Thirty-three patients with chronic hepatitis C/non-A, non-B were included in a randomized controlled study of interferon-alpha 2b (IFN-alpha 2b) treatment, 3 x 10(6) U three times weekly for 36 weeks. Using an immunoperoxidase technique, frozen liver biopsy specimens were examined with MoAbs for the presence of T helper cells (CD4), T suppressor/cytotoxic cells (CD8), total T cells (CD2) and B cells (CD22) before and after treatment. beta 2-microglobulin (beta 2-MG) expression on hepatocytes was semiquantified using a scoring system on sections from paraffin-embedded biopsy specimens. Serum levels of beta 2-MG were analysed with a radioimmunoassay technique. Intralobular T helper and T suppressor/cytotoxic cells declined significantly in the treated patients but not in the controls. The portal CD4/CD8 ratio did not change. Before treatment, serum beta 2-MG levels and hepatocyte beta 2-MG expression were significantly higher in patients with chronic active hepatitis compared to patients with chronic persistent hepatitis. Serum beta 2-MG levels increased significantly in responders during IFN treatment, with a maximum after 12 weeks. However, in the liver, the hepatocyte beta 2-MG expression was significantly decreased after treatment. Thus, IFN-alpha treatment does not seem to induce an increased HLA class I antigen hepatocyte expression in chronic non-A, non-B hepatitis, which favours the hypothesis that its anti-viral effects are more important in modulating the disease activity.
In this study, we investigated a possible association between the degree of macrophage activation - as measured by serum neopterin concentrations - and disturbances of iron metabolism, determined by the concentrations of ferritin and serum iron, in patients with malignant disorders. Additionally we evaluated correlations between these factors and the degree and type of anaemia. Seventy-three patients, who suffered from non-Hodgkin's lymphoma (NHL) (n = 43), Hodgkin's disease (n = 11), myeloma or monoclonal gammopathy of unknown significance (n = 9), myelodysplastic syndrome (n = 1), and solid tumours (n = 9), were examined. Mean neopterin levels were raised in all groups, patients with NHL showing the highest concentrations. Ferritin but not neopterin concentrations were higher in males than in females. A significant correlation was found between neopterin and ferritin concentrations (p less than 0.01). Considering only female patients the strength of the correlation was the same (p less than 0.02). In addition, we found inverse correlations of neopterin with haemoglobin and iron concentrations (all p less than 0.01). Similar relationships existed in patients during follow-up. Our results support the hypothesis of an association between the degree of activation of macrophages and the development of anaemia by a shift or iron towards the storage sites.
Two 19 year old patients with juvenile chronic arthritis developed liver toxicity during treatment with sulphasalazine. A significant increase in the levels of liver enzymes in serum samples was noticed in relation to the initiation of treatment in one patient and to the increase in dose in the second. The enzymes returned to normal levels 14 days after the drug had been stopped. A rechallenge in one of the patients caused re-exacerbation. This is the first report of liver toxicity induced by sulphasalazine in juvenile chronic arthritis. As spontaneous liver involvement in juvenile chronic arthritis is not rare, the possibility of drug induced hepatitis should be recognised in these patients.
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