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Neopterin

About: Neopterin is a research topic. Over the lifetime, 2579 publications have been published within this topic receiving 67337 citations. The topic is also known as: D-erythro-neopterin & D-(+)-neopterin.


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Journal ArticleDOI
TL;DR: It is demonstrated that macrophages stimulated with supernatant from activated T cells release large amounts of neopterin into culture supernatants, indicating that a metabolic pathway so far exclusively known in context with the generation of an essential cofactor of neurotransmitter-synthesis during immune responses is also activated in M phi under stringent control by immune IFN-like lymphokines.
Abstract: Neopterin, a compound derived from GTP, represents a precursor molecule of biopterin that is an essential cofactor in neurotransmitter synthesis. We have recently reported that in vivo as well as in vitro immune responses are accompanied by an increased release of neopterin and that this phenomenon can be used for the biochemical monitoring of diseases accompanied by hyperimmune stimulation. This article deals with the cellular origin and the control of this immune response-associated neopterin release in vitro. Using highly purified or monoclonal cellular reagents we demonstrate that macrophages (M phi) stimulated with supernatants from activated T cells release large amounts of neopterin into culture supernatants. Further experiments involving induction of neopterin release from M phi with various human recombinant interferons (IFNs) or neutralization of the effect of T cell supernatants with various monoclonal anti-IFN antibodies revealed immune IFN as the active principle. It thus appears that a metabolic pathway so far exclusively known in context with the generation of an essential cofactor of neurotransmitter-synthesis during immune responses is also activated in M phi under stringent control by immune IFN-like lymphokines.

1,083 citations

Journal ArticleDOI
TL;DR: In this article, the authors evaluated three cellular and five serologic markers that are affected by infection with the human immunodeficiency virus type 1 (HIV-1) for their ability to predict the progression to clinical AIDS, and concluded that progression to AIDS was predicted most accurately by the level of CD4+ T cells in combination with the serum level of either neopterin or beta 2-microglobulin.
Abstract: We evaluated three cellular and five serologic markers that are affected by infection with the human immunodeficiency virus type 1 (HIV-1) for their ability to predict the progression to clinical acquired immunodeficiency syndrome (AIDS). The cellular markers were the number of CD4+ T cells, the number of CD8+ T cells, and the ratio of CD4+ T cells to CD8+ T cells. The serologic markers were the serum levels of neopterin (a product of stimulated macrophages), beta 2-microglobulin, soluble interleukin-2 receptors, IgA, and HIV p24 antigen. We evaluated the usefulness of these measures as markers of the progression to AIDS prospectively, over four years, in a cohort of 395 HIV-seropositive homosexual men who were initially free of AIDS. CD4+ T cells (expressed as an absolute number, a percentage of lymphocytes, or a ratio of CD4+ to CD8+ T cells) were the best single predictor of the progression to AIDS, but the serum neopterin and beta 2-microglobulin levels each had nearly as much predictive power. The neopterin level appeared to be a slightly better predictor than the beta 2-microglobulin level. The levels of IgA, interleukin-2 receptors, and p24 antigen had less predictive value. A stepwise multivariate analysis indicated that the best predictors, in descending order, were CD4+ T cells (the percentage of lymphocytes or the CD4+: CD8+ ratio), the serum level of neopterin or beta 2-microglobulin, the level of IgA, that of interleukin-2 receptors, and that of p24 antigen. The last three markers had little additional predictive power beyond that of the first two. We conclude that of the eight markers studied, progression to AIDS was predicted most accurately by the level of CD4+ T cells in combination with the serum level of either neopterin or beta 2-microglobulin. At least one of these two serum markers, which reflect immune activation, should be used along with measurement of CD4+ T cells in disease-classification schemes and in the evaluation of responses to therapy.

1,035 citations

Journal ArticleDOI
TL;DR: Neopterin production provides prognostic information in patients with malignant tumor diseases and in HIV-infected individuals, high levels being associated with poorer survival expectations and the extent of oxidative stress can be estimated by neopterin measurements.
Abstract: Increased amounts of neopterin are produced by human monocytes / macrophages upon stimulation with the cytokine interferon-γ. Therefore, measurement of neopterin concentrations in body fluids like serum, cerebrospinal fluid or urine provides information about activation of T helper cell 1 derived cellular immune activation. Increased neopterin production is found in infections by viruses including human immunodeficiency virus (HIV), infections by intracellular living bacteria and parasites, autoimmune diseases, malignant tumor diseases and in allograft rejection episodes. But also in neurological and in cardiovascular diseases cellular immune activation indicated by increased neopterin production, is found. Major diagnostic applications of neopterin measurements are, e.g. monitoring of allograft recipients to recognize immunological complications early. Neopterin production provides prognostic information in patients with malignant tumor diseases and in HIV-infected individuals, high levels being associated with poorer survival expectations. Neopterin measurements are also useful to monitor therapy in patients with autoimmune disorders and in individuals with HIV infection. Screening of neopterin concentrations in blood donations allows to detect acute infections in a non-specific way and improves safety of blood transfusions. As high neopterin production is associated with increased production of reactive oxygen species and with low serum concentrations of antioxidants like α-tocopherol, neopterin can also be regarded as a marker of reactive oxygen species formed by the activated cellular immune system. Therefore, by neopterin measurements not only the extent of cellular immune activation but also the extent of oxidative stress can be estimated.

664 citations

Journal ArticleDOI
TL;DR: Neopterin studies reveal that preactivation of cell-mediated immunity is associated with poor prognosis in cancer patients and in human immunodeficiency virus infection, neopterin levels increase in parallel with progressive disease, are inversely correlated with CD4 + /CD8 + T-cell subset ratios and are of predictive significance.

585 citations

Journal ArticleDOI
TL;DR: Fatigued breast cancer survivors showed elevations in serum markers associated with proinflammatory cytokine activity an average of 5 years after diagnosis, which suggest mechanisms through which enduring immune activation may occur, including alterations in cortisol and in lymphocyte subsets.
Abstract: Objective Fatigue is a common problem among cancer patients and survivors, yet the mechanisms underlying the occurrence and persistence of this symptom are not known. Activation of the immune system may evoke feelings of fatigue, which are mediated by proinflammatory cytokines. We examined whether fatigued breast cancer survivors would show elevations in proinflammatory cytokines and markers of cytokine activity compared with nonfatigued survivors. Differences in lymphocyte subsets, cortisol, and behavioral symptoms associated with proinflammatory cytokines were also assessed. Methods Forty breast cancer survivors (20 fatigued, 20 nonfatigued) provided blood samples at visits scheduled to control for diurnal variability. Cytokines, soluble markers of cytokine activity, and cortisol were measured by immunoassay and lymphocyte subsets by flow cytometry. Participants also completed questionnaires measuring demographic, medical, and behavioral variables. Results Fatigued breast cancer survivors had significantly higher serum levels of several markers associated with proinflammatory cytokine activity than nonfatigued survivors, including interleukin-1 receptor antagonist (IL-1ra), soluble tumor necrosis factor receptor type II (sTNF-RII), and neopterin. They were also more likely to report behavioral problems that co-occur with fatigue in the context of immune activation. Fatigued survivors had significantly lower serum levels of cortisol than the nonfatigued group as well as differences in two lymphocyte populations. Conclusions Fatigued breast cancer survivors showed elevations in serum markers associated with proinflammatory cytokine activity an average of 5 years after diagnosis. Results suggest mechanisms through which enduring immune activation may occur, including alterations in cortisol and in lymphocyte subsets.

515 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202356
2022104
202151
202065
201969
201875