Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002871 (anemia)
 52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Laboratory observations suggest that, in some myelodysplastic syndromes (MDS), immune mechanisms may contribute to the impaired blood cell production. Tumor necrosis factor alpha (TNF-alpha), a potent inhibitor of haematopoiesis, has been hypothesized to mediate suppressive effects in MDS: TNF-alpha levels are elevated and correlated with marrow apoptosis and cytopenia. Inhibition of TNF-alpha production using the soluble TNF receptor (Enbrel) has been successful in rheumatoid arthritis, and we have now applied the same principle to MDS. We determined spontaneous TNF-alpha production by marrow cells in MDS; TNF-alpha production was elevated (> mean + 2 x SD of controls) in > 1/3 of patients, but did not correlate with clinical parameters. Sixteen patients participated in a 3-month pilot study of Enbrel. The drug was well tolerated and 15 patients were evaluable. Of these, one became temporarily (14 weeks) transfusion independent. In another patient, absolute neutrophil count (ANC) rose from 0.5 x 10(9)/l to 0.84 x 10(9)/l. Serious infections were seen in two out of six neutropenic patients. Progression to refractory anaemia with excess blasts in transformation (RAEBt) or leukaemia was observed in three patients. When the effects of Enbrel on haematopoietic colony formation were studied, no significant increase was seen in MDS and there was no correlation with TNF-alpha levels. Although anti-TNF therapy with Enbrel was well tolerated at the dosages used in MDS, its efficacy as a single agent appears low.
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PMID:A pilot study of the recombinant soluble human tumour necrosis factor receptor (p75)-Fc fusion protein in patients with myelodysplastic syndrome. 1191 41

The use of human recombinant erythropoietin (rHuEpo) has been approved by the Food and Drug Administration (FDA) in patients with anemia and cancer. Although good results have been obtained, it is too expensive to permit its use massively. For the purpose of evaluating the therapeutic effect of rHuEpo, including toxicity, predictive response variables and quality of life parameters, a prospective trial was carried out in patients with anemia and cancer. Hematimetric parameters, ferritin, Epo, cytokines, transfusions and quality of life were registered. A total of 36 patients were treated in the protocol (34 were evaluable): 16 men and 20 women, with a medium age 56.4 years; 27 patients were treated with chemotherapy (16 with cisplatinum); 15 patients presented medullar infiltration. In 73.5% patients an increase in the level of hemoglobin was registered, and in 64.7% its normalisation was attained. Transfusional requirements were reduced by 50%. The hemoglobin increase greater than 0.5 g/dl at the second week of treatment was the most significant variable of early response. Patients treated with cisplatinum, seric ferritin lower than 1,100 ng/dl and those without medullar tumoral infiltration responded best. Serum Epo, cytokines (IL-1, IL-6 and TNF) and reticulocyte count at the second week did not correlate with response. Quality of life parameters were better in patients with good response to rHuEpo. It can be concluded that good results in the treatment of patients with anemia and cancer are obtained with rHuEpo.
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PMID:[Predictive response variables to recombinant human erythropoietin treatment in patients with anemia and cancer]. 1196 49

About half of all the patients with CHF are anemic (they have a hemoglobin of < 12 g%). The prevalence and severity of this anemia increase with increasing severity of the CHF. The anemia is caused by a combination of poor nutrition, associated renal insufficiency causing inappropriately low Erythropoietin (EPO) levels, bone marrow depression and EPO resistance caused by excessive TNF alpha and other factors, gastrointestinal blood loss caused by aspirin, ACE inhibitors, EPO loss in the urine with proteinuria, and hemodilution caused by the excessive plasma volume. Studies have shown that the anemia is an independent risk factor for death in CHF, almost doubling the mortality rate. Correction of the anemia with subcutaneous EPO and IV iron improves cardiac function and functional capacity, helps prevent the progression of renal failure, markedly reduces hospitalization and diuretic doses, and improves self assessed quality of life. This so-called Cardio Renal Anemia Syndrome is very common in CHF. Its successful treatment demands close cooperation between cardiologists and nephrologists.
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PMID:The importance of anemia and its correction in the management of severe congestive heart failure. 1245 37

TNF is considered one of the inflammatory cytokines and contributes mainly to the generation of anemia of chronic disease (ACD). In nude mice TNF has been reported to impair iron metabolism and erythropoiesis, leading to anemia with a low serum iron and preserved iron stores. In this work, we established a murine model for ACD based on sublethal cecal ligation and puncture (CLP) with ensuing protracted peritonitis. Starting on Day 3 after CLP, a severe protracted depression of erythropoiesis in the bone marrow was noted. Two weeks after CLP, we observed a moderate normochromic anemia, low serum iron concentration, and preserved iron stores consistent with transient ACD. To determine whether TNF contributes to the development of ACD in vivo, we neutralized TNF after CLP shortly before and during the phase of most severe bone marrow depression to prevent anemia. Additionally, we studied TNF-deficient mice undergoing CLP. Two weeks after CLP, we determined red blood count, hemoglobin concentration, hematocrit, serum iron concentration, and iron stores in spleens of wild-type mice, TNF-deficient mice, and mice after neutralization of TNF. Neutralization of TNF after CLP could not prevent mice from contracting anemia. Accordingly, TNF-deficient mice developed anemia to the same extent as wild-type mice. Serum iron concentration was lowered and iron stores were overloaded in both TNF-deficient and wild-type mice after CLP. Our results clearly demonstrate that TNF is not a mediator of ACD in our model with transient anemia induced by protracted septic peritonitis.
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PMID:TNF-independent development of transient anemia of chronic disease in a mouse model of protracted septic peritonitis. 1469 Dec 92

Although IFN-gamma is essential for host control of mycobacterial infection, the mechanisms by which the cytokine restricts pathogen growth are only partially understood. LRG-47 is an IFN-inducible GTP-binding protein previously shown to be required for IFN-gamma-dependent host resistance to acute Listeria monocytogenes and Toxoplasma gondii infections. To examine the role of LRG-47 in control of mycobacterial infection, LRG-47(-/-) and wild-type mice were infected with Mycobacterium avium, and host responses were analyzed. LRG-47 protein was strongly induced in livers of infected wild-type animals in an IFN-gamma-dependent manner. LRG-47(-/-) mice were unable to control bacterial replication, but survived the acute phase, succumbing 11-16 wk postinfection. IFN-gamma-primed, bone marrow-derived macrophages from LRG-47(-/-) and wild-type animals produced equivalent levels of TNF and NO upon M. avium infection in vitro and developed similar intracellular bacterial loads. In addition, priming for IFN-gamma production was observed in T cells isolated from infected LRG-47(-/-) mice. Importantly, however, mycobacterial granulomas in LRG-47(-/-) mice showed a marked lymphocyte deficiency. Further examination of these animals revealed a profound systemic lymphopenia and anemia triggered by infection. As LRG47(-/-) T lymphocytes were found to both survive and confer resistance to M. avium in recipient recombinase-activating gene-2(-/-) mice, the defect in cellular response and bacterial control in LRG-47(-/-) mice may also depend on a factor(s) expressed in a nonlymphocyte compartment. These findings establish a role for LRG-47 in host control of mycobacteria and demonstrate that in the context of the IFN-gamma response to persistent infection, LRG-47 can have downstream regulatory effects on lymphocyte survival.
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PMID:Mice deficient in LRG-47 display increased susceptibility to mycobacterial infection associated with the induction of lymphopenia. 1470 92

To investigate if severe malarial anemia is associated with specific cytokine overproduction, we evaluated serum levels of soluble Fas ligand (sFasL), tumor necrosis factor (TNF-alpha) and interleukin-10 (IL-10) from three groups of young children with Plasmodium falciparum infection (asymptomatic cases, uncomplicated malaria cases and severe malarial anemia cases), in a hyperendemic area of Gabon. In uncomplicated cases, only TNF levels were significantly (p < 0.001) increased in comparison to asymptomatic cases with P. falciparum infection. High levels of sFasL, TNF-alpha and IL-10 were associated with low hemoglobin concentrations, sFasL levels were significantly higher in children with severe malarial anemia (p < 0.001) as compared to both other groups. The parasite density was positively correlated with IL-10, TNF-alpha and sFasL levels. TNF-alpha and sFasL, but not IL-10 or parasitemia, were independent predictors of hemoglobin concentrations. These results suggest that, in malaria, a specific dysregulation of the cytokine balance may lead to complications such as severe anemia.
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PMID:Severe malarial anemia associated with increased soluble Fas ligand (sFasL) concentrations in Gabonese children. 1471 16

Interferon-gamma (IFN-gamma) is considered one of the main inflammatory cytokines contributing to the generation of anemia of chronic disease (ACD). In this study, we used a previously described murine model for ACD based on sublethal cecal ligation and puncture (CLP) with ensuing protracted peritonitis. Within 2 weeks after CLP, a moderate normochromic anemia with low serum iron concentration and preserved iron stores develops, which is consistent with ACD. In order to determine whether IFN-gamma contributes to the development of ACD in vivo, we neutralized IFN-gamma after CLP shortly before and during the phase of most severe bone marrow depression in order to prevent anemia. Additionally, we studied IFN-gamma receptor-deficient mice that underwent CLP. Two weeks after CLP, we determined the red blood cell count, hemoglobin concentration, hematocrit, serum iron concentration, and iron stores in spleens of wild-type mice, IFN-gamma receptor-deficient mice, and mice after neutralization of IFN-gamma. Neutralization of IFN-gamma after CLP could not prevent mice from becoming anemic. Accordingly, IFN-gamma receptor-deficient mice developed anemia to the same extent as wild-type mice. Serum iron concentration was lowered both in IFN-gamma receptor-deficient and wild-type mice. Iron stores in untreated IFN-gamma receptor-deficient mice were elevated compared to untreated wild-type mice. After CLP both IFN-gamma receptor-deficient and wild-type mice had equally overloaded iron stores. Additional neutralization of TNF in IFN-gamma receptor-deficient mice also did not attenuate CLP-induced anemia. Our results clearly demonstrate that neither IFN-gamma alone nor in combination with TNF is a mediator of ACD in our model with transient anemia induced by protracted septic peritonitis.
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PMID:Failure of interferon-gamma and tumor necrosis factor in mediating anemia of chronic disease in a mouse model of protracted septic peritonitis. 1614 16

The anaemia associated with chronic renal failure is multi-factorial. Although a relative erythropoietin deficiency is a major factor, it has also been recognized in recent times that uraemia is a chronic inflammatory state, and thus patients with renal failure also develop anaemia due to mechanisms associated with chronic inflammation. Thus, patients with chronic renal failure have activation of various immune cells, both monocytes and T-cells. These mononuclear cells have also been shown to release pro-inflammatory cytokines such as IL-1, IL-6, TNF-alfa and interferon gamma. These cytokines, particularly TNF-alfa and interferon gamma, are known to cause significant suppression of erythropoiesis. The exact molecular mechanism for this effect is not yet clear, but interferon gamma is an important stimulator of apoptosis in various cell types, including erythroid progenitor cells. This effect may be potentiated by other cytokines such as TNF-alfa, and this might then antagonise the anti-apoptotic action of erythropoietin on erythroid progenitors cells, thus reducing responsiveness to exogenous erythropoietic therapy. Chronic renal failure is also associated with increased hepcidin production which may also exacerbate the anaemia by inducing a functional iron deficiency in such patients.
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PMID:Hyporesponsiveness to erythropoietic therapy due to chronic inflammation. 1628 56

IFN-gamma is known to be required for host control of intracellular Trypanosoma cruzi infection in mice, although the basis of its protective function is poorly understood. LRG-47 is an IFN-inducible p47GTPase that has been shown to regulate host resistance to intracellular pathogens. To investigate the possible role of LRG-47 in IFN-gamma-dependent control of T. cruzi infection, LRG-47 knockout (KO) and wild-type (WT) mice were infected with the Y strain of this parasite, and host responses were analyzed. When assayed on day 12 after parasite inoculation, LRG-47 KO mice, in contrast to IFN-gamma KO mice, controlled early parasitemia almost as effectively as WT animals. However, the infected LRG-47 KO mice displayed a rebound in parasite growth on day 15, and all succumbed to the infection by day 19. Additional analysis indicated that LRG-47-deficient mice exhibit unimpaired proinflammatory responses throughout the infection. Instead, reactivated disease in the KO animals was associated with severe splenic and thymic atrophy, anemia, and thrombocytopenia not observed in their WT counterparts. In addition, in vitro studies revealed that IFN-gamma-stimulated LRG-47 KO macrophages display defective intracellular killing of amastigotes despite normal expression of TNF and NO synthetase type 2 and that both NO synthetase type 2 and LRG-47 are required for optimum IFN-gamma-dependent restriction of parasite growth. Together, these data establish that LRG-47 can influence pathogen control by simultaneously regulating macrophage-microbicidal activity and hemopoietic function.
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PMID:Mice deficient in LRG-47 display enhanced susceptibility to Trypanosoma cruzi infection associated with defective hemopoiesis and intracellular control of parasite growth. 1633 55

Fluorescence in situ hybridization and comparative genomic hybridization characterized 6p rearrangements in eight primary and in 10 secondary myeloid disorders (including one patient with Fanconi anemia) and found different molecular lesions in each group. In primary disorders, 6p abnormalities, isolated in six patients, were highly heterogeneous with different breakpoints along the 6p arm. Reciprocal translocations were found in seven. In the 10 patients with secondary acute myeloid leukemia/myelodysplastic syndrome (AML/MDS), the short arm of chromosome 6 was involved in unbalanced translocations in 7. The other three patients showed full or partial trisomy of the 6p arm, that is, i(6)(p10) (one patient) and dup(6)(p) (two patients). In 5/7 patients with unbalanced translocations, DNA sequences were overrepresented at band 6p21 as either cryptic duplications (three patients) or cryptic low-copy gains (two patients). In the eight patients with cytogenetic or cryptic 6p gains, we identified a common overrepresented region extending for 5-6 megabases from the TNF gene to the ETV-7 gene. 6p abnormalities were isolated karyotype changes in four patients. Consequently, in secondary AML/MDS, we hypothesize that 6p gains are major pathogenetic events arising from acquired and/or congenital genomic instability.
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PMID:Genomic gain at 6p21: a new cryptic molecular rearrangement in secondary myelodysplastic syndrome and acute myeloid leukemia. 1661 24


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