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)

Hemophagocytic lymphohistiocytosis (HLH), also referred to as familial erythrophagocytic lymphohistiocytosis, is a rare disorder of infancy associated with proliferation of activated histiocytes and T cells, anemia, thrombocytopenia, and fevers. This disorder appears to be due to the uncontrolled activation of T cells producing IL-2, tumor necrosis factor-alpha, and interferon-gamma. Untreated, the disorder is universally fatal. Various deficits in immune function have been described during acute disease activity including impaired T cell function, impaired monocyte-mediated antibody-dependent cytotoxicity, impaired natural killer cell function, and impaired IL-1 production. We examined natural killer cell function in familial HLH patients to determine whether this finding was consistently associated with the disease. We also examined natural killer cell function in asymptomatic parents and siblings of patients. Impaired natural killer cell function was identified in all patients and in some family members, including obligate carrier parents. This implies that one potential genetic defect in HLH may result in depressed natural killer function, but that this may not be sufficient to reliably predict eventual progression to disease.
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PMID:Defective natural killer cell function in patients with hemophagocytic lymphohistiocytosis and in first degree relatives. 977 32

Exposure of hematopoietic progenitor cells (HPC) from mice and humans with Fanconi anemia group C (FAC) to interferon-gamma (IFN-gamma) or tumor necrosis factor-alpha (TNF-alpha) at doses too low to inhibit growth of normal HPC induces profound apoptotic responses. Because the IFN-gamma hypersensitivity of cells lacking the FAC protein is mediated, in part, through priming of the Fas pathway, and because several other members of this family are capable of inducing apoptosis either alone or in concert with each other, we tested the hypothesis that IFN-gamma induces increased expression of members of the TNF receptor (TNFR) superfamily in cells nullizygous for the FAC gene. Using isogenic human Epstein-Barr virus-transformed lymphoblast cell lines and c-kit+ bone marrow cells from mice with inactivating mutations of the FAC locus, we quantified mRNA levels by reverse transcriptase polymerase chain reaction and surface expression of the gene products by flow cytometry of TNFR1, TNFR2, Fas, CD30, CD40, and nerve growth factor receptor. We found that neither constitutive nor IFN-gamma-induced expression of these receptors was influenced by the absence of a functional FAC gene product, and expression of these receptors was not suppressed in nullizygous cells complemented with the normal FAC cDNA. We conclude that, although exaggerated apoptotic responses in FAC-deficient cells are at least partially mediated through activation of members of the TNFR superfamily, the normal FAC protein does not function as a direct suppressor of this family of molecules and inactivation of FAC does not augment expression of these proteins.
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PMID:The Fanconi anemia group C gene product modulates apoptotic responses to tumor necrosis factor-alpha and Fas ligand but does not suppress expression of receptors of the tumor necrosis factor receptor superfamily. 992 38

Serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1alpha (IL-1alpha), and interferon-gamma (IFN-gamma) were estimated by conventional ELISA kits in 60, 42, and 58 Thai patients, respectively, with beta(o)-thalassemia HbE and found to be above the normal range in 13%, 21%, and 33% of the patients, respectively. Using high-sensitivity ELISA systems, an additional 10 beta(o)-thal/HbE patients were compared with 9 controls for concentrations of circulating TNF-alpha and IL-1beta, and 9 and 5 patients, respectively, but only 1 and none of the controls, respectively, showed values above the normal ranges. In patients with abnormally high IFN-gamma levels, basal hemoglobin values were significantly lower than in those with normal levels of the cytokine (mean +/- SEM: 6.03+/-0.24 vs. 7.08+/-0.18, p < 0.05), although circulating concentrations of soluble transferrin receptors (sTrF) and absolute reticulocyte counts were similar in the two groups. Patients with raised or normal levels of TNF-alpha, IL-1alpha, or IL-1beta had similar basal hemoglobin values. In a phagocytosis assay, monocytes of patients with raised serum levels of IFN-gamma showed significantly more attached or ingested IgG-coated red cells than those of patients with normal concentrations of the cytokine (mean +/- SEM: 192+/-22 vs. 140+/-14 per 100 monocytes, p < 0.05). Moreover, in 3 of 4 of the former patients, the number of attached or ingested IgG-coated red cells per 100 monocytes was above the 95% reference limit for the latter patients. The results suggest that IFN-gamma aggravates the anemia of beta(o)-thal/HbE by activating mononuclear phagocytes for destruction of red cells but not by inhibiting erythropoiesis. The elevated serum levels of TNF-alpha and IL-1 could contribute to complications of the disease, such as cachexia and thromboembolic phenomena.
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PMID:Serum levels of tumor necrosis factor-alpha, interleukin-1, and interferon-gamma in beta(o)-thalassemia/HbE and their clinical significance. 1009 Mar 95

Following intravenous inoculation with horse blood-infected with the agent of human granulocytic ehrlichiosis (HGE) from a human fatality, two rhesus macaques (Macaca mulatta) exhibited pyrexia and lethargy on days 4-12 postinfection (PI). Hematology revealed neutropenia, thrombocytopenia, and anemia, with ehrlichial morulae in monocytes and neutrophils on days 4-12. Blood was polymerase chain reaction (PCR)-positive on days 4-12 and bone marrow was PCR-positive on day 11. There was a minor increase in gamma-glutamyl transpeptidase on day 12 and serum interferon-gamma levels increased by day 18. Seroconversion occurred on day 20 PI to a titer of 100 by day 22. Western blot bands characteristic of HGE included 25-, 44-, 80-, 94-, 105-, and 125-kD bands. There was generalized lymphohistiocytic infiltration in the liver, spleen, lymph nodes, and other tissues. The liver had focal hepatocyte apoptosis. There was HGE DNA (by PCR) only in the spleen. Comparable findings were not observed in a monkey that received uninfected horse blood as a control. This animal model of human disease is important for further studies of HGE diagnosis, management, and pathogenesis.
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PMID:A simian model of human granulocytic ehrlichiosis. 1040 32

The use of serotherapy to treat patients with plasma cell dyscrasias (PCDs) has been sought by us and others. Candidate antigens that have been targeted or proposed for targeting in PCDs include the immunoglobulin idiotype, CD19, CD38, CD54, CD126, HM1.24, and Muc-1 core protein. Unfortunately, many of these antigens are not ideal for use in serotherapy since they are not selectively expressed, are either shed or secreted, or have not been fully characterized. Serotherapy with an anti-CD19 monoclonal antibody (B4) conjugated to a blocked ricin toxin had no significant activity in patients with multiple myeloma (MM). Circulating CD20+ clonotypic B cells have been detected in the circulation of most MM and Waldenstrom's macroglobulinemia (WM) patients. Plasma cells from most WM patients express CD20, but most MM patient plasma cells either lack CD20 or express it weakly. In view of recent successes with anti-CD20-directed serotherapy in other B-cell malignancies, we initiated a phase II trial to study the anti-CD20 monoclonal antibody rituximab (Rituxan; IDEC Pharmaceuticals, San Diego, CA, and Genentech, Inc, San Francisco, CA) in patients with MM. We describe two PCD patients (one with WM and one with MM) who responded to therapy. By flow cytometric analysis, CD20+ plasma cells and B cells present in the bone marrow and peripheral blood of a patient with MM disappeared with response to rituximab therapy. However, residual CD20- tumor cells remained in the bone marrow following rituximab therapy, and after 6 months this patient progressed with CD20- myeloma cells. As a potential strategy to overcome this limitation, we demonstrated that interferon-gamma at pharmacologically achievable levels induced CD20 expression on these CD20- plasma cells, consistent with our recent findings that interferon-gamma is a potent inducer of CD20 expression on MM patient plasma cells and B cells. We also characterize a response to rituximab with a decrease in paraprotein and resolution of anemia in a patient with WM whose response to rituximab is ongoing after 19+ months. This preliminary experience supports the potential use of serotherapy targeting CD20 in PCDs. Our studies further suggest that interferon-gamma may enhance CD20 expression on MM plasma cells, thereby increasing their susceptibility to anti-CD20 monoclonal antibody therapies.
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PMID:Treatment of plasma cell dyscrasias by antibody-mediated immunotherapy. 1056 Oct 24

A syndrome of chronic diarrhea, vomiting, and failure to thrive was described 35 years ago. The syndrome was caused by damage in the jejunum after ingestion of cow's milk. Symptoms appeared in young infants shortly after introduction of cow's milk formula. Patients had moderate steatorrhea, decreased absorption of D-xylose, and, often, iron-deficiency anemia and hypoproteinemia. They had strong IgA and IgG antibodies to cow's milk. IgE antibodies to cow's milk were negative, as a rule. Indicators of cell-mediated immune reaction to cow's milk proteins were often positive. Patients were tolerant to cow's milk by the age of 3 years. Malabsorption was due to damage to the jejunal mucosa: Varying villus atrophy was associated with inflammation in surface epithelium and lamina propria. The epithelial cell renewal rate increased. Surface epithelial cells decreased in height, with short, furry microvilli and large aggregates of lysozymes. The number of intraepithelial lymphocytes was markedly increased, but normalized during cow's milk elimination. Most of these lymphocytes had alpha/beta T-cell receptors, and many were cytotoxic. Some specimens had an increase in gamma/delta T-cell receptor-bearing cells. In the lamina propria, CD4+ cells predominated, and some of them were activated. IgA- and IgM-containing cells were markedly increased during cow's milk exposure, but IgE cells were not abnormal. The density of eosinophils was moderately increased. Secretion of interferon-gamma by cells isolated from patients' intestines was markedly increased. Morphologic and immunologic findings suggest that T-cell-mediated reaction to proteins in cow's milk is present in the small intestines of patients with this syndrome and causes this enteropathy.
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PMID:Food-induced malabsorption syndromes. 1063 1

objective To investigate if severe malarial anaemia is associated with a specific immune response pattern, we determined serum levels of neopterin (a marker of activation of macrophages by interferon-gamma) and of the anti-inflammatory cytokines, interleukins 4 and 10. methods Zambian children < 6 years of age presenting to a rural hospital with cerebral malaria were studied. Twenty-one children with admission haemoglobin concentrations </= 5 g/dl were classified as having severe anaemia and 40 with haemoglobin concentrations >/= 7 g/dl served as a control group. results Logistic regression modelling indicated that a 10-fold rise in serum neopterin concentrations was associated with a 50-fold increase in the estimated odds of having severe anaemia (P = 0.015), while a 10-fold rise in serum interleukin 4 concentrations was associated with a 10-fold decrease in the estimated odds of having severe anaemia (P = 0.023). Increasing serum interleukin 10 concentrations, measured in less than half of the subjects, were associated with a nonsignificant reduction in the odds of having severe anaemia (P = 0.095). conclusion Development of severe malarial anaemia may be directly associated with serum neopterin concentrations and inversely correlated with serum interleukin 4 levels.
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PMID:Markers of inflammation in children with severe malarial anaemia 1081 20

In vitro and in vivo, tryptophan degradation was found to be associated with T cell functional loss and tolerance induction. In systemic lupus erythematosus (SLE) besides the Th2-type cytokine interleukin-10, Th1-type cytokines including interferon-gamma (IFN-gamma) are expressed especially during exacerbation of the disease. IFN-gamma stimulates the enzyme indoleamine (2,3)-dioxygenase (IDO) converting tryptophan to the metabolite kynurenine which in macrophages is subsequently degraded to other, partly neurotoxic compounds like quinolinic acid, and finally to nicrotinamides. We measured kynurenine and tryptophan concentrations in the sera of 55 SLE patients. In these patients, the concentrations of tryptophan (median, interquartile range: 53.9, 45.7-64.1 microM) were lower (p < 0.0001), and the kynurenine concentrations (2.45, 1.75-3.40 microM) were increased (p < 0.0005) compared to healthy blood donors (70.0, 63.8-80.6; 1.80, 1.45-2.27 microM, respectively). Also the kynurenine per tryptophan quotients (K/T), which allow to estimate IDO activity, were significantly higher in patients than in normals (0.043, 0.033-0.062 vs. 0.027, 0.021-0.030; p < 0.0001), indicating enhanced IDO-induced tryptophan degradation in SLE. There was no significant relationship between tryptophan, kynurenine and the SLEDAI, and also the correlation of K/T with SLEDAI was rather weak (rs = 0.243, p < 0.05). Higher K/T was found in patients presenting with serositis (p = 0.01), decrease of complement (c3, c4; p < 0.01) and blood count change (anemia, leucopenia, lymphopenia; p = 0.032) than in patients without such disease manifestations. The significant correlation found between K/T and neopterin (rs = 0.808, p < 0.001), a marker of immune activation, points to a role of immune activation to be responsible for tryptophan degradation in SLE patients.
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PMID:Enhanced tryptophan degradation in systemic lupus erythematosus. 1083 18

We report a 40-year-old man who presented with acute onset of hemophagocytic syndrome (HPS) after allogeneic bone marrow transplantation (alloBMT) for acute myelogenous leukemia. On day 8 after alloBMT, the patient suddenly manifested high-grade fever, transfusion-resistant severe anemia, and thrombocytopenia. Neither veno-occlusive disease nor thrombotic microangiopathy was documented. The level of ferritin in serum was elevated to 1192 ng/mL. A bone marrow aspiration test on day 16 showed a markedly increased number of activated macrophages showing massive hemophagocytosis. Serum levels of interferon-gamma, soluble interleukin-2 receptor, interleukin-6, tumor necrosis factor-alpha, and macrophage colony-stimulating factor (M-CSF) were elevated. From these findings, we determined his transfusion-resistant cytopenias to be attributable to HPS. No viruses (including cytomegalovirus, Epstein-Barr virus, human herpes-virus-6, parvovirus B19, and adenovirus B11) were detected in serum or urine by polymerase chain reaction amplification. We speculate that in addition to the administration of M-CSF, hypercytokinemia during the early phase post-alloBMT might have contributed to the onset of HPS in this patient. Methylprednisolone pulse therapy was very effective for the treatment of the HPS. This case reveals that HPS could develop after alloBMT, even when engraftment of hematopoietic cells is not confirmed.
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PMID:Early onset of hemophagocytic syndrome following allogeneic bone marrow transplantation. 1103 76

Protective immunity against Plasmodium falciparum requires constant exposure to the pathogen. T cell-mediated immune responses are induced by T cell epitopes of pre-erythrocytic stage antigens of P. falciparum and involve HLA-restricted CD4 and CD8 cells. Cytotoxic T cell responses to a conserved epitope of P. falciparum liver stage antigen (LSA) type 1 are restricted by the HLA class I allele Bw53. The role of HLA class II alleles in mediating cellular responses against P. falciparum LSA-1 has not yet been demonstrated. In a longitudinal study performed for >4 years, associations were found between the HLA class II allele DQB1*0501 and protection from malaria anemia and malarial reinfections in Gabonese children. Children carrying DQB1*0501 had a higher frequency of interferon-gamma responses to LSA-1 T cell epitopes, compared with noncarriers.
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PMID:HLA-DQB1*0501-restricted Th1 type immune responses to Plasmodium falciparum liver stage antigen 1 protect against malaria anemia and reinfections. 1107 5


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