Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

3'-azido-3'-deoxythymidine (AZT), the first chemotherapeutic drug approved by FDA for treatment of HIV-infected patients and still used in combination therapy, has been shown to induce, upon prolonged exposure, severe bone marrow toxicity manifested as anemia, neutropenia and siderosis. These toxic effects are caused by inhibition of heme synthesis and, as a consequence, transferrin receptor (TfR) number appears increased and so iron taken up by cells. Since iron overload can promote the frequency and severity of many infections, siderosis is viewed as a further burden for AIDS patients. We have previously demonstrated that AZT-treated K562 cells showed an increase of the number of TfRs located on the surface of the plasma membrane without affecting their biosynthesis, but slowing down their endocytotic pathway. In spite of the higher number of receptors on the plasma-membrane of AZT-treated cells, intracellular accumulation of iron showed a similar level in control and in drug-exposed cells. The chelating ability of AZT and of its phosphorylated derivatives, both in an acellular system and in K562 cells, was also checked. The results demonstrated that AZT and AZTMP were uneffective as iron chelators, while AZTTP displayed a significant capacity to remove iron from transferrin (Tf). Our results suggest that AZT may be not directly involved in the iron overloading observed upon its prolonged use in AIDS therapy. The iron accumulation found in these patients is instead caused by other unknown mechanisms that need further studies to be clarified.
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PMID:Effects of AZT on cellular iron homeostasis. 1525 65

Gallium nitrate inhibits the growth of various lymphoma cell lines in vitro and exhibits antitumor activity in patients with lymphoma. The mechanism(s) of cytotoxicity is (are) only partly understood but appears to involve a two-step process: (1) targeting of gallium to cells, and (2) acting on multiple, specific intracellular processes. Gallium shares certain chemical properties with iron; therefore, it binds avidly to the iron transport protein transferrin. Transferrin-gallium complexes preferentially target cells that express transferrin receptors on their surface. Expression of transferrin receptors is particularly high on lymphoma cells. Cellular uptake of the gallium-transferrin complex leads to inhibition of cellular proliferation primarily via disruption of iron transport and homeostasis and blockade of ribonucleotide reductase. Recent studies have shown that cellular uptake of gallium leads to activation of caspases and induction of apoptosis. In phase II trials in patients with relapsed or refractory lymphoma, the antitumor activity of gallium nitrate is similar to, or better than, that of other commonly used chemotherapeutic agents. Gallium nitrate is not myelosuppressive and may be used in patients with neutropenia or thrombocytopenia. A multicenter trial to evaluate the use of gallium nitrate in patients with relapsed non-Hodgkin's lymphoma is currently ongoing.
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PMID:Apoptotic mechanisms of gallium nitrate: basic and clinical investigations. 1565 Nov 76

Iron chelation is needed to prevent damage to the heart, liver and endocrine glands from iron overload in patients with refractory anaemias who receive regular blood transfusions. Desferrioxamine is still the first-line drug, but because of its expense in many countries, and lack of compliance because of difficulty with administration, there is a major need for an orally active (and cheaper) chelating drug. Seventeen years after the first clinical trials deferiprone, which is orally active, has emerged as suitable for patients for whom desferrioxamine is, for one reason or another, inadequate. Many patients are successfully chelated at a dose of deferiprone 75 mg/kg/day. Some patients may need higher doses (up to 100 mg/kg), or combination therapy of deferiprone every day and desferrioxamine on several days each week. Recent data suggest that deferiprone may be superior to desferrioxamine at protecting the heart from iron overload. The side-effects of deferiprone--agranulocytosis, neutropenia, gastrointestinal symptoms, arthropathy, transient changes in liver enzymes, and zinc deficiency--are now well recognized; they result in discontinuation of the drug in only 5-10% of patients. Deferiprone is now licensed in 43 countries for thalassaemia major patients for whom desferrioxamine is inadequate. If results of current trials confirm its superiority at reducing cardiac damage, it may well become the first-line drug for many patients.
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PMID:Deferiprone therapy for transfusional iron overload. 1573 92

HIV infection is associated with numerous abnormalities affecting both the myeloid and lymphoid lineages. We studied the features associated with peripheral cytopenias as the first sign of HIV infection in children. Peripheral blood (PB) counts, PB and bone marrow (BM) lymphocyte subsets, as well as viral load and serum levels of ferritin, vitamin B12, and folic acid were determined. Five children were naive of treatment (Group 1) and three were under HAART (Group 2). In Group 1 all patients had anemia of chronic disease. One had a bone marrow culture positive for Mycobacterium avium intracellulare and pancytopenia. Besides this, neutropenia and thrombocytopenia were seen in one patient each. In Group 2 anemia was found in all, neutropenia in one, and thrombocytopenia in two patients. Peripheral blood cytopenias were due to HAART toxicity in one patient. In the other two they were due to iron or folate deficiency. Bone marrow cytology showed cell abnormalities mainly in granulocytic precursors and megakaryocytes. All except two (taking HAART) patients had a high viral load. There was a straight correlation between viral load in PB and bone marrow. Viral load was correlated with peripheral CD4 but not with CD8 lymphocytes. A decrease in bone marrow B lymphocytes was seen in all patients. The introduction of HAART improved peripheral cytopenias. Bone marrow examination was useful for determining the etiology of the cytopenias and for detection of opportunistic infection. Hemopoietic cell abnormalities were similar to those seen in adults and indicative of HIV infection.
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PMID:Bone marrow features in children with HIV infection and peripheral blood cytopenias. 1584 Jul 62

There are few extensive studies about clinicopathological findings of spontaneous canine babesiosis caused by a large form of the parasite found in Europe. To further characterize and describe clinicopathological findings in dogs affected with this large form of Babesia in northeastern Italy, we evaluated 23 Italian dogs with canine babesiosis by means of clinical history, physical examination, hematological, biochemical, hemostatic tests, serum electrophoresis and urinalysis. Seventeen dogs (74%) had recently traveled on a hunting trip (within 5-15 days of being presented to the clinic) to Bosnia and Herzegovina (n=7), to Croatia (n=8) and to Hungary (n=2). The duration of clinical signs ranged from 1 to 5 days prior to the arrival at the clinic. The main clinical signs were dehydration (100%), apathy (74%), anorexia or decrease appetite (70%) and fever (68%). The anemia was present in 74% of the dogs and classified as mild (35%), moderate (59%) and severe (6%). In all cases, the anemia was normocytic and normochromic. Only three dogs presented erythrocyte regeneration. Seventy percent of dogs had hemolytic anemia and 30% had non-hemolytic anemia. Sixty-nine percent of dogs showed leucopenia and 74% neutropenia. Leucocitosis, due to mature neutrophilia and lymphocytosis, was present in one dog. Activated lymphocytes were noted in 61% of dogs. In all dogs, thrombocytopenia and an elevated hyperfibrinogenemia were present. Significant prolonged activated partial thromboplastin time (aPTT) was only found in one case. In four dogs, both plasma fibrinogen/fibrin degradation products (FDPs) and D-Dimer were increased. Antithrombin (AT) was slightly decreased in 11 of the 23 dogs. In the majority of cases, mild elevation of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), creatinekinase (CK), total bilirubin and lactic acid and decrease of total iron and total iron binding capacity (TIBC) were present. In conclusion, the main clinicopathological findings were a mild to severe thrombocytopenia, a mild to moderate hemolytic anemia, neutropenia and hyperfibrinogenemia.
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PMID:Clinicopathological findings in naturally occurring cases of babesiosis caused by large form Babesia from dogs of northeastern Italy. 1611 10

We evaluated the risk factors for infection of 367 consecutive myeloma patients who underwent high-dose melphalan and autologous stem cell transplantation (ASCT). Examination of bone marrow iron stores (BMIS) prior to ASCT was used to evaluate body iron stores. Other variables included age, sex, active smoking, myeloma remission status, severity of mucositis and duration of severe neutropenia post-ASCT (<100 absolute neutrophils counts (ANC)/microl). Median age was 56 years; 61% of patients were males. 140 episodes of severe infections occurred in 116 patients, including bacteremia (73), pneumonia (40), severe colitis (25) and bacteremia with septic shock (two). The infection incidence per 1,000 days at risk was 45.2. Pre-ASCT risk factors for severe infection by univariate analysis were increased BMIS (OR=2.686; 95% CI 1.707-4.226; P<0.0001), smoking (OR=1.565; 95% CI 1.005-2.437; P=0.0474) and male gender (OR=1.624; 95% CI 1.019-2.589; P=0.0414). Increased BMIS (OR=2.716; 95% CI 1.720-4.287; P<0.0001) and smoking (OR=1.714; 95% CI 1.081-2.718; P=0.022) remained significant by multivariate analysis. Duration of ANC <100 micro/l (OR=1.129; 95% CI 1.039-1.226; P=0.0069 and OR=1.127; 95% CI 1.038-1.224; P=0.0045 by both univariate and multivariate analysis, respectively) was the only post-ASCT risk factor for infection. Increased pre-transplant BMIS and smoking are significant predictors of severe infection after myeloablative chemotherapy followed by ASCT in myeloma patients.
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PMID:Iron overload is a major risk factor for severe infection after autologous stem cell transplantation: a study of 367 myeloma patients. 1653 17

Deferiprone (L1) has been recommended as an effective oral chelation therapy for patients with beta-thalassemia major (TM). From 1999 to 2004, 114 patients with TM from five treatment centers were enrolled in this program: iron (Fe) was chelated with L1 in 57 patients, deferoxamine (DFO) in 26, and combined L1/DFO therapy in 31. We found that serum ferritin (SF) was significantly lower in nine patients receiving L1 for more than 5 years (p = 0.04), 22 patients receiving L1 for 1-2 years (p < 0.01) and 31 receiving the combined therapy (p = 0.01), yet significantly higher in those receiving DFO only (p < 0.01). One patient showed transient neutropenia; arthropathy in one patient and gastrointestinal upset in two were noted, with no significant change in alanine aminotransferase (ALT) level. Of 17 patients who were submitted to a liver biopsy, 15 showed no significant change in hepatic fibrosis scores after therapy with L1. None of the 88 patients, including 31 who received the combined therapy, have abandoned oral L1 treatment due to adverse effects. Results of this study proved that L1 or combined therapy with L1 and DFO is effective in reducing SP; incidence of adverse events was low in patients with TM.
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PMID:Deferiprone or deferoxamine vs. combination therapy in patients with beta-thalassemia major: a case study in Taiwan. 1654 Apr 25

A controlled, open-label and randomized study was conducted to evaluate the safety and efficacy of the oral iron chelator deferiprone (L1) in thalassemia major patients from Hong Kong. Forty-nine patients were recruited in total (median age: 20 years; range: 8 to 40 years). The division of the patients was determined based on liver iron content and put into either the poorly-chelated (Group I) or well-chelated (Group II) groups. In Group I, 20 patients received combined therapy of L1 daily plus desferrioxamine (DFO), in a reduced frequency of twice weekly, while the control group consisted of 16 patients who were treated with DFO alone. In Group II, six patients received L1 only, while the control group consisted of seven patients treated with DFO alone. Only patients who participated for longer than 6 months were analyzed for efficacy (n = 44). The median study period was 18 months. Transient and mild gastrointestinal upset (31%), joint pain (15%) and liver enzyme elevation (23%) were the most common side effects noted for L1. No case of neutropenia was observed in this study. Serum ferritin (SF) levels showed significant decline in the poorly-chelated patients using combined therapy (L1 and reduced frequency DFO) as compared to those on DFO alone. However, their pre- and post-study liver iron content was not significantly different. Evaluation of the well-chelated group demonstrated no significant change in SF or liver iron content in both the study and control arms. We conclude that the short-term use of L1, with or without DFO, was safe and efficacious in our Chinese patient cohort. The long-term efficacy of reducing iron overload by treatment regimens including L1 requires further study.
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PMID:A randomized controlled study evaluating the safety and efficacy of deferiprone treatment in thalassemia major patients from Hong Kong. 1679 52

The incidental discovery of neutropenia during routine blood counting represents a common problem for clinicians. However, there are no reported data of systematic evaluations of adults with incidental neutropenia. As such, this was the aim of the present study. Ninety-seven adults with incidental neutropenia were submitted to a clinical and laboratory approach including medical evaluation, complete blood count (CBC), serial CBC, direct and indirect antiglobulin test, bone marrow smear and biopsy, assessment of folate, vitamin B12 and iron status, serum liver enzymes, serum proteins, serological exams for hepatitis B and C virus, cytomegalovirus, mononucleosis, human immunodeficiency virus and toxoplasmosis, detection of lupus erythematosus cells, antinuclear and anti-DNA antibodies and rheumatoid factor, dosage of free thyroxin and thyrotropin, chest roentgenogram and abdominal echography. Chronic idiopathic neutropenia of adults was identified in 34.0% of the individuals, neutropenia due to exposure to chemical agents was seen in 16.5%, infectious diseases in 9.3%, autoimmune diseases in 9.3%, haematological diseases in 9.3%, thyroid disorders in 8.2%, ethnic neutropenia in 7.2%, drug-related neutropenia in 2.1%, cyclic neutropenia in 2.1% and iron deficiency in 2.1%. Recovery or improvement of the neutrophil count was seen upon treatment or recuperation from infectious, autoimmune, haematological and thyroid diseases and iron supplementation. We conclude that the evaluation of individuals with incidental neutropenia using a structured approach may make the identification of clinically silent diseases possible, and provide an opportunity for early treatment, avoiding complications of the diseases and consequences of neutropenia.
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PMID:Causes of incidental neutropenia in adulthood. 1680 47

Copper deficiency is a rare complication of enteral nutrition. Haematologic abnormalities such as neutropenia and anaemia, but not pancytopenia, have been described associated to copper deficiency. We report the case of a patient requiring long term enteral nutrition through jejunostomy who developed copper deficiency and pancytopenia. In 1991, a 47-year-old woman was admitted with severe gastroesophageal mucositis after an attempted suicide with caustic intake. Enteral nutrition with a commercial, polymeric, fiber-containing formula was started. Twenty-eight months later, the patient developed anemia and neutropenia that did not respond to combined iron and parenteral vitamin B(12) supplementation. In 1996 the patient showed pancytopenia and low serum levels of copper and ceruloplasmin. Pancytopenia improved after copper supplementation. Possible mechanism causing copper deficiency and pancytopenia are discussed. We conclude that assessment of copper status is advisable in patients receiving long-term enteral nutrition by jejunostomy.
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PMID:Copper deficiency with pancytopenia due to enteral nutrition through jejunostomy. 1684 85


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