Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Desferrioxamine (DFX) remains the most effective and safe iron chelator for treatment of patients with transfusional iron overload. It is usually given by intermittent subcutaneous infusions for 8-12 h on 4-6 days weekly using a battery-driven pump. Disposable balloon infusers provide a suitable method of giving continuous subcutaneous infusions with improved patient compliance. For patients with cardiac abnormalities due to iron overload, continuous intravenous desferrioxamine is essential to eliminate toxic plasma non-transferrin bound iron and to reduce body iron stores. Deferiprone (L1, l-2 dimethyl-3hydroxy-pyrid-4-one) is a less effective iron chelator but has the advantage of being orally active. Long-term trials in which patients have taken 75 mg/kg/day have shown that deferiprone is capable of maintaining body iron stores at safe levels in a proportion of thalassaemia major patients but body iron stores, assessed by liver biopsy remain at high levels (> 15.0 mg/g dry weight) in a substantial number of patients. These concentrations have been associated with tissue damage. Trials of increased doses of deferiprone (up to 100 mg/kg/day) or of combined therapy with daily deferiprone and DFX or 1 or 2 days each week are being carried out in an attempt to achieve lower body iron burden in these patients. Preliminary results show that the drugs can be given safely together and urine iron excretion produced is additive, implying that the drugs chelate different body iron pools. Patients previously well chelated with serum ferritin levels less than 2500 micrograms/L have the fewest side-effects from deferiprone and usually may be kept at the same level of body iron for periods of at least 4 years, assessed by serum ferritin and urine iron excretion. The side-effects of deferiprone result in some patients discontinuing therapy. These side-effects, especially arthropathy, mainly occur in previously poorly chelated and so the most heavily iron-loaded patients. Nausea and other gastrointestinal symptoms, agranulocytosis or milder degrees of neutropenia account with arthropathy for nearly all the withdrawals from deferiprone therapy. Patients with cardiomyopathy due to iron overload should be given intravenous DFX rather than deferiprone. Deferiprone, licensed for pharmaceutical use in India, awaits official approval for widespread clinical use in Western Europe and North America. Meanwhile, attempts to find new orally active iron chelators and improved methods of administration of desferrioxamine are in progress.
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PMID:Iron chelation therapy. 935 Jan 80

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

Deferasirox (ICL670) is a once-daily oral iron chelator developed for the treatment of chronic iron overload from blood transfusions. A comparative phase 3 trial was conducted to demonstrate the efficacy of deferasirox in regularly transfused patients with beta-thalassemia aged 2 years or older. Patients were randomized and received treatment with deferasirox (n = 296) or deferoxamine (n = 290), with dosing of each according to baseline liver iron concentration (LIC). The primary endpoint was maintenance or reduction of LIC; secondary endpoints included safety and tolerability, change in serum ferritin level, and net body iron balance. In both arms, patients with LIC values of 7 mg Fe/g dry weight (dw) or higher had significant and similar dose-dependent reductions in LIC and serum ferritin, and effects on net body iron balance. However, the primary endpoint was not met in the overall population, possibly due to the fact that proportionally lower doses of deferasirox relative to deferoxamine were administered to patients with LIC values less than 7 mg Fe/g dw. The most common adverse events included rash, gastrointestinal disturbances, and mild nonprogressive increases in serum creatinine. No agranulocytosis, arthropathy, or growth failure was associated with deferasirox administration. Deferasirox is a promising once-daily oral therapy for the treatment of transfusional iron overload.
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PMID:A phase 3 study of deferasirox (ICL670), a once-daily oral iron chelator, in patients with beta-thalassemia. 1692 97

Due to its excessive cost thalassemia management is a major health care problem in Sri Lanka. The majority of doctors are using only desferrioxamine (DFO), in grossly inadequate doses mainly because of its unavailability. Deferiprone (L1), which is more affordable, is not used due to fear of toxicity, as previously reported. Arthropathy attributed to L1 has been observed in some patients, and has led to the discontinuation of the drug in all patients, without scientific rationale. The proposed thalassemia prevention project for Uva Province is based on prevention of marriages between carriers. This could be achieved by carrier screening and counseling of teenagers and adolescents well before they select their partners. In Sri Lanka, people find their marriage partners at their work place or universities, by themselves, or with the help of professional marriage brokers (they are called Kapuwa), through relatives and close friends. This process of finding a partner may also be helped by paper advertisements. However, in addition to the appearance and attitude of the prospective partner, the caste, social background and horoscope are major considerations in selecting a partner. Even when they select partners on their own at the work place or university, they keep these factors in the back of their minds to ensure social acceptance. Many relationships are given up due to objections and advice from parents when the caste or social background does not match. A horoscope is a written document that almost every child gets, written by a professional horoscope reader and depending on the time of birth. It is believed, according to the horoscope, that a person's attitudes, desires, future prospects of finding a suitable partner, could be predicted. It is rare to proceed with a marriage if the horoscope does not match. These customs are considered less seriously among educated people when they find their partner at the work place or university. The concept of thalassemia risk-free marriages advocates promotion of marriages where at least one partner is a non-carrier. Success of such a project could be monitored at the time of marriage. This opinion survey indicates that the public is motivated to promote carrier screening and the prevention of thalassemia.
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PMID:Thalassemia treatment and prevention in Uva Province, Sri Lanka: a public opinion survey. 1679 53

Although most persons with parvovirus B19 infection are asymptomatic or have mild, nonspecific, cold-like symptoms, several clinical conditions have been linked to the virus. Parvovirus B19 usually infects children and causes the classic "slapped-cheek" rash of erythema infectiosum (fifth disease). The virus is highly infectious and spreads mainly through respiratory droplets. By the time the rash appears, the virus is no longer infectious. The virus also may cause acute or persistent arthropathy and papular, purpuric eruptions on the hands and feet ("gloves and socks" syndrome) in adults. Parvovirus B19 infection can trigger an acute cessation of red blood cell production, causing transient aplastic crisis, chronic red cell aplasia, hydrops fetalis, or congenital anemia. This is even more likely in patients with illnesses that have already shortened the lifespan of erythrocytes (e.g., iron deficiency anemia, human immunodeficiency virus, sickle cell disease, thalassemia, spherocytosis). A clinical diagnosis can be made without laboratory confirmation if erythema infectiosum is present. If laboratory confirmation is needed, serum immunoglobulin M testing is recommended for immunocompetent patients; viral DNA testing is recommended for patients in aplastic crisis and for those who are immunocompromised. Treatment is usually supportive, although some patients may require transfusions or intravenous immune globulin therapy. Most patients recover completely.
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PMID:Clinical presentations of parvovirus B19 infection. 1730 69

Patients with thalassemia major requiring regular blood transfusions accumulate iron that is toxic to the heart, liver, and endocrine systems. The following prospective, randomized trial was carried out to determine the effectiveness, in children and young adults, of combined deferiprone (DFP) and deferoxamine (DFO) in reducing transfusional iron overload compared to either drug alone and to assess the safety and tolerability of DFP. Sixty-six patients were randomized into three treatment arms: daily DFP combined with DFO twice weekly; daily DFP only; and DFO only 5 days/week. Fifty-six patients completed the 54 weeks and were assessed by different indices. A significant reduction of liver iron concentration and serum ferritin was observed in all three arms while significant reduction of liver iron score was observed in patients on combination therapy only. Cardiac function did not significantly change in any arm. Compliance improved in patients who received combined therapy. Toxicity of DFP was mild to moderate and acceptable; most commonly, transient arthropathy and nausea/vomiting were observed. Thus, combination therapy has shown to be effective in reducing iron overload in thalassemia patients.
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PMID:Iron chelation in thalassemia: combined or monotherapy? The Egyptian experience. 1835 37

Deferiprone (DFP) has been evaluated in a wide range of disorders, but most data come from transfusion-dependent thalassemia. The safety and tolerability profile includes gastrointestinal complaints, liver enzymes elevation, weight gain, arthropathy, neutropenia, and agranulocytosis. The last requires close monitoring of blood count and precludes the use of DFP in conditions with bone marrow abnormalities. The efficacy profile is similar among the three available chelators. For DFP, the choice of dosage is crucial to optimize the effect on liver iron concentration, according to the iron load degree and transfusional iron input. Growing evidence indicates that DFP, alone or in combination with deferoxamine, is effective in removing cardiac iron and preventing cardiac iron load. The available data consolidate an important role of DFP in the management of iron overload. There is a need to compare directly the relative value of the available chelators in the long-term prevention of iron toxicity by well-designed randomized controlled trials.
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PMID:Deferiprone. 2071 76

Deferiprone is an orally active iron-chelating agent used in the management of transfusion-related hemosiderosis. It has been in clinical use for over 20 years and has been shown to be effective in reducing cardiac iron load and improving cardiac function. As cardiac siderosis is the leading cause of death in patients with transfusion-dependent thalassemia, deferiprone helps to improve the overall prognosis of these patients. It is relatively well tolerated with gastrointestinal symptoms being the commonest side effects. Agranulocytosis (0.5%), neutropenia (9%), thrombocytopenia (up to 45%) and arthropathy (20%) are the most important side effects and may require discontinuation of therapy. Regular monitoring of blood counts is recommended for patients on deferiprone therapy.
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PMID:Safety and efficacy of iron chelation therapy with deferiprone in patients with transfusion-dependent thalassemia. 2361 17

Human parvovirus B19 (B19V) causes myriads of clinical diseases; however, owing to lack of awareness and undetermined clinical impact, it has failed to become a virus pathogen of global concern. Cryptically, B19V causes significant morbidity and mortality. Half of the world population and 60 per cent of Indians are known to be serologically naive and are at risk of acquiring B19V infections. Cumulatively, our data showed 21.3 per cent B19V-infected patients with juvenile chronic arthropathy, recurrent abortions, multi-transfused thalassaemia and leukaemia. In addition, B19V-infected cases that ended fatally included patients with pure red cell aplasia, fulminant hepatitis and haemophagocytic syndrome. Novel clinical associations of B19V observed were amegakaryocytic thrombocytopaenia, myositis and non-occlusive ischaemic gangrene of bowel. B19V possesses multiple receptors which are distributed widely in human tissues. Vascular endothelial cell infection by B19V causes endothelialitis and vasculitic injuries besides antibody-dependent enhancement which empowered B19V to cause multiorgan diseases. Owing to lack of suitable animal model for B19V, true causal role remains to be determined, but numerous reports on B19V infections substantiate a causal role in multiorgan diseases. Hence, B19V infections need to be recognized, investigated and treated besides making efforts on vaccine developments.
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PMID:Clinical impact & pathogenic mechanisms of human parvovirus B19: A multiorgan disease inflictor incognito. 3066