ascorbic-acid and Transfusion-Reaction

Topics: Ascorbic Acid; Clinical Trials as Topic; Hepatitis, Viral, Human; Humans; Placebos; Transfusion Reaction

In vitro data suggest that vitamin C alters numerous parameters of immune function and might have potential as an agent which prevents infection. When an uncontrolled Japanese trial claimed efficacy of vitamin C in preventing posttransfusion hepatitis, a randomized double-blind controlled trial was initiated to determine if this claim of vitamin C efficacy could be confirmed. For 2 days before surgery and 2 wk after operation, cardiac surgery patients received orally either a lactose placebo or 800 mg of vitamin C four times daily. One hundred seventy-five patients completed the study. Highly significant elevations of plasma vitamin C were seen in the vitamin C treatment group as compared to the placebo group (p < 0.0005), but no significant difference in the incidence of posttransfusion hepatitis (p < 0.50) or the clinical course of hepatitis was seen between the two treatment groups.

Topics: Alanine Transaminase; Ascorbic Acid; Aspartate Aminotransferases; Cardiovascular Diseases; Double-Blind Method; Female; Hepatitis; Hepatitis B Surface Antigens; Humans; Male; Middle Aged; Placebos; Transfusion Reaction

Globally, β-thalassemia major (β-TM) is one of the most common hereditary disorders. Multiple blood transfusions, that are a life-saving therapy in patients with β-TM, is a major source of iron overload. Iron overload can lead to significant morbidity and mortality. Research evidence indicates that oxidative stress induced by iron overload, is one of the major precipitating causes of vitamin C deficiency in β-TM patients. It has previously been shown that patients with β-TM have significantly lower levels of vitamin C as compared to healthy individuals. It is believed that vitamin C can reduce both ferric (Fe(3+)) and ferrous (Fe(2+)) ions, and also facilitate the accessibility of iron to chelators through increase of iron release from the reticuloendothelial system. Despite the potential benefits of vitamin C in patients with β-TM, several areas of concern exist that should be addressed by high quality research designs. Some recommendations have been provided through this study.

Topics: Ascorbic Acid; Ascorbic Acid Deficiency; beta-Thalassemia; Contraindications; Dietary Supplements; Humans; Iron Overload; Nutrition Policy; Oxidative Stress; Transfusion Reaction

Pathogenesis of diabetes-related microvascular complications involving oxidative damage by free radicals has been demonstrated. Free radical generation has been shown to derive largely from iron. Our objectives, therefore, were to determine if there is an increased incidence and/or an accelerated course of nephropathy in patients with diabetes, secondary to transfusional hemochromatosis, and to examine whether free radical activity contributes to the development of this complication.. We evaluated nine patients with homozygous beta-thalassemia, complicated by clinically overt diabetes, for diabetic nephropathy over a 7-year period. Lipid peroxidation was quantified by measuring the presence of 20 saturated and unsaturated aldehydes, and results were compared with five normotensive type 1 diabetic patients without iron overload.. Nephropathy developed in five of nine patients (55%) after a mean duration of overt diabetes of 3.6 +/- 2.0 years. Three patients showed evidence of progressive microalbuminuria over a 7-year period (24.7-46.2, 52.2-430.1, and 17.7-54.3 micrograms/min, respectively). Two patients with borderline microalbuminuria (19.9 and 14.5 micrograms/min, respectively) demonstrated stable albumin excretion rates over the follow-up period. Total aldehyde concentration was significantly higher in beta-thalassemia diabetic patients, compared with nonthalassemic diabetic control subjects (8,106 +/- 1,280 vs. 4,594 +/- 247 nmol/l; P < 0.0001). The three patients with progressive microalbuminuria demonstrated significantly higher total aldehyde concentration, compared with the other beta-thalassemia diabetic patients with stable albumin excretion (9,428 +/- 337 vs. 7,445 +/- 1,003 nmol/l; P < 0.01). Serum vitamin E concentrations were significantly lower in beta-thalassemia patients with diabetes, compared with diabetic patients without iron overload (12.1 +/- 6.0 vs. 25.9 +/- 11.4 mumol/l; P = 0.02). Serum vitamin C concentrations did not differ between the two groups. Multiple regression analysis demonstrated total aldehyde concentration to be the most significant predictor for the development of microalbuminuria (P = 0.01), followed by the duration of diabetes (P = 0.02) and glycemic control (P = 0.02).. Early development and an accelerated course of diabetic nephropathy in iron-loaded patients with beta-thalassemia are observed. These findings may be attributed to high oxidative stress in these patients, which is secondary to iron-derived free radicals and to the patients' diminished antioxidant reserves.

Topics: Adult; Albuminuria; Aldehydes; Antioxidants; Ascorbic Acid; beta-Thalassemia; Blood Glucose; Blood Pressure; Diabetes Complications; Diabetes Mellitus; Diabetic Nephropathies; Fructosamine; Homozygote; Humans; Iron; Kidney Function Tests; Lipid Peroxidation; Oxidative Stress; Retrospective Studies; Transfusion Reaction; Vitamin E

It is well-documented that iron chelation by desferrioxamine protects/improves the cardiac function in blood transfusion-dependent children suffering from beta-thalassaemia. In patients who do not become dependent upon blood transfusion until adulthood (ANT-patients), iron chelation by desferrioxamine may affect the cardiac function in unknown ways, presumably because age-related changes in the heart may cause iron chelation to affect the cardiac function in different ways. We therefore followed the left ventricular ejection fraction (LVEF) by multigated radionuclide angiography in 16 iron-loaded ANT-patients during iron chelation alone and after increasing the efficacy of chelation by vitamin C supplementation. During 12 months of iron chelation the mean LVEF fell significantly from 63.3% to 58.0% (p=0.04). Individual changes in LVEF did not correlate significantly with age but with the pretreatment liver iron concentration. After initiation of vitamin C supplementation, the mean LVEF increased from 55.9% to 65.3% (p=0.01). Our data suggest that in ANT-patients prolonged desferrioxamine treatment without vitamin C supplementation may be associated with reduced LVEF, whereas vitamin C supplementation seems to benefit the cardiac function. Similar findings have not been described in beta-thalassaemia and may hence be specific for ANT-patients. However, our findings have to be confirmed by controlled studies.

Topics: Adolescent; Adult; Aged; Aging; Antidotes; Ascorbic Acid; beta-Thalassemia; Chelating Agents; Coronary Angiography; Deferoxamine; Female; Humans; Injections, Subcutaneous; Iron Overload; Male; Middle Aged; Transfusion Reaction; Ventricular Function, Left

Blood transfusion is the second most important mechanism of transmission of Chagas' disease, and crystal violet is currently used in blood banks in endemic areas in attempts to eliminate such transmission. A photodynamic action of crystal violet against Trypanosoma cruzi trypomastigotes in blood has been detected. This action was enhanced by addition of sodium ascorbate. Photoirradiation of whole blood containing crystal violet increased the concentration of ascorbyl radical and the generation of superoxide anion. Similar results were observed in incubations containing ascorbate and crystal violet in the absence of blood. Hydrogen peroxide generation was also detected in these incubations, thus confirming redox cycling of crystal violet under aerobic conditions. Since photoirradiation and addition of sodium ascorbate reduces significantly the effective dose and time of contact of crystal violet with T. cruzi-infected blood, a possible practical application of these findings is envisaged.

Topics: Animals; Ascorbic Acid; Chagas Disease; Drug Synergism; Electron Spin Resonance Spectroscopy; Free Radicals; Gentian Violet; Mice; Oxidation-Reduction; Oxygen; Photochemistry; Transfusion Reaction; Trypanosoma cruzi

The iron chelating ability and potential toxicity of subcutaneous infusions of the calcium and zinc salts of diethylene triamine penta-acetic acid (DTPA) have been assessed in metabolic balance studies in 2 iron-loaded thalassaemic patients. Infusions of calcium DTPA were locally well tolerated and the drug was as effective as desferrioxamine in mobilising iron. However, daily infusions in the 1st patient also produced symptomatic zinc depletion which could not be controlled by simultaneous oral zinc supplements. Zinc DTPA proved ineffective as an iron chelator, but zinc balance could be maintained in the 2nd patient by combining intermittent (every 4 d) use of calcium DTPA with oral zinc supplements. Combined studies with desferrioxamine and calcium DTPA showed the drugs to have additive effects, probably as a result of the chelation of iron from different body sites.

Topics: Administration, Oral; Adult; Ascorbic Acid; Child; Deferoxamine; Dose-Response Relationship, Drug; Drug Combinations; Female; Humans; Injections, Subcutaneous; Iron; Iron Chelating Agents; Male; Pentetic Acid; Sulfates; Thalassemia; Transfusion Reaction; Zinc; Zinc Sulfate

Topics: Anemia; Ascorbic Acid; Deferoxamine; Genes, Recessive; Hemochromatosis; Humans; Intestinal Absorption; Iron; Transfusion Reaction

Topics: Adult; Ascorbic Acid; Deferoxamine; Dose-Response Relationship, Drug; Feces; Hemosiderosis; Humans; Intestinal Absorption; Iron; Thalassemia; Transfusion Reaction

Topics: Ascorbic Acid; Clinical Trials as Topic; gamma-Globulins; Hepatitis, Viral, Human; Humans; Transfusion Reaction

Topics: Administration, Oral; Adult; Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Deferoxamine; Female; Guinea Pigs; Hemosiderosis; Humans; Injections, Subcutaneous; Iron; Male; Scurvy; Thalassemia; Transfusion Reaction

Topics: Adult; Ascorbic Acid; Ascorbic Acid Deficiency; Female; Humans; Iron; Scurvy; Thalassemia; Transfusion Reaction

The application of noninvasive techniques to the evaluation of cardiac function in iron overload has identified a high incidence of abnormalities in asymptomatic patients prior to the onset of overt cardiac deterioration. Of the tests we have used, radionuclide cineangiography appears to be the most sensitive because it can be conveniently applied during the physiological stress of exercise. Other tests of cardiac function that include stress are also likely to be more sensitive than resting measurements of cardiac function. Systematic application of these techniques to the study of patients on iron chelation therapy should results in an early determination of the efficacy of such treatment.

Topics: Adolescent; Adult; Ascorbic Acid; Child; Child, Preschool; Deferoxamine; Heart; Heart Diseases; Heart Failure; Heart Function Tests; Humans; Iron; Thalassemia; Transfusion Reaction

The effect of 12 and 24 h continuous subcutaneous infusion of desferrioxamine (D.F.) on urinary iron excretion was compared in 13 patients with beta-thalassaemia major and 1 with congenital sideroblastic anaemia, all of whom were receiving regular blood-transfusions. 750 mg D.F. given over a 12 h period, gave a mean total (30 h) iron excretion of 17-5 mg, which was not statistically different from the mean iron excretion of 21-5 mg when the same dose was delivered over 24 h. 1500 mg D.F. gave a mean urinary iron excretion of 28-1 mg with a 12 h infusion, which was significantly less than the mean iron excretion of 39-6 mg with 24 h infusion. The 1500 mg dose gave a significant increase in iron excretion compared with the 750 mg dose when given by either 12 h or 24 h infusion. 7 of 8 patients, given D.F. over a 12 h period, had increased iron excretion when the dose was increased from 750 to 2000 mg. When the dose was increased to 4000 mg, however, the effect on iron excretion was variable. On the other hand, ascorbic-acid therapy was invariably associated with increased iron excretion after subcutaneous D.F. In twelve studies at different dose levels of D.F., ascorbate therapy was associated with increased iron excretion ranging from 24 to 245%. It is concluded that in most patients with transfusional iron overload subcutaneous D.F over a 12 h period, at a dose ranging from 2 to 4 g daily with ascorbic-acid saturation, is at present the most satisfactory method of removing excess iron.

Topics: Administration, Oral; Adolescent; Adult; Anemia, Sideroblastic; Ascorbic Acid; Child; Deferoxamine; Dose-Response Relationship, Drug; Drug Synergism; Drug Therapy, Combination; Female; Hemosiderosis; Humans; Infusions, Parenteral; Iron; Male; Skin; Thalassemia; Transfusion Reaction

Adult patients with transfusional hemosiderosis were given ascorbic acid and treated with the iron chelator, desferrioxamine B. The drug was administered by continuous subcutaneous or intravenous infusions using a light weight portable constant infusion device. On this regimen, four of the five patients studied were able to excrete significant amounts of iron (greater than 35 mg/da) when receiving a daily desferrioxamine dose of 1.5 to 2.2 g. Continuous subcutaneous infusion was well tolerated and about 80 per cent as effective as intravenous therapy in chelating iron. The number of prior transfusions, the hepatic iron content and the serum ferritin levels appear to be useful in predicting which patients will respond to iron chelation therapy, especially if there is little bone marrow erythropoietic activity. One patient with ineffective erythropoiesis did not have significantly increased hepatic iron stores but responded to the administration of desferrioxamine. Continuous subcutaneously administered desferrioxamine may prove to be adaptable for long-term outpatient therapy, allowing patients with ongoing transfusion requirements to go into negative iron balance. Long-term studies will be needed to demonstrate reversal of endocrine, hepatic and cardiac dysfunction secondary to iron deposition in these patients.

Topics: Adult; Aged; Ascorbic Acid; Biopsy, Needle; Deferoxamine; Female; Ferritins; Hemosiderosis; Humans; Infusions, Parenteral; Iron; Liver; Liver Cirrhosis; Male; Middle Aged; Primary Myelofibrosis; Transfusion Reaction

Topics: Adult; Anemia, Sideroblastic; Ascorbic Acid; Deferoxamine; Drug Administration Schedule; Female; Hemosiderosis; Humans; Injections, Intravenous; Injections, Subcutaneous; Iron; Male; Middle Aged; Primary Myelofibrosis; Thalassemia; Transfusion Reaction

Topics: Adolescent; Adult; Ascorbic Acid; Child; Child, Preschool; Deferoxamine; Humans; Hypersplenism; Infant; Iron; Splenectomy; Thalassemia; Transfusion Reaction; United Kingdom

Blood was obtained from 11 healthy voluteers, mixed with two standard types of anticoagulant used in blood transfusion centres and stored for 21-28 days at 4 degrees C. Leucocyte ascorbic acid (LAA) fell to deficient levels after 7 days in all cases. There were no corresponding changes in plasma ascorbic acid (PAA) levels. LAA and PAA were measured before, during and after surgery in 5 control patients who underwent definitive operations for benign peptic ulceration and in 4 patients under-going surgery for bleeding peptic ulceration. The average amount of blood administered to the latter group was 10 units. There was a fall in LAA and PAA in both groups of patients after operation. This fall had returned to normal by 7 days in the controls, but the LAA remained at a deficient level at 7 days in the patients who had bled. Deficient ascorbic acid in stored blood may contribute to low leucocyte ascorbic acid levels in patients after blood transfusion and may contribute to the increased complication rate when surgery is undertaken in these patients.

Topics: Adult; Ascorbic Acid; Ascorbic Acid Deficiency; Blood Preservation; Female; Humans; Leukocytes; Male; Peptic Ulcer; Peptic Ulcer Hemorrhage; Stomach Ulcer; Transfusion Reaction

Topics: Adolescent; Adult; Ascorbic Acid; Blood Transfusion; Calcium; Conjunctiva; Evaluation Studies as Topic; Female; Glucose; Humans; Male; Middle Aged; Myopia; Niacinamide; Retinal Vessels; Thiamine; Transfusion Reaction; Visual Acuity; Visual Fields; Vitreous Body

Topics: Administration, Oral; Adolescent; Adult; Age Factors; Ascorbic Acid; Child; Child, Preschool; Deferoxamine; Drug Synergism; Humans; Iron; Thalassemia; Transfusion Reaction

Topics: Adolescent; Ascorbic Acid; Child; Child, Preschool; Cyprus; Deferoxamine; Drug Synergism; Humans; Iron; Liver; Thalassemia; Time Factors; Transfusion Reaction

Topics: Ascorbic Acid; Chelating Agents; Child; Child, Preschool; Deferoxamine; Humans; Intestinal Absorption; Iron; Pentetic Acid; Thalassemia; Transfusion Reaction

Topics: Ascorbic Acid; Ascorbic Acid Deficiency; Deferoxamine; Hemochromatosis; Humans; Iron; Leukocytes; Male; Siderosis; Transfusion Reaction