ascorbic-acid and Sickle-Cell-Trait

This paper reviews the factors governing the rate of iron loading and iron toxicity in the thalassaemia syndromes and sickle cell disease. It outlines the main determinants of iron mobilization by the iron-chelating drug, desferrioxamine, together with the effects of this drug in clinical practice.

Topics: Anemia, Sickle Cell; Ascorbic Acid; Deferoxamine; Drug Administration Schedule; Forecasting; Humans; Iron; Iron Chelating Agents; Sickle Cell Trait; Thalassemia

Erythrocytes from sickle cell anaemia (SCA) patients continuously produce larger amounts of pro-oxidants than normal cells. Oxidative stress seems to primarily affect the membrane and results in haemolysis. The use of antioxidants in vitro reduces the generation of pro-oxidants. To evaluate the impact of vitamins C (VitC) and E (VitE) supplementation in SCA patients, patients over 18 years were randomly assigned to receive VitC 1400 mg + VitE 800 mg per day or placebo orally for 180 d. Eighty-three patients were enrolled (44 vitamins, 39 placebo), median age 27 (18-68) years, 64% female. There were no significant differences between the two groups regarding clinical complications or baseline laboratorial tests. Sixty percent of the patients were VitC deficient, 70% were VitE deficient. Supplementation significantly increased serum VitC and E. However, no significant changes in haemoglobin levels were observed, and, unexpectedly, there was a significant increase in haemolytic markers with vitamin supplementation. In conclusion, VitC + VitE supplementation did not improve anaemia and, surprisingly, increased markers of haemolysis in patients with SCA and S-β(0) -thalassaemia. The exact mechanisms to explain this findings and their clinical significance remain to be determined.

Topics: Adolescent; Adult; Aged; Anemia, Sickle Cell; Antioxidants; Ascorbic Acid; Biomarkers; Dietary Supplements; Double-Blind Method; Drug Utilization; Female; Hemolysis; Hospitalization; Humans; Inflammation; Male; Middle Aged; Oxidative Stress; Quality of Life; Reactive Oxygen Species; Sickle Cell Trait; Thalassemia; Vitamin E; Young Adult

Topics: Anemia, Sickle Cell; Animals; Ascorbic Acid; Copper; Hemolysis; Humans; Rats; Risk; Sheep; Sickle Cell Trait

In vivo incubations of Hgb SC erythrocytes showed significantly more sickling in anterior chambers characterized by high concentrations of ascorbic acid than in anterior chambers with low concentrations of ascorbic acid (normal guinea pigs compared with scorbutic guinea pigs and normal guinea pigs compared with normal rats). Low concentrations of ascorbic acid, however, did not completely eliminate intracameral sickling. Because acetazolamide raises the concentration of aqueous humor ascorbate, it should be used with considerable discretion when treating hyphema and secondary glaucoma caused by sickle cells. Methazolamide may be more desirable.

Topics: Acetazolamide; Anemia, Sickle Cell; Animals; Anterior Chamber; Aqueous Humor; Ascorbic Acid; Erythrocytes, Abnormal; Glaucoma; Guinea Pigs; Hemoglobin, Sickle; Humans; Hyphema; Injections; Male; Rats; Sickle Cell Trait