title: Antioxidant vitamins C and E supplementation increases markers of haemolysis in sickle cell anaemia patients: a randomized, double-blind, placebo-controlled trial.
abstract: 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.
authors.affiliation: Hematology and Blood Transfusion Department, Federal University of São Paulo, UNIFESP, São Paulo, Brazil.
authors.forename: Martha M
authors.initials: MM
authors.lastname: Arruda
authors.forename: Grazielle
authors.initials: G
authors.lastname: Mecabo
authors.forename: Celso A
authors.initials: CA
authors.lastname: Rodrigues
authors.forename: Sandra S
authors.initials: SS
authors.lastname: Matsuda
authors.forename: Iara B
authors.initials: IB
authors.lastname: Rabelo
authors.forename: Maria S
authors.initials: MS
authors.lastname: Figueiredo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000755:Anemia, Sickle Cell / Q000097:blood* / Q000188:drug therapy; D000975:Antioxidants / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D015415:Biomarkers; D019587:Dietary Supplements / Q000009:adverse effects*; D004311:Double-Blind Method; D004363:Drug Utilization / Q000706:statistics & numerical data; D005260:Female; D006461:Hemolysis / Q000187:drug effects*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007249:Inflammation / Q000097:blood; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D011788:Quality of Life; D017382:Reactive Oxygen Species; D012805:Sickle Cell Trait / Q000097:blood / Q000188:drug therapy / Q000235:genetics; D013789:Thalassemia / Q000097:blood / Q000188:drug therapy / Q000235:genetics; D014810:Vitamin E / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D017382:Reactive Oxygen Species; D014810:Vitamin E; D001205:Ascorbic Acid