Antioxidant vitaminsCandEsupplementation increases markers of haemolysis in sickle cell anaemia patients: a randomized, double‐blind, placebo‐controlled trial

Abstract

SummaryErythrocytes 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-b 0 -thalassaemia. The exact mechanisms to explain this findings and their clinical significance remain to be determined.

Pharmacotherapeutical strategies in the prevention of acute, vaso-occlusive pain in sickle cell disease: a systematic review

“…[56][57][58][59][60][61][62][63] Three studies did not use a placebo intervention for their control group. 43,54,56 A majority of studies were performed in North America (n 5 10), 33,46,47,51,61,62,[64][65][66][67][68] Africa (n 5 9), 38,42,52,55,56,59,[69][70][71] and Latin America (n 5 8).…”

“…43,54,56 A majority of studies were performed in North America (n 5 10), 33,46,47,51,61,62,[64][65][66][67][68] Africa (n 5 9), 38,42,52,55,56,59,[69][70][71] and Latin America (n 5 8). 40,44,48,49,53,54,57,72 Four studies were performed on multiple continents. 58,60,63,73 The number of patients per study ranged from 9 to 341.…”

“…A majority of studies were limited to patients with the HbSS or HbSb 0 genotype (n 5 26). 37,38,42,44,45,[48][49][50][51][52][53][54][55][56][57][59][60][61]63,64,66,67,[69][70][71]74 A summary overview of the characteristics, risk of bias, and primary outcomes of the included studies is provided in Table 1. The complete results of our risk-of-bias assessment and a detailed overview of the primary and secondary outcomes of this review per study are provided in supplemental Tables 2 and 3, respectively.…”

“…57 Niihara et al 34,61 (N 5 230) reported that treatment with the oral amino acid L-glutamine over 48 weeks in patients with HbSS and HbSb 0 disease reduced the number of sickle-cell crises, hospitalizations, and hospital days when compared with placebo (Table 1). Also, the number of days to first sickle-cell crisis was significantly higher and crisis severity seemed to be lower in the L-glutamine group.…”

Oxidative stress and labile plasmatic iron in anemic patients following blood therapy

“…However, more studies are necessary to better understand the mechanism(s) associated with iron-induced oxidative changes, to minimize the side effects associated to blood transfusion therapy, and to provide some clinical benefits. As antioxidant supplementation is not entirely safe and may cause unfavorable effects to different patients, more discussion on its potential benefits is warranted [39] .…”