Plasma monomeric ApoA1 and high-density lipoprotein bound ApoA1 are markedly decreased and associated with low levels of lipophilic antioxidants in sickle cell disease: A potential new pathway for therapy

Eur J Haematol. 2024 Dec;113(6):788-797. doi: 10.1111/ejh.14288. Epub 2024 Aug 20.

Abstract

Patients with sickle cell disease (SCD) exhibit high levels of reactive oxygen species and low plasma levels of lipophilic antioxidants, which may contribute to end-organ damage and disease sequelae. Apolipoprotein A1, the major apolipoprotein of high-density lipoprotein (HDL), is mainly secreted by the intestine and liver in the form of monomeric ApoA1 (mApoA1) present in plasma. Cholesterol and α-tocopherol are delivered to ApoA1 via the ATP-binding cassette transporter, subfamily A, member 1 (ABCA1). We measured cholesterol, mApoA1, ApoA1, and lipophilic antioxidants in the plasma of 17 patients with SCD and 40 healthy volunteers. Mean HDL cholesterol (-C) levels in SCD patients and healthy subjects were 59.3 and 48.1 mg/dL, respectively, and plasma lutein, zeaxanthin, and α-tocopherol were 64.0%, 68.7%, and 9.1% lower, respectively. To compare SCD to healthy subjects with similar HDL-C, we also performed subgroup analyses of healthy subjects with HDL-C above or below the mean. In SCD, the mApoA1 level was 30.4 μg/mL; 80% lower than 141 μg/mL measured in healthy volunteers with similar HDL-C (56.7 mg/dL). The mApoA1 level was also 38.4% greater in the higher versus lower HDL-C subgroups (p = .002). In the higher HDL-C subgroup, lutein and zeaxanthin transported by HDL were 48.9% (p = .01) and 41.9% (p = .02) higher, respectively, whereas α-tocopherol was 31.7% higher (p = .003), compared to the lower HDL-C subgroup. Plasma mApoA1 may be a marker of the capacity of HDL to capture and deliver liposoluble antioxidants, and treatments which raise HDL may benefit patients with high oxidative stress as exemplified by SCD.

Keywords: ApoA1; HDL; lutein; zeaxanthin; α‐tocopherol.

MeSH terms

  • Adult
  • Anemia, Sickle Cell* / blood
  • Anemia, Sickle Cell* / drug therapy
  • Antioxidants* / metabolism
  • Apolipoprotein A-I* / blood
  • Biomarkers / blood
  • Case-Control Studies
  • Cholesterol, HDL / blood
  • Female
  • Humans
  • Lipoproteins, HDL* / blood
  • Male
  • Middle Aged
  • Protein Binding
  • Young Adult
  • alpha-Tocopherol / blood

Substances

  • Antioxidants
  • Apolipoprotein A-I
  • Lipoproteins, HDL
  • APOA1 protein, human
  • alpha-Tocopherol
  • Cholesterol, HDL
  • Biomarkers