Plasma Ischemia-Modified Albumin Levels and Dynamic Thiol/ Disulfide Balance in Sickle Cell Disease: A Case-Control Study

Abstract

Objective: Sickle cell disease (SCD), described as a group of inherited blood disorders, affects millions of people throughout the world and is particularly common in the southern part of Turkey. We aimed to determine the relationship between ischemia-modified albumin (IMA) and the dynamic thiol/disulfide balance in SCD. Materials and Methods: Fifty-four adult SCD patients and 30 healthy controls were included in the study. The 54 adult patients included 30 (56%) males and 24 (44%) females with a mean age of 28.3+-8.4 years (minimum-maximum: 18-46 years). Of the 54 patients, 46 had homozygous sickle cell anemia (HbSS) and 8 had sickle/β-thalassemia (HbS/β+-thalassemia). Fasting blood samples were collected. After centrifugation at 1500×g for 10 min, plasma samples were portioned and stored at -80 °C. IMA levels were determined by albumin cobalt binding test, a colorimetric method. Total and native thiols and disulfide were analyzed with a novel spectrophotometric method. Results: We found significantly lower levels of native thiol (-SH) (284.0+-86.3 μmol/L), disulfide levels (14.6+-7 μmol/L), and total thiols (-SH + -S-S-) (313.0+-89.3 μmol/L) in SCD patients compared to healthy controls (respectively 417.0+-54.2, 22.7+-11.3, and 462.0+-58.7 μmol/L). Plasma albumin levels (34.9+-7.9 g/L) were lower and IMA levels (13.6+-3.1 g/L) were higher in SCD patients compared to controls (respectively 43.5+-3.1 and 8.4+-1.6 g/L). Plasma albumin levels were strongly correlated with both plasma native (r=0.853; p=0.0001) and total thiols (r=0.866; p=0.0001). Conclusion: Decreased plasma native and total thiol levels and increased IMA levels are related to increased oxidative stress and provide an indirect and quick reflection of the oxidative damage in SCD patients.

Keywords

• sickle cell disease
• thiol/disulfide homeostasis
• oxidative stress
• ischemia-modified albumin