Abstract: FR-PO405

Association between Serum Albumin Level and Incidence of ESRD in Patients with Immunoglobulin A Nephropathy: A Possible Role of Albumin as an Antioxidant Agent

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 301 CKD: Risk Factors for Incidence and Progression

Authors

  • Kawai, Yasuhiro, Kyushu University, Graduate School of Medical Sciences, Fukuoka City, Fukuoka, Japan
  • Masutani, Kosuke, Kyushu University, Graduate School of Medical Sciences, Fukuoka City, Fukuoka, Japan
  • Torisu, Kumiko, Kyushu University, Graduate School of Medical Sciences, Fukuoka City, Fukuoka, Japan
  • Katafuchi, Ritsuko, National Fukuoka-Higashi Medical Center, Koga, Fukuoka, Japan
  • Tanaka, Shigeru, Fukuoka Dental College, Fukuoka, Japan
  • Tsuchimoto, Akihiro, Kyushu University, Graduate School of Medical Sciences, Fukuoka City, Fukuoka, Japan
  • Mitsuiki, Koji, Kyushu University, Graduate School of Medical Sciences, Fukuoka City, Fukuoka, Japan
  • Tsuruya, Kazuhiko, Kyushu University, Graduate School of Medical Sciences, Fukuoka City, Fukuoka, Japan
  • Kitazono, Takanari, Kyushu University, Graduate School of Medical Sciences, Fukuoka City, Fukuoka, Japan
Background

Serum albumin is the most abundant intravascular protein and the major intravascular antioxidant. The association between serum albumin and the incidence of end-stage renal disease (ESRD) in patients with IgA nephropathy (IgAN) is not fully understood.

Methods

We retrospectively investigated 1,352 patients who were diagnosed with IgAN by kidney biopsy from seven institutions in Japan between October 1979 and December 2010. Patients were divided into three groups by tertile of serum albumin value: Low group, Middle group, and High group (≤3.9 g/dL, 4.0–4.3 g/dL, ≥4.4 g/dL, respectively). The association between serum albumin level and the incidence of ESRD was assessed using a Cox proportional hazards model. We also conducted an experiment of dihydroethidium staining for detection of decrease in intracellular superoxide anion induced by hydrogen peroxide in albumin-pretreated mouse mesangial cells.

Results

During the median 5.1-year follow-up period, 152 patients (11.2%) developed ESRD. Participants in Low group had a 1.88-fold (95% confidence intervals, 1.15–3.20) higher risk of the incidence of ESRD than those in High group after adjustment for age, sex, systolic blood pressure, urinary protein excretion, body mass index, estimated glomerular filtration rate, total cholesterol, triglycerides, and pathological parameters of the Oxford classification (M, E, S, T) and extracapillary proliferation (Ex). Furthermore, in in vitro experiments, generation of intracellular superoxide anion, a major form of reactive oxygen species, by hydrogen peroxide was significantly attenuated in albumin-pretreated mouse mesangial cells compared with γ-globulin-pretreated cells.

Conclusion

Low serum albumin level is an independent risk factor of ESRD in patients with IgAN. The mechanism could be explained by the antioxidant capacity of serum albumin.