Apolipoprotein E polymorphism in IgA nephropathy

Background/Aim: To clarify the role of the apolipoprotein E (Apo E) phenoty pe in IgA nephropathy, we investigated its relationship with histological d amage and clinical factors. Methods: The subjects were 104 consecutive pati ents (41 men and 63 women) with IgA nephropathy. The Apo E phenotype was id entified by plasma isoelectric focusing and immunoblotting, and the frequen cies of Apo E alleles were calculated. Results: The frequencies of the phen otypes and the alleles were as follows: 2/2 = 0, 2/3 = 0.086, 3/3 = 0.654, 2/4 = 0.010, 4/3 = 0.211, 4/4 = 0.010, 3/5 = 0.029, epsilon 2 = 0.048, epsi lon 3 = 0.817, epsilon 4 = 0.120, and others = 0.015. There were no signifi cant differences between the IgA nephropathy patients and healthy individua ls in the frequencies of Apo E phenotypes and the alleles. However, the Apo E2 phenotype was significantly more common among patients with severe hist ological damage than in those with mild damage. The serum triglyceride leve ls were significantly elevated, and the Apo E2 phenotype was significantly more prevalent in patients with severe histological damage as compared with those with mild damage. Conclusion: The Apo E2 phenotype appears to be ass ociated with the severity of histological damage in IgA nephropathy.