GAN and acute kidney injury: Isoagglutinin titers of perioperative Ig G and Ig M were significant contributors to the development of AKI (Ig M: odds ratio 1.04, 95% CI 1.02 to 1.08, p < 0.001; Ig G: odds ratio 1.02, 95% CI 0.98 to 1.05, p = 0.125).