S100A6 and chronic kidney disease: Pre-transplant comorbidities including diabetes (hemoglobin A1c > 6.5%), connective tissue disease, chronic kidney disease (the glomerular filtration rate < 60 mL/min/1.73 m2) [7] and gastroesophageal reflux disease (typical symptoms and endoscopic changes) [8], were also assessed in PRA+ and PRA- groups without significance (p = 1.000, 0.100, 0.590 and 1.000, respectively).