ALB and Hypoalbuminemia: Hypoalbuminemia had a significant impact on the end-of-infusion serum MTX, depending on the degree of hypoalbuminemia: MTX > 150 μM was seen in 37%, 32%, 20% and 8% in groups A to D. Serum albumin < 30 g/L was significantly associated with low MTX clearance < 10 L/h/1.73m2 (78% vs. 36%) and high AUC ≥ 1000 μM*h (44% vs. 31%).