Hypoalbuminemia in children with acute lymphoblastic leukemia: relation to asparaginase therapy and impact on high dose methotrexate elimination.

PURPOSE

High-dose methotrexate (HDMTX) therapy is an important component in treatment regimens for acute lymphoblastic leukemia (ALL). Courses are associated with a risk of renal injury, delayed elimination, and increased systemic toxicity. Recently hypoalbuminemia has been recognized as yet another risk factor.

METHODS

To examine the impact of serum albumin we reviewed 325 HDMTX 5 g/m2 courses in a cohort of 51 children treated on the NOPHO ALL 2008 protocol, dividing the courses into four groups with different levels of baseline albumin (A < 25 g/L, B 25-29 g/L, C 30-34 g/L and D ≥ 35 g/L).

RESULTS

Hypoalbuminemia was present in 51% of the courses, mostly in the early phases of chemotherapy while asparaginase therapy is ongoing, and especially if given less than 2 weeks after a dose (78%). 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%). The frequency of rising creatinine or prolonged elimination was not increased, but the risk of stomatitis was significantly higher (42% vs. 19%).

CONCLUSION

Low serum albumin is caused by concurrent asparaginase therapy and has a clinically significant impact on MTX disposition. Guidelines for administering HDMTX may need adjustment if serum albumin < 30 g/L, and, if possible, HDMTX courses should not be scheduled soon after asparaginase doses.