Materials and methods
We retrospectively reviewed the medical records of all children aged
under 15 years and diagnosed with AML who received an AML chemotherapy
protocol from May 2003 to August 2019 at the Pediatric Oncology
Division, Department of Pediatrics, Songklanagarind Hospital, the major
tertiary care-referral center in Southern Thailand. The study was
approved by the Human Research Ethics Committee of the institute.
Clinical data including gender, age, tumour morphology, flow cytometry,
treatment courses and laboratory investigations were collected. The
treatment protocol was divided into 3 periods. From 2003-2008, most
patients received chemotherapy consisting of the
Berlin-Frankfurt-Münster (BFM)-83 regimen.11 Between
2008 and 2014, the chemotherapy regimen involved 6 cycles of the BFM-98
regimen.12 After 2014, all patients received
chemotherapy according to the Children’s Oncology
Group.13 All patients underwent similar laboratory
investigation protocols for each session of chemotherapy treatment
including renal function. Posttreatment responses were evaluated after
patients completed the induction chemotherapy course. Overall survival
was calculated from the date of the first diagnosis to date of death or
last follow-up.
We defined AKI following the Kidney Disease: Improving Global Outcomes
(KDIGO) criteria,14 i.e. a rise in serum creatinine
(SCr) ≥ 0.3 mg/dL within 48 hours or 1.5-fold from baseline over 7 days
from nadir to peak and higher than upper normal SCr for age. Severe AKI
was defined as AKI stage 3 (SCr rise of at least 3-fold from baseline in
7 days). Estimated glomerular filtration rate (eGFR) was used to
determine renal function by calculating creatinine clearance using the
original Schwartz formula with a modified Jaffe
assay15 and modified Schwartz formula with enzymatic
creatinine results (after May 2011).16 An eGFR was
considered normal if ≥ 90 mL/min/1.73 m2. Tumor lysis
syndrome was diagnosed by the presence of two or more of the following
abnormal conditions: hyperkalemia (≥ 6 mmol/L), hyperuricemia (≥ 8
mmol/L), hyperphosphatemia (≥ 6.5 mmol/L), and hypocalcemia (<
7 mmol/L) within 3 days before or 7 days after the initiation of
chemotherapy according to the Cairo and Bishop
criteria.17 Septic shock was defined as per
international pediatric sepsis consensus guidelines.18