Data Collection
Demographic and clinical data were collected for each subject, including age at diagnosis, gender, ALL risk category, number of nephrotoxic agents received prior, number of hospitalizations, need for vasopressors, need for radiation therapy, obesity, current steroid use, history of AKI, and echocardiograms. Urine samples were collected at the time of study enrollment to assess for protein to creatinine and albumin to creatinine ratios. Serum creatinine obtained as standard of care at multiple times throughout ALL treatment was recorded from time of ALL diagnosis and then at three-month intervals up to time of study enrollment. Serum creatinine was measured using enzymatic method. Estimated glomerular filtration rate (eGFR) was calculated using bedside Schwartz and CKD-EPI creatinine equations 2009, depending on age of the subject24,25.
BP was measured by standard oscillometric methods at each clinic visit. Children 6 years and older were eligible for measurement of BP by ABPM. If they consented/assented to ABPM, a manual BP was obtained in the upper extremity and the appropriate size ABPM cuff and monitor were placed. The ABPM automatically measured BP values (systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MAP)) every 20-30 minutes for a 24-hour period. If the subject was less than 6 years old or declined to wear an ABPM, a manual BP was obtained in clinic. If the BP was > 90thpercentile two repeat BP measuring were obtained at separate follow-up visits.