Renal Dysfunction
The overall prevalence of a history of AKI in our cohort was high, with 15 subjects (33%, 95% CI: 20-49%) developing AKI at least once. The majority of AKI occurred at time of diagnosis (10/15, 66.7%). Of the 15 subjects with AKI, 13 (86.7%) had KDIGO stage 1 AKI, 1 (6.7%) had KDIGO stage 2 AKI, and 1 (6.7%) had KDIGO stage 3 AKI. In the 28 high-risk ALL patients, 13 had AKI (46%), while in the 17 standard-risk ALL patients, only 2 had AKI (11.8%). Those treated with high-risk ALL therapy were more likely to have AKI than those treated with standard-risk ALL therapy (P = 0.017). In univariate analysis, predictors for AKI included increasing age at time of diagnosis (median age with AKI 9.5yr vs median age with no AKI 4.3yr, P = 0.006) and high-risk ALL (P = 0.026). Interestingly, number of nephrotoxic agents, number hospitalizations, and need for vasopressors were not found to be significant risk factors for AKI.
No patients in this short period of follow-up demonstrated CKD. However, 13 of 45 patients (28.9%, 95% CI: 16.4-44.3%) had hyperfiltration, which represents a supraphysiologic elevation in GFR. Last recorded GFR for patients are shown in figure 1. The mean last GFR was 146.1ml/min/1.73m2 (range 74-228 ml/min/1.73m2). The median month that last GFR was calculated was 30 months (range 15-60 months) post diagnosis. In the 28 high-risk ALL patients, 9 had hyperfiltration (32.1%). In the 17 standard-risk ALL patients, 4 had hyperfiltration (23.5%). In light of the small sample size, no variable was identified as a risk factor for developing hyperfiltration.
Urinalysis was completed in 41 patients, as 4 were unable to provide a sample. Eleven of 41 patients (24%) had abnormal urinalysis. One patient (2%) had proteinuria alone, 6 patients (15%) had albuminuria alone, and 3 patients (7%) had combined proteinuria and albuminuria. Univariate analysis in the proteinuria group was not performed due to small sample size. Univariate analysis in the microalbuminuria group did not result in identification of any significant risk factors.