The aim of the study was to evaluate kidney function in children after unilateral nephrectomy caused by Wilms' tumour. The study included 40 former patients of the Department of Paediatric Surgery, who underwent complex therapy of Wilms' tumour at the age from 6 months to 8 years (mean 3.42 +/- 2.5 years). In all patients unilateral nephrectomy was performed and chemotherapy was administered. Additionally 24 out of 40 patients underwent radiotherapy. The time of follow-up was 5-26 years (mean 12.2 +/- 5 years). The patients were divided into 2 groups: la--observation time over 10 years, lb--observation time less than 10 years. Another division was made depending on radiotherapy factor: group R+ (24 patients) and group R-(16 patients). The control group consisted of age-matched 24 persons. In all patients the following was evaluated: endogenous creatinine clearance (Ckr), TRP, RH2O, serum and urine concentrations of electrolytes (Na, K, Ca, P), serum concentration of beta 2-microglobulin (beta 2-M) and urine excretion of beta 2-M and NAG.
Results: In all patients Ckr was significantly higher than in the controls. The highest values of Ckr were found in group la, and the difference in relation to group lb was significant (p < 0.02). No difference of Ckr was seen between groups R+ and R-. The mean urinary concentration of beta 2-M was similar in all groups of patients and significantly higher than in the controls. Serum concentration of beta 2-M and urine activity of NAG in all patients were within the normal range. Urine excretion of Na was significantly higher in all patients comparing to controls.
Conclusions: 1. In children, who underwent Wilms' tumour therapy, glomerular hyperfiltration may occur even many years after nephrectomy. 2. Higher urinary excretion of beta 2-M and Na along with normal NAG activity and normal excretion of other electrolytes are the evidence of persistent although slight renal function impairment. 3. Children after complex therapy for Wilms' tumour should be under nephrological care for a long time.