Título

EVALUATION OF RENAL FUNCTION PARAMETERS IN PEDIATRIC ONCOLOGY PATIENTS SUBMITTED TO CHEMOTHERAPY IN A TERTIARY HOSPITAL

Resumo

Introduction: Solid tumors are rare in the pediatric age range, although it exerts an important impact on child mortality. Chemotherapy constitutes the standard protocol in cancer treatment and some of the most commonly used drugs, including cisplatin, ifosfamide, cyclophosphamide, carboplatin and methotrexate, are nephrotoxic and may deflagrate kidney damage. Therefore, patients at risk for nephrotoxicity must be monitored with blood pressure measurements and analysis of renal function parameters. Usually, this evaluation is based only on the determination of urea and creatinine plasma concentrations and on the quantification of proteinuria, which do not reflect immediate changes in renal function, underestimating the nephrotoxicity induced by chemotherapy, especially in children. Objective: To evaluate renal function following potentially nephrotoxic chemotherapy treatment in children. Methods: This cross-sectional study included 41 patients undergoing potentially nephrotoxic chemotherapy drugs. The evaluation comprised (1) physical examination, measurement weight, height and blood pressure; (2) blood analysis for urea, creatinine, sodium, potassium, calcium, phosphorus, magnesium, chlorine, venous blood gases, glucose, cholesterol, triglycerides and total proteins and fractions; (3) urine evaluation considering routine urinalysis and determination of osmolarity, pH, microalbuminuria, beta-2-microglobulin levels (B2MG), electrolytes and creatinine. Data collection and the study protocol tests were performed during a routine visit. Results: Only one patient had elevated serum creatinine and consequent reduction of GFR (78ml/min/1.73m²). However, 12 patients had glomerular hyperfiltration (GFR above 140ml/min/1.73m²). All patients presented normal microalbuminuria (<30mcg/mg). B2MG measurements were higher than the reference range. Creatinine was strongly and positively correlated with B2MG levels (r>0.70 and p<0.001) and the estimated GFR was negatively correlated with this same parameter (r<0 and p<0.001). The variables creatinine, systolic arterial pressure and cholesterol were included in a linear regression prediction model, which showed that the higher the measures of these independent variables, the greater the extent of B2MG. Conclusion: All patients had B2MG levels above the reference values and one-third had hyperfiltration. Both findings can be considered as potential biomarkers of renal injury in children treated with nephrotoxic chemotherapy.

Área

Nefrologia Pediátrica

Autores

LARISSA BRAGA COSTA, Larissa Braga Costa, Katharina Lanza, Vitória Andrade Palmeira, Fernanda Rodrigues Tiburcio, Ana Cristina Simões e Silva