[1] Karolinska Univ Hosp, Div Paediat, Dept Clin Sci Intervent & Technol, Karolinska Inst, S-14186 Huddinge, Sweden
[2] Hosp Italiano Buenos Aires, Serv Nefrol Pediat, Hop Italiano, Buenos Aires, DF, Argentina
[3] Hosp Italiano Buenos Aires, Unidad Hipertens Arterial, Serv Clin Med, Buenos Aires, DF, Argentina