Background. Autosomal dominant polycystic kidney disease is one of the most common inherited disorders with a prevalence of 1 : 1000 and is responsible for cca 10 % of end-stage renal disease in adult patients. Renal insufficiency is a rare symptom of ADPKD in children, however, there are some symptoms, which can occur already in childhood. The aim of this study was to detect early signs of renal damage and to reveal the blood pressure profile in children with ADPKD using ABPM (ambulatory blood pressure monitoring). Methods and Results. 32 children (aged 3.4-19.4 years, mean age 12.3) - carriers of PKD - gene with normal GFR, diagnosed on the basis of a positive family history and characteristic ultrasound features, and in 21 cases also indirect DNA analysis revealed positive results. 11/32 children (34 %) presented arterial hypertension detected by ABPM (values higher than 95th centile of normal individuals). The mean of ABPM values of all patients was significantly higher than normal children (p < 0.01), 76 % patients had values above the 50th centile. Signs of renal damage (proteinuria, microalbuminuria, decreased renal concentrating capacity, pathological excretion of tubular markers) were found in 22-64 % of investigated children. Significantly higher renal volume and renal length were found in more than 1/3 of the children, renal volume and length higher than the mean of healthy children in about 90 % of patients and a significant correlation between ABPM parameters and renal length and volume (p < 0.05). Conclusions. The results of this study show, that the signs of renal damage and arterial hypertension occur relatively often in children with ADPKD despite still normal GFR. This justifies the early diagnosis of ADPKD especially as it reveals the most important treatable complication of ADPKD - arterial hypertension. These findings emphasise the importance of early diagnosis in children from families with ADPKD. Probably, early treatment of hypertension could even postpone the otherwise common end-stage renal damage in adult patients with ADPKD. Careful follow up of all children with ADPKD is strongly recommended, above all the blood pressure should be controlled.

        Key words: autosomal dominant polycystic kidney disease, ABPM, hypertension, early renal damage.