Study purpose: to establish the relationship of hematuria inurolithiasisafter LT on individual platelet reactivity. 

Material and methods: The study included 67 patients with chronic ob-structive pyelonephritis who were admitted to urology department for lithotripsy. Cavitation contact ultrasonic lithotripsy was carried out using Karl Storz-Calcuson apparatus. To verify the degree of hematuria red blood cells per 1 ml of urine was calculated by Nechiporenko method. Evaluation of platelet aggregation was carried out on Chrono-log (USA) aggregometer using ADP and adrenaline concentrations EC50.Platelets were isolated by centrifugation from citrated peripheral blood. Results: 24 hours after LT53 (79.1%) patients had microscopic hematuria – the number of red blood cells was 18.5±10.9x103RBC/ml (95% CI 1.0 – 58.5x103 RBC/ml). 14 (20.9%) patients had gross hematuria – number of red blood cells in urine reached 250±64.8x103RBC/ml (95% CI: 142.5 – 450x103 RBC/ml). It was found thatthe size and location of the calculus, activity of inflammatory process in the urinary tract and changing of individual platelet reactivity influenced the severity of hematuria at urolithiasis and after lithotripsy. In case of microhematuria after elimination of calculi there was low platelet response to ADP and adrenaline. In case of gross hematuria adrenoreactivity (35±8.4%) was 1.8 times higher than in case of microscopic hematuria (p=0.02), whereas beforeLT differences in platelet aggregation under the action of adrenaline between the two groups were absent (p=0.37). ADP-induced platelet aggregation before and after lithotripsy was characterized as normoreactive (respectively 52.5±6.1% and 57.0±12.5%) in the presence of grosshematuria. Different agonist effect on platelets in patients with the micro and gross hematuria after lithotripsy reflects the individual reactivity. The interaction of adrenaline and ADP may be regarded as a mechanism for stimulating platelet and limitations of hematuria.