Improving treatment and imaging in ADPKD

Autosomal dominant polycystic kidney disease is the most prevalent hereditary kidney disease. It leads to numerous cysts in the kidneys, which leads to kidney failure between 50 to 70 years of age. Ten percent of patients in dialysis in the Netherlands have polycystic kidney disease. It is known that the hormone vasopressin is elevated and detrimental in polycystic kidney disease. Recently, the first drug has become available that slows disease progression, this drug (tolvaptan) blocks vasopressin. The most important side-effect of tolvaptan is an increased urine production, up to 8 liters per day. We studied whether lifestyle factors could influence vasopressin and found that increased water intake and lowered salt intake lead to lower vasopressin concentrations. We also found that a lower sodium diet leads to a lower urine production when using tolvaptan. In one patient that used tolvaptan, the addition of hydrochlorothiazide (an antihypertensive) also led to less urine production. In this thesis we also investigated optimization of kidney volume measurement. In polycystic kidney disease, the kidneys strongly grow in size. Kidney volume is an early predictor of future disease progression. Kidney volume measurement is currently very time consuming (up to two hours). We found that two estimation methods can assess the size of the kidneys relatively reliably. Furthermore, we helped in the development of an automated program that can measure the kidneys in a matter of seconds. We found out that this program is as accurate in measurement of kidney volumes as manual tracing