genitourinary disorders
Autosomal Dominant Polycystic Kidney Disease (ADPKD)
Pathophysiology of ADPKD
Polycystin 1 may regulate tubular epithelial cell adhesion and differentiation; polycystin 2 may function as an ion channel, with mutations causing fluid secretion into cysts. Mutations in these proteins may alter the function of renal cilia, which enable tubular cells to sense flow rates. A leading hypothesis proposes that tubular cell proliferation and differentiation are linked to flow rate and that ciliary dysfunction may thus lead to cystic transformation. Vasopressinpromotes cell growth and fluid secretion via the cyclic AMP pathway, which leads to increase in the size and number of cysts in polycystic kidney disease. Early in the disorder, tubules dilate and slowly fill with glomerular filtrate. Eventually, the tubules separate from the functioning nephron and fill with secreted rather than filtered fluid, forming cysts. Hemorrhage into cysts may occur, causing hematuria. Patients are also at higher risk of acute Introduction to Urinary Tract Infections (UTIs) , cyst infections, and Extrarenal manifestationsare common: Hepatic Cysts are present in most patients; these typically do not affect liver function. Patients also have a higher incidence of pancreatic and intestinal cysts, Diverticular Disease of the Stomach and Small Bowel , and inguinal and Valvular heart disorders (most often Mitral Valve Prolapse (MVP) and Aortic regurgitation results from aortic root dilation due to arterial wall changes (including aortic aneurysm). Coronary artery aneurysms occur. Cerebral aneurysms are present in about 4% of young adults and up to 10% of older adults. Aneurysms rupture in 65 to 75% of patients, usually before age 50; risk factors include family history of aneurysm or rupture, larger aneurysms, and poorly controlled Hypertension . 