Polycystic Kidney Disease

Polycystic Kidney Disease Definition Multiple cysts develop in the kidneys Epidemiology The most common inherited chronic kidney disease Prevalence in males and females is about the same Autosomal dominant polycystic kidney disease is the most common form Causes Autosomal dominant Most common form Complete penetrance variable expressivity Most commonly bilateral PKD1 on chromosome 16 PKD2 on chromosome 4 Family history Autosomal recessive Most commonly bilateral PKHD1 chromosome 6 Autosomal dominant vs autosomal recessive Autosomal Dominant Autosomal Recessive Only need to inherit from either mum or dad Both parents must carry the mutated gene Usually presents in adulthood Manifest in infancy or in utero 30 to 40 Both kidneys enlarged at birth Large fluid filled cysts sponge like cysts CKD or KF originate from collecting ducts Clinical features Autosomal Dominant Polycystic Kidney Disease Symptoms most commonly after 30 But can happen earlier or in childhood Symptoms are less severe in patients with the PKD2 mutations PKD2 is associated with a later onset than PKD1 Renal Symptoms Extrarenal Symptoms Hepatic cysts Pancreatic cysts Colonic diverticulosis Mild polyuria Abdominal or inguinal hernias Macroscopic haematuria Heart valve defects Recurrent UTIs Bronchiectasis Urinary tract stones High risk or aneurysm rupture Features of CKD Pericardial effusion Palpable and enlarged kidney Pericardial effusion Coronary artery aneurysm Aortic aneurysm In utero can cause oligohydramnios Autosomal Recessive Polycystic Kidney Disease Symptoms happen during utero, infancy or childhood Renal symptoms Extrarenal symptoms HTN Usually resistant to monotherapy Oliguria Early manifestation Haematuria Complications of HTN Proteinuria HF Features of CKD Cerebrovascular disease In utero Renal disease Oliguria Congenital liver disease and portal fibrosis oligohydramnios Progressive liver failure Features of portal HTN Cholangitis Ix Labs CBC Anaemia of chronic disease KFTs Elevated Cr and BUN Low eGFR Urine studies Proteinuria Genetic testing ARPDK gold standard ADPKD Abdominal U/S ADPKD Renal cysts multiple B/L anechoic round lesions of varying sizes B/L renal involvement Hepatic or pancreatic or splenic cysts Kidney stones ARPKD Renal cysts multiple B/L anechoic round lesions of equal size B/L renal enlargement with diffuse increased echogenicity Hepatic cysts Hepatic portal fibrosis CT or MRI If U/S is inconclusive B/L renal enlargement Multiple cysts that are hypodense, well demarcated, nonseptated and thin walled MR angiography brain To screen for saccular aneurysm Indications: Family history of aneurysm or SAH Planned extensive surgery High risk jobs e.g. driving DDx Renal cysts Acquired cystic kidney disease Muticystic dysplastic kidney disease Nephronophthisis Obstructive cystic dysplasia Medullary sponge kidney Management Supportive Lifestyle High fluid intake prevent kidney stone formation and may slow cyst progression Blood pressure management General measurement Early UTI Tx prevent cyst infection Avoid nephrotoxic drug and vasopressin agnoists Genetic counselling Tolvaptan Vasopressin receptor antagonists Reduced cAMP inhibits cyst growth Management of complications ESRD Only cure is kidney transplant SAH Portal HTN Complications CKD Hypertension Most common Kidney failure Prognosis 50% of patients with the dominant type develop ESRD Autosomal recessive has worse prognosis Diagnosed shortly after birth high perinatal mortality