polycystic kidney disease

Etiology

• inherited disease
  • see adult & childhood polycystic kidney disease
  • von Hippel-Lindau disease (autosomal dominant)
• acquired renal cystic disease
  • associated with long-term renal insufficiency
  • can affect up to 50% of patients on long-term dialysis

Epidemiology

• autosomal dominant polycystic kidney disease is the most common inherited kidney disorder; 5% of ESRD cases

Pathology

• polycystic kidney disease affecting the kidneys & the hepatic biliary

Genetics

• autosomal dominant forms: defects in PKHD1 & PKHD2
• defects in PKHD1 are the cause of all typical forms of autosomal recessive polycystic kidney disease

Clinical manifestations

• clinical spectrum is widely variable
• most cases present during infancy
• hypertension at a young age
• flank pain
• gross hematuria
• palplable irregular kidneys or liver
  • polycystic liver disease in 80-90%
• nephrolithiasis

Laboratory

• urinalysis:
  • hematuria
  • proteinuria (low grade)
• genotyping not routinely performed

Radiology

• renal ultrasound will identify renal cysts
  • enlarged kidneys with autosomal dominant form
  • complete ultrasound of abdomen
    • screen for hepatic involvement in autosomal dominant form
• complete ultrasound of the abdomen to screen for polycystic liver disease
• routine screening for intracranial aneurysm not indicated
• MR angiography vs CT angiography if family history consistent with ruptured cerebral aneurysm
  • offer for autosomal dominant form regardless of family history
    • not so
  • caution with use of gadolinium contrast in patients with severe renal impairment

Complications

• subarachnoid hemorrhage from intracranial aneurysm*
• renal cysts are prone to hemorrhage in patients with autosomal dominant polycystic kidney disease
• cyst infection
• increased risk for multiple cancers
  • kidney cancer (RR=2.5)
    • 30-fold increased risk of renal cell carcinoma with acquired form
      • flank pain, hematuria, erythrocytosis (high blood hemoglobin)
  • colon cancer (RR=1.6)
  • liver cancer (RR=1.5).
• mitral valve prolapse*
• hepatic cysts*
• diverticulosis*
• cardiovascular disease as type-of chronic kidney disease

* autosomal dominant forms

* autosomal recessive forms associated with pediatric ESRD, hepatic fibrosis, portal hypertension, pulmonary hypoplasia, oligohydramnios, Potter syndrome

Differential diagnosis

• rupture of renal cyst can mimic nephrolithiasis

Management

• ACE inhibitor or ARB for hypertension if renal function permits
  • target blood pressure is < 130/80 mm Hg
• tolvaptan delays progression of renal failure in rapidly progressive autosomal dominant forms
• empiric antibiotic therapy for suspected infected cysts
  • fluoroquinolone
  • trimethoprim/sufamethazole (Bactrim, Septra)
• avoid NSAIDs, aspirin
• partial nephrectomy for cysts suspicious for malignancy
  • radical nephrectomy if ESRD
• treatment of cardiovascular risk factors - statins
• no specific therapy for autosomal recessive form

More general terms

• chronic kidney disease (CKD)

More specific terms

• acquired polycystic kidney disease
• adult polycystic kidney disease; autosomal dominant polycystic kidney disease
• childhood polycystic kidney disease
• infantile polycystic kidney disease (autosomal recessive)
• medullary cystic kidney disease
• medullary sponge kidney disease
• nephronophthisis

Patient information

polycystic kidney disease patient information