Diagnosis

Polycystic kidney disease

Etiology

Cause [3et]

• Autosomal dominant (1 in 800): Mutations to PKD1 (85%) or PKD2 (15%)

• Autosomal recessive (1 in 30,000): Mutations in the PKHD1 gene on chromosome 6p12

  • Also called infantile polycystic kidney disease

Pathophysiology [3et]

1. Abnormal cell growth that cause ballooning of the tubule in a nephron leading to cyst formation

2. Cyst formation can occur in proximal and distal tubules but is most common in the distal nephron and collecting duct

3. The cyst enlarges due to fluid secretion into the cyst and destroying nearby renal tissue and promote renal fibrosis

4. Clinical presentation:

   • Pain

   • Cyst infection

   • Cyst bleeding

   • Kidney failure

5. Increased risk for developing Intracranial aneurysm, liver cysts, heart valve disease and abdominal hernias

Complications [3et]

• End-stage kidney disease

• Ruptured cerebral aneurysm

• Hepatic cysts

• Associated with diverticular disease, nephrolithiasis, and abdominal wall or inguinal hernias

Epidemiology

Incidence per 100.000 [gww][etp][esd][bof][ys3]

Approach

• Blood test: Na, K, Ca, Ph, creatinine, WBC, lipid concentrations, PTH, vitamin D

• Urine stix/culture

• Urine microsopy

• Ultrasound abdomen

• CT abdomen

• Genetic testing

Diagnostic criteria [esd]

1. Definite: Ravine-Pei criteria with family history and/or proven genetic mutation

2. Likely: Bilateral enlarged kidneys with >10 cysts and absence of CKD or other cystic disease

3. Possible: Normally or mildly enlarged kidneys with cysts > 97.5th percentile and absence of CKD or other cystic disease

Ultrasound Criteria for ADPKD: [3et]

• Ages 15 to 29 years: 2 or more cysts, unilateral or bilateral.

• Ages 30 to 59 years: 2 or more cysts in each kidney.

• Ages 60 years or older: 4 or more cysts in each kidney.

Treatment

1. Non-operative management: [k3e][3et]

   1. Dietary modifications:

      • Three liters of PO fluids daily to suppress vasopressin, thereby decreasing cAMP production and inhibiting cyst production

      • Limit sodium intake to less than 2 grams per day

   2. Control blood pressure: ACEI (enalapril, lisinopril) or ARB (valsartan, telmisartan, losartan, irbesartan, candesartan, olmesartan)

   3. Maintain electrolyte levels: calcium carbonate, calcium acetate, sevelamer, lanthanum carbonate, calcitriol, diuretics

   4. Antibiotics due to kidney cyst infection: ciprofloxacin, ceftriaxone, clindamycin, TMX/SMP

   5. Treat hematuria

   6. Analgesia due to abdominal pain caused by enlarged kidneys

   7. Slow kidney function decline

   8. Hemodialysis/peritoneal dialysis

2. Surgical intervention:

   1. Surgical drainage of infected cysts: ultrasonography- or CT-guided puncture

   2. Excision/drainage of the outer walls of cysts

   3. Nephrectomy:

      • Severe pain

      • Cyst hemorrhage/hematuria

      • Cyst infection

      • Renal cell carcinoma

      • Calculi in nonfunctioning kidneys with persistent urinary tract infections

      • To increase the abdominal capacity for a future renal transplant

   4. Kidney transplantation

Differential diagnoses

Acute renal failure, Ascites, Bardet-Biedl syndrome, Bladder cancer, Chronic renal failure, Diabetes mellitus, Eclampsia, Heart failure, HIV, Medullary sponge kidney disease, Multiple myeloma, Myocardial infarction, Orofaciodigial syndrome, Ovarian cancer, Preeclampsia, Renal cyst, Renal dysplasia, Rhabdomyolysis, Tuberous sclerosis, Urinary tract infection, Urolithiasis, Von Hippel-Lindau disease