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Polycystic Kidney Disease

Practice Essentials

Autosomal dominant polycystic kidney disease (ADPKD) is a multisystemic and progressive disorder characterized by cyst formation and enlargement in the kidney (see the image below) and other organs (eg, liver, pancreas, spleen).
Up to 50% of patients with ADPKD require renal replacement therapy by 60 years of age.

Polycystic kidney.

Polycystic kidney.

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Signs and symptoms

Pain—in the abdomen, flank, or back—is the most common initial complaint, and it is almost universally present in patients with ADPKD. Dull aching and an uncomfortable sensation of heaviness may result from a large polycystic liver.

The pain can be caused by any of the following:

Enlargement of one or more cysts

Bleeding: May be confined inside the cyst or lead to gross hematuria with passage of clots or a perinephric hematoma

UTI (eg, acute pyelonephritis, infected cysts, perinephric abscess)

Nephrolithiasis and renal colic

Rarely, a coincidental hypernephroma

See Presentation for more detail.

Diagnosis

Examination in patients with ADPKD may demonstrate the following:

Hypertension: One of the most common early manifestations of ADPKD,
in which increased diastolic BP is the rule; clinical course in ADPKD is usually more severe early on, then becomes less problematic as the renal insufficiency progresses

Palpable, bilateral flank masses: In advanced ADPKD

Nodular hepatomegaly: In severe polycystic liver disease

Rarely, symptoms related to renal failure (eg, pallor, uremic fetor, dry skin, edema)

Testing

Routine laboratory studies include the following:

Serum chemistry profile, including calcium and phosphorus

CBC count

Urinalysis

Urine culture

Uric acid determination

Intact PTH assay

Genetic testing may be performed, in which the major indication is for genetic screening in young adults with negative ultrasonographic findings who are being considered as potential kidney donors.

Staging

Staging of renal failure is by glomerular filtration rate (GFR), as follows:

Stage 1: GFR above 90 mL/min

Stage 2: GFR 60-90 mL/min

Stage 3: GFR 30-60 mL/min

Stage 4: GFR 15-30 mL/min

Stage 5: GFR below 15 mL/min

Imaging studies

Radiologic studies used in the evaluation of ADPKD include the following:

Ultrasonography: Technique of choice for patients with ADPKD and for screening patients’ family members; useful for exploring abdominal extrarenal features of ADPKD (eg, liver cysts, pancreatic cysts)

CT scanning: Not routine; useful in doubtful pediatric cases or in complicated cases (eg, kidney stone, suspected tumor)

MRI: Not routine; helpful in distinguishing renal cell carcinoma from simple cysts; criterion standard to help determine renal volume for clinical trials when testing drugs for ADPKD; best imaging tool for monitoring kidney size after treatment, as an indication of disease progress.

MRA: Not routine; preferred imaging technique for diagnosing ADPKD-related intracranial aneurysms

Ultrasonographic diagnostic criteria for ADPKD1 are as follows
:

At least 2 cysts in 1 kidney or 1 cyst in each kidney in an at-risk patient younger than 30 years

At least 2 cysts in each kidney in an at-risk patient aged 30-59 years

At least 4 cysts in each kidney for an at-risk patient aged 60 years or older

Ultrasonographic diagnostic criteria for ADPKD in patients with a family history but unknown genotype are as follows
:

Three or more (unilateral or bilateral) renal cysts in patients aged 15-39 years

Two or more cysts in each kidney in patients aged 30-59 years

Fewer than 2 renal cysts in the findings provides a negative predictive value of 100% and can be considered sufficient for ruling out disease in at-risk individuals older than 40 years.

Indications for MRA are as follows
:

Family history of stroke or intracranial aneurysms

Development of symptoms suggesting an intracranial aneurysm

Job or hobby in which a loss of consciousness may be lethal

Past history of intracranial aneurysms

See Workup for more detail.

Management

Management of ADPKD includes the following:

Control blood pressure: Drugs of choice are ACEIs (eg, captopril, enalapril, lisinopril) or ARBs (eg, valsartan, telmisartan, losartan, irbesartan, candesartan, olmesartan)

Control abnormalities related to renal failure: Drugs to maintain electrolyte levels (eg, calcium carbonate, calcium acetate, sevelamer, lanthanum carbonate, calcitriol [possibly], diuretics, blood pressure medications)

Treat UTIs

Treat cyst infections: Gyrase inhibitors (eg, ciprofloxacin, chloramphenicol, clindamycin, levofloxacin); dihydrofolic acid inhibitors (TMX/SMP)

Treat hematuria: Possibly analgesic plus copious oral hydration

Reduce abdominal pain produced by enlarged kidneys

Prevent cardiac valve infection in patients with intrinsic valve disease

Reduce kidney function decline in adults at risk of rapidly progressive ADPKD (tolvaptan [Jynarque])

Surgical intervention in ADPKD includes the following:

Surgical drainage: Usually in conjunction with ultrasonographically guided puncture; in cases of infected renal/hepatic cysts not responding to conventional antibiotics

Open or fiberoptic-guided surgery: For excision/drainage of the outer walls of cysts to ablate symptoms

Nephrectomy: Last resort for pain control in patients with inaccessible cysts in the renal medullae; bilateral nephrectomy in patients with severe hepatic involvement

Partial hepatectomy: To manage massive hepatomegaly

Liver transplantation: In cases of portal hypertension due to polycystic liver or hepatomegaly with nonresectable areas

Patients with ADPKD who progress to end-stage renal disease may require the following procedures:

Hemodialysis

Peritoneal dialysis

Renal transplantation

See Treatment and Medication for more detail. For a discussion of ADPKD in children, see Pediatric Polycystic Kidney Disease.

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