What are the treatment and monitoring options for cystic kidney disease?

Treatment and Monitoring of Cystic Kidney Disease

For patients with cystic kidney disease, comprehensive management should focus on blood pressure control, regular monitoring of kidney function, risk stratification, and consideration of disease-modifying therapy for rapid progressors, with specific approaches tailored to the type of cystic kidney disease. 1

Diagnosis and Classification

Initial Assessment

• Use ultrasonography as the primary radiological method for screening and initial diagnosis 2
• For ADPKD (Autosomal Dominant Polycystic Kidney Disease):
  • Sonographic detection of one or more cysts in an at-risk child is highly suggestive of ADPKD 2
  • A negative scan cannot rule out ADPKD in childhood 2

Risk Stratification

• For ADPKD, use disease-specific, externally validated prediction equations 2
• MRI is the gold standard for measuring height-adjusted total kidney volume (htTKV) 1
• Mayo Imaging Classification categorizes ADPKD patients into five prognostic categories:

  Class	Description
  1A	Slowest progression
  1B	Slow progression
  1C	Moderate progression
  1D	Rapid progression
  1E	Most rapid progression
  1

Genetic Testing Indications

• Recommended for:
  • Infants with very-early-onset symptomatic disease 2
  • Children with negative family history and progressive disease 2
  • Renal tumor syndromes 3

Monitoring Protocol

Blood Pressure Monitoring

• Annual standardized office BP measurement for children and adolescents with ADPKD 2
• 24-hour ambulatory BP monitoring for:
  • Children aged <5 years with very-early-onset or early-onset ADPKD 2
  • Children with BP >75th percentile 2
• Target BP:
  • <50th percentile for age, sex, and height in children 2
  • <110/70 mm Hg in adolescents with ADPKD and high BP 2

Kidney Function Assessment

• Regular monitoring of eGFR to establish baseline and track progression 2, 1
• Monitor albuminuria using Albumin/Creatinine Ratio (ACR) 2, 1
• A doubling of ACR on subsequent testing warrants evaluation 2

Imaging Follow-up

• MRI for accurate htTKV measurement in cooperative patients 1
• Ultrasound for children or non-cooperative patients 1
• CT scans provide comparable accuracy to MRI but involve radiation exposure 1

Treatment Approaches

Blood Pressure Control

• First-line therapy: ACE inhibitors or ARBs 2, 1
• Target BP to be <50th percentile for age, sex, and height in children 2
• Target BP <110/70 mm Hg in adolescents with ADPKD and high BP 2

Disease-Modifying Therapy

• Tolvaptan (vasopressin V2 receptor antagonist):
  • Indicated for patients at risk of rapid progression (Mayo Classes 1C-1E) 1
  • First FDA-approved treatment to slow ADPKD progression 1
  • Currently not recommended for routine use in children, but off-label use can be considered in selected cases 2

Lifestyle Modifications

• Low sodium intake to reduce kidney growth 1
• Moderate-intensity physical activity for at least 150 minutes per week 2
• Avoid sedentary behavior 2
• Maintain normal weight 2, 1
• Adequate hydration to reduce vasopressin effects 1

Medications Not Recommended

• mTOR inhibitors and somatostatin analogues are not recommended for children with ADPKD 2
• No consensus on the use of statins in children with ADPKD 2

Comprehensive Care Approach

Multidisciplinary Care

• A 2-year kidney failure risk of >10% should determine timing of multidisciplinary care 2
• Follow a comprehensive, multidisciplinary, and holistic care pathway for children with ADPKD 2
• Consider referral to specialists (renal dietitians, physical therapy, etc.) 2

Monitoring for Complications

• Regular assessment for:
  • Urinary tract infections
  • Cyst hemorrhage
  • Renal stones
  • Gross hematuria
  • Extrarenal manifestations (liver cysts, cerebral aneurysms) 1
• Echocardiography to exclude left ventricular hypertrophy in children and adolescents with ADPKD and high BP 2

Preparation for Advanced Disease

• A 2-year kidney failure risk threshold of >40% should determine timing of preparation for kidney replacement therapy 2
• Planning should include vascular access planning or referral for transplantation 2

Special Considerations in Pediatric Patients

• Children with ADPKD should be monitored by a pediatric nephrologist 2
• Early hypertension correlates with cyst volume in children 1
• htTKV correlates with hypertension status and predicts hypertension development in children 1

By implementing this comprehensive monitoring and treatment approach, healthcare providers can effectively manage cystic kidney disease, slow disease progression, and improve quality of life for affected individuals.