What is the recommended management for a child with polycystic kidney disease (PKD)?

Management of Polycystic Kidney Disease in Children

Children with autosomal dominant polycystic kidney disease (ADPKD) require regular blood pressure monitoring, lifestyle modifications focused on salt restriction and weight management, and ultrasonography for symptomatic evaluation, but routine serial imaging to monitor disease progression is not recommended in asymptomatic cases. 1

Diagnostic Approach and Screening

For At-Risk Children (Positive Family History)

Parents should receive non-directional counseling about two equally valid approaches 1:

• Option 1: Regular clinical screening without diagnostic testing, monitoring for treatable manifestations (hypertension, proteinuria) with the option for later diagnostic confirmation 1
• Option 2: Immediate diagnostic screening via ultrasonography or genetic testing 1

For children <15 years with positive family history, one or more kidney cysts on ultrasound is highly suggestive of ADPKD 2, 3. However, a normal ultrasound does not exclude ADPKD; rescreening should occur at intervals no shorter than 3 years 3.

Imaging Modality Selection

• Ultrasonography is the preferred diagnostic and monitoring tool for children with ADPKD 3
• MRI requires sedation in children <6 years, is more expensive, and offers no established diagnostic criteria for children <15 years 3
• MRI may be appropriate for adolescents in clinical trials or children with very large kidneys 1

Core Clinical Monitoring

Blood Pressure Management

Regular blood pressure monitoring is essential as hypertension affects 6-22% of children with ADPKD and correlates with kidney volume and disease progression 4, 5. The correlation between hypertension and kidney volume has been demonstrated in multiple pediatric studies 1.

Proteinuria Screening

Monitor for proteinuria regularly, as 58% of children with ADPKD demonstrate albuminuria (microalbuminuria in 48%, macroalbuminuria in 10%) 4. This occurs even with preserved GFR and represents a modifiable risk factor 5.

Renal Function Assessment

• GFR remains normal (>90 ml/min/1.73m²) in 88% of children with ADPKD 4
• 12% may have decreased GFR (<90), while 21% experience hyperfiltration (>135) 4
• eGFR decline is a suitable progression marker only in the small subgroup with very advanced ADPKD 1

Lifestyle Interventions

Salt Restriction (Critical Priority)

Children with ADPKD should achieve the recommended salt intake for healthy children, which may require dietician assistance 1. In adults with ADPKD, urinary sodium excretion correlates with kidney growth, and higher sodium intake increases risk of 50% eGFR reduction, ESRD, or death 1. Salt restriction lowers blood pressure and proteinuria in adults with ADPKD 1.

Weight Management

Maintaining normal weight is essential as obesity independently predicts faster renal function loss in adults with early ADPKD 1. Apply general pediatric population lifestyle recommendations, as no evidence suggests they don't apply to children with ADPKD 1.

Fluid and Protein Intake

• Avoid dehydration; encourage drinking to satisfy thirst 1
• High water intake to suppress vasopressin lacks confirmed benefit from interventional studies, with ongoing trials 1
• Avoid unnecessary protein restriction to reduce malnutrition risk, as low-protein diets showed no GFR benefit in pediatric CKD trials 1

Management of Complications

Urinary Tract Infections

Apply standard pediatric UTI diagnostic and treatment protocols 1. For suspected upper UTI, obtain urine and blood cultures plus renal ultrasonography 1.

Macroscopic Hematuria

Occurs in 5-15% of children with ADPKD 1. Ultrasonography is the first-line imaging modality to rule out stones or urinary tract obstruction 1.

Cyst Infection (Rare in Children)

If suspected, F-FDG-PET/CT is superior to contrast CT or MRI for diagnosis and localization in adults, though this can produce false-negative results 1. Treatment requires long-term antibiotics with high failure rates 1.

Screening for Extrarenal Manifestations

What NOT to Screen

• Do not screen for mitral valve prolapse in children without a heart murmur (prevalence 12%, similar to healthy children) 1
• Do not screen for intracranial aneurysms in children 1
• Do not screen regularly for liver cysts (prevalence <5% in children, no severe cases reported) 1

When to Refer to Specialized Centers

Early referral is recommended for 1:

• Very-early-onset ADPKD or autosomal recessive PKD-like presentations
• TSC2/PKD1 contiguous gene syndrome requiring multidisciplinary care

Important Caveats

Avoid vasopressin analogues for nocturnal enuresis in children with severe ADPKD (>10 cysts), as they demonstrate decreased urinary concentrating ability 1. Children with ≤10 cysts show no significant decrease in concentrating ability 1.

Hyperlipidemia is present in 54% of children at presentation and persists despite pharmacotherapy, representing another modifiable risk factor requiring attention 5.

Maternal inheritance predominates (51% of cases), with 89% having known family history at presentation 5. Prenatal cases are characterized by bilateral renal findings and 89% maternal inheritance 5.