What are the Pei (P) criteria for diagnosing autosomal dominant polycystic kidney disease (ADPKD)?

Pei Criteria for Diagnosing Autosomal Dominant Polycystic Kidney Disease (ADPKD)

The Pei criteria for diagnosing ADPKD are age-dependent ultrasound criteria based on the number of kidney cysts present in individuals with a family history of ADPKD. 1

Ultrasound Diagnostic Criteria (Pei Criteria)

For individuals with a positive family history of ADPKD:

• Ages 15-39 years:

  • Diagnosis confirmed: ≥3 total kidney cysts
  • Diagnosis ruled out: ≤1 kidney cyst 1

• Ages 40-59 years:

  • Diagnosis confirmed: ≥2 cysts in each kidney
  • Diagnosis ruled out: ≤2 cysts total 1

• Age ≥60 years:

  • Diagnosis confirmed: ≥4 cysts in each kidney 1

MRI Diagnostic Criteria

For individuals aged 16-40 years with a positive family history:

• Diagnosis confirmed: >10 total kidney cysts
• Diagnosis ruled out: <5 total kidney cysts 1, 2

Diagnostic Algorithm

For Adults with Positive Family History:

1. Start with abdominal ultrasound as first-line imaging 1
2. Apply age-specific ultrasound criteria as outlined above 1
3. If results are equivocal or atypical, proceed to MRI or genetic testing 1
4. In genetically resolved families, targeted genetic testing for the specific family variant is usually sufficient 1

For Adults with Incidentally Detected Kidney Cysts (No Known Family History):

1. If multiple cysts are present or there are atypical findings, follow the diagnostic algorithm for those with family history 1
2. If diagnosis remains uncertain after ultrasound, proceed to MRI 1
3. Consider genetic testing, particularly for PKD1 and PKD2 mutations 1

Important Considerations

• These ultrasound and MRI criteria apply only to families with pathogenic variants of PKD1 or PKD2, not to those with pathogenic variants of minor genes 1

• Genetic testing is particularly valuable in cases with:

  • Few kidney cysts
  • Variable intrafamilial disease severity
  • Discordant imaging and glomerular filtration rate
  • Negative family history
  • Young (aged <30 years) living-related kidney donors at risk of ADPKD
  • Family planning considerations 1

• For children under 15 years with a positive family history, the presence of one or more kidney cysts is highly suggestive of ADPKD 2, 3

• The Mayo Imaging Classification (MIC) can be used to predict future decline in kidney function and timing of kidney failure in patients with confirmed ADPKD 1

Diagnostic Pitfalls

• Ultrasound has lower sensitivity compared to MRI, especially in younger patients 4, 5
• Several inherited diseases may mimic ADPKD with kidney and/or liver cysts 1
• The severity of ADPKD varies based on the causal gene (PKD1 > PKD2), type of PKD1 mutation, sex, and environmental factors 1
• GANAB mutations, typically associated with milder disease, can occasionally present with severe ADPKD 6