ADPKD (Autosomal Dominant Polycystic Kidney Disease)

Key points

• Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease causing kidney failure; it is most often caused by PKD1 or PKD2 variants. Prevalence varies by population, so the old fixed '1 in 1,000 Caucasians' statement should not be memorised.
• In an at-risk adult aged 15–39 years, ≥3 renal cysts in total (unilateral or bilateral) strongly support ADPKD; age and family history must be considered.
• In an at-risk adult aged 40–59 years, ≥2 cysts in each kidney support the diagnosis.
• In an at-risk adult aged ≥60 years, ≥4 cysts in each kidney support the diagnosis. These ultrasound criteria apply to adults with an appropriate family-risk context; atypical cases may require MRI/genetic assessment. Tolvaptan is considered separately according to progression risk.
• Tolvaptan is not restricted simply to CKD stage 2–3. KDIGO 2025 recommends considering it in adults with ADPKD and eGFR ≥25 mL/min/1.73 m² who are at risk of rapid progression .
• Rapid progression can be supported by Mayo Imaging Classification 1C–1E or a sustained historical eGFR decline of about ≥3 mL/min/1.73 m²/year ; current KDIGO 2025 therefore uses risk of rapid progression rather than the old CKD-stage-only rule.
• MRCP discriminator: family history + bilateral enlarged cystic kidneys + hypertension/haematuria/CKD → ADPKD.
• Current KDIGO 2025: tolvaptan is recommended for adults with eGFR ≥25 who are at risk of rapid progression, rather than simply because they have stage 2–3 CKD.