Table 2.

European Renal Association–European Dialysis and Transplant Association algorithm to identify rapidly progressive ADPKD

Steps	Criteria	Limitations
1	Exclusion of slow progressors by eGFR indexed for age above high cut-off values	Not helpful in 18- to 30-yr-old patients. Incorrect in many 30- to 40-yr-old patients with CKD stage 1 and 40- to 50-yr-old patients with CKD stage 1 or 2
1	Inclusion of patients with eGFR indexed for age compatible with rapid progression	Does not exclude factors other than rapid ADPKD progression contributing to the reduced eGFR
2	eGFR decline ≥5 ml/min per 1.73 m2 in 1 yr or ≥2.5 ml/min per 1.73 m2 per yr over 5 yr	High variability of eGFR values >60 ml/min per 1.73 m2; historical factors affecting historical values often unavailable
3	TKV increase >5% per year by repeated measurements (preferably three or more, each at least 6 mo apart)	Very few patients will have three or more MRIs or CTs; does not exclude atypical cases; requires precise measurements (planimetry or stereology); rates of TKV increase in patients with PKD1 and PKD2 mutations are similar
4	Mayo image class 1C, 1D, or 1E	Cost, but this is minor compared with the cost of tolvaptan and safety laboratory testing
4	Kidney length by ultrasound >16.5 cm in patients aged <45 yr	Operator-dependent measurements; young patients with lengths <16.5 cm may have rapidly progressive disease; atypical patients with slow progression may have lengths >16.5 cm because of large cysts
4	PROPKD score >6	Not helpful in patients aged <35 yr unless already hypertensive and have experienced urologic complications