I have read the Consensus Document on Autosomal Dominant Polycystic Kidney1 that the Spanish Society of Nephrology (Sociedad Española de Nefrología, SEN) drafted and published on its website and I would like to make some of comments on what has been exposed in that document.

They are based on the lack of definition of the term “rapid progressor” by the EMA2 to establish some criteria that seem to me to be inaccurate. Anyone who starts renal replacement therapy before the mean global age for starting renal replacement therapy in Spain (65 years old) is considered a rapid progressor. If a disease takes an average of X years to reach the terminal stage, the rapid progressors would be all those patients who reach that point before that X average, and slow progressors, who last longer than the average for that process. I believe that the overall average age at initiation of renal replacement therapy should not be used as a reference point since other diseases present at more advanced ages (diabetic nephropathy and nephroangiosclerosis) have an impact and therefore increase that average age. According to the logic used by the authors, it could also be said that any person who starts dialysis before the average life expectancy of the general population (80.6 years in men and 86 in women before the pandemic)3 is a rapid progressor. Therefore most of our patients could be included in that definition. In type 1 polycystic kidney disease, the average onset of end-stage kidney failure is 54 years old,4,5 and that should be, in my opinion, the point at which a person with polycystic disease is considered a rapid or slow progressor.

In addition, it is suggested to start treatment with tolvaptan in patients until 60 years old. I have only seen one study6 (REPRISE) including patients >55 years. In that study, in the subgroup of patients >55 years old, the difference in progression was similar with respect to the placebo group (GFR drop: 2.54 vs 2.34ml/min [p=0.65]). The study included a limited number of patients, but no other study affirms otherwise; therefore, no treatment should be started at these ages outside of a controlled clinical trial.

I believe that the society allows us to manage public funds, that are limited, with a commitment to maximum efficiency. That means using them in those cases in which these treatments are truly useful. If we cannot manage these funds, we will totally lose the capacity of managing them.