The perceived overall cohort risk is heavily influenced by different diagnostic approaches.
Centres with a low threshold for renal biopsy for patients with mild urine abnormality, particularly those working in countries where urine screening programs are established, will likely diagnose IgAN in a larger number of patients with mild disease and good prognosis, thus favourably influencing the overall outcome of the cohort.
It is generally accepted that:
- <10% have complete resolution of urinary abnormalities
- Episodes of macroscopic haematuria become less frequent with time after diagnosis, although majority of patients will have persistent microscopic haematuria
- 5% will reach ESRD per year
- 25-30% will require renal replacement therapy within 20-25 years
Recurrence after renal transplantation:
- This is assuming increasing importance as a cause of graft failure as control of rejection improves
- It is typically slowly progressive although occasional patients will have a rapidly progressive course
- At 5 years a 5% risk of graft failure due to recurrence, a 13% risk of significant graft dysfunction, and a risk of IgA deposition of at least 50%.
- The risk of graft loss increases to 25% if first graft was lost to recurrence
- There is no consistent evidence that these risks differ between living and cadaveric donors
- There is no evidence that immunosuppressive regimen alters incidence of IgAN recurrence or the prognosis of recurrence in the short term