Diagnosis of IgA nephropathy from 2009, with a minimum follow-up for nephropathy of 5 years

Diagnosis of IgA nephropathy during the study period

Diagnosis of Lupus or ANCA-associated vasculitis or polycystic kidney disease

Collection of 3 blood tubes at inclusion and relapse (arm 1) or at inclusion, initiation of treatment and at 3 and 6 months post-diagnosis (arm 2)

Patient with a diagnosis before the start of the study: IgA nephropathy with a GFR of less than 45 ml/min/1.73 m2 and/or proteinuria >0.5 g/day and/or hematuria (microscopic or macroscopic) will be considered progressive.

Patient with diagnosis during the study: will be considered as progressive an IgA nephropathy for which the GFR will decrease compared to the inclusion (diagnosis) of more than 5 ml/min/1.73 m2 and/or with a proteinuria >0.5 g/day and/or with a microscopic hematuria on at least one of the samples carried out in a period of one year after the diagnosis.