Investigators finally analyzed the association between anti-PLA2R1 titers at presentation in the different ELISAs and the subsequent clinical outcome. The mean anti-PLA2R1 activity was significantly different between group A and R in mouse ELISA in both univariate and multivariate analyses (p =0.006 and p =0.02, respectively) but not in human and rabbit ELISAs. An analysis of the mouse ELISA titers defines a threshold of 605 RU/ml above which 100% of patients had a poor prognosis, but no such threshold could be defined in rabbit and human ELISA. Patients with anti-mouse PLA2R1 activity over 605 RU/ml showed a significantly lower survival without doubling of serum creatinine or ESKD (p=0.002 using the log-rank test), but patients in the highest tertile of anti-PLA2R1 activity in rabbit and human ELISAs did not show a significant increased risk of renal failure progression. The results suggest that the specific detection of particular anti-PLA2R1 autoantibodies using the novel anti-mouse PLA2R1 ELISA can identify MN patients at risk for ESKD. The aim is to confirm these result on a prospective cohort.We propose to measure on a prospective cohort at the time of MN diagnosis if high titer of anti-mPLA2R1 Ab (anti-mouse phospholipase A2 receptor1 antibodies) is associated with nephrotic proteinuria (over 3.5 g/g) or increased of creatininemia over 30% at month 6, 12 and 18. An ancillary study will try to characterised the nephrogenic epitope conserved between human, rabbit and mouse.