Table 2.

Sensitivity and specificity of the C3-dominant or -isolated criteria on IF to capture the presence of intramembranous electron-dense deposits, LPVs, and/or C3NeF and low serum C3 and normal C4 in patients with C3G/MPGN

CategoriesPrevalenceP ValueC3G
C3GIC-MPGNSensitivity, %Specificity, %
All patients
 Intramembranous electron-dense deposits0.270.04<0.0018953
 LPVs and/or C3NeF0.640.490.075956
 Low serum C3 and normal C40.780.700.235655
Only patients with C3G and isolated C3 versus patients with IC-MPGN and 3+ staining in any of Ig or C1qa
 Intramembranous electron-dense deposits0.240.030.038956
 LPVs and/or C3NeF0.530.470.625255
 Low serum C3 and normal C40.760.680.465258
  • a Patients with C3G and 3+ C3 staining and no Ig or C1q staining on IF and patients with IC-MPGN and 3+ staining in at least one of the Igs or C1q.