C3 nephritis factor

C3 nephritis factor (C3Nef) is an IgG autoantibody of the alternative pathway C3 convertase (C3b, Bb). C3Nef binds to C3b and Bb at a ratio of 1: 1, which can stabilize this enzyme and prevent C3b- Inactivation of INA and B1H results in the activation of C3 and other complement components via the alternative pathway. In the detection of C3Nef, normal human serum and the test serum are generally co-bred in the presence of EGTA. If natural C3 is consumed or converted into C3 lysate (C3SP) in normal human serum, it means that C3Nef exists in the test serum.