Hypocomplementaemia caused by C3 nephritic factors (C3 NeF): clinical findings and the coincidence of C3 NeF type II with anti-C1q autoantibodies
OBJECTIVES: The main purposes were to document manifestations associated with prolonged or clinically unexplained C3 deficiency and to approximate how often hypocomplementaemia of this kind is caused by C3 nephritic factors (C3 NeF), i.e. autoantibodies to alternative pathway C3 convertases. We also wished to distinguish between C3 NeF types I and II and to assess coincident autoantibody responses