Abstract: The present invention concerns a method for classifying a disorder associated with the complement system comprising the detection of the presence of C3/C5 convertase complexes as well as Ig/C1q and MBL/MASP complexes. Moreover the invention refers to a method for determining whether a patient will be responsive to a modulator of the complements system, a method for determining the disorder course of a patient with a disorder associated with the complement system and a method for determining whether a candidate compound is suitable for the treatment of a disorder if the complement system and the respective kits.