Abstract: In some embodiments, the present invention provides methods for treating pregnant patients at risk of adverse pregnancy outcome, including, in some embodiments, by measuring one or more of a level of iC3b, intact C3, and total C3.

Abstract: In some embodiments, the present invention provides methods for predicting flare in subjects with autoimmune disease (e.g., lupus erythematosus). In some embodiments, pending flares may be reduced in severity and/or prevented from clinical manifestation in their entirety using provided methods. In some embodiments, the present invention provides methods for preventing or reducing the severity of a flare including the steps of determining in a sample from a subject suffering from lupus erythematosus a complement activation potential, administering a treatment or implementing a change in treatment if the complement activation potential is about 25% or higher, wherein a complement activation potential of about 25% or higher indicates that the subject will experience a flare within 30 days.