C4A and autoimmune disease: Bento et al.3, in 2001, used the following protocol in the investigation of possible etiopathogenic factors involved in the origin of the disease, which are: complete blood count, hemosedimentation rate, glycemic curve, and 5-hour insulin levels, serological tests for syphilis, toxoplasmosis, cytomegalovirus, rubella, measles, autoimmune disease factors (rheumatoid factor, C3, C4, reactive C protein, LE cell, antinucleus factor, ASLO, native anti-DNA, alpha 1 glucoprotein, and IgE dosage), which were all used in our protocol.