Ten serum samples from the patient with bullous pemphigoid with the baseruent mernbrane zone autoantibody titers of 320 or greater were tested, by the method of in vitro complement immunofluorescence, for their ability to fix Factor B and properdin in addition to Clq, C4 and C3. Five samples yielded positive C3 and properdin staining reaciions while four samples demonstrated positive Factor B stainings. All ten samples yieled positive C3, C4 and Clq staining reactions, Heat inactivation or treatment of the complement source with EDTA, MG2-EGTA abolished both C3, properdin and Factor B staining in all ten cases. This result suggest that pemphigoid antibody will fix properdin and Factor B in addition to Clq, C4 and C3, a phenomenon explained by assembly of the C3b amplification mechanism following activation of the classical pathway of complement system.
Complement Factor B* ; Complement System Proteins ; Edetic Acid ; Fluorescent Antibody Technique ; Hot Temperature ; Humans ; Pemphigoid, Bullous* ; Properdin*