Arthus Reaction Locally injected antigen Activation of complement releases in immuneindividual Local immune-complex inflammatory mediators C5a C3a. Local inflammation,increased fluid with lgG antibody fommation and CAa C5a also induces and protein release,phagocytosis, mast-cell degranulation and blood vessel occlusion C3a 1-2hours 1997 Current Biology Ltd./Garland Publishing.Inc.Arthus Reaction