Formalin-fixed and paraffin-embedded human transplanted kidney stained with C4A monoclonal antibody, clone A24-T (Cat # MAB9758) shows diffuse strong positive immunostaining of peritubular and glomerular capillaries (A), indicating acute antibody mediated rejection and diffuse strong positive immunostaining of dilated peritubular moderate capillaries (B), indicating acute antibody mediated rejection. Kindly performed and provided by Marian Svajdler, MD and Dr. Lucia Frohlichova from Louis Pasteur University Hospital Department of Pathology, Kosice, Slovak Republic.
This gene encodes the acidic form of complement factor 4, part of the classical activation pathway. The protein is expressed as a single chain precursor which is proteolytically cleaved into a trimer of alpha, beta, and gamma chains prior to secretion. The trimer provides a surface for interaction between the antigen-antibody complex and other complement components. The alpha chain may be cleaved to release C4 anaphylatoxin, a mediator of local inflammation. Deficiency of this protein is associated with systemic lupus erythematosus and type I diabetes mellitus. This gene localizes to the major histocompatibility complex (MHC) class III region on chromosome 6. Varying haplotypes of this gene cluster exist, such that individuals may have 1, 2, or 3 copies of this gene. [provided by RefSeq
C4A anaphylatoxin,OTTHUMP00000029266,Rodgers form of C4,acidic C4,complement component 4A