Anti-C4d antibody [A24-T]

Supplementary info

This supplementary information is collated from multiple sources and compiled automatically.

Activity summary

C4d also known as the C4d complement is a degradation product of the complement component C4. It has a molecular weight of approximately 45 kDa. This protein is commonly expressed on the surfaces of endothelial cells in various tissues where it plays a role in the immune response. The presence of C4d on tissues is often detected using techniques like immunohistochemistry (IHC) also referred to as C4d IHC or C4d immunostain providing valuable insights into complement activation.

Biological function summary

The C4d protein acts as a marker for complement activation and is part of the larger complement cascade. C4d is primarily associated with the classical pathway and serves as an indicator of complement-mediated cell injury. The degradation of C4 into C4d is usually seen in immune responses where antibodies recognize antigens triggering sequence activation in the complement pathway. C4d's role as a marker facilitates the differentiation between antibody-mediated injury and other types of tissue damage.

Pathways

This complement protein gets involved in the classical pathway of the complement system which plays a critical role in innate and adaptive immunity. It is related to other proteins like C3 and C1q which are additional components within this pathway. These interactions are significant for the clearance of pathogens and also assist in enhancing the humoral immune response by promoting the deposition of complement on pathogenic surfaces.

Associated diseases and disorders

C4d presence becomes particularly significant in conditions like transplant rejection and systemic lupus erythematosus (SLE). In transplant rejection its deposition on tissue samples might indicate antibody-mediated rejection where C4d binds to the tissue signaling an immune response against the transplanted organ. Additionally in SLE C4d's relation to other proteins such as C3 and C1q confirms its involvement in autoimmune responses where the immune system mistakenly targets the body's own tissues leading to chronic inflammation and damage.