Question

in terms of E-C4d, what is C4d and what makes it deposit on the blood cell?

Answer 1

Complement component C4d is a fragment of C4b that is generated on activation of classical complement pathway on IgG and IgM. It is breakdown product of C4b which is bound to endothelial proteins.  

This acts as marker for complement activation.

Trauma resulting from accident which involves anatomical injury which is linked to blood loss results in acute inflammatory response activating the complement system . It is also seen in multi organ failure.

In conditions like Systemic Lupus Erthyematosus (SLE) , C4d complement fragments deposit on the surface of blood cells.

This complement activation affects the function of red blood cells in trauma patients affecting blood circulation.

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