C3d (Polyclonal), RPab

Summary and Explanation

Complement component 3, or C3, is a protein of the immune system that plays a central role in the complement system and contributes to innate immunity. Its activation is required for both classical and alternative complement activation pathways. C3d deposition in the renal transplant PTCs (peritubular capillaries) is indicative of AR (acute rejection) with subsequent high probability of graft loss.

Anti-C3d combined with anti-C4d can be utilized as a tool for diagnosis of AR and warrant prompt and aggressive anti-rejection treatment. C3d is also a helpful adjunct in the diagnosis of bullous pemphigoid (BP) and perhaps pemphigus vulgaris (PV), especially in the cases in which only formalin-fixed, paraffin embedded tissue is available for analysis.