Mouse anti Human C4d antibody, clone 10-11 recognizes the secreted protein complement component 4d (C4d). The presence of C4d in renal peritubular capillaries is a key indicator for acute antibody-mediated rejection [AMR] (
Collins et al. 1999.).C4d was accepted in 2003 into the Banff classification for identification of acute AMR (
Racusen et al. 2003). Mouse anti Human C4d antibody, clone 10-11 is specific for C4d, a marker that can be used in the detection of acute AMR for kidney, heart, pancreas and lung allografts. C4d is regarded as a key marker of antibody-mediated cell injury and humoral rejection (
Sacks and Chowdhury 2002).Complement 1 complex cleaves complement 4 (C4) to form C4b and C4a. C4b levels are strictly regulated. Single site cleavage of the C4b’s alpha chain by Factor I forms iC4b and blocks C3 convertase, inhibiting opsonization and activation of the classical pathway. This requires C4 binding protein or CR1 as a cofactor. iC4b is further degraded into C4d and C4c. C4b’s short half life means that C4d is present in serum at high enough concentrations to make it a useful marker for classical complement activation (
Collins et al. 1999).Mouse anti Human C4d antibody, clone 10-11 is used to detect the biomarker C4d which has been described as a “footprint” of antibody mediated tissue rejection (
Sacks and Chowdhury 2002). The internal thioester of C4b becomes exposed during cleavage to C4d and forms a covalent bond with the cell surface. The longer half-life of covalently bound C4d makes it a footprint of complement activation long after weakly bound antibodies have been cleared by the blood stream (
Sacks and Chowdhury 2002).C4 has also been linked to susceptibility to systemic lupus erythematosus (
Yang et al. 2004) and rheumatoid arthritis (
Makinde et al. 1989).