And patients in an earlier heart-lung bypass trial did almost as well, suffering 40% less muscle damage with the antibody than without it.Alexion is also trying its antibody in other settings where complement runs amok the autoimmune diseases rheumatoid arthritis and lupus.
It may thus provide a rationale for the observation of Kapadia et al. that the most significant attenuation caused by the loss of the MHV-68 RCA protein was observed in the CNS, an organ where complement levels are actually considered to be rather low [23].
This is different from the situation in vivo where complement activation plays an important role.
In encephalitis and ischaemic infarction cases, the time from pathological insult to death was short in comparison to Alzheimer's disease and MS where complement expression and activation is maintained over years.
The importance of complement proteins in the cell-cell interactions has previously been shown in the antigen-presenting cells (APCs) and T cell cognate complexes in the T cell/APC interface, where complement proteins secreted by APCs regulate T cell proliferation and differentiation (Kemper and, Atkinson 2007; Longhi et al., 2006; Peng et al., 2008; Sacks, 2010; Strainic et al., 2008).
In AMD, where complement is already clearly implicated in a causative role, loss of macular cones is a major cause of vision loss and our results here suggest that complement activation may either directly cause cone cell death, or sensitize cones to other insults.
Its prognostic value in CRC may be related to recent reports, where complement factor H was found to be highly expressed in cutaneous squamous cell carcinoma (cSCC) (Riihila et al, 2014) and non-small cell lung cancer (NSCLC) (Cui et al, 2011) cells, and where it was associated with progression in cSCC and prognosis in NSCLC.
These unresolved issues have taken on greater importance with the advent of antibody-based therapeutics, most notably with agents like the anti-CD20 monoclonal antibody rituximab, where complement-dependent cytotoxicity (CDC) might be important for the elimination of pathogenic B cells (reviewed in [ 26]).
This is in accordance with our present findings in polymicrobial sepsis where complement activation was completely abolished in the treated group, which probably is a main explanation for the reduced IL-8 release, although an additional effect of blocking CD14 is likely for both mediators.
Eculizumab has been shown to reverse the hemolysis and thrombocytopenia and to resolve severe tissue injury from TMA in anti-phospholipid antibody syndrome and in antibody-mediated rejection from anti-HLA and anti-ABO antibodies, situations where complement is activated via the classical pathway [ 17, 18].
