Opsonic effect of equine plasma from different donors

Effect of plasma transfusion on neutrophil function in healthy and septic foals

“…As was the case for the current study, other studies 20 have reported that phagocytosis could not be positively correlated to serum IgG concentration and these authors have suggested that complement is a more important mediator of phagocytosis in the horse than IgG. 31 Although present in lower concentrations than IgG, IgM binds Gram negative bacteria more efficiently than IgG. As septicaemia and related conditions in foals are due primarily to Gram negative organisms, it is possible that complement, IgM or other factors may be more important determinants of neonatal resistance to sepsis than IgG.…”

Rhodococcus equihyperimmune plasma decreases pneumonia severity after a randomised experimental challenge of neonatal foals

“…Although the mechanism of antibody protection has not been fully elucidated, in vitro studies have shown that opsonisation by antibodies enhances uptake and killing of R equi by phagocytic cells (Martens and others 1987, 1989b). Thus, plasma from horses vaccinated with R equi augmented phagocytic activity of neutrophils (Grondahl and others 1997). Likewise, opsonisation of R equi with specific antibodies from commercially available HIP promoted phagocytic function of neutrophils and macrophages (Dawson and others 2011).…”

Immunogenicity of synthetic Rhodococcus equi virulence-associated protein peptides in neonate foals

“…Opsonic protective mechanisms (Martens et al, 1987;Hietala and Ardans, 1987;Grondahl et al, 1997;Demmers et al, 2001). Passive immunization with hyper-immune plasma, a cost prohibitive procedure for most owners, inconsistently reduced the prevalence of the disease in foals from endemically affected farms (Madigan et al, 1991;Giguere et al, 2002).…”