CD301b/MGL2 MNPs are key drivers of autoimmune MVD in K/B.g7 mice and are also present in human rheumatic heart disease. We define key inflammatory molecules that drive MVD in this model, including Syk, TNF, interleukin-6, very late antigen-4, and vascular cell adhesion molecule-1.

No abstract

Recent studies have reported pathologically elevated plasma histamine levels in adult patients during and after open heart surgery. In paediatric practice, the increased use of donor-blood primes might be expected to produce even greater rises in the histamine levels, by creating histamine release in the prime before initial perfusion commences. The present study covered 40 arbitrarily chosen paediatric cases. Pathologically elevated plasma histamine levels (greater than 1 ng/ml) were found in the prime of 26 out of 37 cases (73%). Histamine levels were substantially higher than levels encountered in previously reported studies, and massively elevated prime histamine levels (greater than 80 ng/ml) were encountered in 9 out of the 40 cases (22%). These results suggest that in conventional paediatric cardiac surgical practice, the prime content of histamine is markedly elevated in the majority of patients. The inevitable delivery of this prime histamine load at the onset of perfusion might be expected to produce systemic pathological effects.

We have previously reported our findings of very high plasma histamine levels in the extracorporeal blood primes of infants undergoing cardiopulmonary bypass (CPB) for correction of congenital cardiac defects and have now extended this enquiry to examine the whole peri-operative period. In this preliminary study, samples of blood for plasma histamine were drawn from a mixed group of congenital cardiac patients featuring varying degrees of cyanosis, differing hypothermic operative conditions and utilising two oxygenator systems. Despite the diversity of this group a common pattern of histamine release emerged with a clear origin at the commencement of bypass, and continuing during the operative period. Our results suggest that priming procedures using stored donor blood provide a major contributing source of histamine release with inevitable deleterious consequences to the post-operative outcome.