Introduction: Congenital heart malformations are risk factors that make children susceptible to infections resulting in inflammation.
Material and methods: The concentration of histamine as a modulator of inflammation was quantified in pericardial fluid and expression of histamine H(4) receptor (H(4)R) and histamine-releasing factor (HRF) was determined at mRNA and protein levels. Samples of pericardium and pericardial fluid were obtained during cardiac reconstruction surgery in children.
Results: In children with pericarditis, increased levels of histamine were found and expression of H(4)R was localized on mast cells. Expression of HRF was independent of presence or absence of inflammation in pericardium and was localized within stationary epithelial cells.
Conclusion: Results indicate that involvement of H4R in pericardial inflammation depends on penetration of mast cells into inflamed tissue, but HRF may not be directly involved in inflammatory reaction of the pericardium.