CD14 expression on monocytes and soluble CD14 plasma levels in correlation to the promotor polymorphism of the endotoxin receptor CD14 gene in patients with inactive Crohn's disease

Background/Aims: The association of the single nucleotide polymorphism. in the promotor of the lipopolysaccharide receptor CD14 gene (T/C at position -159) with Crohn's disease has recently been demonstrated. This CD14 polymorphism is a potential predisposition factor responsible for inter-individual differing inflammatory reactions involving the CD14 receptor. We studied the correlation between the CD14 genotype (CC, CT, TT) and the membrane-bound CD14 monocyte expression and soluble CD14 in patients with inactive Crohn's disease. Methodology: In 23 patients and 29 healthy volunteers the membrane-bound CD14 density on unstimulated monocytes and soluble CD14 plasma levels were examined using quantitative flow cytometry and enzyme-linked immunosorbent assay. Results: In normal controls membrane-bound CD14 monocyte density did not differ significantly between the genotypes CC, CT, or TT. In contrast, patients with inactive Crohn's disease and genotype TT showed a significantly lower membrane-bound CD14 density on monocytes compared to patients with genotype CC. Soluble CD14 plasma levels were significantly higher in patients with inactive Crohn's disease compared to the same genotype of healthy controls, but there was no significant difference between the genotypes CC, CT, and TT. Conclusions: Our data show that the membrane-bound CD14 monocyte expression and the soluble CD14 plasma levels in patients with inactive Crohn's disease completely differ from that in healthy individuals. In order to develop individualized therapy strategies further studies should be carried out to evaluate whether the TT genotype is associated with differences in the clinical course of Crohn's disease and in the response to antibacterial treatment.