Fig. 6.

Effect of statin on indoleamine 2,3-dioxygenase (IDO) expression and cytokine secretion in cells from healthy controls (HC) and chronic idiopathic urticaria (CIU) patients. CD14⁺ cells (a,b) and peripheral blood mononuclear cells (PBMCs) (c) from HC (n = 7, open bars) and CIU patients (n = 4–7, closed bars) were cultured with 25 µm simvastatin (S) for 24 h and stimulated with lipopolysaccharide (LPS) for 24 h (PBMC) or 2 h (CD14⁺); CD14⁺ culture supernatant levels of tumour necrosis factor (TNF)-α (a) and macrophage inflammatory protein (MIP)-1α (b) were determined by enzyme-linked immunosorbent assay (ELISA). IDO mRNA expression was assessed by real-time polymerase chain reaction. Results are expressed as mean ± standard error of the mean. *P < 0·05; **P < 0·01.