Expression of CCR5 in Behçet's disease

Expression of cytokines, chemokines, and chemokine receptors in oral ulcers of patients with Behcet's disease (BD) and recurrent aphthous stomatitis is Th1‐associated, although Th2‐association is also observed in patients with BD

OBJECTIVE

Although the pathogenesis of Behcet's disease (BD) is unknown, immune dysfunction appears to be involved. To improve understanding of the role of T cells and cytokines in BD, the current study analysed the localization and extent of expression of T cell subsets, cytokines, chemokines, and chemokine receptors in oral ulcers from BD patients and for comparison in oral ulcers from patients with recurrent aphthous stomatitis (RAS), as well as in healthy oral mucosa.

METHODS

Biopsies from oral ulcers of 25 BD patients and 19 RAS patients and oral mucosa from six healthy volunteers were immunoperoxidase stained.

RESULTS

Both CD4- and CD8-positive T cells were present in the oral ulcers of BD and RAS patients. The T helper (Th)1 cytokines interleukin (IL)-12, interferon (IFN)-gamma, and tumour necrosis factor (TNF)alpha and the Th1-associated chemokine receptors CCR5 and CXCR3 were increased in both patient groups as compared to normal controls, indicating the involvement of a Th1 immune response in the immunopathology of both BD and RAS. However, the Th2 cytokine IL-4 was only observed in oral ulcers of BD patients but not in RAS patients.

CONCLUSION

This is the first study that shows the presence of pro-inflammatory cytokines, as well as Th1-associated chemokine receptors, in the oral ulcers of BD patients, as well as RAS patients, at a protein level. However, the expression of the Th2 cytokine IL-4 within the oral lesions of only BD patients is suggestive of a more complex antigenic stimuli in BD patients compared with RAS patients.

Caspase-9 expression is increased in endothelial cells of active Behçet's disease patients

BACKGROUND

Behçet's disease is a multisystem disease of unknown etiology. Caspase-9 is responsible for initiating the caspase activation cascade during apoptosis. The aim of this study was to examine caspase-9 expression in both endothelial and perivascular infiltrates of patients with active Behçet's disease.

METHODS

Fifteen patients with active Behçet's disease, attending the First Dermatology Department, Ankara Numune Hospital, Ankara, Turkey between June 2003 and December 2005, were included in the study. Oral biopsy specimens from nine healthy volunteers were taken as the healthy control group, and skin biopsies from 18 psoriasis patients were used as the inflammatory control group. The specimens were examined with caspase-9 primary antibody. Statistical analyses were performed using SPSS 11.5.

RESULTS

The mean caspase-9-positive endothelial cell counts were 7.17 +/- 2.45 in active Behçet's disease, 4.81 +/- 0.76 in healthy controls, and 4.35 +/- 1.34 in inflammatory controls. The difference between Behçet's disease and healthy controls was statistically significant, with increased endothelial staining in active Behçet's disease (P = 0.049). The difference between Behçet's disease and inflammatory controls was also statistically significant; the rate of staining was higher in Behçet's disease (P = 0.006). The mean caspase-9-positive dermal perivascular cell counts were 5.15 +/- 2.32 in Behçet's disease, 3.32 +/- 0.82 in healthy controls, and 5.54 +/- 4.95 in inflammatory controls. These values did not show any statistically significant difference (P = 0.407).

CONCLUSION

Endothelial cells are one of the key cells in Behçet's disease, and our findings support the role of endothelial cells in the etiopathogenesis of Behçet's disease.

Involvement of Th1 cells and heat shock protein 60 in the pathogenesis of intestinal Behcet's disease

Involvement of excessive Th1 cell functions and heat shock protein expression in the pathogenesis of Behcet's disease (BD) has been reported. In this study we have characterized immune responses in intestinal lesions of BD. Peripheral blood lymphocytes (PBL) of BD and healthy controls (HC) and tissue specimens of intestinal Behcet's disease (intestinal BD), Crohn's disease (CD) and ulcerative colitis (UC) were analysed for mRNA and protein expression by reverse transcriptase-polymerase chain reaction (PCR) and immunohistochemistry, respectively. PBL of BD patients expressed the Th1-related chemokine receptor, CCR5 and CXCR3 preferentially compared with those of healthy controls. Intestinal lesions of BD expressed interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha and interleukin (IL)-12 mRNA, indicating Th1 skewed responses in vivo. mRNA of Txk, a Tec family tyrosine kinase specific to Th1 cells, was expressed in the lesions, suggesting its contribution to the Th1-dominant responses. In the intestinal samples, CCR5 was detected in all the cases with BD, whereas Th2-related CCR3 and CCR4 were detected randomly, mainly in the cases with inactive BD and those receiving large amounts of prednisolone, indicating the Th1-dominant immune responses in the intestinal lesions. As the ligands of CCR5, MIP1alpha and MIP1beta were detected, whereas RANTES was not. Heat shock protein (HSP) 60 was expressed in PBL and intestinal tissues of BD. Th1-dominant immune responses and HSP60 expression may induce the inflammatory responses and thus be associated with the pathogenesis of intestinal BD.