HSP 60 expression in mucocutaneous lesions of Behçet's disease.

BACKGROUND

Heat shock protein (60 kd HSP) has been implicated in the etiology of Behçet's disease, but its expression at sites of inflammation is unknown.

OBJECTIVE

Our aim was to investigate local HSP 60 expression and to quantify T-cell receptor (TCR) gamma delta-positive cells, which are known to respond to HSP peptides.

METHODS

Patients with active Behçet's disease (n = 21) and controls (n = 18) were included. Flow cytometric analysis was performed on peripheral blood to investigate TCR gamma delta-positive cell counts. Biopsies were performed on active skin lesions, and immunohistochemical analysis was performed by a streptavidin-biotin method using the monoclonal ML-30 antibody; HSP staining intensity and distribution were evaluated in a blinded fashion. Immunohistochemical studies were performed to quantify TCR gamma delta-positive cells at lesional sites.

RESULTS

Mucocutaneous lesions of patients with Behçet's disease had statistically significantly increased expression of HSP 60/65. Peripheral blood TCR gamma delta-positive cell counts were similar in both groups. However, lesional skin of patients with Behçet's disease had significantly increased gamma delta-positive T-cell counts.

CONCLUSION

Up-regulation of HSP expression was found at lesional skin sites in Behçet's disease. The increased number of TCR gamma delta-positive cells, which are known to respond to HSP peptides, may support the function of HSPs in the etiology of Behçet's disease. However, these findings may also be an epiphenomenon that needs to be further investigated.