Serum levels of free heat shock protein 70 and anti-HSP70 are elevated in Behçet's disease.

ABSTRACT

OBJECTIVES: As heat shock proteins (HSPs) are described as candidate self-antigens in Behçet's disease (BD), free HSP70 and anti-HSP70 levels were measured in the sera of patients to investigate their role in the pathogenesis of BD. METHODS: Free human HSP70 levels were measured in the sera of patients with BD and compared to disease controls [patients with rheumatoid arthritis (RA) or recurrent oral ulcerations (ROU)] and healthy controls (HC) using ELISA. Anti-HSP70 antibody levels were also determined. RESULTS: Free human HSP70 levels were significantly elevated in BD sera (1.12+/-0.86 ng/ml) compared to HC (0.67+/-0.46 ng/ml, BD vs. HC p<0.001). However similarly elevated levels were also present in ROU (0.95+/-1.01 ng/ml, p<0.05) and RA (1.1+/-23.3 ng/ml, p<0.01). Anti-HSP70 antibody levels were also significantly higher in BD (668+/-658 microg/ml) compared to HC (490+/-742.05 microg/ml, p<0.05). However no significant anti-HSP70 antibody responses were observed in ROU (634.7+/-548.21 microg/ml) and RA (431.8+/-840.98 microg/ml). No association of any organ manifestation, the disease duration, or treatment with HSP70 or anti-HSP70 antibody levels were observed in BD. A correlation between HSP70 and anti-HSP70 levels was only found in HC (p=0.007). CONCLUSION: Free human HSP70 and anti-HSP70 antibodies are both elevated in patients with BD. HSP70-mediated innate and adaptive immune responses may participate in proinflammatory cytokine activation and tissue destruction in BD.