Peripheral blood mononuclear cell responses to heat shock proteins and their derived synthetic peptides in juvenile idiopathic arthritis patients

Background Sequence homology and cross reactivity between microbial and human heat shock proteins (hsps) led to the concept that hsps might be involved in the etiopathogenesis of autoimmune diseases. Objective In our study we stimulated peripheral blood mononuclear cells (PBMC) of patients with juvenile idiopathic arthritis (JIA) and healthy controls with various hsp-derived peptides together with the whole molecules of corresponding hsp. Methods PBMC were cultured with recombinant human hsp60 (rh-hsp60), rh-hsp70, Mycobacterium bovis hsp65 (M.bovis hsp65), P562–571 human hsp60, P180–188 M. bovis hsp65, P450–463 human hsp70 and P545–554 cytokeratin derived synthetic peptides. Cell responses were measured after incorporation of ³H-thymidine and expressed as stimulation indices. Results and conclusion We found elevated proliferative response to rh-hsp60, M. bovis hsp65 and P562–571 human hsp60 derived peptide in patients with JIA polyarthritis. Significantly elevated proliferation to P180–188 M. bovis hsp65 was found in JIA lasting more than 2 years. None of the particular clinical characteristics (RF, ANA, HLA B27 and disease activity) seemed to be associated with hsp or hsp-derived synthetic peptide proliferative response in the JIA cohort. Received 26 September 2005; returned for revision 13 December 2005; accepted by G. Wallace 3 January 2006