Elevated levels of circulating heat shock protein 70 (Hsp70) in peripheraland renal vascular disease

Heat shock proteins (Hsp) are families of phylogenetically conserved molecu les that have a range of cytoprotective and intracellular functional roles. Reactivity to heat shock proteins has been implicated in the development o f autoimmune disease and tissue expression of heat shock proteins and incre ased levels of anti-Hsp antibodies have also been reported in vascular dise ase. This study compared circulating levels of Hsp60 and Hsp70 and antihuma n Hsp60, antihuman Hsp70, and antimycobacterial Hsp65 antibodies in periphe ral (PVD) and renal (RVD) vascular disease with those in age- and sex-match ed controls. Levels of Hsp70 were higher in both PVD (median 580 vs 40; P < 0.01) and RVD (median 160 vs 0; P < 0.03), whereas there were no differenc es in Hsp60 levels. Anti-Hsp60 antibody levels were elevated in PVD (146 vs 81 arbitrary units/ml: P < 0.04), but not RVD. This is the first study to demonstrate increased levels of circulating Hsp70 in pathological disease s tates; however, its physiological role remains to be determined.