Antibodies to mycobacterial 65 kDa heat shock protein in systemic sclerosis (scleroderma)

It has been reported that immunity to the 65 kDa heat shock protein of Mycobacterium tuberculosis (MT-hsp65) not only accompanies rheumatoid arthritis (RA), but may also be characteristic of chronic inflammation. We now report serum antibodies to MT-hsp65 in 47% of systemic sclerosis (SSc), 38% of primary Raynaud's phenomenon (PRP) and 5% of systemic lupus erythematosus (SLE). Antibody levels were higher in patients with active or progressive SSc and correlated with the degree of skin fibrosis. Thus, immunity to MT-hsp65 appears in SSc and is not limited to RA. However, it does show some degree of specificity beyond chronic inflammation: PRP patients have a higher reactivity than do SLE patients.