Autoantibodies against
heat shock protein (hsp) 60 have been reported to be detected in sera of non-obese diabetic mice, in an experimental model of
IDDM. However, there are only a few studies which have examined
IDDM patients for
antibodies against mammalian hsp60. We produced murine hsp60 derived from pancreatic beta cells which has high homology to human hsp60 and examined
antibodies against the hsp60 in
IDDM patients using an
enzyme-linked
immunosorbent assay. We extended the analysis to patients with other immune-mediated diseases and
non-insulin-dependent diabetes mellitus (
NIDDM). Positive sera for hsp60 antibody were more frequently detected in 13 out of 84
IDDM (15.5%) and 5 out of 25
rheumatoid arthritis patients (20%), when compared to healthy subjects (1/85; 1.2%, P < 0.001 and P < 0.01, respectively). The levels of hsp60
antibodies of
IDDM (0.218 +/- 0.227) and
rheumatoid arthritis patients (0.259 +/- 0.191) were significantly higher than those of healthy subjects (0.076 +/- 0.131, P < 0.001, P < 0.01, respectively). Patients with slowly progressive
IDDM (n = 26), autoimmune
thyroid disease (n = 42), or
NIDDM (n = 40) had levels of hsp60
antibodies similar to those in healthy subjects. We found no relationship between the levels of hsp60
antibodies and islet cell
antibodies (ICA) or
antibodies to
glutamic acid decarboxylase (GAD65) in
IDDM patients. In conclusion, hsp60
antibodies were detected in Japanese
IDDM as well as in
rheumatoid arthritis patients. Although the positivity was low, the detection of hsp60
antibodies may be helpful for diagnosis of
IDDM especially in GAD65 Ab- or JCA-negative Japanese patients.