Elevated anti-alpha-enolase antibody levels in Kawasaki disease

By functioning as a heat-shock protein (HSP), alpha-enolase has an important role in the pathophysiology of multivariant vasculitis. Kawasaki disease (KD) is a type of vasculitis occurring primarily in children. The role of alpha-enolase in KD was assessed by measuring anti-alpha-enolase antibody (Ab) titres in patients with KD and the usefulness of anti-alpha-enolase Ab as a diagnostic tool in atypical KD patients was evaluated.

Anti-alpha-enolase Ab titres were measured by using an enzyme-linked immunosorbent assay (ELISA) in seven normal control patients, nine febrile control patients and 14 KD patients (10 typical KD, four atypical KD). A standard deviation (SD) of 3 above the mean of the normal control group was considered to be positive reactivity. Western blotting using recombinant human alpha-enolase was performed in four KD patients and three normal controls.

With the positive reactivity limited to +3 SD over the mean (>0.6), 10 out of 14 patients (71%) were positive at the acute onset and 12 out of 14 patients (85.7%) were positive before discharge. In total, 12 out of 14 patients (85.7%) were positive either at acute onset or before discharge. All four atypical KD patients showed positive reactivity. Specific positive bands against recombinant human alpha-enolase were detected by western blotting in all four KD patients, but no reactivity was seen in three patients with normal controls.

This is the first study to demonstrate that autoantibodies against the alpha-enolase are present in the sera of KD patients. We suggest that anti-alpha-enolase Ab should be a good candidate for a diagnostic tool in atypical KD.