PGK1 as an immune target in Kawasaki disease.

Kawasaki disease (KD) is an immune-mediated vasculitis with symptoms that mimic febrile illness; the immune origin has been suggested but never proved. First, cell chip technology was used to screen immune targets cells. With the indirect immunofluorescence assay we found that the HeLa cell chip could be recognized by KD patient serum samples. The target cell proteome was extracted as antigens, and antigen recognition reaction was performed using the patients' serum as antibodies and the detected target protein was detected and identified as phosphoglycerate kinase 1 (PGK1). Then PGK1 was produced and tested with enzyme-linked immunosorbent assay (ELISA), Western blotting, immunoprecipitation and competitive inhibition immunofluorescence assay. Immunoglobulin (Ig)G against PGK1 was detected in 46% (23 of 50) sera of KD patients, 13% (five of 38) sera in febrile non-KD patients (FC) and 2·6% (one of 38) sera in healthy donors. As an immune target, PGK1 not only helps understanding of the pathogenesis, it also has potential value in facilitating the laboratory diagnosis of KD.