Representative ELISA results. (A) ELISA reactivities of sera from 12 AA patients and 16 healthy donors against purified His-tagged kinectin were measured at a 1:500 dilution. A positive reaction is defined as an absorbance value exceeding the mean OD absorbance value of sera from healthy donors by 3 SDs. (B) Sera from 8 AA patients were serially diluted, and ELISA reactivities were measured against purified His-tagged kinectin.