New method to detect a diagnostic marker anti-NH2–terminal of α–enolase autoantibody for Hashimoto’s encephalopathy
Makoto Yoneda1, Rinako Nakayama2, Akiko Matsunaga1, Kazuyoshi Togashi2
1Fukui Prefectural University, 2Cosmic Corporation
Objective:
To develop a new rapid and automatic method to detect a diagnostic marker, anti-NH2–terminal of α–enolase (NAE) autoantibody (Ab) for Hashimoto’s encephalopathy (HE).
Background:
HE is a steroid-responsible autoimmune disorder associated with chronic thyroiditis. Patients with HE present with various neuropsychiatric symptoms. We discovered a serum autoantibody against the NAE (anti-NAE Ab) to be a useful diagnostic marker for HE and analyzed more than 4,700 samples by a sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)/immunoblot system. However, this conventional detection method is time-consuming (2 days for 10 samples). Thus, we newly developed a rapid and automatic method to detect the NAE Ab (less than 4 h for 24 samples) by a capillary electrophoresis/blot system using the WesTM system (Protein Simple, CA).
Design/Methods:
We prepared a recombinant NAE protein after the electroporation of the NAE cDNA into human cultured cells HEK293, purified through a Ni column, and used this protein for the detection of anti-NAE Ab. Subsequently, we investigated the specificity/sensitivity and reproducibility by the Wes method as compared to that of the conventional method in patient sera from 11 positives or six negatives for anti-NAE Ab.
Results:
This study demonstrated the positive (81.8%; 9/11), negative (100%; 6/6) and judgment match rates (88.2%; 15/17) of the two methods, leading to good specificity and sensitivity. These data also showed good reproducibility. Thus, the Wes method is useful and reliable in the detection of the NAE Ab.
Conclusions:
The Wes method to detect a diagnostic marker, anti-NAE Ab, for HE is rapid and automatically performed with good specificity, sensitivity, and reproducibility compared to the conventional method.