Abstract:

Objective To screen superior antigens by comparing the performance of three different expressed epitope peptides of tyrosinase, i.e., TYR240-300, TYR240-479 and TYR in detecting anti-tyrosinase IgG antibodies in the sera of patients with progressive vitiligo. Methods Three epitope peptides, i.e. TYR240-300, TYR240-479 and TYR were previously obtained by prokaryotic expression, purified, and identified with Western blotting. Interception ELISA was carried out with the three epitope peptides as antigens and total protein extracts from primary human melanocytes as interception antigens. Also, purified peptides coated on ELISA plates were used as antigens to detect anti-tyrosinase IgG antibodies in sera from 100 patients with progressive vitiligo, and the positivity and titer of antibodies detected by them were compared. Results All the three epitope peptides could be intercepted by natural melanocyte antigens. The positivity of antibodies against TYR 240-300 and TYR 240-479 varied in patients with different types of vitiligo. In detail, anti-TYR 240-300 antibodies and anti-TYR 240-479 antibodies were detected in 32.0% and 62.0% of the 100 patients, 4 and 7 patients with generalized vitiligo, 3 and 4 patients with localized vitiligo, 15 （31.3%） and 29 （60.4%） patients with sporadic vitiligo, 4 （20.0%） and 10 （52.6%） patients with extremity vitiligo, 8 （47.1%） and 14 （82.4%） patients with segmental vitiligo, respectively. Moreover, the positivity of IgG antibodies against TYR 240-479 and TYR was similar （62.5% vs 62.05%） in 40 tested patients with progressive vitiligo. Besides above, the highest titer of antibody against TYR240-479 and TYR both reached 1 ∶ 320, and that against TYR240-300 was 1 ∶ 160. Conclusion TYR240-479 can replace TYR as an antigen for the detection of anti-tyrosinase antibodies in patients with progressive vitiligo.