Detection of antibodies against melanocytes in serum samples from patients with vitiligo and identifi-cation of the associated melanocyte membrane antigens / 中华微生物学和免疫学杂志

ABSTRACT

Objective To detect the autoantibodies against melanocytes in serum samples from pa-tients with vitiligo and to identify the associated membrane antigens .To detect heat shock protein 70 (HSP70) and anti-tyrosinase related protein 1 (TRP-1) antibody in serum samples and to further analyze their correlations .Methods Normal human melanocytes were cultured in vitro.Indirect immunofluorescent assay was used to locate associated antigens .Western blot assay was performed to detect autoantibodies against membrane and cytoplasmic proteins of melanocytes in 50 cases of patients with vitiligo ( including 4 cases with HBV infection ) .Membrane antigens with higher frequencies were identified with protein mass spectrometry analysis .ELISA assay was performed to detect the HSP 70 and anti-TRP-1 antibody in serum samples from 70 patients with vitiligo ( including 10 cases with HBV infection ) .Results The specific anti-gens were detected in the cytoplasm and on the membrane of melanocytes .The membrane antigens were de-tected in 40 out of 50 (80%) randomly selected serum samples as indicated by Western blot assay .The au-toantibodies could react to several membrane antigens with approximate molecular weights (Mr) of 86×103, 75×103, 60×103, 52×103 and 44×103, showing strip positive rates of 36%, 58%, 22%, 2%and 2%re-spectively.The cytoplasmic antigens with Mr of 110×103, 90×103, 75×103, 50×103 and 40×103 were ac-count for 30%of the 50 tested serum samples , showing strip positive rates of 12%, 4%, 12%, 10% and 2% respectively .The positive rates of membrane and cytoplasmic antigens were 15% and 5% respectively for health subjects.Results of protein mass spectrometry analysis indicated that membrane Mr of 86×103 and 75×103 might be Lamin A/C and the membrane protein at a Mr of 60×103 was predicted as Vimentin X1. High titers of anti-TRP-1 antibody in serum samples were detected in patients with vitiligo in combination with HBV infection, which was confirmed to have a positive correlation with HSP 70 (r=0.927, P<0.01). Conclusion A membrane antigen associated with vitiligo was newly identified which might provide evidence for the investigation on the autoimmune pathogenesis of vitiligo and the formation of autoantibodies .A prelim-inary study on the relationship between HBV infection and vitiligo was conducted through detecting the HSP70 and anti-TRP-1 antibody in serum samples .