Y Hisamatsu

Publications (2)7.33 Total impact

• Article: The detection of IgG and IgA autoantibodies to desmocollins 1-3 by enzyme-linked immunosorbent assays using baculovirus-expressed proteins, in atypical pemphigus but not in typical pemphigus.

  Y Hisamatsu, M Amagai, D R Garrod, T Kanzaki, T Hashimoto
  [show abstract] [hide abstract]
  ABSTRACT: We have shown previously that human desmocollin (Dsc) 1 is recognized by IgA autoantibodies of subcorneal pustular dermatosis (SPD) type IgA pemphigus. However, the presence of IgG anti-Dsc autoantibodies is still controversial, and antibodies to Dsc2 and Dsc3 have not been clearly identified. To investigate this by producing recombinant proteins consisting of the entire extracellular domains of human Dsc1, 2 and 3 in baculovirus, and to use them to establish an enzyme-linked immunosorbent assay (ELISA). By this ELISA, we examined in total 165 cases of various types of autoimmune bullous diseases, as well as 23 normal controls. None of 45 sera of classical pemphigus showed either IgG or IgA antibodies to any Dsc. In contrast, one atypical pemphigus serum showed both IgG and IgA antibodies to Dsc1, which were adsorbed by incubation with Dsc1 baculoprotein. Furthermore, this ELISA detected both IgA and IgG anti-Dsc3 antibodies in one atypical case, and IgA antibodies to both Dsc2 and Dsc3 in another. This reactivity was confirmed by positive IgA immunofluorescence with Dsc2 and Dsc3 expressed on COS-7 cells. These results show that both IgG and IgA autoantibodies against all of Dsc1-3 are present in the sera of particular cases of nonclassical pemphigus, except for IgG antibodies to Dsc2, but that they are not detected in classical pemphigus. Unexpectedly, although IgA antibodies of all of eight SPD type IgA pemphigus sera reacted with Dsc1 expressed on COS-7 cells, only one serum was positive in Dsc1 ELISA for IgA. This result indicates either that Dscs expressed by baculovirus may not adopt the correct conformation or that Dscs may need association with other molecules to express all the epitopes for autoantibodies.
  British Journal of Dermatology 08/2004; 151(1):73-83. · 3.67 Impact Factor
• Article: Epidermolysis bullosa acquisita sera react with distinct epitopes on the NC1 and NC2 domains of type VII collagen: study using immunoblotting of domain-specific recombinant proteins and postembedding immunoelectron microscopy.

  N Ishii, M Yoshida, Y Hisamatsu, A Ishida-Yamamoto, H Nakane, H Iizuka, T Tanaka, T Hashimoto
  [show abstract] [hide abstract]
  ABSTRACT: The sera of epidermolysis bullosa acquisita (EBA) react with type VII collagen, a major component of anchoring fibrils, in which the major epitopes have been considered to be present in the N-terminal noncollagenous (NC) 1 domain. To determine whether there are also epitopes in the C-terminal NC2 domain, and to determine their ultrastructural localization. Immunoblotting using recombinant proteins of the NC1 and NC2 domains of type VII collagen, and postembedding immunoelectron microscopy. Twenty of 28 EBA sera tested reacted with the NC1 domain and eight sera reacted with the NC2 domain. The sera that reacted with the NC1 domain showed immunoreactivity within the lamina densa and the sera that reacted with the NC2 domain showed immunoreactivity in the dermis 300-360 nm below the lamina densa. This study clearly identified the presence of epitopes in the NC2 domain, and showed that the epitope in the NC1 domain is present in the lamina densa and that the epitope in the NC2 domain is in the dermis below the lamina densa.
  British Journal of Dermatology 06/2004; 150(5):843-51. · 3.67 Impact Factor