Background: Paraneoplastic pemphigus (PNP) is an autoimmune mucocutaneous disease. We previously reported that B cells in a Castleman tumour associated with PNP produced autoantibodies. However, it is uncertain whethe...Background: Paraneoplastic pemphigus (PNP) is an autoimmune mucocutaneous disease. We previously reported that B cells in a Castleman tumour associated with PNP produced autoantibodies. However, it is uncertain whether the production of autoantibodies from the associated tumour is a common mechanism in PNP. Objectives: To investigate autoantibody production in a thymoma and a follicular dendritic cell sarcoma that were excised from two patients with PNP. Methods: Tumour cells were cultured, and their surface markers were identified. Indirect immunofluorescence, immunoblotting and enzyme- linked immunosorbent assay (ELISA) using culture media from the tumours were used to detect PNP autoantibodies. Results: B cells with markers (CD22+ , surface membrane IgG+ and surface membrane IgM+ ) of mature B lymphocytes constituted a proportion of cultured tumour cells in both tumours. Western blot showed that the medium from both the thymoma and the follicular dendritic cell sarcoma cells recognized 190- kDa periplakin and 210- kDa envoplakin bands of human epithelial proteins as well as recombinant linker regions of periplakin, envoplakin, desmoplakin and bullous pemphigoid antigen 1. ELISA was positive for antidesmoglein 3 antibody. Conclusions: The presence and localization in tumours of B lymphocyte clones against proteins of the plakin family and desmoglein 3 in skin may not be confined to PNP with Castleman disease, but is possibly a common mechanism in PNP associated with various tumours.展开更多
文摘Background: Paraneoplastic pemphigus (PNP) is an autoimmune mucocutaneous disease. We previously reported that B cells in a Castleman tumour associated with PNP produced autoantibodies. However, it is uncertain whether the production of autoantibodies from the associated tumour is a common mechanism in PNP. Objectives: To investigate autoantibody production in a thymoma and a follicular dendritic cell sarcoma that were excised from two patients with PNP. Methods: Tumour cells were cultured, and their surface markers were identified. Indirect immunofluorescence, immunoblotting and enzyme- linked immunosorbent assay (ELISA) using culture media from the tumours were used to detect PNP autoantibodies. Results: B cells with markers (CD22+ , surface membrane IgG+ and surface membrane IgM+ ) of mature B lymphocytes constituted a proportion of cultured tumour cells in both tumours. Western blot showed that the medium from both the thymoma and the follicular dendritic cell sarcoma cells recognized 190- kDa periplakin and 210- kDa envoplakin bands of human epithelial proteins as well as recombinant linker regions of periplakin, envoplakin, desmoplakin and bullous pemphigoid antigen 1. ELISA was positive for antidesmoglein 3 antibody. Conclusions: The presence and localization in tumours of B lymphocyte clones against proteins of the plakin family and desmoglein 3 in skin may not be confined to PNP with Castleman disease, but is possibly a common mechanism in PNP associated with various tumours.
