Serum autoantibodies against the dermal-epidermal junction in patients with chronic pruritic disorders, elderly individuals and blood donors prospectively recruited.

BACKGROUND: Bullous pemphigoid (BP) is a subepidermal blistering autoimmune disease characterized by autoantibodies against two structural proteins of the epidermal basal membrane zone (BMZ), BP180 (type XVII collagen) and BP230. Patients are usually old and suffer from severe pruritus. Advanced age and severe pruritus have been hypothesized as potential risk factors for the development of autoantibodies in BP. OBJECTIVES: To prospectively determine anti-BMZ antibodies in sera from patients with advanced age and/or pruritus compared with regular blood donors. METHODS: Sera from (i) patients with chronic pruritic skin disorders (PSD, n = 78; mean age 62 years), (ii) patients with noninflammatory skin disease aged ≥ 70 years (n = 93; mean age 78 years), and (iii) blood donors (n = 50; mean age 41 years) were included. A large panel of validated test systems used for routine diagnosis were employed comprising indirect immunofluorescence (IF) microscopy on monkey oesophagus and human salt-split skin, BP180 NC16A- and BP230-specific enzyme-linked immunosorbent assay (ELISA) systems, and immunoblotting with various substrates, including LAD-1 (the soluble ectodomain of BP180), BP180, BP230, laminin 332, p200 antigen, laminin γ1 and type VII collagen. RESULTS: No statistically significant difference was seen between the three study groups. The same result was obtained when data for IF microscopy, ELISA and immunoblotting were analysed separately. CONCLUSIONS: Neither advanced age nor chronic pruritus have been verified as risk factors for autoantibodies against the epidermal BMZ.

Characterization of Wue-1, a novel monoclonal antibody that stimulates the growth of plasmacytoma cell lines.

A new monoclonal antibody, Wue-1, which specifically recognizes normal and malignant plasma cells, is characterized. Biochemical studies showed that monoclonal antibodies (mAbs) recognize a protein of 94 kDa. Using triple-staining flow cytometry and double-labeling immunohistochemical techniques, two populations of plasma cells, i.e. lymphoplasmocytoid plasma cells located in the germinal center of lymphoid organs and reticular plasma cells at the paracortex or medullary cords of secondary lymphoid tissues, were distinguished. Wue-1 is expressed when B-cell markers become lost and secretory activity with plasma cell morphology appears. Cell surface markers were identified on normal plasma cells and compared with their malignant counterpart in vivo. Terminal plasma-cellular differentiation of malignant low- and high-grade B-cell lymphoma and anaplastic plasmacytoma, otherwise difficult to identify with conventional B-cell markers on tissue sections or fluorescence-activated cell sorter analyses, were detectable by Wue-1. In cell culture, Wue-1 enhanced the proliferation of myeloma cell lines but not normal plasma cells in a dose-dependent manner. Since Wue-1-induced proliferation was increased by interleukin (IL)-6, Wue-1 recognizes a so far unidentified antigen with functional properties. Therefore, Wue-1 represents a useful new tool for therapy and for the in vivo and in vitro studying of B-cell lymphomas and the mechanisms of B-cell differentiation.