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. What's already known about this topic? Bullous pemphigoid (BP) is by far the most frequent autoimmune bullous dermatosis; it mainly affects the elderly, and is associated with severe pruritus. Autoantibodies against the epidermal basal membrane zone (BMZ) have previously been reported in patients with chronic pruritic dermatoses and elderly individuals. Therefore, chronic pruritus and old age were suggested as risk factors for BP. What does this study add? This prospective controlled study assayed sera from a large number of patients with pruritic dermatoses and elderly individuals using validated test systems and found no increased autoantibody reactivity against the epidermal BMZ compared with blood donors. Thus, old age and chronic pruritus do not appear to be factors for the development of autoantibodies against the epidermal BMZ.