Publication details
Mucous membrane pemphigoid diagnostics with western blot analysis
| Authors | |
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| Year of publication | 2024 |
| Type | Conference abstract |
| Citation | |
| Description | Background: Mucous membrane pemphigoid (MMP) is a heterogeneous disease with several described target antigens. Serological diagnostics with immunofluorescence has low sensitivity and ELISA is not commercially available. A western blot analysis (WB), aimed at finding specific target antigens, would help to improve the differential diagnosis of these blistering diseases. Aim: To investigate the possibility of using WB analysis for differential diagnosis of MMP. Methods: 73 sera of patients with MMP, ocular pemphigoid (OCP), EBA (epidermolysis bullosa acquisita), BP (bullous pemphigoid) and undefined mucosal blistering diseases were examined by WB on HaCat cell and/or extracellular matrix lysates. Human serum was used as a negative control. The most abundant 60 kDa band was examined by proteomic analysis. Results: WB showed reactivity of patients’ sera with several bands of different molecular weights in the range of 20-180 kDa. Interestingly, the bands with lower molecular weights of 80, 60, 38 and 30 kDa were mostly represented. The most frequently represented band of 60 kDa was selected for proteomic analysis. The preliminary results show 1252 proteins in band 60 kDa of the cell substrate, including fragments of laminin alpha-3, beta-3, and gamma-2, integrin alpha-2, alpha-6, beta-4, collagen XVII and 7 other extracellular matrix proteins. We proved the reactivity at beta-4 integrin fragment IC3.4.1 (1489-1510), which was previously demonstrated as possible epitope for OCP autoantibodies binding (Rashid et al., 2013). Conclusion: WB analysis confirmed the presence of autoantibodies in the sera of MMP patients. Theyreacted with many bands mainly in lower molecular weights than the target proteins (integrins and laminins). The 60 kDa band appeared to be the most frequent and thus diagnostically interesting. Proteomic analysis showed that fragments of target proteins including the diagnostically significant fragment of beta-4 integrin were present. It is evident that the WB analysis is not specific enough for diagnostic purposes, however positivity of band of 60kDa may be a useful marker in diagnostic process, especially in OCP, in which the other diagnostic tools are limited. |