Detection of α–defensin in blister fluids as potential biomarkers for bullous pemphigoid patients by matrix-assisted laser desorption ionization/time-of-flight mass spectrometry

Bullous pemphigoid (BP) is a chronic blistering disease that manifests as multiple tense bullae on the limbs and body. Detecting biomarkers present in skin fluids may assist in the early diagnosis and treatment of BP. In this study, a modern mass spectrometric method was developed for screening biomarkers in blister fluids collected from patients. Blister fluids collected from BP patients and physically injured patients were analyzed and compared using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The blister fluids were mixed with MALDI matrix solution on the target plate; after drying, they were analyzed by MALDI-TOF MS. Alpha-defensins 1–3 were detected in the samples collected from all BP patients and absent in all patients with physical injuries. Therefore, alpha-defensins 1–3 are potential biomarkers for BP and can be used to differentiate between blisters caused by BP and those caused by physical injuries. Compared to traditional skin biopsy methods that use immunofluorescent stains, analyzing biomarkers in blister fluids using MALDI-TOF is a more rapid and less invasive method. MALDI-TOF-MS is a non-invasive and efficient method that is able to rapidly distinguish between blisters caused by BP and those caused by physical injuries. •MALDI-TOF/MS is a non-invasive and time saving method to detect blister fluids.•Alpha-defensins were detected in blister fluid caused by bullous pemphigoid.•The detection limit of α‑defensins in the blisters was estimated to be 1.0 × 10−6 M.