Diagnostic utility of gingival biopsy for pemphigus vulgaris and mucosa membrane pemphigoid: A 10-year cohort study

Oral biopsy has been widely performed for the diagnosis of pemphigus vulgaris (PV) and mucosa membrane pemphigoid (MMP). It is more convenient to obtain normal-appearing mucosal tissues with high sensitivity of direct immunofluorescence (DIF) compared to the perilesional mucosa. This study was developed within a retrospective cohort between 2013 and 2023 including 84 PV patients and 74 MMP patients. The hematoxylin-eosin positivity of normal-appearing gingiva was 91.8% for PV and 73.7% for MMP. The DIF positivity of normal-appearing gingiva was 96.1% and 96.3% for PV and MMP, respectively. Compared with the perilesional mucosa (68.8%), the DIF positivity of normal-appearing gingiva (73.7%) was similar to each other in PV, while it was significantly higher (73.3% vs. 96.3%) in MMP (P = 0.02). Our results suggest that normal-appearing gingiva appears to be a good alternative biopsy site for the diagnosis of MMP and those pure gingival PV.