Abstract: 【Abstract】 Objective To apply combined serological diagnostic methods for anti-BP180-type and anti-laminin 332 （Ln332）-type mucous membrane pemphigoid （MMP）, and to summarize their clinical and immunoserological characteristics. Methods A retrospective analysis was conducted on the data from 52 patients clinically suspected of having MMP at the Hospital of Dermatology, Chinese Academy of Medical Sciences from January 2017 to February 2022. Serum samples were collected, and combined serological tests, including indirect immunofluorescence on salt-split skin, enzyme-linked immunosorbent assay, and immunoblotting, were performed to analyze the immunoserological and clinical characteristics of the patients. The Fisher′s exact test was used to compare the lesion occurrence rates between groups. Results Among the 52 patients clinically suspected of MMP, 32 （61.5%） were diagnosed with anti-BP180-type MMP, 10 （19.2%） with anti-Ln332-type MMP, and 4 （7.7%） with anti-BP180- and anti-Ln332-type MMP due to the presence of both anti-BP180 and anti-Ln332 antibodies; 2 tested positive for IgG on the epidermal side of salt-split skin, but no target antigens were identified by serological tests, and they were diagnosed with MMP （subtype pending）; 4 tested negative by immunoserological tests. Ocular involvement was observed in 6 out of 10 patients with anti-Ln332-type MMP, whereas only 6 out of 32 anti-BP180-type MMP patients （18.8%） had ocular symptoms, and there was a significant difference in the occurrence rate of ocular involvement between the two groups （P = 0.02）; the occurrence rates of nasal involvement and multi-mucosal involvement were significantly higher in the anti-Ln332-type MMP patients （50%［5/10］, 90%［9/10］, respectively） than in the anti-BP180-type MMP patients （0, 25%［8/32］, respectively, both P < 0.001）. Scar formation occurred in 6 out of 10 anti-Ln332-type MMP patients, but occurred in only 6 out of 32 anti-BP180-type patients （18.8%, P = 0.02）. Conclusion The combination of indirect immunofluorescence on salt-split skin, enzyme-linked immunosorbent assay, and immunoblotting could effectively identify anti-BP180 and anti-Ln332 autoantibodies in MMP patients, with BP180 being the most common target antigen; compared with anti-BP180-type MMP, anti-Ln332-type MMP appeared to be more frequently involve the ocular and nasal mucosae, associated with the involvement of multiple mucosal sites, carrying a higher risk of scar formation.

Key words: Pemphigoid, benign mucous membrane, Fluorescent antibody technique, indirect, Enzyme-linked immunosorbent assay, Immunoblotting, BP180, Laminin332, Salt-split skin