Researchers organize bullous pemphigoid by three main profiles

Researchers identified three different clusters of bullous pemphigoid, the most common autoimmune blistering disorder, according to a study published in the Journal of American Academy of Dermatology.

According to the researchers, bullous pemphigoid (BP) is characterized by erythematous patches with or without blisters. Common diagnosis criteria include age older than 70 years, absence of atrophic scars or mucosal involvement and predominant involvement of the neck and head.

However, atypical presentations with mucosal involvement have been previously described in up to 30% of patients.

“The aim of this study was to investigate, without prior hypotheses, whether there are different clinical and biological phenotypes of BP characterized by different outcomes,” Florine Guerrois, MD, of Cochin Hospital in Paris, and colleagues wrote.

Guerrois and colleagues reviewed records from the immunological departments of two hospitals for patients with positive ELISA results for autoantibodies against BP180NC16A and/or BP230. They included 279 patients in their study, 74 of whom had mucosal involvement affecting the mouth (n = 70) and the epiglottis (n = 14).

The researchers partitioned patients into three clusters. Cluster 1, which corresponded to the “classical phenotype of BP,” was characterized by anti-BP230 autoantibodies in older patients with low-severity clinical presentation and no mucosal involvement. Cluster 2 included patients with moderate severity of BP, such as fewer than 100 blisters per patient and mucosal lesions in 38% of cases. Cluster 3 comprised younger patients with more severe disease, such as more than 100 blisters, mucosal involvement and epiglottic lesions (40%).

The 155 patients in cluster 1 were aged older than those in cluster 2 or cluster 3 (median age, 85 years vs. 80 years vs. 75 years, respectively; P < .0001). They also had a significantly higher frequency of pauci- or non-bullous BP compared with cluster 2 and cluster 3 (41% vs. 16% vs. 6%; P < .0001). At 7%, cluster 1 saw little mucosal involvement. Also, 87% of patients in this group had anti-BP230 antibodies, including 64% who presented with antibodies against both BP180NC16A and BP230.

Cluster 3 saw 40% of patients with more extensive cutaneous clinical presentation of more than 100 blisters compared with the 2% of patients in cluster 1 or 0% in cluster 2 (P < .0001). They also had a higher frequency of mucosal involvement at 91% compared with 7% in cluster 1 and 38% in cluster 2 (P < .0001).

Disease control at 6 months and 1 year was poorer and relapse frequency more common in cluster 3 compared with cluster 1 and cluster 2.

“One group of younger patients presents severe forms with intermediate characteristics overlapping with those of [mucous membrane pemphigoid],” Guerrois and colleagues wrote. “Recognition of this subtype could help to improve treatment strategies.”