Clinical Outcomes and Prognostic Factors in Bullous Pemphigoid Patients: A 15-Year Review in China

There are limited data on clinical outcomes and prognosis factors for bullous pemphigoid (BP) at long-term follow-up.

We aimed to investigate the clinical outcomes and prognostic factors in BP patients.

This retrospective study was performed between January 1, 2009 and December 31, 2023 in Shandong Province, China. The primary outcomes were the rates and predictive factors of mortality, complete remission off-therapy (CROT), and relapse by Cox proportional hazards models or logistic regression analyses. Nomograms for BP mortality and CROT were also described.

Of the 1063 BP patients enrolled, 45 were excluded due to loss to follow-up. The cohort comprised 1018 BP patients to analyze. A total of 344 (33.8%) patients died, with cumulative 1-, 3-, and 5-year mortality rates of 22.8%, 31.2%, and 34.5%, respectively. Increased age at onset (HR = 1.08), body surface area (BSA) involvement 10-30%, BSA involvement > 30% (HR = 7.19; HR = 9.84, respectively), double-positive IgG and C3 on DIF (HR = 1.37), and systemic corticosteroid in combination  with immunosuppressants treatments (HR = 0.50) were associated with mortality. A total of 321 (31.5%) patients achieved CROT. Cumulative CROT rates at 1, 3, and 5 years were 10.9%, 32.9%, and 47.5%, respectively. Shorter diagnosis delay time (HR = 1.01), baseline anti-BP180 antibody < 50 IU/mL (HR = 1.48) and systemic drugs other than corticosteroid treatment (HR = 1.68) were associated with CROT. Predictive models demonstrated outstanding performance in classifying mortality at 1, 3, and 5 years (AUCs 0.83, 0.86, 0.88), but moderate classification for CROT (AUCs 0.67, 0.62, 0.63). A total of 749 (73.6%) patients experienced relapses.

This study, the first large cohort to examine long-term outcomes in BP patients, identifies risk factors for mortality and CROT, offering key insights for clinicians to improve prognosis and reduce relapse rates.