Risk factors predisposing relapse of bullous pemphigoid at initial diagnosis: A retrospective cohort study of 205 patients.

BACKGROUND

Previous studies have revealed the factors associated with the relapse of bullous pemphigoid (BP). This study aims to assess the characteristics of BP patients at the time of initial diagnosis and a potential association with subsequent relapse occurrences.

METHODS

A retrospective cohort study was conducted on 205 BP patients from January 2009 to May 2022 at the Peking Union Medical College Hospital in Beijing, China. The median follow-up duration was 2.7 years. We conducted univariate and multivariate analyses on various clinical indicators (e.g., lesional involvements and medical history) and laboratory test results.

RESULTS

Among the 205 patients, 118 (57.6 %) relapsed during the follow-up period. Univariate analysis revealed several factors associated with relapse, which were greater age [Hazard Ratio (HR)1.018, 95 % confidence interval (CI) 1.004-1.032] (p = 0.010), a past medical history of thyroid diseases [HR 3.674, 95 % CI 1.472-9.167] (p = 0.005), hematological disease complications [HR 4.123, 95 % CI 1.301-13.061] (p = 0.016), negative C3 deposition in direct immunofluorescence [HR 0.574, 95 % CI 0.374-0.883] (p = 0.011) and prealbumin level less than 200 mg/L[HR 0.580, 95 % CI 0.351-0.957] (p = 0.033). Multivariate analysis demonstrated that patients with negative C3 deposition in direct immunofluorescence [HR 0.524, 95 % CI 0.296-0.927] (p = 0.026) and prealbumin levels below 200 mg/L [HR 0.541, 95 % CI 0.301-0.974] (p = 0.041) were associated with further relapses of BP.

CONCLUSIONS

Negative C3 deposition in direct immunofluorescence and a prealbumin level below 200 mg/L at initial diagnosis served as predictive markers for future relapses of BP. Systemic evaluation of BP patients at initial diagnosis could be essential in helping prevent recurrences and achieve more effective disease management.