Re-evaluation of the natural course of bullous pemphigoid. A prospective study

Mixed Individual-Aggregate Data on All-Cause Mortality in Bullous Pemphigoid: A Meta-analysis

Importance

The 1-year standardized mortality ratio (SMR) of bullous pemphigoid (BP) has been reported as 2.15 to 7.56 and lower in the US than in Europe.

Objective

To estimate the worldwide 1-year SMR of BP.

Data Sources

PubMed, Embase, Cochrane Library, Google Scholar, Lissa, and gray literature (eg, medRxiv) were screened for studies of BP published from inception to June 10, 2020, with review of reference lists.

Study Selection

Retrospective and prospective studies reporting 1-year all-cause mortality rate in patients with BP and providing age statistics (eg, mean [SD]).

Data Extraction and Synthesis

Two reviewers independently extracted the data. The 1-year SMR was computed in studies reporting 1-year mortality by combining information on age obtained from studies with aggregate data and individual data. Risk of representativity, misclassification, and attrition bias were assessed by a custom tool.

Main Outcomes and Measures

The primary end point was the worldwide 1-year SMR. Secondary analysis included comparison of 1-year SMRs between continents in a meta-regression.

Results

Three studies were performed in the US (n = 260), 1 in South America (n = 45), 16 in Asia (n = 1903), and 36 in Europe (n = 10 132) for a total of 56 unique studies and 12 340 unique patients included in the meta-analysis (mean [SD] age, 77.3 [12.7] years; 55.9% women). The mean (SD) patient age in the United States was 75.6 (13.7) years; in Asia, 73.8 (13.6) years; and in Europe, 78.1 (12.3) years. The worldwide 1-year SMR was estimated at 2.93 (95% CI, 2.59-3.28; I2 = 85.6%) for all 56 studies. The 1-year SMR in the US was 2.40 (95% CI, 0.89-3.90; I2 = 86.3%) for 3 studies; in Asia, 3.53 (95% CI, 2.85-4.20; I2 = 86.3%) for 16 studies; and in Europe, 2.77 (95% CI, 2.35-3.19; I2 = 86.3%) for 36 studies. After adjustment on the expected 1-year mortality rate, the European 1-year SMR did not differ significantly from the 1-year SMR in the United States (-0.48 vs Europe; 95% CI, -2.09 to 1.14; P = .56) and Asia (0.51 vs Europe; 95% CI, -0.56 to 1.58; P = .35). Risk of attrition bias was high (>10% censorship) in 16 studies (28.6%), low in 16 (28.6%), and unclear in 24 (42.9%). Only 4 studies (7.1%) had a sampling method guaranteeing the representativity of BP cases in a population.

Conclusions and Relevance

Although heterogeneity was high and overall quality of follow-up was poor, this meta-analysis confirms the high mortality rate among patients with BP.

Association of Immunosuppressants with Mortality of Patients with Bullous Pemphigoid: A Nationwide Population-Based Cohort Study

BACKGROUND

Bullous pemphigoid (BP) is a common autoimmune blistering skin disease with substantial mortality.

OBJECTIVE

To identify whether the use of immunosuppressants was associated with reduced mortality in BP patients.

METHODS

The data for this study were obtained from the National Health Insurance Research Database in Taiwan from January 1, 1997 to December 31, 2013. Those BP patients receiving any immunosuppressant for ≥28 days per month for 3 consecutive months were defined as the immunosuppressant cohort. In total, 452 BP patients on immunosuppressants were matched 1:4 by age, sex, propensity score of comorbidities, and use of tetracycline with 1,808 BP patients taking only corticosteroids.

RESULTS

The immunosuppressant cohort had a significantly lower 5-year mortality rate than the corticosteroid cohort (0.57 vs. 0.67). In the multivariable regression analysis adjusted for covariates, the use of immunosuppressants significantly reduced the risk of mortality (hazard ratio [HR]: 0.78, 95% confidence interval [CI]: 0.68-0.90, p < 0.001). Hyperlipidemia also reduced risk of mortality. However, age, diabetes, renal disease, chronic obstructive pulmonary disease, cerebrovascular disease, and dementia were significant risk factors for mortality. In the subgroup analysis, the risk of mortality decreased most substantially in those aged <70 years (HR: 0.45, 95% CI: 0.28-0.72).

CONCLUSION

Immunosuppressant use was associated with a 22% reduced risk of BP mortality. The effects were more substantial in those aged <70 years, with a 55% reduced risk of mortality.

Relapse of bullous pemphigoid: an update on this stubborn clinical problem

Bullous pemphigoid (BP) is a chronic autoimmune blistering disorder that has a predilection for the elderly. It is characterized by a poor prognosis due to its high mortality rate and the tendency to relapse. The relapse rate of BP ranges from 27.87% to 53% after disease remission, while the majority of relapses occur early (within 6 months) during remission. Clinical interventions aimed to prevent early relapses could reduce potential complications from first-line treatment and make follow-up care easier for clinicians in practice, thus improving the prognosis of BP and the quality of patients' lives. In this article, we attempt to review previous studies from the medical literature concerning relapse and risk factors related to relapse in BP patients. Treatments found to be able to reduce or increase relapse rate were also discussed. We propose that clinicians be aware of these risk factors and manage proper treatment accordingly. Key Messages   • The relapse rate of bullous pemphigoid ranges from 27.87% to 53% after disease remission, while the majority of relapses occur early (within 6 months) during remission.   • Ageing, disease severity, neurological disorder, serum ECP, BAFF, IL-17, IL-23, CXCL10 and anti-BP180 antibody levels have been shown to be related to relapse, while confirmation studies are needed before using them for guidance for relapse prevention.   • Longer usage of corticosteroid with a low dose, combination of immunosuppressants and intravenous immunoglobulin are helpful in lowering relapse rate.

Anti-Type VII Collagen Antibodies Are Identified in a Subpopulation of Bullous Pemphigoid Patients With Relapse

Bullous pemphigoid (BP) is an autoimmune bullous skin disease characterized by anti-BP180 and anti-BP230 autoantibodies (AAbs). Mucous membrane involvement is an uncommon clinical feature of BP which may evoke epidermolysis bullosa acquisita, another skin autoimmune disease characterized by anti-type VII collagen AAbs. We therefore evaluated the presence of anti-type VII collagen AAbs in the serum of BP patients with and without mucosal lesions at time of diagnosis and under therapy. Anti-BP180, anti-BP230, and anti-type VII collagen AAbs were measured by ELISA in the serum of unselected patients fulfilling clinical and histo/immunopathological BP criteria at baseline (n = 71) and at time of relapse (n = 24). At baseline, anti-type VII collagen AAbs were detected in 2 out of 24 patients with BP presenting with mucosal involvement, but not in patients without mucosal lesions (n = 47). At the time of relapse, 10 out of 24 BP patients either displayed a significant induction or increase of concentrations of anti-type VII collagen AAbs (P < 0.01), independently of mucosal involvement. Those 10 relapsing BP patients were also characterized by a sustained high concentration of anti-BP180 AAb, whereas the serum anti-BP230 AAb concentrations did not vary in BP patients with relapse according to the presence of anti-type VII collagen AAbs. Thus, our study showed that anti-type VII collagen along with anti-BP180 AAbs detection stratified BP patients at time of relapse, illustrating a still dysregulated immune response that could reflect a potential epitope spreading mechanism in those BP patients.

Bullous Pemphigoid: A Review of its Diagnosis, Associations and Treatment

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease in Western countries, and typically affects the elderly. BP is immunologically characterized by tissue-bound and circulating autoantibodies directed against either the BP antigen 180 (BP180, or BPAG2) or the BP antigen 230 (BP230, or BPAG1e), or even both, which are components of hemidesmosomes involved in the dermal-epidermal cohesion. Risk factors for BP include old age, neurologic diseases (dementia, Parkinson's disease, cerebrovascular disease), and some particular drugs, including loop diuretics, spironolactone and neuroleptics. The spectrum of clinical presentations is extremely broad. Clinically, BP is an intensely pruritic erythematous eruption with widespread blister formation. In the early stages, or in atypical, non-bullous variants of the disease, only excoriated, eczematous or urticarial lesions (either localized or generalized) are present. The diagnosis of BP relies on immunopathologic findings, especially based on both direct and indirect immunofluorescence microscopy observations, as well as on anti-BP180/BP230 enzyme-linked immunosorbent assays (ELISAs). BP is usually a chronic disease, with spontaneous exacerbations and remissions, which may be accompanied by significant morbidity. In the past decade, potent topical corticosteroids have emerged as an effective and safe first-line treatment for BP, but their long-term feasibility is still controversial. Newer therapeutic agents targeting molecules involved in the inflammatory cascade associated with BP represent future alternatives to classical immunosuppressant drugs for maintenance therapy.