Association between bullous pemphigoid and atopic dermatitis: a population-based case-control study in Taiwan

A case of bullous pemphigoid following administration of anti-IL-31 receptor A antibody

Bullous pemphigoid (BP), an autoimmune bullous dermatosis, occurs predominantly in older individuals. Nemolizumab, a humanized monoclonal antibody against the interleukin (IL)-31 receptor A, is used to treat severe atopic dermatitis (AD) in Japan. However, it can cause several adverse events, such as exacerbation of AD, erythema, and eosinophilia. Herein, we describe a case of prurigo-type AD developing BP after nemolizumab administration. A 62-year-old man with prurigo-type AD and asthma presented with serious, refractory itching. After nemolizumab injection, his pruritus was relieved for 2 days. However, on day 3, erythema with blisters and erosions suddenly appeared throughout his body. Pathological examination showed typical BP and the patient's serum anti-BP180-NC16a antibody level was 882.5 U/mL. Oral prednisolone (PSL) was initiated and nemolizumab was never used again. Despite high-dose PSL, new blisters continued to develop, with a rapid elevation of anti-BP180-NC16a antibodies to 6930 U/mL. Adding high-dose cyclosporine and intravenous gamma globulin reduced new blister formation after 9 weeks, and PSL and cyclosporine were gradually tapered. Dupilumab, an anti-IL-4 receptor antibody, was initiated after 16 weeks, resulting in continued remission without PSL and cyclosporine. The sudden occurrence of BP in this case suggested that the patient had occult BP before the nemolizumab initiation and that nemolizumab exacerbated BP and made it overt. Blocking the IL-31 pathway may exacerbate inflammation in AD or BP, resulting in the acceleration of blister formation. This may be countered by blocking the IL-4/13 pathway with dupilumab. To our knowledge, this is the first case of nemolizumab-exacerbated BP.

Causal association between psoriasis vulgaris and bullous pemphigoid: a two-sample bidirectional Mendelian randomization study

Background

The association between psoriasis vulgaris and bullous pemphigoid (BP) remains largely unknown.

Objectives

To investigate whether there is a causal effect between psoriasis vulgaris and BP.

Methods

Two-sample bidirectional Mendelian randomization (MR) analyses were conducted using publicly released genome-wide association studies (GWAS) summary statistics. The GWAS summary statistics for BP were downloaded online from FinnGen Biobank Documentation of the R12 release, which includes 219 BP cases and 218,066 controls. The GWAS data for psoriasis vulgaris were extracted from Sakaue et al., which comprises 5072 cases and 478,102 controls. Single-nucleotide polymorphisms (SNPs) associated with exposure were selected as instrumental variables by performing additional quality control steps. The inverse-variance-weighted (IVW) method was used for the primary MR analyses, and the MR-Egger regression, weighted mode method, weighted median method, and simple mode were employed for sensitivity analyses. The MR-Egger intercept test and "leave-one-out" sensitivity analysis were performed to evaluate the horizontal pleiotropy and the potentially influential SNPs, respectively.

Results

Genetically determined log odds of psoriasis vulgaris were associated with an increased risk of BP (IVW: odds ratio (OR) = 1.263, 95% confidence interval (CI): 1.013-1.575, P=0.038). Sensitivity analyses by the weighted mode (OR=1.255, 95%CI: 0.973-1.618, P=0.106), MR Egger (OR=1.315, 95%CI: 0.951-1.817, P=0.126), simple mode (OR=1.414, 95%CI: 0.823-2.429, P=0.234) and weighted median method (OR=1.177, 95%CI: 0.889-1.559, P=0.254) derived directionally consistent relationship between the genetically predicted log odds of psoriasis vulgaris and risks of developing BP. On the contrary, we found that genetically predicted BP had no significant effect on psoriasis vulgaris (IVW: OR=0.996, P= 0.707), indicating the unidirectionality of the relationship. MR-Egger intercept tests showed no evidence of horizontal pleiotropy. No influential SNP driving the results was detected by the leave-one-out sensitivity analysis.

Conclusions

Our results suggested that psoriasis vulgaris causally increases the risk of BP, highlighting the need for potential strategies for the prevention and early diagnosis of comorbid BP in patients with psoriasis vulgaris. Further researches into this association and underlying mechanisms are warranted.

Assoziation zwischen chronischer Nierenerkrankung und dem Risiko für bullöses Pemphigoid: eine nationale bevölkerungsbasierte Kohortenstudie

Hintergrund

Studien haben gezeigt, dass das bullöse Pemphigoid (BP) auch bei Patienten mit chronischer Nierenerkrankung (CKD, chronic kidney disease) auftritt. Unklar ist, wie hoch das BP‐Risiko bei CKD‐Patienten ist.

Zielsetzung

Es sollte untersucht werden, ob eine CKD das BP‐Risiko erhöht.

Methodik

Die Studienteilnehmer wurden für den Zeitraum von 2007 bis 2018 aus der nationalen Datenbank der taiwanesischen Krankenversicherung rekrutiert. Insgesamt wurden 637 664 neu diagnostizierte Patienten mit CKD sowie 637 664 nach Alter, Geschlecht und Komorbidität übereinstimmende Kontrollpersonen ohne CKD in die Untersuchung aufgenommen. Zur Bewertung des BP‐Risikos kam ein Modell für konkurrierende Risiken zum Einsatz.

Ergebnisse

Nach Adjustierung für Alter, Geschlecht und Komorbidität im multivariaten Modell zeigte sich die CKD als signifikanter Risikofaktor für BP (adjustierte Hazard Ratio [aHR]: 1,29; 95%‐Konfidenzintervall [KI]: 1,17–1,42; p < 0,001). CKD‐Patienten wurden in die Gruppen dialysepflichtig und nicht‐dialysepflichtig unterteilt und mit den Patienten ohne CKD verglichen. Es zeigte sich, dass dialysepflichtige CKD‐Patienten das höchste BP‐Risiko aufwiesen (aHR 1,75; 95%‐KI 1,51–2,03), gefolgt von nicht‐dialysepflichtigen CKD‐Patienten (aHR 1,20; 95%‐KI 1,08–1,32).

Limitationen

Detaillierte Laborbefunde zur Einschätzung des CKD‐Schweregrads fehlten.

Schlussfolgerungen

Im Vergleich zu Personen ohne CKD hatten Patienten mit CKD ein 1,3‐fach erhöhtes BP‐Risiko. Bei Patienten mit dialysepflichtiger CKD war das Risiko 1,8‐fach erhöht.

Comorbidity in bullous pemphigoid: up-date and clinical implications

Bullous pemphigoid is the most common autoimmune blistering disease in industrialized countries and particularly affects the elderly. In this patient population, comorbid diseases are frequent and may complicate management and treatment of bullous pemphigoid. A better understanding why distinct diseases are more frequent in bullous pemphigoid patients may lead to new pathophysiological insights and - as a consequence - result in better patient care. The association of bullous pemphigoid with neurological and psychiatric diseases is well known and confirmed by several case-control studies. Association with further diseases such as malignancy and metabolic diseases are still discussed controversially. In recent years new relationships between bullous pemphigoid and autoimmune as well as inflammatory skin diseases have been reported. This review provides a systematic overview on studies addressing comorbidity in bullous pemphigoid patients. Increasing the awareness of both, common and rare comorbid diseases, may enable clinicians to optimize patient support and individualized treatment of bullous pemphigoid.