COVID-19 vaccine acceptance and hesitancy in patients with immunobullous diseases: a cross-sectional study of the International Pemphigus and Pemphigoid Foundation

Patients with autoimmune bullous diseases (AIBDs) have faced considerable challenges during the COVID-19 outbreak.¹ SARS-CoV-2 vaccines became an important public health solution, but the pandemic raised awareness of vaccine hesitancy.² We aimed to investigate the currently unknown general vaccination status among AIBD patients to better inform vaccine practices in this cohort of potentially life-threatening inflammatory disorders.

[Anti-laminin 332 mucous membrane pemphigoid with irreversible ocular and tracheobronchial involvement : Delayed diagnosis of a severe autoimmune bullous disease]

A 53-year-old man presented with a 37-year history of erosive and scarring mucosal lesions of several organs. An initial diagnosis of Stevens-Johnson syndrome was maintained for many years. Due to late correct diagnosis of an anti-laminin 332 mucous membrane pemphigoid and the fact that early, targeted, intensified immunosuppressive therapy was not initiated, the disease led to almost complete loss of vision and obstruction of airways.

Calcitriol exerts anti-inflammatory effects in keratinocytes treated with autoantibodies from a patient with bullous pemphigoid

BACKGROUND

The hormonally active vitamin D metabolite calcitriol and its analogues exert potent effects on cellular differentiation and regulation of immune responses. Although topical vitamin D analogues are widely used for treatment of psoriasis and vitamin D has been increasingly implicated in prevention and protection from several autoimmune diseases, experimental and clinical data in autoimmune bullous diseases are generally lacking.

OBJECTIVE

Here, we investigated the effects of calcitriol on keratinocytes treated by bullous pemphigoid (BP) autoantibodies.

METHODS

Human keratinocyte (HaCaT) cells were treated with purified human BP or normal IgG from one BP patient and healthy subject, respectively, in the absence or presence of calcitriol and effects on (i) cell viability, (ii) IL-6 and IL-8 secretion, (iii) STAT3 and NFκB activation, (iv) heat shock protein 70 (Hsp70) level, and (v) vitamin D receptor (VDR) expression were studied.

RESULTS

We found that BP IgG-induced IL-6 and IL-8 release from HaCaT cells was reduced in the presence of non-toxic doses of calcitriol. Additionally, calcitriol blunted BP IgG-mediated STAT3 phosphorylation and NFκB activity, whereas Hsp70 and VDR expression were not affected.

CONCLUSION

Although the results of this study are based on autoantibodies prepared from a single patient, they show that calcitriol protects from BP IgG-induced inflammatory processes in vitro, thus favouring its potential inclusion into the therapeutic repertoire of BP.

[Anti-p200/anti-laminin γ1 pemphigoid and BP180 NC16A/4575- positive mucous membrane pemphigoid : late diagnosis in a patient with disease-related loss of vision and multiple previous surgical interventions]

A 87-year-old woman presented with a three-year history of partially erosive, partially bullous skin and mucosal lesions, symblepharon of both eyelids as well as dysphagia. To date, multiple excisions of the skin lesions, which had been described as "skin tumors" by surgeons, had been performed. The synopsis of histology, direct and indirect immunofluorescence established the diagnosis of anti-p200/anti-laminin γ1 pemphigoid and BP180 NC16A/4575- positive mucous membrane pemphigoid with an unusual "epitope-spreading" phenomenon. Due to the late initiation of therapy, the disease-related loss of vision unfortunately was irreversible.

Relapse-associated autoantibodies to BP180 in a patient with anti-p200 pemphigoid

Anti-p200 pemphigoid and bullous pemphigoid (BP) are autoimmune subepidermal blistering diseases characterized by autoantibodies to a 200-kDa dermal antigen (p200) and two hemidesmosomal proteins (BP180 and BP230), respectively. We report a 70-year-old man with haemorrhagic blisters, widespread crusted erosions, and the immunopathological characteristics of anti-p200 pemphigoid. Treatment with doxycycline, topical corticosteroids and immunoadsorption led to rapid clinical remission. However, 19 weeks later, a relapse occurred with generalized itchy urticarial erythema and tense blisters. At this time, both strong dermal and epidermal IgG staining was detected by indirect immunofluorescence microscopy on salt-split skin, and autoantibodies against both p200 and the 16th noncollagenous (NC16A) domain of BP180 were found. Interestingly, the relapse was associated not only with the detection of autoantibodies to a second autoantigen (BP180), but also with an altered clinical phenotype. This case was a unique occasion to directly monitor the emergence of intermolecular epitope spreading during the course of an autoimmune bullous disorder.

Clearance rates of circulating and tissue-bound autoantibodies to type VII collagen in experimental epidermolysis bullosa acquisita

BACKGROUND

Epidermolysis bullosa acquisita (EBA) is a severe autoimmune skin disease characterized by autoantibodies to type VII collagen, the major component of anchoring fibrils. In this and other autoimmune bullous dermatoses, specific autoantibody detection systems are not only of diagnostic use but also allow monitoring of circulating and skin-bound autoantibodies during the course of the disease. However, little is known about their natural clearance rates in these different compartments.

OBJECTIVES

To study clearance rates of circulating and tissue-bound autoantibodies to type VII collagen in experimental EBA.

METHODS

Using offspring from mice with experimentally induced EBA, we examined retention times of diaplacentally transmitted autoantibodies to type VII collagen in serum of neonatal mice by enzyme-linked immunosorbent assay and of immunoreactant deposits in skin by direct immunofluorescence microscopy. Additionally, the pathogenic potential of transmitted autoantibodies was evaluated in descendant mice.

RESULTS

Immediately after birth, comparable levels of pathogenic antibody concentrations were observed in maternal and neonatal mice. The clearance time of skin-bound autoantibodies was twice as long as that of circulating autoantibodies (8 and 4 weeks, respectively). Maternofetal transfer of pathogenic autoantibodies produced specific immunopathological (IgG, IgG1, IgG2a/b and complement C3 deposits) but not histological or clinical alterations in skin of offspring mice.

CONCLUSIONS

Although still to be confirmed in humans, our findings add to the knowledge on turnover rates of circulating and skin-bound autoantibodies in autoimmune bullous dermatoses, which in turn may facilitate a more specific monitoring of these antibodies during the disease course, reduce the need for repeated skin biopsies, and may also be helpful in guiding treatment decisions.

Rituximab (anti-CD20) zur Behandlung von bullösen Autoimmundermatosen

Treatment of autoimmune bullous diseases can often be challenging and primarily consists of conventional systemic corticosteroids and other immunosuppressant agents. Rituximab is a chimeric monoclonal antibody against human CD20 leading to a transitory B-cell depletion with a lowering of autoantibody levels. Applications for autoimmune diseases have emerged in recent years and case reports support the use of rituximab in different autoimmune blistering disorders. Of the patients treated, 90% showed significant clinical improvement. In about a third of these patients, a clinical remission requiring further immunosuppressive medication was achieved, and in about a quarter, complete long-term remission was induced. About one third of patients suffered from serious adverse events after rituximab treatment. The combination of rituximab and intravenous immune globulin or immunoadsorption appears to be advantageous in severe cases. Randomized controlled trials are necessary to better determine the efficacy and adverse effects of rituximab in the treatment of autoimmune blistering diseases.