Linear IgA Bullous Dermatosis

IntroductionRituximab (RTX) is a monoclonal antibody targeting CD20, a transmembrane protein expressed on B cells, causing B cell depletion. RTX has shown great efficacy in studies of pemphigus vulgaris, but data of pemphigoid diseases are limited.ObjectiveTo assess the effectiveness and safety of RTX in pemphigoid diseases.MethodsThe medical records of 28 patients with pemphigoid diseases that were treated with RTX were reviewed retrospectively. Early and late endpoints, defined according to international consensus, were disease control (DC), partial remission (PR), complete remission (CR), and relapses. Safety was measured by reported adverse events.ResultsPatients with bullous pemphigoid (n = 8), mucous membrane pemphigoid (n = 14), epidermolysis bullosa acquisita (n = 5), and linear IgA disease (n = 1) were included. Treatment with 500 mg RTX (n = 6) or 1,000 mg RTX (n = 22) was administered on days 1 and 15. Eight patients received additional 500 mg RTX at months 6 and 12. Overall, DC was achieved in 67.9%, PR in 57.1%, and CR in 21.4% of the cases. During follow-up, 66.7% patients relapsed. Repeated treatment with RTX led to remission (PR or CR) in 85.7% of the retreated cases. No significant difference in response between pemphigoid subtypes was found. IgA-dominant cases (n = 5) achieved less DC (20 vs. 81.3%; p = 0.007), less PR (20 vs. 62.5%; p = 0.149), and less CR (0 vs. 18.8%; p = 0.549) compared to IgG-dominant cases (n = 16). Five severe adverse events and three deaths were reported. One death was possibly related to RTX and one death was disease related.ConclusionRTX can be effective in recalcitrant IgG-dominant pemphigoid diseases, however not in those where IgA is dominant.

BackgroundLinear IgA bullous dermatosis (LABD) is a rare autoimmune subepithelial vesiculobullous disease due to IgA autoantibodies directed against different antigens of the basement membrane zone (BMZ) of the skin and/or mucosae. It affects mainly preschool-aged children and adults, with only few studies on large series. The aim of this study was to assess possible differences between adults and children regarding clinical presentation, immunopathologic features, management and course of the disease.MethodsA retrospective review of 38 LABD patients, followed-up from November 2006 to September 2018, was performed.ResultsOf 38 patients, 27 were adults and 11 children. Mean age at diagnosis was 5.4 years and 60.6 years in the pediatric and adult group, respectively. Considering both groups, limbs were the most commonly involved site (73.7%), followed by trunk (55.3%), head (36.8%) and buttocks (13.2%). Interestingly, head (p = 0.008), particularly perioral (p = 0.001), involvement, as well as "string of pearls" arrangement (p = 0.03), were more prevalent in children. Mucosal involvement was seen in 9 (23.7%) patients and was more frequent in children than adults (45.5% vs 14.8%, respectively, p = 0.09). Linear IgA deposits along the BMZ were observed in 30 patients (78.9%), while linear/granular IgA deposits in 8 patients (21.1%). Dapsone was the most commonly used drug (78.9%) and complete remission was achieved in most cases (81.6%).ConclusionsOur epidemiological and clinicopathological findings relative to a large cohort of LABD patients are mostly consistent with the literature data. Interestingly, head, notably perioral, involvement and "string of pearls" arrangement occurred more frequently in the paediatric than adult group. The above clinical parameters may be regarded as diagnostic tools for LABD in children.

Several sporadic cases, in which direct and indirect immunofluorescence studies simultaneously detected IgG and IgA autoantibodies to keratinocyte cell surfaces, have been reported mainly under the name of IgG/IgA pemphigus. However, there have been no systematic studies for this condition. In this study, we collected 30 cases of this condition from our cohort of more than 5,000 autoimmune bullous disease cases, which were consulted for our diagnostic methods from other institutes, and summarized their clinical and immunological findings. Clinically, there was no male-female prevalence, mean age of disease onset was 55.6 years, and mean duration before this condition was suspected was 18 months. The patients showed clinically bullous and pustular skin lesions preferentially on the trunk and extremities, and histopathologically intraepidermal pustules and blisters with infiltration of neutrophils and eosinophils. Immunologically, ELISAs frequently detected IgG and IgA autoantibodies to both desmogleins and desmocollins. From the characteristic clinical, histopathological, and immunological features, which are considerably different from those in classical IgG types of pemphigus, we propose this disease as a new disease entity with preferential name of intercellular IgG/IgA dermatosis (IGAD). This was the largest study of IGAD to date.

BackgroundLinear IgA bullous dermatosis (LABD) is an uncommon disease with only a few reported studies in large series with long follow-up periods.ObjectivesTo evaluate the clinical presentation, immunopathological features, management, and disease course in LABD patients.MethodsData including demographics, clinical features, histopathological and immunofluorescence findings of LABD patients, in addition to the preferred treatments and responses to treatments were evaluated.ResultsAmong 26 patients diagnosed with LABD, 17 (65.4%) were female. The mean age was 40.3 ± 22.4 (6‒80) years of whom 21 were adults. The most common mucosal involvement was oral (n = 9, 34.6%). Continuous linear IgA deposition was present on the basement membrane zone of all patients in addition to C3 (n = 13), IgG (n = 9), IgM (n = 4), and fibrinogen (n = 4). Three patients were lost to follow-up without any treatment. Dapsone was the treatment of choice in most (n = 21, 91.3%) patients in addition to systemic corticosteroids (n = 17), azathioprine (n = 3), tetracycline and nicotinamide (n = 2). Complete and partial remissions were achieved in 11 (47.8%) and 12 (52.2%) patients, respectively, in a mean follow-up period of 45.9 ± 43.9 (3‒158) months. Furthermore, 17 patients were still under treatment at the end of the follow-up period.Study limitationsRetrospective study conducted in a single center.ConclusionsLABD may occur at two separate peaks, one in the second and the other in the sixth decade of life with a female predominance. Other immunoglobulins may be associated with dominant IgA antibody deposition and the most commonly used therapeutic option for LABD patients was oral dapsone.