Acute myeloid leukemia with paraneoplastic pemphigus successfully treated with a personalized antileukemic and immunosuppressive strategy.

Bullous pemphigoid (BP) is a rare blistering disease often considered a primary sign of a paraneoplastic syndrome. Retrospective studies have established its link with hematological malignancies, particularly lymphoproliferative disorders. Here, we present what we believe to be the inaugural case of successful simultaneous management of BP and de novo acute myeloid leukemia (AML) in a 28-year-old male patient. Given the rarity and severity of both conditions, our treatment strategy aimed to maximize efficacy by combining immunosuppressive therapy (initially plasmapheresis with high-dose corticosteroids, followed by anti-CD20 monoclonal antibody and intravenous immunoglobulins 2 g/m2) with lymphodepleting antileukemic chemotherapy utilizing Fludarabine (FLAG-IDA induction regimen). Following diagnosis, considering the patient's youth and the concurrent presence of two rare and potentially life-threatening diseases, we opted for an aggressive treatment. Upon achieving complete morphological remission of AML with measurable residual disease (MRD) negativity, despite incomplete resolution of BP, we proceeded with high-dose cytarabine consolidation followed by peripheral stem cell harvest and autologous stem cell transplantation (ASCT). Our conditioning regimen for ASCT involved Bu-Cy with the addition of anti-thymocyte globulins. At day + 100 post-ASCT, bone marrow evaluation confirmed morphological remission and MRD negativity. Meanwhile, BP had completely resolved with normalization of BP180 antibody levels.

Type 2 T-Cell Responses against Distinct Epitopes of the Desmoglein 3 Ectodomain in Pemphigus Vulgaris.

Pemphigus vulgaris (PV) is an autoimmune blistering disorder of the skin and/or mucous membranes caused by IgG autoantibodies that predominantly target two transmembrane desmosomal cadherins: desmoglein (DSG)1 and DSG3. DSG-specific T cells play a central role in PV pathogenesis because they provide help to autoreactive B cells for autoantibody production. In this study, we characterized DSG3-specific peripheral T cells in a cohort of 52 patients with PV and 41 healthy controls with regard to cytokine profile and epitope specificity. By ELISpot analysis, type 2 T cells reactive with the DSG3 ectodomain were significantly increased in patients with PV compared with those in healthy controls. By dextramer analysis, CD4+ T cells specific for an epitope within the extracellular domain of DSG3, DSG3(206-220), were found at significantly higher frequencies in patients with PV than in HLA-matched healthy controls. T-cell recognition of two distinct DSG3 epitopes, that is, DSG3(206-220) and DSG3(378-392), correlated significantly, suggesting a synergistic effect in B-cell help. Immunization of HLA-DRB1∗04:02-transgenic mice with PV with the same set of DSG3 peptides induced pathogenic DSG3-specific IgG antibodies, which induced loss of keratinocyte adhesion in vitro. Thus, DSG3 peptide-specific T cells are of particular interest as surrogate markers of disease activity and potential therapeutic targets in PV.

Autoimmune bullous dermatoses in cancer patients treated by immunotherapy: a literature review and Italian multicentric experience.

Cutaneous immune-related adverse events are frequently associated with immune checkpoint inhibitors (ICIs) administration in cancer patients. In fact, these monoclonal antibodies bind the cytotoxic T-lymphocyte antigen-4 and programmed cell death-1/ligand 1 leading to a non-specific activation of the immune system against both tumoral cells and self-antigens. The skin is the most frequently affected organ system appearing involved especially by inflammatory manifestations such as maculopapular, lichenoid, psoriatic, and eczematous eruptions. Although less common, ICI-induced autoimmune blistering diseases have also been reported, with an estimated overall incidence of less than 5%. Bullous pemphigoid-like eruption is the predominant phenotype, while lichen planus pemphigoides, pemphigus vulgaris, and mucous membrane pemphigoid have been described anecdotally. Overall, they have a wide range of clinical presentations and often overlap with each other leading to a delayed diagnosis. Achieving adequate control of skin toxicity in these cases often requires immunosuppressive systemic therapies and/or interruption of ICI treatment, presenting a therapeutic challenge in the context of cancer management. In this study, we present a case series from Italy based on a multicenter, retrospective, observational study, which included 45 patients treated with ICIs who developed ICI-induced bullous pemphigoid. In addition, we performed a comprehensive review to identify the cases reported in the literature on ICI-induced autoimmune bullous diseases. Several theories seeking their underlying pathogenesis have been reported and this work aims to better understand what is known so far on this issue.

Pemphigus: trigger and predisposing factors.

Pemphigus is a life-threatening autoimmune blistering disease affecting skin and mucous membranes. Despite its etiopathogenesis remains largely unknown, several trigger and predisposing factors have been reported. Pemphigus is caused by autoantibodies that target desmoglein 1 and desmoglein 3, impacting desmosome function. However, circulating autoantibodies are often the consequence of a precipitating factor that occurs in predisposed individuals. This review aims to describe and discuss almost all trigger and predisposing factors reported as possible or probable cause of the disease. Among the reported trigger factors that may induce or exacerbate pemphigus, we have found of particular interest: drug intake (especially thiol- and phenol-containing compounds), vaccines, infections, as well as some reports about pregnancy, radiations, emotional stress, pesticides and physical trauma. Moreover, we discuss the possible role of food intake in pemphigus onset and particular attention is given to dietary factors containing thiol, phenol and tannin compounds. A trigger factor is "the straw that breaks the camel's back," and often acts together with predisposing factors. Here we discuss how pemphigus onset may be influenced by genetic susceptibility and comorbidities like thyroid diseases, malignancies and other autoimmune disorders. To identify other hitherto unknown trigger and predisposing factors, well designed prospective studies are needed. In this context, future research should explore their connection with the aim to advance our understanding of pemphigus pathogenesis.

Case report: A rare case of imiquimod-induced atypical pemphigus vulgaris.

Background: Pemphigus vulgaris is an autoimmune intraepithelial bullous disease involving the skin and the mucous membranes. Imiquimod, a topical therapy for skin basal cell carcinoma, is an amine that induces the production of tumor necrosis factor alfa, interleukin-1 and other cytokines. Pemphigus induced by drugs has been frequently reported, mostly after systemic therapy. Case presentation: We present the case of a 50-year-old man who developed skin, intraoral, and genital mucosae lesions 3 days after a treatment with Imiquimod for multiple superficial basal cell carcinoma of the trunk. Direct and indirect immunofluorescence results were compatible with the diagnosis of pemphigus vulgaris. Enzyme-linked immunosorbent assay was negative for desmoglein 1 and 3, but interestingly, by immunoblotting on keratinocyte extracts a band of 170 kDa was obtained by IgG. The patient, after interrupting Imiquimod application, started a treatment with prednisolone and in 4 weeks showed a complete remission. Conclusion: Topical Imiquimod therapy might induce atypical pemphigus vulgaris in some patients.

Anti-laminin 332 antibody detection using biochip immunofluorescence microscopy in a real-life cohort of Italian patients with mucous membrane pemphigoid

Background: Mucous membrane pemphigoid (MMP) with anti-laminin 332 autoantibodies may be associated with malignancies, however, current serological assays have considerable limitations. At present, no commercial test for anti-laminin 332 antibodies is available, restricting the diagnosis to specialized laboratories worldwide. Biochip immunofluorescence microscopy has shown promising results in selected cohorts of laminin 332-MMP patients. Objectives: To detect anti-laminin 332 antibodies by biochip immunofluorescence microscopy in a real-life cohort of MMP patients and compare the results with those from traditional immunoblotting. Materials & Methods: Sera were obtained from 31 patients with MMP, 28 with bullous pemphigoid, five with pemphigus vulgaris, five with paraneoplastic pemphigus, five with linear IgA bullous dermatosis, and 10 controls, and analysed by biochip immunofluorescence using human cells expressing laminin 332. Immunoblotting was performed using purified laminin 332. Results: MMP involved the oral mucosa in 65%, ocular mucosa in 9%, oral and ocular mucosae extensively in 13% as well as other mucosae in 13% of patients. Concomitant cutaneous involvement was reported in 35% of patients. Three MMP patients had an underlying malignancy. Anti-laminin 332 antibodies were detected in 2/31 (6%) cases by both methods. Based on immunoblotting, both laminin 332-positive sera reacted with α3 chain (in one case also with ß3 chain). Both patients with anti-laminin 332 antibodies had extensive mucosal involvement and only one had cancer. Anti-laminin 332 antibodies were not detected in control groups. Conclusion: Biochip immunofluorescence is an appropriate technique to detect anti-laminin 332 antibodies which should be tested in patients with MMP.

Case Report: Management of Malignancy-Exacerbated Pemphigus Vulgaris During COVID-19 Pandemic.

Pemphigus vulgaris is an intraepidermal autoimmune mucocutaneous blistering disease whose etiopathogenesis includes various trigger factors, i.e., drugs and malignancies. We present a case of malignancy-exacerbated pemphigus vulgaris which required a careful diagnostic process in order to rule out paraneoplastic pemphigus, along with the challenges posed by the need of treating both cutaneous and oncologic diseases. Possible post-operative complications post-poned the start of first-line immunosuppressive treatment of pemphigus. Moreover, the infective risks had to be minimized during the peak of the COVID-19 pandemic in Italy. Intravenous immunoglobulins were chosen as "bridge" therapy before the tumor surgical excision, followed by rituximab in post-operative phase.

May Bacterial Infections Trigger Bullous Pemphigoid? Case Report and Review of Literature.

Bullous pemphigoid (BP) is an autoimmune blistering skin disease, mainly observed in the elderly. Infections have been suggested as possible disease triggers. However, infections may even heavily influence the disease clinical course and mortality. A 75-year-old woman was admitted to hospital for severe erythematosus blistering disease, accompanied by hyper-eosinophilia and hyper-IgE. The culture of bullous fluid was positive for Enterococcus faecalis, the blood culture was positive for Staphylococcus aureus, and the urine culture was positive for Proteus mirabilis and Escherichia coli. Moreover, circulating anti-BP180 IgG was present and the histopathological/ultrastructural examination of a lesional skin biopsy was compatible with BP. High eosinophil levels (up to 3170/µL) were found throughout the clinical course, while values below 1000/µL were associated with clinical improvement. The total IgE was 1273 IU/mL, and specific anti-G/V-penicillin/ampicillin IgE antibodies were positive. The patient had a complete clinical recovery in two months with methyl-prednisolone (40 then 20 mg/day) and low-dose azathioprine (50 mg/day) as a steroid-sparing agent. The steroid treatment was tapered until interruption during a one-year period and intravenous immunoglobulins have been administered for three years in order for azathioprine to also be interrupted. The patient stopped any treatment five years ago and, in this period, has always been in good health. In this case, the contemporaneous onset of different bacterial infections and BP is suggestive of bacterial infections acting as BP trigger(s), with allergic and autoimmune pathways contributing to the disease pathogenesis.

Paraneoplastic autoimmune multiorgan syndrome.

Originally described by Anhalt as paraneoplastic pemphigus in 1990, paraneoplastic autoimmune multiorgan syndrome (PAMS) is a potentially lethal blistering disease, characterized by polymorphous clinical features, including mucocutaneous erosions, blisters, lichenoid papules, and erythemas. Several autoantibodies have been detected in serum of PAMS patients, including antiplakins, anti-alpha-2-macroglobulin like 1, and antidesmogleins autoantibodies. The mortality rate of PAMS is up to 90%. This is due on the one hand to the poor response to treatments and on the other hand to the delay in the diagnosis and to the prognosis of the underlying neoplasia.

Bullous Pemphigoid: Trigger and Predisposing Factors.

Bullous pemphigoid (BP) is the most frequent autoimmune subepidermal blistering disease provoked by autoantibodies directed against two hemidesmosomal proteins: BP180 and BP230. Its pathogenesis depends on the interaction between predisposing factors, such as human leukocyte antigen (HLA) genes, comorbidities, aging, and trigger factors. Several trigger factors, such as drugs, thermal or electrical burns, surgical procedures, trauma, ultraviolet irradiation, radiotherapy, chemical preparations, transplants, and infections may induce or exacerbate BP disease. Identification of predisposing and trigger factors can increase the understanding of BP pathogenesis. Furthermore, an accurate anamnesis focused on the recognition of a possible trigger factor can improve prognosis by promptly removing it.

Paraneoplastic Dermatoses: A Brief General Review and an Extensive Analysis of Paraneoplastic Pemphigus and Paraneoplastic Dermatomyositis.

Skin manifestations of systemic disease and malignancy are extremely polymorphous. Clinicians should be familiarized with paraneoplastic dermatoses in order to perform an early diagnosis of the underlying neoplasm. Lack of familiarity with cutaneous clues of internal malignancy may delay diagnosis and treatment of cancer. In this review, we described several paraneoplastic dermatoses and discussed extensively two paradigmatic ones, namely paraneoplastic pemphigus and paraneoplastic dermatomyositis.

Autoantibody Profile of a Cohort of 54 Italian Patients with Linear IgA Bullous Dermatosis: LAD-1 Denoted as a Major Auto-antigen of the Lamina Lucida Subtype.

Linear IgA bullous dermatosis (LABD) is characterized by presence of multiple IgA autoantibodies, and a comparatively lesser number of IgG antibodies, directed against different hemidesmosomal antigens. The main autoantigens are LAD-1, LABD-97, BP180 and BP230, type VII collagen and laminin 332. We retrospectively studied the serology of 54 Italian patients with LABD using enzyme-linked immunosorbent assay (ELISA), immunoblotting assay, and indirect immunofluorescence on monkey oesophagus and salt-split skin. Among these, indirect immunofluorescence of salt-split skin elicits the greatest sensitivity. Sixty-three percent of the sera were observed to be positive, with a lamina lucida pattern observed in 48%, a sub-lamina densa pattern in 2% and a mixed pattern in 13% of the cases. IgA reactivity to LAD-1 on immunoblotting was found in 52% of sera, to BP180-NC16A by ELISA in 32% and to BP230 in 26%. Only 17% of patients possessed circulating IgG autoantibodies. LAD-1 was determined to be a major autoantigen of the lamina lucida subtype. Combined serological assays demonstrated a high sensitivity (82%), suggesting that this approach could support diagnosis when a biopsy is not feasible or direct immunofluorescence results are negative.

Bullous pemphigoid with hyperkeratosis and palmoplantar keratoderma: Three cases.

The clinical features of bullous pemphigoid are extremely polymorphous. Several atypical forms of bullous pemphigoid have been described, and the diagnosis critically relies on immunopathological findings. We describe three bullous pemphigoid patients characterized by palmoplantar keratoderma, diffused hyperkeratotic cutaneous lesions and extremely high levels of immunoglobulin E serum. The diagnosis of bullous pemphigoid should be taken into account in patients presenting diffused hyperkeratotic cutaneous lesions and palmoplantar keratoderma, even in the absence of blisters. Alteration of the keratinization process, that could occur in patients with genetic mutations in desmosomal and hemidesmosomal genes, may also be due to circulating autoantibodies against hemidesmosomal proteins in these bullous pemphigoid patients.

Epidermolysis Bullosa (EB) Acquisita in an Adult Patient with Previously Unrecognized Mild Dystrophic EB and Biallelic COL7A1 Mutations.

Circulating anti-type VII collagen autoantibodies are frequently detected in patients with recessive dystrophic epidermolysis bullosa (RDEB). However, evidence supporting their pathogenic role in inducing epidermolysis bullosa acquisita (EBA) has been provided for only one individual with dominant dystrophic epidermolysis bullosa (DDEB). We describe here a patient who presented with dystrophic toenails since early childhood and developed trauma-induced skin blisters and oral erosions at age 26 years. Direct immunofluorescence showed IgG deposits with a u-serrated pattern along the cutaneous basement membrane zone, while no change in the expression of collagen VII could be detected by antigen mapping. High-titre anti-collagen VII antibodies were detected by enzyme-linked immunoassay (ELISA). In parallel, sequencing of epidermolysis bullosa (EB) genes identified compound heterozygous COL7A1 missense c.410G>A (p.Arg137Gln) and splicing c.3674C>T (p.Ala1225_Gln1241del) mutations, previously unrecognized in dystrophic epidermolysis bullosa (DEB). Thus, our patient had RDEB "nails-only" and developed mechanobullous EBA in adulthood. These data support a pathogenic role of circulating autoantibodies to collagen VII in inducing EBA in selected patients with DEB. Unforeseen worsening of skin symptoms in DEB should prompt laboratory investigations for EBA.

Reengineering chimeric antigen receptor T cells for targeted therapy of autoimmune disease.

Ideally, therapy for autoimmune diseases should eliminate pathogenic autoimmune cells while sparing protective immunity, but feasible strategies for such an approach have been elusive. Here, we show that in the antibody-mediated autoimmune disease pemphigus vulgaris (PV), autoantigen-based chimeric immunoreceptors can direct T cells to kill autoreactive B lymphocytes through the specificity of the B cell receptor (BCR). We engineered human T cells to express a chimeric autoantibody receptor (CAAR), consisting of the PV autoantigen, desmoglein (Dsg) 3, fused to CD137-CD3ζ signaling domains. Dsg3 CAAR-T cells exhibit specific cytotoxicity against cells expressing anti-Dsg3 BCRs in vitro and expand, persist, and specifically eliminate Dsg3-specific B cells in vivo. CAAR-T cells may provide an effective and universal strategy for specific targeting of autoreactive B cells in antibody-mediated autoimmune disease.