Myasthenia gravis, paraneoplastic pemphigus and thymoma, a rare triade

S2k guidelines on the management of paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome initiated by the European Academy of Dermatology and Venereology (EADV)

BACKGROUND

Paraneoplastic pemphigus (PNP), also called paraneoplastic autoimmune multiorgan syndrome (PAMS), is a rare autoimmune disease with mucocutaneous and multi-organ involvement. PNP/PAMS is typically associated with lymphoproliferative or haematological malignancies, and less frequently with solid malignancies. The mortality rate of PNP/PAMS is elevated owing to the increased risk of severe infections and disease-associated complications, such as bronchiolitis obliterans.

OBJECTIVES

These guidelines summarize evidence-based and expert-based recommendations (S2k level) for the clinical characterization, diagnosis and management of PNP/PAMS. They have been initiated by the Task Force Autoimmune Blistering Diseases of the European Academy of Dermatology and Venereology with the contribution of physicians from all relevant disciplines. The degree of consent among all task force members was included.

RESULTS

Chronic severe mucositis and polymorphic skin lesions are clue clinical characteristics of PNP/PAMS. A complete assessment of the patient with suspected PNP/PAMS, requiring histopathological study and immunopathological investigations, including direct and indirect immunofluorescence, ELISA and, where available, immunoblotting/immunoprecipitation, is recommended to achieve a diagnosis of PNP/PAMS. Detection of anti-envoplakin antibodies and/or circulating antibodies binding to the rat bladder epithelium at indirect immunofluorescence is the most specific tool for the diagnosis of PNP/PAMS in a patient with compatible clinical and anamnestic features. Treatment of PNP/PAMS is highly challenging. Systemic steroids up to 1.5 mg/kg/day are recommended as first-line option. Rituximab is also recommended in patients with PNP/PAMS secondary to lymphoproliferative conditions but might also be considered in cases of PNP/PAMS associated with solid tumours. A multidisciplinary approach involving pneumologists, ophthalmologists and onco-haematologists is recommended for optimal management of the patients.

CONCLUSIONS

These are the first European guidelines for the diagnosis and management of PNP/PAMS. Diagnostic criteria and therapeutic recommendations will require further validation by prospective studies.

A systematic review of paraneoplastic syndromes associated with thymoma: Treatment modalities, recurrence, and outcomes in resected cases

OBJECTIVE

Paraneoplastic syndromes associated with thymomas remain incompletely understood. The objective was to examine the association between surgically resected thymomas and paraneoplastic syndromes over the past half century.

METHODS

A primary PubMed/MEDLINE search was used to identify published articles describing paraneoplastic syndromes associated with thymomas from 1960 to 2019. A secondary search identified additional articles referenced in the articles found in the primary search. Kaplan-Meier and log-rank test were used for time-to-event data analyses.

RESULTS

From 407 articles describing 507 patients, 123 different paraneoplastic syndromes were associated with thymoma. The 5 most common paraneoplastic syndromes were myasthenia gravis, pure red cell aplasia, lichen planus, Good syndrome, and limbic encephalitis. Complete or partial resolution of paraneoplastic syndrome symptoms after surgery was noted in 76% of patients, of whom 21% had a relapse or new paraneoplastic syndrome onset after surgery. The most common adjunctive therapy associated with resolution of paraneoplastic syndrome was corticosteroids (30%). For all patients after surgery, thymoma recurrence was observed in 17% of cases, whereas recurrence of paraneoplastic syndrome was observed in 34% of cases, and both were observed in approximately 11% of cases. The 5- and 10-year overall survivals were 78% and 66%, respectively. Improved overall survival was associated with patients who had total resolution from paraneoplastic syndrome.

CONCLUSIONS

A comprehensive assessment of publications over the past half century suggests that a multimodal treatment approach that includes surgical resection of thymomas is able to achieve paraneoplastic syndrome resolution in a majority of patients. Onset of new paraneoplastic syndromes after surgery is associated with the recurrence of the first paraneoplastic syndrome, and resolution of paraneoplastic syndrome is associated with improved overall survival.

Thymoma-Associated Paraneoplastic Autoimmune Multiorgan Syndrome-From Pemphigus to Lichenoid Dermatitis

Introduction: Paraneoplastic autoimmune multi-organ syndrome (PAMS) is a rare clinical condition characterized by variable and heterogeneous clinical phenotypes in the presence of neoplasias which largely depend on the activation of humoral and cellular immune responses. Clinically, these patients present with a spectrum of antibody-driven pemphigus-like lesions to graft-vs.-host-disease-like exanthemas with a lichenoid inflammatory infiltrate in the skin. PAMS is occasionally associated with thymoma, in which altered immune surveillance eventually leads to multiorgan autoimmunity which often includes variable cutaneous symptoms. This disorder is associated with a profound disturbance of peripheral immune tolerance against human autoantigens. Objectives: We here present a patient with relapsing thymoma who developed PAMS with several cutaneous and extracutaneous autoimmune disorders. Materials: Peripheral blood mononuclear cells (PBMC), sera, and lesional skin biopsies were obtained at different clinical disease stages. Peripheral T cell subsets were characterized phenotypically and the cytokine profile of the peripheral blood T cellular response against distinct epidermal and dermal autoantigens of the skin was analyzed by ELISpot assay. Serological screening was performed by ELISA and immunoblot analysis. Skin biopsies were subjected to immunohistochemical analysis of distinct T cell subsets. Thymoma tissue was analyzed for the presence of T regulatory cells and compared with adult thymus and indolent thymoma. Results and Conclusions: In the present case, thymoma was the cause of the observed multi-organ autoimmune syndromes as its recurrence and surgical removal was associated with the relapse and regression of the cutaneous symptoms, respectively. Initially, the patient presented with two autoimmune disorders with Th2/Th1 imbalance, myasthenia gravis (MG) and pemphigus foliaceus (PF), which regressed upon immunosuppressive treatment. Months later, the patient developed a lichenoid exanthema with a Th1-dominated skin infiltrate. Further clinical evaluation revealed the recurrence of the thymoma and the lichenoid exanthema gradually regressed upon thymectomy. Our contention that T cell recognition against distinct cutaneous autoantigens, such as desmoglein 1 (Dsg1), shifted from a Th2 to a Th1-dominated immune response could not be fully substantiated as the patient was on a stringent immunosuppressive treatment regimen. We could only observe a decrease of the initially present serum IgG autoantibodies against Dsg1. Phenotypic analysis of the associated thymoma showed a lower number of T regulatory cells compared to adult thymus and indolent thymoma, suggesting that impaired thymus-derived immune surveillance had a direct impact on the outcome of the observed cutaneous autoimmune disorders.

Robotic trans-subxiphoid extended thymectomy in a patient with thymoma-associated pemphigus

We herein firstly reported that a patient with thymoma-associated pemphigus (TAP) underwent a robotic-assisted trans-subxiphoid thoracoscopic extended thymectomy and then achieved stable resolution. The patient, a 47-year-old male, was first admitted to our hospital owing to stomatitis and bullae of the trunk after four months' prednisone treatment. On admission, chest computed tomography (CT) revealed an anterior-mediastinal mass and it was initially diagnosed as a thymoma. He was positive for anti-BP (bullous pemphigoid)-180 antibody and anti-desmoglein 3 antibody. Then, a robotic-assisted thymectomy was performed, following which, the anti-BP-180 and anti-desmoglein 3 antibody titres have declined. The patient's mucocutaneous lesions improved, and the steroid dose was gradually decreased from 60 to 40 mg/day. According to previous reports, and the experience of the presented case, we therefore believe that early extended thymectomy is an effective therapeutic intervention for TAP.

Poly-autoimmunity in patients with myasthenia gravis: A single-center experience

We evaluated the co-occurrence of autoimmune diseases (ADs) in a large population of myasthenia gravis (MG) patients from a single center. Our survey included 984 patients, 904 with anti-acetylcholine receptor antibodies and 80 with anti-muscle specific kinase antibodies. The anti-acetylcholine receptor positive population included patients with early-onset (age at onset ≤ 50 years), late-onset and thymoma-associated disease. Follow-up ranged 2-40 years. Two-hundred and fourteen ADs were diagnosed in 185 patients; 26 of them had two or more ADs in association with MG. Thyroid disorders were the most common and, together with vitiligo and thrombocytopenia, occurred in all disease subsets. Otherwise, there was a broad variability with partial overlap among patient groups. The highest rate of ADs was observed in early-onset patients, while clusters, i.e. 2 or more ADs other than MG in the same individual, were more common among thymoma cases. Thirty-four diseases were diagnosed at the same time, 88 occurred before and 92 after the onset of MG. On multivariate analysis, immunosuppressive treatment was the only independent variable which negatively influenced the risk of developing other ADs in our cohort.

Prevalence of myasthenia gravis and associated autoantibodies in paraneoplastic pemphigus and their correlations with symptoms and prognosis

BACKGROUND

Paraneoplastic pemphigus (PNP) involves multiple organs, but little is known about its neurological involvement.

OBJECTIVES

To investigate the symptoms, prognosis and profiles of associated autoantibodies in myasthenia gravis (MG), and their correlations in patients with PNP.

METHODS

Fifty-eight patients with PNP were assessed for myasthenic symptoms and laboratory evidence. Serum autoantibodies against acetylcholine receptor (AChR), acetylcholinesterase (AChE), titin, ryanodine receptor (RyR) and muscle-specific kinase (MuSK) were measured by enzyme-linked immunosorbent assay. Patients with pemphigus vulgaris (PV), pemphigus foliaceus (PF), connective tissue disease (CTD) and non-PNP MG (NP-MG), and healthy donors, served as controls. These autoantibodies in PNP were also compared in the presence or absence of dyspnoea or muscle weakness. Cox regression and log-rank tests were used for survival analysis.

RESULTS

Overall 39% of patients with PNP experienced muscle weakness, and 35% were diagnosed with MG. Moreover, 35% had positive anti-AChR and 28% had anti-AChE antibodies, similarly to NP-MG (33% and 17%, respectively, P > 0·05). However, both were negative in all patients with PV, PF and CTD and healthy donors (P < 0·005). No other antibodies showed significant differences among groups. Anti-AChR and anti-AChE antibody levels were significantly increased in patients with PNP with dyspnoea, while anti-AChR, anti-titin and anti-RyR were significantly increased in patients with PNP with muscle weakness (P < 0·05). Nevertheless, levels and positive rates of these autoantibodies showed no significant differences between PNP with Castleman disease and thymoma. Although anti-AChE levels impacted survival duration (P  =  0·027, odds ratio 3·14), MG complications did not affect the overall survival percentage in PNP.

CONCLUSIONS

MG is a complication of PNP. Anti-AChR and anti-AChE antibodies are prominent in patients with PNP, especially those with dyspnoea.

Autoimmune bullous diseases associations

The presence of one autoimmune disorder helps lead to the discovery of other autoimmune conditions. It is thought that diseases in which autoimmunity is a feature tend to be associated together more often than one can ascribe to chance. A variety of diseases have been implicated in the onset of intraepidermal and subepidermal autoimmune diseases. The presence of one autoimmune disease should alert the physician to watch for a second immunologic disorder. A list of autoimmune bullous diseases associations includes autoimmune bullous diseases, pemphigus, pemphigoid, epidermolysis bullosa acquisita, dermatitis herpetiformis (Duhring), linear immunoglobulin A disease, and multiple autoimmune syndrome.

Paraneoplastic pemphigus regression after thymoma resection

Background

Among human neoplasms thymomas are associated with highest frequency with paraneoplastic autoimmune diseases.

Case presentation

A case of a 42-year-old woman with paraneoplastic pemphigus as the first manifestation of thymoma is reported. Transsternal complete thymoma resection achieved pemphigus regression. The clinical correlations between pemphigus and thymoma are presented.

Conclusion

Our case report provides further evidence for the important role of autoantibodies in the pathogenesis of paraneoplastic skin diseases in thymoma patients. It also documents the improvement of the associated pemphigus after radical treatment of the thymoma.