Autoimmune Pathophysiology Research Articles

Safety and tolerability of tegoprubart in patients with amyotrophic lateral sclerosis: A Phase 2A clinical trial.

The interaction of CD40L and its receptor CD40 on activated T cells and B cells respectively control pro-inflammatory activation in the pathophysiology of autoimmunity and transplant rejection. Previous studies have implicated signaling pathways involving CD40L (interchangeably referred to as CD154), as well as adaptive and innate immune cell activation, in the induction of neuroinflammation in neurodegenerative diseases. This study aimed to assess the safety, tolerability, and impact on pro-inflammatory biomarker profiles of an anti CD40L antibody, tegoprubart, in individuals with amyotrophic lateral sclerosis (ALS). In this multicenter dose-escalating open-label Phase 2A study, 54 participants with a diagnosis of ALS received 6 infusions of tegoprubart administered intravenously every 2 weeks. The study was comprised of 4 dose cohorts: 1 mg/kg, 2 mg/kg, 4 mg/kg, and 8 mg/kg. The primary endpoint of the study was safety and tolerability. Exploratory endpoints assessed the pharmacokinetics of tegoprubart as well as anti-drug antibody (ADA) responses, changes in disease progression utilizing the Revised ALS Functional Rating Scale (ALSFRS-R), CD154 target engagement, changes in pro-inflammatory biomarkers, and neurofilament light chain (NFL). Seventy subjects were screened, and 54 subjects were enrolled in the study. Forty-nine of 54 subjects completed the study (90.7%) receiving all 6 infusions of tegoprubart and completing their final follow-up visit. The most common treatment emergent adverse events (TEAEs) overall (>10%) were fatigue (25.9%), falls (22.2%), headaches (20.4%), and muscle spasms (11.1%). Mean tegoprubart plasma concentrations increased proportionally with increasing dose with a half-life of approximately 24 days. ADA titers were low and circulating levels of tegoprubart were as predicted for all cohorts. Tegoprubart demonstrated dose dependent target engagement associated and a reduction in 18 pro-inflammatory biomarkers in circulation. Tegoprubart appeared to be safe and well tolerated in adults with ALS demonstrating dose-dependent reduction in pro-inflammatory chemokines and cytokines associated with ALS. These results warrant further clinical studies with sufficient power and duration to assess clinical outcomes as a potential treatment for adults with ALS. Clintrials.gov ID:NCT04322149.

NeuroBehcet’s-related intracranial hypertension without cerebral venous thrombosis: case report and review of literature

BackgroundWe present a rare case of NeuroBehcet’s-related intracranial hypertension without cerebral venous thrombosis (NBrIHwCVT), occurring as the first presentation of NeuroBehcet’s. In addition, we describe the novel use of subcutaneous tocilizumab for this indication. This is followed by a review of the literature on this topic.CaseThe patient was a 28-year-old lady of Southern Chinese origin with a known history of Behcet’s disease with oral ulcers and ocular findings for which she was on mycophenolate mofetil and adalimumab. She presented with a headache and bilateral disc swelling associated with an intracranial pressure (ICP) of > 40cmH20. There were no structural lesions or cerebral venous thrombosis (CVT) on imaging. Initial lumbar puncture had raised leucocytes and protein. We discuss diagnostic challenges given persistently elevated ICP despite subsequent non-inflammatory cerebrospinal fluid (CSF) profiles and non-response to acetazolamide. She eventually showed a response to immunosuppressant therapy in the form of pulsed methylprednisolone, cyclophosphamide and subsequently subcutaneous tocilizumab, supporting the diagnosis of NBrIHwCVT. Complete normalization of ICP remains challenging. Her disease course was severe, unusual for her ethnicity.Literature reviewWe identified 34 patients (including ours) from 14 publications. We found that the majority of NBrIHwCVT patients were young (average age of 34 years), with a slight female preponderance. Of the 17 cases in the literature with available data on CSF profile, none had raised leucocytes whilst one patient had elevated protein. Patients were generally treated with steroids and occasionally azathioprine, in line with the suspected autoimmune pathophysiology. Of 22 patients with data on outcome, six (27%) were noted to have recurrence of symptoms generally occurring a few months later.ConclusionAs demonstrated by this case, NBrIHwCVT can present with BD with raised ICP even if there is no prior history of NB, central Asian ethnicity, cerebral venous thrombosis or features of inflammation on the CSF. We demonstrated how novel use of Tocilizumab may have a role in the management of NBrIHwCVT. Based on our literature review, patients were more likely to be young, female, display a non-inflammatory CSF picture, be treated with steroids and harbour a possibility of recurrence.

Thyroidectomy for Euthyroid Patients with Hashimoto Disease and Persistent Symptoms: An Observational, Postrandomization Study.

Despite adequate hormone substitution in Hashimoto disease, some patients may have persistent symptoms with a possible autoimmune pathophysiology. A recent randomized trial (RCT) using patient-reported outcome measures as the primary endpoint showed benefit in total thyroidectomy, but at a cost of high complication rates. To verify results from the RCT in an observational study including a wider range of patients and explore means of predicting who may benefit from such surgery. A total of 154 patients with Hashimoto disease, euthyroid with or without thyroid hormone substitution, and persistent Hashimoto-related symptoms were subjected to total thyroidectomy and followed for 18 months after surgery. The primary outcome was the General Health (GH) dimensional score in the Short Form-36 Health Survey (SF-36). Eighteen months after surgery, a clinically significant improvement in GH was seen, similar to the findings in the previous RCT. Anti-TPO antibody titers were markedly reduced after surgery, but preoperative titers or other preoperative parameters could not predict the outcome of surgery. Three (1.9%) of 154 patients experienced permanent unilateral recurrent nerve palsy and six (3.9%) experienced hypoparathyroidism after surgery. Thyroidectomy had a beneficial symptom-reducing effect in euthyroid patients with Hashimoto disease and persistent symptoms. The pathophysiology of residual symptoms remains unclear, and surgical complication rates are high. If thyroidectomy is considered as a treatment option, it should be performed in dedicated centers with experienced endocrine surgeons and as part of further studies on persistent symptoms. This trial is registered with NCT-02319538.

Restoring immune tolerance in pemphigus vulgaris

Intravenous immunoglobulin (IVIg), a preparation of polyclonal serum IgG pooled from numerous blood donors, has been used for nearly three decades and is proving to be an efficient treatment for many autoimmune blistering diseases, including pemphigus vulgaris (PV). Despite its widespread use and therapeutic success, its mechanisms of action are not completely understood. Some of its anti-inflammatory and immunomodulatory actions have been studied. In this study, the authors present a twenty-year follow-up of 21 patients with clinical and immunopathological confirmed PV, treated with IVIg as monotherapy, according to an established published protocol. IVIg therapy produced long-term sustained, clinical, serological, and immunopathological remission. For 20 y, these patients received no drugs and experienced no disease. This observation suggests that there was the establishment of immune balance or restoration of immune regulation in these PV patients. Twelve (57%) patients experienced no relapse during follow-up. Six (29%) patients experienced a relapse due to acute stress or post-coronavirus infection and/or vaccination. Reinstitution of IVIg resulted in prompt sustained recovery. Three (14.2%) patients, in clinical and serological remission, died due to unrelated causes. No severe adverse effects from IVIg were documented in all 21 patients. The simultaneous or sequential anti-inflammatory and immunomodulatory effects of IVIg may have influenced the long-term clinical remission observed. This study provides a human prototype to examine the pathophysiology of autoimmunity and a model to study immune regulation and mechanisms that can facilitate restoring immune tolerance.

Daratumumab for autoimmune diseases: a systematic review

ObjectiveRefractory autoimmune diseases remain a significant challenge in clinical practice and new therapeutic options are needed. This systematic review evaluates the existing reported data on the CD38-targeting antibody daratumumab as...

Growth differentiation factor 15 (GDF-15) in endocrinology.

Human growth differentiation factor 15 (GDF-15) is a widely distributed protein that has shown to play multiple roles in both physiological and pathological conditions. In healthy individuals, GDF-15 is mainly expressed in the placenta, followed by the prostate, although low levels of expression have also been detected in different organs. GDF-15 acts through a recently identified receptor called glial-derived neurotrophic factor (GDNF) receptor alpha-like (GFRAL) which signals through the rearranged during transfection (RET) tyrosine kinase receptor. The effects of GDF-15 are pleiotropic and include appetite regulation, and actions on metabolism, pregnancy, cell survival, immune response, and inflammation. GDF-15 also plays different roles in the pathophysiology of cardiovascular disease, autoimmunity, cancer-associated anorexia/cachexia, and diabetes. In recent years, several studies have reported a link between GDF-15 and the endocrine system. In this review, we up-date and summarize the relevant investigations of the relationships between GDF-15 and different endocrine conditions. We also assess the potential pathogenic role and potential therapeutic applications of GDF-15 in the field of endocrinology.

Post Infectious Triggered Anti-Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD) via CMV in an Immunocompetent Host (P10-5.030)

<h3>Objective:</h3> N/A <h3>Background:</h3> A previously healthy, immunocompetent 38-year-old female presented with initial complaints of subacute, waxing and waning high grade fevers, general malaise, and muscle aches for two weeks. Acutely she developed severe lumbar radiculopathy with significant urinary retention and bilateral lower extremity weakness leading to ED presentation. The patient was subsequently admitted with rapidly progressive lower extremity paraplegia and brisk reflexes over a 24-hour span. MRI imaging was notable for longitudinally extensive transverse myelitis (LETM) over continuous cervical and thoracic segments with significant gray matter involvement and left parahippocampal FLAIR hyperintensities Serum subsequently demonstrated positive anti-CMV IgM/IgG antibodies with a PCR load of 61 copies/mL indicative of a CMV infection with low viremia. LP CSF was CMV PCR negative with mildly elevated opening pressures and trace neurotrophic pleocytosis. Given stagnant clinical changes after five days of IV steroids, plasmapheresis was initiated with marked improvements in functional lower extremity strength. Soon afterwards, initial presenting lab work resulted, demonstrating high serum titers (1:2560) of anti-MOG antibodies. <h3>Design/Methods:</h3> N/A <h3>Results:</h3> N/A <h3>Conclusions:</h3> In immunocompetent hosts, CMV infection itself is a rarely described cause of inflammatory myelopathy with only 14 prescribed cases. With both deep gray matter FLAIR hyperintensities and cervical and thoracic LETM, a concomitant para-infectious CMV and new MOGAD is unlikely in our clinical setting. Additionally, systemic findings typically indicative of severe CMV infections such as retinitis, pericarditis/myocarditis, transaminitis, thrombocytopenia, and leukopenia were absent. Given prior reports of sequence similarities between MOG T-cell epitopes and a major capsid protein of CMV, molecular mimicry between antigen presenting cells has been hypothesized. Here we detail a first described case report of a possible post-infectious MOG antibody transverse myelitis triggered presumptively via CMV infection. Furthermore, presenting in an immunocompetent host, our case report highlights a further wrinkle into the pathophysiology and presence of post infectious triggered autoimmunity for MOGAD. <b>Disclosure:</b> Dr. Chen has nothing to disclose. Dr. Kwon has nothing to disclose.

Respiratory tract Moraxella catarrhalis and Klebsiella pneumoniae can promote pathogenicity of myelin-reactive Th17 cells

The respiratory tract is home to a diverse microbial community whose influence on local and systemic immune responses is only beginning to be appreciated. The airways have been linked with the trafficking of myelin-specific T-cells in the preclinical stages of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Th17 cells are important pathogenic effectors in MS and EAE but are innocuous immediately following differentiation. Upregulation of the cytokine GM-CSF appears to be a critical step in their acquisition of pathogenic potential, but little is known about the mechanisms that mediate this process. Here, primed myelin-specific Th17 cells were transferred to congenic recipient mice prior to exposure to various human respiratory tract-associated bacteria and T-cell trafficking, phenotype and the severity of resulting EAE were monitored. Disease was exacerbated in mice exposed to the Proteobacteria Moraxella catarrhalis and Klebsiella pneumoniae, but not the Firmicute Veillonella parvula, and this was associated with significantly increased GM-CSF+ and GM-CSF+IFNγ+ ex-Th17-like donor CD4 T cells in the lungs and central nervous system (CNS) of these mice. These findings support the concept that respiratory bacteria may contribute to the pathophysiology of CNS autoimmunity by modulating pathogenicity in crucial T-cell subsets that orchestrate neuroinflammation.

Serum amyloid A-A potential therapeutic target for hyper-inflammatory syndrome associated with COVID-19.

Serum amyloid-A (SAA) is associated with inflammatory disorders such as rheumatoid arthritis, Familial Mediterranean Fever, sarcoidosis, and vasculitis. There is accumulating evidence that SAA is a reliable biomarker for these autoinflammatory and rheumatic diseases and may contribute to their pathophysiology. Hyperinflammatory syndrome associated with COVID-19 is a complex interaction between infection and autoimmunity and elevation of SAA is strongly correlated with severity of the inflammation. In this review we highlight the involvement of SAA in these different inflammatory conditions, consider its potential role and discuss whether it could be a potential target for treatment of the hyperinflammatory state of COVID-19 with many potential advantages and fewer adverse effects. Additional studies linking SAA to the pathophysiology of COVID-19 hyper-inflammation and autoimmunity are needed to establish the causal relationship and the therapeutic potential of inhibitors of SAA activity.

Cell-Specific and Variant-Linked Alterations in Expression of ERAP1, ERAP2, and LNPEP Aminopeptidases in Psoriasis

ERAP1, ERAP2, and LNPEP are aminopeptidases implicated in autoimmune pathophysiology. In this study, we show that ERAP2 is upregulated and ERAP1 is downregulated in patients with psoriasis who are homozygous for autoimmune-linked variants of ERAP. We also demonstrate that aminopeptidase expression is not uniform in the skin. Specifically, the intracellular antigen-processing aminopeptidases ERAP1 and ERAP2 are strongly expressed in basal and early spinous layer keratinocytes, whereas granular layer keratinocytes expressed predominantly LNPEP, an aminopeptidase specialized in the processing of extracellular antigens for presentation to T cells. In psoriasis, basal keratinocytes also expressed the T-cell- and monocyte-attracting chemokine, CCL2, and the T-cell-supporting cytokine, IL-15. In contrast, TGF-β1 was the major cytokine expressed by healthy control basal keratinocytes. SFRP2-high dermal fibroblasts were also noted to have an ERAP2-high expression phenotype and elevated HLA-C. In psoriasis, the SFRP2-high fibroblast subpopulation also expressed elevated CXCL14. From these results, we postulate that (i) an increased ERAP2/ERAP1 ratio results in altered antigen processing, a potential mechanism by which ERAP risk alleles predispose individuals to autoimmunity; (ii) ERAP2-high expressing cells display a unique major histocompatibility complex-bound peptidome generated from intracellular antigens; and (iii) the granular layer peptidome is skewed toward extracellular antigens.

Trained immunity as a possible newcomer in autoinflammatory and autoimmune diseases pathophysiology.

Autoimmune disorders have been well characterized over the years and many pathways-but not all of them-have been found to explain their pathophysiology. Autoinflammatory disorders, on the other hand, are still hiding most of their molecular and cellular mechanisms. During the past few years, a newcomer has challenged the idea that only adaptive immunity could display memory response. Trained immunity is defined by innate immune responses that are faster and stronger to a second stimulus than to the first one, being the same or not. In response to the trained immunity inducer, and through metabolic and epigenetic changes of hematopoietic stem and progenitor cells in the bone marrow that are transmitted to their cellular progeny (peripheral trained immunity), or directly of tissue-resident cells (local innate immunity), innate cells responsiveness and functions upon stimulation are improved in the long-term. Innate immunity can be beneficial, but it could also be detrimental when maladaptive. Here, we discuss how trained immunity could contribute to the physiopathology of autoimmune and autoinflammatory diseases.

Adult-onset idiopathic opsoclonus-myoclonus syndrome.

Opsoclonus-myoclonus syndrome is extremely uncommon in adults with an autoimmune pathophysiology. Because of the rarity of the syndrome, international recognition of opsoclonus-myoclonus-ataxia syndrome needs to be improved urgently. Therefore, the goal of this study was to raise the awareness of the opsoclonus-myoclonus-ataxia syndrome and help doctors in better diagnosing and using immunotherapy. We present a case study of an adult-onset case of idiopathic opsoclonus-myoclonus syndrome characterized by spontaneous arrhythmic multidirectional conjugate eye movements, myoclonus, ataxia, sleep disorders, and intense fear. Additionally, we conduct a literature search and summarize the pathophysiology, clinical presentation, diagnosis, and treatment of opsoclonus-myoclonus-ataxia syndrome. Immunotherapies successfully treated the patient's opsoclonus, myoclonus, and ataxia. Further, the article also includes an update summary of the opsoclonus-myoclonus-ataxia syndrome. The prevalence of residual sequela in adults with opsoclonus-myoclonus-ataxia syndrome is low. Early diagnosis and treatment may result in a better prognosis. Furthermore, combined immunotherapy is expected to reduce the incidence of refractory and reoccurring opsoclonus-myoclonus-ataxia syndrome.

Experimental approaches to assess melanocytes mosaicism in segmental vitiligo

Vitiligo is an autoimmune disease of the skin that results in localized or disseminated white macules. One common feature of several existing classification protocols is the distribution of the disease into two main subtypes, non-segmental vitiligo (NSV) and segmental vitiligo (SV). SV is characterized by depigmentation spreading within one or more skin segments while NSV is widespread. Several clinical-epidemiological observations suggest that SV has distinct autoimmune pathophysiology compared to NSV. Furthermore, the clinical distribution pattern of SV lesions closely resembles other melanocyte mosaicism diseases. These observations led us to hypothesize that SV is caused by a localized autoimmune reaction targeting epidermal mosaicism melanocytes. Here, we proposed examples of experimental approaches to assess mosaicism in SV patients.

Targeting B cells and plasma cells in autoimmune diseases: From established treatments to novel therapeutic approaches.

Autoimmune diseases are characterized by the recognition of self-antigens by the immune system, which leads to inflammation and tissue damage. B cells are directly and indirectly involved in the pathophysiology of autoimmunity, both via antigen-presentation to T cells and production of proinflammatory cytokines and/or autoantibodies. Consequently, B lineage cells have been identified as therapeutic targets in autoimmune diseases. B cell depleting strategies have proven beneficial in the treatment of rheumatoid arthritis (RA), systemic lupus erythematous (SLE), ANCA-associated vasculitis (AAV), multiple sclerosis (MS), and a wide range of other immune-mediated inflammatory diseases (IMIDs). However, not all patients respond to treatment or may not reach (drug-free) remission. Moreover, B cell depleting therapies do not always target all B cell subsets, such as short-lived and long-lived plasma cells. These cells play an active role in autoimmunity and in certain diseases their depletion would be beneficial to achieve disease remission. In the current review article, we provide an overview of novel strategies to target B lineage cells in autoimmune diseases, with the focus on rheumatic diseases. Both advanced therapies that have recently become available and more experimental treatments that may reach the clinic in the near future are discussed.

Utility of Antibodies in the Diagnoses of Thyroid Diseases: A Review Article.

Thyroid problems are among the most widespread endocrine illnesses, affectingindividuals in India andthe global population. A thyroid function test is used to diagnose, screen, and monitor patients. Hyperthyroidism is a clinical condition due to excessive circulation of thyroid hormone; in contrast, hypothyroidism is due to a deficiency of thyroid hormone. Graves' disease (GD) is a form of hyperthyroidism due to thyroid-stimulating hormonereceptor autoantibodies (TRAb), and anti-thyroid peroxidase antibodies (anti-TPO antibodies). The most common reason for hypothyroidism is Hashimoto's thyroiditis (HT), in which patients have thyroid receptor antibodies (TRAb), antibodies to thyroid peroxidase (TPO), and thyroglobulin antibodies.Many essential genes, including the thyroid-specific genes thyroglobulin (TSGT), TSH-receptor gene, human leukocyte antigen (HLA) genes, cytotoxic T lymphocyte-associated antigen (CTLA)genes, thyroglobulin gene, vitamin D receptor gene, and many immune-regulatory geneswere associated with autoimmune thyroid diseases' (AITDs') etiology. This review paper aims to determine if antibodies are beneficial in detecting autoimmune thyroid disease or not. We have also discussed the etiology of autoimmune thyroid illness, serum antibodies in autoimmune thyroid disease, pathophysiology, and TSH receptor features.

İlaç alerjisi olan hastalarda otoantikor sıklığı

Introduction: This study is aimed to analyze the autoantibody frequency in patients with drug allergy. Descriptive, observational research on drug allergy will contribute to the creation of new hypotheses about the pathophysiology of autoimmunity.Methods: The data of patients who were registered in the Training and Research Hospital database until the end of December 31, 2018 and diagnosed with drug allergy were retrospectively evaluated. Overall, 617 adult patients who had been diagnosed as “allergy status to drugs,” according to ICD 10, and had had at least one autoantibody result were included in the study.Results: The frequency of having at least one autoantibody varied between 0% and 92.1%. The most commonly detected autoantibody was rheumatoid factor (RF) (n = 241; 92.1%). The second most common one was anti-tissue transglutaminase IgA antibody (Anti-tTG-IgA) (n=22; 68.2%). The frequencies of anti-thyroglobulin (Anti-TG), anti-thyroid peroxidase (anti-TPO), and anti-double stranded DNA (Anti-dsDNA) were 65.2% (n = 155), 59.7% (n = 159), and 43.6% (n= 55), respectively.Conclusions: Many drugs can trigger the development of autoantibodies with no progression to autoimmune disease. Autoantibodies should be suspected in patients with allergies to medications. Observational research on drug allergy will contribute to the creation of new hypotheses about the pathophysiology of autoimmunity. Numerous studies in this area can enable us to discuss the widespread use of risky drugs in a more objective way. We think that our study will shed light on the relationship between drug reaction and autoimmune diseases.Keywords: Autoantibodies, autoimmunity, drug allergy, drug hypersensitivity

OC-056 AUTOIMMUNE/INFLAMMATORY SYNDROME INDUCED BY SYNTHETIC HERNIA MESH IN ADULTS – DESCRIPTION OF THE PATHOPHYSIOLOGY AND SYSTEMATIC REVIEW OF THE EVIDENCE

Abstract Background There is an increasing number of patients following hernia surgery with implanted mesh reporting symptoms that could indicate autoimmune or allergic reactions. ‘Allergy’ to metals, drugs, and chemicals is well recognised. However, allergy or autoimmunity caused by mesh has not been proven by a scientific method to date. The aim of this study was twofold: to describe the pathophysiology of autoimmunity and foreign body reaction and to undertake a systematic review of mesh implanted at the time of hernia repair and the subsequent development of autoimmune disease. Methods A systematic review using the PRISMA guidelines was undertaken. Pubmed, Google Scholar, and Cochrane databases were searched for English-written articles published between 2000 and 2021. The search was performed using keywords “hernia”, “mesh”, “autoimmunity”, “ASIA”, “immune response”, “autoimmune response” Results Seven papers, were included in the final analysis – three systematic reviews, three cohort studies and one case report. Much of the current data regarding the association of hernia mesh and autoimmunity relies on retrospective cohort studies and/or case reports with limited availability of cofounding factor data linked to autoimmune disease. Three systematic reviews have discussed this topic, each with different approach and none of them has identified causality between the use of mesh and development of autoimmune disease. Conclusion There is evidence that certain biomaterials can lead to immune dysregulation and induce autoimmunity. However, this has never been proven with synthetic hernia mesh. The bias in trials are high. And scientific studies have not been undertaken mesh-related autoimmunity.

Adult-onset autoimmune diabetes.

Adult-onset autoimmune (AOA) diabetes pathophysiology starts with immune changes, followed by dysglycaemia and overt disease. AOA diabetes can occur as classic type 1 diabetes when associated with severe loss of insulin secretion. More frequently, it is diagnosed as latent autoimmune diabetes in adults, a slowly progressing form with late onset, a long period not requiring insulin, and it is often misdiagnosed as type 2 diabetes. As its clinical presentation varies remarkably and immune markers often lack specificity, it is challenging to classify each case ad hoc, especially when insulin treatment is not required at diagnosis. Proper care of AOA diabetes aims to prevent complications and to improve quality of life and life expectancy. To achieve these goals, attention should be paid to lifestyle factors, with the aid of pharmacological therapies properly tailored to each individual clinical setting. Given the heterogeneity of the disease, choosing the right therapy for AOA diabetes is challenging. Most of the trials testing disease-modifying therapies for autoimmune diabetes are conducted in people with childhood onset, whereas non-insulin diabetes therapies have mostly been studied in the larger population with type 2 diabetes. More randomized controlled trials of therapeutic agents in AOA diabetes are needed.

Combined treatment with radiotherapy, chemotherapy and avelumab results in regression of metastatic Merkel cell carcinoma and improvement of associated Lambert-Eaton myasthenic syndrome: A case report.

Merkel cell carcinoma (MCC) is a rare and highly aggressive neuroendocrine malignancy arising from mechanoreceptors in the basal epidermis. Due to a pronounced risk of spread and a high propensity for recurrence after treatment, immediate treatment is of utmost importance. Lambert-Eaton myasthenic syndrome (LEMS) is a paraneoplastic phenomenon affecting the muscles with autoimmune pathophysiology, and >50% of known cases are associated with an underlying malignancy. In the present report, the case of a 67-year-old man presenting with progressive proximal muscle weakness, autonomic dysfunction and involuntary weight loss is described. Symptoms and detection of voltage-gated calcium channel antibodies were consistent with LEMS. Distant metastases were found in the inguinal and iliac lymph nodes, and these were immunohistochemically confirmed to be of epithelial and neuroendocrine origin, consistent with MCC. Local radiotherapy and chemotherapy improved the symptoms; however, a change of treatment was required due to the side effects of the chemotherapy. Avelumab, an immune checkpoint inhibitor, was therefore introduced, and within a year the patient did not only experience tumor remission but also exhibited marked improvements in muscle strength and mobility. At present, 2 years later, the MCC is still in remission. To the best of our knowledge, the present report is the first to describe MCC with associated LEMS, which was successfully treated with avelumab after previous radiotherapy and chemotherapy, with both improved functional motor recovery and tumor reduction. In conclusion, the present case report demonstrated that the present treatment strategy is a potential treatment option and could thus be considered in similar cases.

Alemtuzumab-induced immune phenotype and repertoire changes: implications for secondary autoimmunity.

Alemtuzumab is a monoclonal antibody that causes rapid depletion of CD52-expressing immune cells. It has proven to be highly efficacious in active relapsing–remitting multiple sclerosis; however, the high risk of secondary autoimmune disorders has greatly complicated its use. Thus, deeper insight into the pathophysiology of secondary autoimmunity and potential biomarkers is urgently needed. The most critical time points in the decision-making process for alemtuzumab therapy are before or at Month 12, where the ability to identify secondary autoimmunity risk would be instrumental. Therefore, we investigated components of blood and CSF of up to 106 multiple sclerosis patients before and after alemtuzumab treatment focusing on those critical time points.Consistent with previous reports, deep flow cytometric immune-cell profiling (n = 30) demonstrated major effects on adaptive rather than innate immunity, which favoured regulatory immune cell subsets within the repopulation. The longitudinally studied CSF compartment (n = 18) mainly mirrored the immunological effects observed in the periphery. Alemtuzumab-induced changes including increased numbers of naïve CD4+ T cells and B cells as well as a clonal renewal of CD4+ T- and B-cell repertoires were partly reminiscent of haematopoietic stem cell transplantation; in contrast, thymopoiesis was reduced and clonal renewal of T-cell repertoires after alemtuzumab was incomplete. Stratification for secondary autoimmunity did not show clear immununological cellular or proteomic traits or signatures associated with secondary autoimmunity. However, a restricted T-cell repertoire with hyperexpanded T-cell clones at baseline, which persisted and demonstrated further expansion at Month 12 by homeostatic proliferation, identified patients developing secondary autoimmune disorders (n = 7 without secondary autoimmunity versus n = 5 with secondary autoimmunity). Those processes were followed by an expansion of memory B-cell clones irrespective of persistence, which we detected shortly after the diagnosis of secondary autoimmune disease.In conclusion, our data demonstrate that (i) peripheral immunological alterations following alemtuzumab are mirrored by longitudinal changes in the CSF; (ii) incomplete T-cell repertoire renewal and reduced thymopoiesis contribute to a proautoimmune state after alemtuzumab; (iii) proteomics and surface immunological phenotyping do not identify patients at risk for secondary autoimmune disorders; (iv) homeostatic proliferation with disparate dynamics of clonal T- and B-cell expansions are associated with secondary autoimmunity; and (v) hyperexpanded T-cell clones at baseline and Month 12 may be used as a biomarker for the risk of alemtuzumab-induced autoimmunity.