Murine MHC-Deficient Nonobese Diabetic Mice Carrying Human HLA-DQ8 Develop Severe Myocarditis and Myositis in Response to Anti-PD-1 Immune Checkpoint Inhibitor Cancer Therapy.

Myocarditis has emerged as an immune-related adverse event of immune checkpoint inhibitor (ICI) cancer therapy associated with significant mortality. To ensure patients continue to safely benefit from life-saving cancer therapy, an understanding of fundamental immunological phenomena underlying ICI myocarditis is essential. We recently developed the NOD-cMHCI/II-/-.DQ8 mouse model that spontaneously develops myocarditis with lower mortality than observed in previous HLA-DQ8 NOD mouse strains. Our strain was rendered murine MHC class I and II deficient using CRISPR/Cas9 technology, making it a genetically clean platform for dissecting CD4+ T cell-mediated myocarditis in the absence of classically selected CD8+ T cells. These mice are highly susceptible to myocarditis and acute heart failure following anti-PD-1 ICI-induced treatment. Additionally, anti-PD-1 administration accelerates skeletal muscle myositis. Using histology, flow cytometry, adoptive transfers, and RNA sequencing analyses, we performed a thorough characterization of cardiac and skeletal muscle T cells, identifying shared and unique characteristics of both populations. Taken together, this report details a mouse model with features of a rare, but highly lethal clinical presentation of overlapping myocarditis and myositis following ICI therapy. This study sheds light on underlying immunological mechanisms in ICI myocarditis and provides the basis for further detailed analyses of diagnostic and therapeutic strategies.

Lactobacillus delbrueckii alleviates lipopolysaccharide-induced muscle inflammation and atrophy in weaned piglets associated with inhibition of endoplasmic reticulum stress and protein degradation.

Pro-inflammatory cytokines in muscle play a pivotal role in physiological responses and in the pathophysiology of inflammatory disease and muscle atrophy. Lactobacillus delbrueckii (LD), as a kind of probiotics, has inhibitory effects on pro-inflammatory cytokines associated with various inflammatory diseases. This study was conducted to explore the effect of dietary LD on the lipopolysaccharide (LPS)-induced muscle inflammation and atrophy in piglets and to elucidate the underlying mechanism. A total of 36 weaned piglets (Duroc × Landrace × Large Yorkshire) were allotted into three groups with six replicates (pens) of two piglets: (1) Nonchallenged control; (2) LPS-challenged (LPS); (3) 0.2% LD diet and LPS-challenged (LD+LPS). On d 29, the piglets were injected intraperitoneally with LPS or sterilized saline, respectively. All piglets were slaughtered at 4 h after LPS or saline injection, the blood and muscle samples were collected for further analysis. Our results showed that dietary supplementation of LD significantly attenuated LPS-induced production of pro-inflammatory cytokines IL-6 and TNF-α in both serum and muscle of the piglets. Concomitantly, pretreating the piglets with LD also clearly inhibited LPS-induced nuclear translocation of NF-κB p65 subunits in the muscle, which correlated with the anti-inflammatory effects of LD on the muscle of piglets. Meanwhile, LPS-induced muscle atrophy, indicated by a higher expression of muscle atrophy F-box, muscle RING finger protein (MuRF1), forkhead box O 1, and autophagy-related protein 5 (ATG5) at the transcriptional level, whereas pretreatment with LD led to inhibition of these upregulations, particularly genes for MuRF1 and ATG5. Moreover, LPS-induced mRNA expression of endoplasmic reticulum stress markers, such as eukaryotic translational initiation factor 2α (eIF-2α) was suppressed by pretreatment with LD, which was accompanied by a decrease in the protein expression levels of IRE1α and GRP78. Additionally, LD significantly prevented muscle cell apoptotic death induced by LPS. Taken together, our data indicate that the anti-inflammatory effect of LD supply on muscle atrophy of piglets could be likely regulated by inhibiting the secretion of pro-inflammatory cytokines through the inactivation of the ER stress/NF-κB singling pathway, along with the reduction in protein degradation.

Increased myositis and possible myocarditis in melanoma patients treated with immune checkpoint inhibitors in the COVID-19 era.

BACKGROUND: Immune checkpoint inhibitor (ICI)-mediated myocarditis results in significant morbidity and mortality. At our institution, we noted an increased incidence of ICI-mediated myocarditis cases, leading to further investigation in our database of advanced melanoma patients treated with ICI therapy. METHODS: A single-center, retrospective cohort analysis of patients with advanced melanoma identified cases of ICI-mediated myocarditis and myositis. RESULTS: 366 patients with advanced melanoma received a dose of ICI from September 2014 to October 2019. Of these patients, there were 0 cases of ICI-mediated myocarditis (0%, 95% CI 0%-1.0%) and 2 cases of ICI-mediated myositis (0.55%, 95% CI 0.07%-1.96%). From November 2019 to December 2021, an additional 246 patients with advanced melanoma were identified. Of these patients, 10 (4.1%, 95% CI 1.97%-7.35%) developed ICI-mediated myocarditis and 10 developed ICI-mediated myositis. CONCLUSION: Our study suggests an increase in prevalence of ICI-mediated muscle damage including myositis and myocarditis in the COVID-19 era. Differentiation of these patients and further risk stratification may allow for development of guidelines for nuanced management of this serious complication.

Spontaneous development of myasthenia gravis and myositis following treatment with pembrolizumab: a case report.

BACKGROUND: Immune checkpoint inhibitors are a relatively new advancement in the world of cancer therapy. As such, their adverse effects have yet to be fully understood, with only recent literature documenting autoimmune phenomena secondary to their utilization. Specific immune checkpoint inhibitors have recently been linked with the development of myasthenia gravis, which is classically known to manifest spontaneously in patients. Given the relative rarity of this presentation, the risk of misdiagnosis and subsequent mortality and morbidity is concerning. CASE PRESENTATION: We discuss the case of a 73-year-old male who presented with clinical symptoms of myasthenia gravis and myositis shortly after beginning treatment with Pembrolizumab. The diagnosis of myasthenia gravis was initially missed at an outside hospital, which delayed initiation of proper treatment. CONCLUSION: While the incidence of "de-novo" diseases secondary to immune checkpoint inhibitors might be increasing, guidelines regarding best treatment options do not yet exist, leaving many providers at a loss when faced with making clinical decisions surrounding patients with De novo myasthenia gravis. Thus, our goal is to underscore the importance of early recognition of this disease, and emphasize the need for a standard of care as immune checkpoint inhibitors usage becomes more prevalent.

Atezolizumab-induced myositis in a patient with small-cell lung cancer.

OBJECTIVE: Myositis, an inflammatory disease affecting muscles, is a rare and potentially fatal immune-related adverse event associated with immune checkpoint inhibitors. There are limited data on its clinical features and management. CASE PRESENTATION: Atezolizumab, in combination with etoposide and carboplatin, was initiated in the patient diagnosed with metastatic small-cell lung cancer. After four cycles, maintenance atezolizumab was initiated. At the third visit of the maintenance therapy, the patient reported weakness, edema, and tightness in the muscles that had progressed over the course of a week. Mild solid-food dysphagia was also observed. Neutrophilic leukocytosis with elevated creatine phosphokinase (9234 U/L), erythrocyte sedimentation rate (111 mm/h), and transaminase levels were observed. A diagnosis of myositis was considered based on clinical findings. Atezolizumab was omitted and an oral 0.5 mg/kg/day dose of methylprednisolone was administered. The myositis resolved within 10 days. During the treatment of myositis, the patient underwent prophylactic cranial irradiation. The steroid dose was tapered off within 35 days and then atezolizumab was restarted. CONCLUSION: The literature contains only a few case reports about atezolizumab-induced myositis, highlighting the challenges in defining its clinical features and management. Prompt diagnosis and treatment are crucial to prevent severe complications, such as myocarditis or respiratory muscle paralysis.

Managing suspected myasthenia gravis and myositis induced by pembrolizumab in a Jehovah's Witness sarcoma patient.

INTRODUCTION: Immune checkpoint inhibitors (ICIs) can cause a spectrum of adverse events known as immune-related adverse events (irAEs) that resemble autoimmune responses. Immune-mediated myasthenia gravis (MG) is a rare and serious neurologic adverse event that has been associated with ICIs requiring prompt treatment. In the Jehovah's Witness population, typical management of these adverse events may not be options, and alternative treatment choices would be needed. CASE REPORT: 73-year-old Jehovah's Witness patient with high-grade undifferentiated pleiomorphic sarcoma who developed immune-mediated MG approximately 4 weeks after initiation of pembrolizumab. On the day of admission, the patient presented with a three-day history of worsening ptosis, right greater than left. He was later found to be seronegative for MG. MANAGEMENT AND OUTCOME: The patient required therapy with pyridostigmine, steroids, and agreed to plasma exchange (PLEX) prior to discharge. He achieved near resolution of his neurologic symptoms, and pembrolizumab was discontinued. He later underwent radical resection of the left thigh soft tissue sarcoma and superficial inguinal lymph node dissection. He is now on active surveillance. DISCUSSION: While neurologic adverse events typically present 6 weeks after initiation of ICIs, MG has been reported occurring as early as 4 weeks after initiation. This rare and serious adverse event requires prompt treatment, and clinicians need to be aware of the alternative treatment options in this unique patient population. Early conversations regarding blood products and factions must be had to develop a treatment plan in accordance with the patient's personal decisions.

Immune checkpoint inhibitors induced side effects of the peripheral nervous system.

PURPOSE OF REVIEW: This review highlights recent knowledge on the diagnosis and treatment of immune checkpoint inhibitor-induced neurological side effects (irNAE) focussing on the neuromuscular system. RECENT FINDINGS: irNAEs mainly resemble sporadic neuromuscular autoimmune diseases and paraneoplastic neurological syndromes. However, neurological symptoms may be unspecific (muscle weakness, fatigue) in the oncological setting and carry the risk of misdiagnosis and delayed therapeutic intervention. The role of disease-specific neuromuscular autoantibodies in the diagnosis is controversial as preexisting autoantibodies may otherwise be present before immune checkpoint inhibitor (ICI) treatment without clinical symptoms and may not develop in case of irNAE manifestation. A new necrotising form of myositis (irMyositis) has been described presenting with facial weakness and ptosis mimicking myasthenia gravis. It comes along with a high rate of severe myocarditis accounting for a triad overlap syndrome (myasthenia/myositis/myocarditis). The role of modern biologicals in the treatment of irNAEs has to be determined. SUMMARY: irNAEs are rare but carry the risk of permanent morbidity and mortality. Early suspicion and diagnosis are key to prevent neurological sequelae. Beyond interruption of ICI administration, treatment corresponds to sporadic autoimmune diseases. The myasthenia/myositis/myocarditis overlap syndrome deserves special attention as it carries the highest risk of mortality. The role of neurotoxic pretreatment regimens, preexisting subclinical neurological autoimmune diseases and the risk of ICI-re-challenge after irNAEs has to be further investigated.

Rheumatologic immune checkpoint inhibitor-related adverse events.

PURPOSE OF REVIEW: Immune check point inhibitors (ICIs) are a unique class of cancer treatments that harness the body's innate antitumor response. Although these medications have transformed oncology care, they also lead to generalized immune activation that can result in toxicities across a spectrum of organ systems called immune-related adverse events. This article reviews the most common rheumatologic immune-related adverse events and their management. RECENT FINDINGS: Inflammatory arthritis, polymyalgia rheumatic, sicca symptoms, systemic sclerosis, myositis, and vasculitis have all been reported as ICI adverse events. Treatment includes nonsteroidal anti-inflammatory drugs, glucocorticoids, traditional DMARDs, and biologics. SUMMARY: Rheumatologists have an important role in the management of patients with rheumatologic immune-related adverse events. Working with our oncology colleagues, we can help manage rheumatologic immune-related adverse events while optimally preserving ICI's antitumor effects.

Mogamulizumab-Associated Myositis With and Without Myasthenia Gravis and/or Myocarditis in Patients With T-Cell Lymphoma.

Mogamulizumab is being increasingly prescribed for the treatment of T-cell lymphomas (MF/SS/ATLL). We conducted a retrospective cohort study to identify muscular immune-related adverse events (irAEs) associated with mogamulizumab in patients with T-cell lymphoma followed at Dana-Farber Cancer Institute from January 2015 to June 2022. We identified 5 cases of mogamulizumab-associated myositis and/or myocarditis (MAM/Mc), 2 additionally affected by myasthenia gravis, among 42 patients with T-cell lymphoma. Three cases experienced -mogamulizumab-associated rash (MAR) prior to developing MAM/Mc. The incidence (n = 5/42, 11.9%) of muscular mogamulizumab-associated irAEs may be higher than has been previously reported in clinical trials and may be of late onset (a median of 5 cycles and as late as 100 days from the last infusion). We highlight the utility of IVIG, together with systemic corticosteroids, for the treatment of these potentially fatal side effects associated with mogamulizumab therapy.

Transcriptomic profiling reveals distinct subsets of immune checkpoint inhibitor induced myositis.

OBJECTIVES: Inflammatory myopathy or myositis is a heterogeneous family of immune-mediated diseases including dermatomyositis (DM), antisynthetase syndrome (AS), immune-mediated necrotising myopathy (IMNM) and inclusion body myositis (IBM). Immune checkpoint inhibitors (ICIs) can also cause myositis (ICI-myositis). This study was designed to define gene expression patterns in muscle biopsies from patients with ICI-myositis. METHODS: Bulk RNA sequencing was performed on 200 muscle biopsies (35 ICI-myositis, 44 DM, 18 AS, 54 IMNM, 16 IBM and 33 normal muscle biopsies) and single nuclei RNA sequencing was performed on 22 muscle biopsies (seven ICI-myositis, four DM, three AS, six IMNM and two IBM). RESULTS: Unsupervised clustering defined three distinct transcriptomic subsets of ICI-myositis: ICI-DM, ICI-MYO1 and ICI-MYO2. ICI-DM included patients with DM and anti-TIF1γ autoantibodies who, like DM patients, overexpressed type 1 interferon-inducible genes. ICI-MYO1 patients had highly inflammatory muscle biopsies and included all patients that developed coexisting myocarditis. ICI-MYO2 was composed of patients with predominant necrotising pathology and low levels of muscle inflammation. The type 2 interferon pathway was activated both in ICI-DM and ICI-MYO1. Unlike the other types of myositis, all three subsets of ICI-myositis patients overexpressed genes involved in the IL6 pathway. CONCLUSIONS: We identified three distinct types of ICI-myositis based on transcriptomic analyses. The IL6 pathway was overexpressed in all groups, the type I interferon pathway activation was specific for ICI-DM, the type 2 IFN pathway was overexpressed in both ICI-DM and ICI-MYO1 and only ICI-MYO1 patients developed myocarditis.

Clinical characteristics, treatment and outcome of nivolumab-induced myasthenia gravis.

BACKGROUND: To investigate the clinical features of nivolumab-induced myasthenia gravis (MG) and provide evidence for the rational use of nivolumab in the clinic. METHODS: We collected case reports and case series of nivolumab-induced MG for retrospective analysis by searching Chinese and English databases from 2014 to October 31, 2022. RESULTS: Of the 67 patients included, the median age was 72.5 years (range 34-86), including 44 males (65.7%). MG occurred in the median 2nd treatment cycle (range, 1st-6th) after nivolumab treatment, being mild in 12 patients (17.9%) and moderate to severe in 44 patients (65.7%). Ptosis (n = 48,71.6%), diplopia (n = 34,50.7%), dyspnea (n = 30, 44.8%), limb muscle weakness (n = 30, 44.8%) and dysphagia (n = 27, 40.3%) were the most common symptoms. Fifty-six patients (83.6%) were classified as having generalized myasthenia gravis (GMG), the remaining 11 patients (16.4%) isolated ocular myasthenia gravis (OMG). Twenty-one patients (31.3%) had MG combined with myositis, 10 patients (14.9%) had myocarditis, and 9 patients (13.4%) had both myositis and myocarditis. Forty patients (59.7%) were positive for anti-acetylcholine receptor antibodies. The serum creatine kinase level was significantly increased in 37 patients (55.2%), with a median value of 4000 IU/L (219,14229). After discontinuation of nivolumab and immunosuppressive therapy, 46 patients (68.7%) finally recovered or improved their MG symptoms, while 15 patients (22.4%) did not recover. Eleven patients (16.4%) died of MG complications. CONCLUSION: MG is a serious and rare adverse reaction to nivolumab. Nivolumab-induced MG should be timely and correctly identified, and immunotherapy should be given.

Rituximab-induced hypogammaglobulinaemia in patients affected by idiopathic inflammatory myopathies: a multicentre study.

OBJECTIVES: Rituximab (RTX) is an anti-CD20 chimeric monoclonal antibody recommended as off-label treatment in patients with idiopathic inflammatory myopathies (IIM). The present study aimed to evaluate changes in immunoglobulin (Ig) levels during RTX-treatment and their potential association with infections in a cohort of IIM patients. METHODS: Patients evaluated in the Myositis clinic belonging to the Rheumatology Units of Siena, Bari and Palermo University Hospitals, and treated for the first time with RTX were enrolled. Demographic, clinical, laboratory and treatment variables, including previous and concomitant immunosuppressive drugs and glucocorticoid (GC) dosage were analysed before (T0) and after 6 (T1) and 12 (T2) months of RTX treatment. RESULTS: Thirty patients (median age, IQR 56 (42-66); 22 female) were selected. During the observational period, low levels of IgG (<700 mg/dl) and IgM (<40 mg/dl) occurred in 10% and 17% of patients, respectively. However, no one showed severe (IgG<400 mg/dl) hypogammaglobulinaemia. IgA concentrations were lower at T1 than T0 (p=0.0218), while IgG concentrations were lower at T2 compared to those at baseline (p=0.0335). IgM concentrations were lower at T1 and T2 than T0 (p<0.0001), as well at T2 than T1 (p=0.0215). Three patients suffered major infections, two others had paucisymptomatic COVID-19, one suffered from mild zoster. GC dosages at T0 were inversely correlated with IgA T0 concentrations (p=0.004, r=- 0.514). No correlation was found between demographic, clinical and treatment variables and Ig serum levels. CONCLUSIONS: Hypogammaglobulinaemia following RTX is uncommon in IIM and is not related to any clinical variables, including GC dosage and previous treatments. IgG and IgM monitoring after RTX treatment does not seem useful in stratifying patients who require closer safety monitoring and prevention of infection, due to the lack of association between hypogammaglobulinaemia and the onset of severe infections.

Improved outcomes with early immunosuppression in patients with immune-checkpoint inhibitor induced myasthenia gravis, myocarditis and myositis: a case series.

PURPOSE: Myasthenia gravis (MG) is a rare but life-threatening complication of immune-checkpoint inhibitor (ICI) therapy and often co-presents with myositis and myocarditis. Previous case series of ICI-related MG have reported high mortality rates. We present a series of ten patients from a tertiary oncology centre outlining outcomes of an early multi-modal immunosuppression strategy. METHODS: We reviewed The Christie Hospital database of immunotherapy-related toxicity from 2017 to 2020. Symptom severity was assessed using the Myasthenia Gravis Foundation of America (MGFA) classification. RESULTS: Ten patients with ICI-related MG were identified. All patients presented following 1 (n = 4) or 2 (n = 6) cycles of ICI. Symptom progression was rapid with a median of 3 days from onset of symptoms to admission. Concomitant myositis and myocarditis were observed in nine patients. AChR or MuSK autoantibodies were positive in six patients. All patients received urgent treatment with intravenous methylprednisolone (IVMP) and eight received intravenous immunoglobulin (IVIG). A single patient died from myasthenia-related symptoms; the remaining 9 patients were successfully discharged. CONCLUSION: In our cohort, we demonstrate good outcomes associated with early intensive immunosuppressive treatment with IVIG and IVMP. An agreed national treatment protocol or clinical discussion forum would be beneficial.

Challenges in the diagnosis and management of immune-mediated necrotising myopathy (IMNM) in a patient on long-term statins.

Immune-mediated necrotising myopathy (IMNM) is a severe and poorly understood complication of statin use. Prompt management with immunosuppressive treatment is often needed to control the condition, which differs from the management of the more commonly recognised statin-induced myopathy. We present a case report and brief review of the literature regarding the pathogenesis, diagnosis, and management of anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) positive IMNM (HMGCR IMNM). There are no randomised clinical trials, but several smaller studies and cases suggest a triple therapy of corticosteroids, IVIG, and a corticosteroid-sparing immunosuppressant appears efficacious in patients with IMNM and proximal weakness. The mechanism of statin-induced IMNM is uncertain, and this is further complicated by the reports of HMGCR IMNM in statin-naïve patients, including children. We present a case of biopsy-confirmed HMGCR IMNM in a woman taking daily statins for treatment of hypercholesterolaemia for 4 years. She presented with symptoms consistent with a urinary tract infection (UTI), including muscle weakness. She was treated as an isolated case of UTI. One month later, she presented again with worsening weakness in her shoulders and hips. Creatine kinase was elevated, and MRI showed increased signal with STIR sequences in both thighs. Anti-HMGCR was positive and leg biopsy-confirmed necrotising changes. Stopping her statin prescription and a short course of prednisolone did not improve her muscle weakness. Adding methotrexate resulted in eventual resolution of her symptoms. IMNM should be considered as a differential in any patient taking statins presenting with muscle weakness, and this case suggests that immunosuppressant therapy in addition to cessation of statins is effective at treating IMNM. Clinical trials are needed to further investigate the efficacy of different combinations of immunosuppressants.

Atezolizumab-associated myositis in a patient with unresectable hepatocellular carcinoma.

INTRODUCTION: Combination treatment with atezolizumab and bevacizumab is the preferred first-line treatment for patients with unresectable or metastatic hepatocellular carcinoma with a Child-Pugh Class A liver function. Reactivation of the antitumor immune response with atezolizumab can result in the development of immune-related adverse events including colitis, skin rash, endocrinopathies, pneumonitis, and nephritis with renal dysfunction. However, the occurrence of myositis with immune checkpoint inhibitors is rare. CASE REPORT: We report on a 67-year-old male patient with an initial diagnosis of hepatocellular carcinoma, stage IV, unresectable with underlying cirrhosis who experienced atezolizumab-associated myositis. MANAGEMENT AND OUTCOME: Utilization of the American Society of Clinical Oncology guideline on managing immune checkpoint inhibitors adverse events helped guide the ordering of pertinent labs for monitoring and pharmacologic treatment. In our case, atezolizumab-induced myositis was resolved via a combination of corticosteroids, intravenous immunoglobulins, and plasmapheresis. DISCUSSION: Recognition of the signs and symptoms of atezolizumab-associated myositis is recommended and utilization of the American Society of Clinical Oncology guideline to guide management and treatment of associated symptoms.

A case report and literature review on respiratory failure with immune checkpoint inhibitors: a life-threatening adverse event.

Neuromuscular associated respiratory failure is a rare toxicity of immunotherapy for malignant tumors. In most cases, it may overlap with the symptoms of the primary disease or myocarditis, myositis and myasthenia gravis, resulting in difficult etiological diagnosis. Early detection and optimal treatment are still topics that need attention. Here, a case of 51-year-old male lung cancer patient with sintilimab-associated myasthenia gravis, myositis, and myocarditis overlap syndrome involving the diaphragm who developed severe type II respiratory failure was reported. After high-dose methylprednisolone, immunoglobulin and pyridostigmine intravenous injection with non-invasive positive pressure ventilation, the patient's symptoms improved significantly and was discharged. One year later, the patient received immunotherapy again due to tumor progression. After 53 days, he developed dyspnea again. Chest X-ray demonstrated marked elevation of the diaphragm, and the electromyogram demonstrated dysfunction of diaphragm. With rapid diagnosis and timely treatment, the patient was finally discharged safely. A comprehensive search of PubMed, EMBASE was performed to identify all previously reported cases of immune checkpoint inhibitors-associated respiratory failure. The potential mechanisms of respiratory failure caused by ICI-associated diaphragmatic dysfunction may be related to T cell-mediated immune disturbances and we proposed possible diagnostic processes. For patients with unexplained respiratory failure who are receiving immunotherapy, standardized diagnostic strategies should be implemented immediately on admission before deciding whether to conduct a more invasive diagnostic procedure or empirical treatment.

Pembrolizumab-Induced Fatal Myasthenia, Myocarditis, and Myositis in a Patient with Metastatic Melanoma: Autopsy, Histological, and Immunohistochemical Findings-A Case Report and Literature Review.

Immune checkpoint inhibitors (ICIs) represent a major advance in cancer treatment. The lowered immune tolerance induced by ICIs brought to light a series of immune-related adverse events (irAEs). Pembrolizumab belongs to the ICI class and is a humanized IgG4 anti-PD-1 antibody that blocks the interaction between PD-1 and PD-L1. The ICI-related irAEs involving various organ systems and myocarditis are uncommon (incidence of 0.04% to 1.14%), but they are associated with a high reported mortality. Unlike idiopathic inflammatory myositis, ICI-related myositis has been reported to frequently co-occur with myocarditis. The triad of myasthenia, myositis, and myocarditis must not be underestimated as they can rapidly deteriorate, leading to death. Herein we report a case of a patient with metastatic melanoma who fatally developed myasthenia gravis, myocarditis, and myositis, after a single cycle of pembrolizumab. Considering evidence from the literature review, autopsy, histological, and immunohistochemical investigations on heart and skeletal muscle are presented and discussed, also from a medical-legal perspective.

Rheumatic Immune-Related Adverse Events due to Immune Checkpoint Inhibitors-A 2023 Update.

With the aging of the population, malignancies are becoming common complications in patients with rheumatoid arthritis (RA), particularly in elderly patients. Such malignancies often interfere with RA treatment. Among several therapeutic agents, immune checkpoint inhibitors (ICIs) which antagonize immunological brakes on T lymphocytes have emerged as a promising treatment option for a variety of malignancies. In parallel, evidence has accumulated that ICIs are associated with numerous immune-related adverse events (irAEs), such as hypophysitis, myocarditis, pneumonitis, and colitis. Moreover, ICIs not only exacerbate pre-existing autoimmune diseases, but also cause de novo rheumatic disease-like symptoms, such as arthritis, myositis, and vasculitis, which are currently termed rheumatic irAEs. Rheumatic irAEs differ from classical rheumatic diseases in multiple aspects, and treatment should be individualized based on the severity. Close collaboration with oncologists is critical for preventing irreversible organ damage. This review summarizes the current evidence regarding the mechanisms and management of rheumatic irAEs with focus on arthritis, myositis, and vasculitis. Based on these findings, potential therapeutic strategies against rheumatic irAEs are discussed.

Neurological adverse events of immune checkpoint inhibitors: An update of clinical presentations, diagnosis, and management.

The use of immune checkpoint inhibitors (ICIs) has represented a major advance in cancer treatment. By enhancing endogenous immune responses to destroy cancer cells, ICIs can cause immune-related adverse events (irAEs), with possible involvement of any organ system. IrAEs are frequent, particularly those involving the skin or the endocrine system, and usually completely reversible after temporary immunosuppression, while neurological irAEs (n-irAEs) are relatively rare, often severe, and they carry a considerable risk of mortality and long-term disability. They usually affect the peripheral nervous system, mainly manifesting as myositis, polyradiculoneuropathy, or cranial neuropathy, and, less frequently, involve the central nervous system, causing encephalitis, meningitis, or myelitis. Although somehow reminiscent of the disorders that neurologists are familiar to deal with in their daily practice, n-irAEs are characterized by distinctive features from their idiopathic counterparts; for instance, myositis may have a predominant oculo-bulbar involvement reminiscent of myasthenia gravis and frequently associates with myocarditis; peripheral neuropathy, although often resembling Guillain-Barré syndrome, usually responds to corticosteroids. Remarkably, several associations between the neurological phenotype and the type of ICIs or the type of cancer have emerged in the last few years, and the growing administration of ICIs in patients with neuroendocrine cancers has led to an increased number of reports of paraneoplastic neurological syndromes (triggered or worsened by ICIs). This review aims to update current knowledge regarding the clinical presentation of n-irAEs. We also discuss the essential parts of the diagnostic approach, and we provide general recommendations for the management of these disorders.

Atorvastatin-induced Myositis and Drug-induced Liver Injury.

Statins are drugs for preventing cardiac events in the elderly population. Statins are well tolerated with a lower reported incidence of serious side effects (<0.15%) like myopathy and elevated transaminases [>3× upper limit of normal (ULN)]. Serious adverse effects of statins like statin-associated myopathy range from mild muscle pain to rhabdomyolysis. Drug-induced liver injury (DILI) is another adverse effect of statin use, typically presenting with an acute hepatocellular liver injury pattern as mixed or cholestatic injury. Symptoms usually disappear after 3 months of discontinuation of statins. Some patients require immunosuppression with steroids, intravenous immunoglobulin, or rituximab for management of rhabdomyolysis. DILI can be rapidly reversed by the stoppage of the statins if the enzyme elevation is more than twice the normal. Elderly patients are particularly at increased risk of such adverse effects, emphasizing a need for rational prescription of statins in older adults and close monitoring. We report a case of an elderly presenting with paraparesis and later diagnosed to be a case of statin-induced myositis that significantly improved with prompt management. How to cite this article: Kashyap K, Bisht K, Dhar M, et al. Atorvastatin-induced Myositis and Drug-induced Liver Injury. J Assoc Physicians India 2023;71(10):96-98.