Targeting enhanced cell death represents a potential therapeutic strategy for VEXAS syndrome.

Objectives: To unravel the mechanisms underlying cell death in the vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome using peripheral blood samples and to assess the clinical value of this knowledge. Methods: Nine patients undergoing treatment for VEXAS syndrome at Yokohama City University Hospital were included in this study. Monocytes and neutrophils were isolated from peripheral blood and then monocytes were differentiated into polarized macrophages. Viable cell counts, cell death assays and measurements of various indicators such as high mobility group box 1 (HMGB1) concentration, extracellular adenosine triphosphate (ATP) concentration, annexin V level and caspase 1, 3 and 7 activities were performed. Results: Elevated cell death of monocytes and neutrophils was observed in VEXAS syndrome patients, as indicated by cultured cell counts and cell death assays. Annexin V assays and measurements of caspase 1, 3 and 7 activities suggested increased apoptosis and pyroptosis in these cells. Serum HMGB1 levels were significantly elevated in VEXAS syndrome patients and decreased after prednisolone (PSL) dose escalation. Monocytes and neutrophils from the VEXAS group exhibited heightened extracellular ATP secretion, which was significantly reduced by soluble PSL co-culture. Conclusion: This study confirms increased cell death of monocytes and neutrophils and damage-associated molecular patterns in VEXAS syndrome, and these findings may be valuable for drug screening, therapeutic strategies and as biomarkers.

The tRNAVal half: A strong endogenous Toll-like receptor 7 ligand with a 5'-terminal universal sequence signature.

Toll-like receptors (TLRs) are crucial components of the innate immune system. Endosomal TLR7 recognizes single-stranded RNAs, yet its endogenous ssRNA ligands are not fully understood. We previously showed that extracellular (ex-) 5'-half molecules of tRNAHisGUG (the 5'-tRNAHisGUG half) in extracellular vesicles (EVs) of human macrophages activate TLR7 when delivered into endosomes of recipient macrophages. Here, we fully explored immunostimulatory ex-5'-tRNA half molecules and identified the 5'-tRNAValCAC/AAC half, the most abundant tRNA-derived RNA in macrophage EVs, as another 5'-tRNA half molecule with strong TLR7 activation capacity. Levels of the ex-5'-tRNAValCAC/AAC half were highly up-regulated in macrophage EVs upon exposure to lipopolysaccharide and in the plasma of patients infected with Mycobacterium tuberculosis. The 5'-tRNAValCAC/AAC half-mediated activation of TLR7 effectively eradicated bacteria infected in macrophages. Mutation analyses of the 5'-tRNAValCAC/AAC half identified the terminal GUUU sequence as a determinant for TLR7 activation. We confirmed that GUUU is the optimal ratio of guanosine and uridine for TLR7 activation; microRNAs or other RNAs with the terminal GUUU motif can indeed stimulate TLR7, establishing the motif as a universal signature for TLR7 activation. These results advance our understanding of endogenous ssRNA ligands of TLR7 and offer insights into diverse TLR7-involved pathologies and their therapeutic strategies.

Association of high disease activity and serum IL-6 levels with the incidence of inflammatory major organ events in Behçet disease: a prospective registry study.

Background: Little is known about the relationship between the disease activity of Behçet disease (BD) and the incidence of inflammatory major organ events. Objectives: In this prospective registry study, we investigated the association between the Behçet Disease Current Activity Form (BDCAF) and incidence of inflammatory major organ events, defined as the inflammation of the ocular, central nervous, intestinal, and vascular systems in BD. Methods: We enrolled participants from Japanese multicenter prospective cohorts. The BDCAF was evaluated annually. BD-related symptoms, including inflammatory major organ events, were monitored. The association between BDCAF and inflammatory major organ events was analyzed by time-to-event analysis. An unsupervised clustering of the participants' BDCAF, therapeutic agents, and multiple serum cytokines was also performed to examine their association with inflammatory major organ events. Results: A total of 260 patients were included. The patients had a median BDCAF score of 2 [Interquartile range, 1-3] at the enrolment and remained disease active at 1- and 2-year follow-ups, indicating residual disease activity in BD. Patients with a BDCAF score of 0 had a longer inflammatory major organ event-free survival at 52 weeks than those with a score of 1 or higher (p=2.2 x 10-4). Clustering analysis revealed that patients who did not achieve remission despite treatment with tumor necrosis factor inhibitors had high serum inflammatory cytokine levels and incidences of inflammatory major organ events. Among the elevated cytokines, IL-6 was associated with inflammatory major organ events. Conclusion: This study suggests that treatment strategies targeting overall disease activity and monitoring residual serum IL-6 may help prevent inflammatory major organ events in BD.

Clinical Challenges of Emerging Acquired Autoinflammatory Diseases, Including VEXAS Syndrome.

Vacuoles, E1-ubiquitin-activating enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome, caused by an acquired mutation in the ubiquitin-activating enzyme ubiquitin-like modifier activating enzyme 1 (UBA1), was discovered in 2020. Since then, many cases have been reported worldwide. Recently, we performed UBA1 genetic testing in suspected cases of VEXAS throughout Japan and investigated the clinical features of these cases. Most cases were elderly patients in their 70s with clinical features consistent with VEXAS syndrome, such as myelodysplastic syndrome, high-grade fever, skin rash, chondritis, and pulmonary infiltration. However, approximately half of the analyzed patients were negative for the UBA1 variant. As the concept of "acquired autoinflammatory diseases", including VEXAS syndrome, has gained popularity, the number of suspected cases is expected to increase. Currently, there are no established diagnostic or treatment guidelines for these conditions, and they need to be urgently developed. This review summarizes the clinical problems faced by patients with acquired autoinflammatory diseases, including VEXAS.

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome presenting as recurrent aseptic peritonitis in a patient receiving peritoneal dialysis: a case report.

BACKGROUND: Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is caused by mutations in the ubiquitin-activating enzyme1 (UBA1) gene and characterised by an overlap between autoinflammatory and haematologic disorders. CASE PRESENTATION: We reported a case of a 67-year-Japanese man receiving peritoneal dialysis (PD) who had recurrent aseptic peritonitis caused by the VEXAS syndrome. He presented with unexplained fevers, headache, abdominal pain, conjunctival hyperaemia, ocular pain, auricular pain, arthralgia, and inflammatory skin lesions. Laboratory investigations showed high serum C-reactive protein concentration and increased cell count in PD effluent. He was treated with antibiotics for PD-related peritonitis, but this was unsuccessful. Fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography images demonstrated intense FDG uptake in his left superficial temporal artery, nasal septum, and bilateral auricles. The working diagnosis was giant cell arteritis, and he was treated with oral prednisolone (PSL) 15 mg daily with good response. However, he was unable to taper the dose to less than 10 mg daily because his symptoms flared up. Since Tocilizumab was initiated, he could taper PSL dose to 2 mg daily. Sanger sequencing of his peripheral blood sample showed a mutation of the UBA1 gene (c.122 T > C; p.Met41Thr). We made a final diagnosis of VEXAS syndrome. He suffered from flare of VEXAS syndrome at PSL of 1 mg daily with his cloudy PD effluent. PSL dose of 11 mg daily relieved the symptom within a few days. CONCLUSIONS: It is crucial to recognise aseptic peritonitis as one of the symptoms of VEXAS syndrome and pay attention to the systemic findings in the patients.

Long-term remission of VEXAS syndrome achieved by a single course of CHOP therapy: A case report.

We herein describe the case of a 52-year-old male patient who presented with fever, arthritis, and neutrophilic dermatosis in 2013 and subsequently experienced macrophage activation syndrome treated with high-dose glucocorticoid therapy. Due to the persistent symptoms refractory to several immunomodulatory and immunosuppressive (IS) drug therapies with dapsone, methotrexate, tacrolimus, infliximab (IFX), and tocilizumab (TCZ), he received prednisolone (PSL) ≥20 mg/day to suppress disease activity. In 2017, Epstein-Barr virus (EBV)-associated haemophagocytic lymphohistiocytosis (HLH) was diagnosed and initially treated with immunochemotherapy consisting of dexamethasone, cyclosporine (CyA), and etoposide (ET). Because of the suboptimal response to the initial therapy, cytoreduction therapy consisting of CHOP (combination chemotherapy consisting of cyclophosphamide, doxorubicin, vincristine, and PSL) was administered. This regimen improved the EBV-associated HLH. Later, the patient's condition stabilised with methylprednisolone 1 mg/day and CyA 100 mg/day. In 2022, ubiquitylation-initiating E1 enzyme (UBA1) variant analysis using Sanger sequencing of peripheral blood leukocytes detected a previously reported somatic variant (NM_003334.3: c.118-1G>C), confirming the diagnosis of vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome. The clinical course in the present case suggested the possibility that CHOP could be a potential treatment option for VEXAS syndrome, in the pathophysiology of which the expansion of clones with UBA1 variant seems to play a pivotal role.

Incidence and Risk of Hematological Adverse Events Associated With Immune Checkpoint Inhibitors: A Systematic Literature Review and Meta-Analysis.

Background: Immune checkpoint inhibitors (ICIs) have been a breakthrough in cancer therapy. ICI therapy is generally better tolerated than cytotoxic chemotherapy; however, hematological adverse events (AEs) have not been fully analyzed. Hence, we performed a meta-analysis to evaluate the incidence and risk of ICI-related hematological AEs. Methods: A systematic literature search was performed using PubMed, EMBASE, Cochrane Library, and the Web of Science Core Collection. Phase III randomized controlled trials (RCTs) involving ICI combination regimens were selected. The experimental group received ICIs with systemic treatment, and the control group received only the same systemic treatment. Odds ratios (ORs) for anemia, neutropenia, and thrombocytopenia were calculated using a random-model meta-analysis. Results: We identified 29 RCTs with 20,033 patients. The estimated incidence rates for anemia of all grades and grades III-V were 36.5% (95% confidence interval (CI) 30.23 - 42.75) and 4.1% (95% CI 3.85 - 4.42), respectively. The incidence of neutropenia (all grades 29.7%, grades III-V 5.3%) and thrombocytopenia (all grades 18.0%, grades III-V 1.6%) was also calculated. Conclusion: Treatment with ICIs seemed unlikely to increase the incidence of anemia, neutropenia, and thrombocytopenia in all grades. However, programmed cell death-1 receptor ligand inhibitors significantly increased the risk of grades III-V thrombocytopenia (OR 1.53; 95% CI 1.11 - 2.11). Further research is needed to examine the potential risk factors.

Replication Study of the Association of GAS6 and PROS1 Polymorphisms with Behçet's Disease in a Japanese Population.

PURPOSE: To investigate whether polymorphisms of GAS6 and PROS1, which each encode protein ligands for a family of tyrosine kinase receptors, are associated with Behçet's disease (BD) in a Japanese population. METHODS: We recruited 734 Japanese patients with BD and 1789 Japanese healthy controls. In all participants, we genotyped two single-nucleotide polymorphisms (SNPs) reportedly associated with BD: rs9577873 in GAS6 and rs4857037 in PROS1. RESULTS: We found that GAS6 rs9577873 was not significantly associated with BD. In contrast, PROS1 rs4857037, specifically the A allele, was associated with increased risk for BD. The A allele was also significantly associated with BD under additive and recessive genetic models. Expression analysis revealed that this allele was significantly associated with increased PROS1 expression. CONCLUSIONS: Our findings suggest that increased PROS1 expression related to the A risk allele of rs4857037 affects tyrosine kinase receptor signaling, contributing to the development of BD.

Clinical and genetic features of Japanese cases of MDS associated with VEXAS syndrome.

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a new disease entity with autoinflammatory disorders (AID) driven by somatic variants in UBA1 that frequently co-exists with myelodysplastic syndromes (MDS). Clinicopathological and molecular features of Japanese cases with VEXAS-associated MDS remain elusive. We previously reported high prevalence of UBA1 variants in Japanese patients with relapsing polychondritis, in which 5 cases co-occurred with MDS. Here, we report clinicopathological and variant profiles of these 5 cases and 2 additional cases of MDS associated with VEXAS syndrome. Clinical characteristics of these cases included high prevalence of macrocytic anemia with marked cytoplasmic vacuoles in myeloid/erythroid precursors and low bone marrow (BM) blast percentages. All cases were classified as low or very low risk by the revised international prognostic scoring system (IPSS-R). Notably, 4 out of 7 cases showed significant improvement of anemia by treatment with prednisolone (PSL) or cyclosporin A (CsA), suggesting that an underlying inflammatory milieu induced by VEXAS syndrome may aggravate macrocytic anemia in VEXAS-associated MDS. Targeted deep sequencing of blood samples suggested that MDS associated with VEXAS syndrome tends to involve a smaller number of genes and lower risk genetic lesions than classical MDS.

Overlap syndrome with antibodies against multiple transfer-RNA components presenting antisynthetase syndrome.

Overlap syndrome is a clinical entity of myositis concomitant with one or more collagen diseases such as systemic lupus erythematosus, systemic sclerosis, and/or rheumatoid arthritis. It is not evident whether the myopathology of overlap syndrome is disease-specific or categorizes one of the four major subsets: inclusion body myositis, immune-mediated necrotizing myopathy, dermatomyositis, and antisynthetase syndrome. We report a patient with overlap syndrome who exhibited autoantibodies against multiple transfer-RNA components by RNA immunoprecipitation, suggesting antisynthetase syndrome. A 64-year-old woman developed systemic lupus erythematosus, systemic sclerosis, and myositis. Muscle biopsy showed perifascicular necrosis and perimysial alkaline phosphatase positivity, suggesting antisynthetase syndrome. Enzyme-linked immunosorbent assay was negative for autoantibodies to aminoacyl transfer-RNA synthetase, whereas RNA immunoprecipitation revealed a novel antibody to multiple transfer-RNA components. Although the myopathology of overlap syndrome may be diagnosed as any one of various subsets, this case suggests that the myopathological features of overlap syndrome may include antisynthetase syndrome.

Cryptococcal meningitis with atypical paradoxical inflammatory reactions after antifungal treatment in acquired immune deficiency syndrome: A case report.

Cryptococcal meningitis (CM) is a life-threatening disease that primarily affects patients with human immunodeficiency virus (HIV). Antifungal therapy with antiretroviral treatment (ART) usually leads to the clinical remission of CM; however, in some cases, these treatments exacerbate intracranial inflammation because of paradoxical inflammatory reaction or immune reconstitution inflammatory syndrome (IRIS). Here we report two CM cases that presented atypical clinical courses attributed to paradoxical inflammatory reactions. The first case was a 43-year-old man with headache and vertigo diagnosed with CM and HIV. The patient's CM not only was refractory to the antifungal combination therapy of liposomal amphotericin B (L-AMB) and fluconazole (FLCZ) but suddenly worsened because of a paradoxical inflammatory reaction after 18 days of treatment. He passed away from brain herniation on day 23. The second case was a 43-year-old man diagnosed with CM and HIV. After receiving antifungal therapy and ART, the patient's status was stable for more than 3 years with undetectable HIV-RNA. He suddenly presented with brain inflammation and was diagnosed with IRIS due to CM (CM-IRIS). His brain lesions were migratory and refractory to various antifungal therapies such as L-AMB, FLCZ, flucytosine, and intrathecal amphotericin B. Although the cryptococcal antigen in the patient's cerebrospinal fluid gradually diminished after continuous antifungal therapies, his cognitive function declined, and right hemiparesis persisted. These two cases of CM presented atypical clinical courses, presumably because of paradoxical inflammatory reactions. It should be noted that the onset of CM-IRIS may not necessarily depend on the timing of ART initiation.

Benefits and risks of haematopoietic stem cell transplantation for systemic sclerosis: A systematic review and meta-analysis.

OBJECTIVES: We aimed to evaluate the efficacy and safety of haematopoietic stem cell transplantation (HSCT) in patients with systemic sclerosis. METHODS: A systematic literature review and meta-analysis were carried out. We compared survival outcomes using the Kaplan-Meier method with patient-level data between HSCT and intravenous pulse cyclophosphamide. Additionally, the incidence rate of treatment-related deaths with HSCT was pooled using a random-effect model. RESULTS: Of the 2091 articles screened, 22 were included: 3 randomized controlled trials and 19 observational studies. HSCT studies showed significant improvement in the skin thickness score and lung function. Despite treatment-related deaths being higher in HSCT than in intravenous pulse cyclophosphamide, the Kaplan-Meier analysis showed a high survival rate of 2 years post-transplant (log-rank, P = 0.004). The pooled frequency of transplant-related death from 700 systemic sclerosis patients was 6.30% (95% confidence interval 4.21-8.38). However, the estimated frequency of treatment-related deaths has been reducing over the last decade. CONCLUSIONS: HSCT is an effective treatment for systemic sclerosis, but the optimal indications must be carefully determined by balancing the risks.

Immune checkpoint inhibitor-induced arthralgia is tightly associated with improved overall survival in cancer patients.

OBJECTIVES: With the increased use of immune checkpoint inhibitors (ICIs) in cancer patients, arthralgia has been the most commonly reported musculoskeletal immune-related adverse event (irAE). We aimed to characterize arthralgia and its association with overall survival (OS). MATERIAL AND METHODS: Randomized controlled trials (RCTs) reporting on data for ICI-induced arthralgia from four online databases were comprehensively investigated. Odds ratios (ORs) with 95% CIs were calculated for arthralgia using a random-effects model meta-analysis. Individual patient data were reconstructed from RCTs assessing OS in patients with or without ICI-induced arthralgia. We also retrospectively collected data on the clinical features and outcomes of ICI-induced arthralgia in the Yokohama City University (YCU) registry. RESULTS: We analysed 14 377 patients from 24 RCTs. The OR of ICI-induced arthralgia was 1.37 (95% CI 1.20, 1.56). Of the 369 patients in the YCU registry, 50 (13.6%) developed ICI-induced arthralgia. Among them, 30 had other grade ≥2 irAEs, which was noticeably more frequent than in those without arthralgia (OR 1.92, 95% CI 1.04, 3.52). By irAE types, a significant difference was found for relative adrenal insufficiency (OR 3.88, 95% CI 1.80, 8.39). In the YCU registry, patients with (vs without) ICI-induced arthralgia had better OS (log-rank, P < 0.001). OS results were validated from RCT patients with matched cancer types, drugs, and time to arthralgia onset (hazard ratio 0.34, 95% CI 0.17, 0.65, P < 0.001). CONCLUSIONS: If arthralgia develops after ICIs, another irAE, such as relative adrenal insufficiency, may have developed. The incidence of arthralgia was associated with better OS, and the condition of patients with irAEs must be carefully evaluated to determine optimal management.

Acute heart failure due to left common iliac arteriovenous fistula: A case of VEXAS syndrome.

We describe the case of a 78-year-old man presenting with multiple oedematous erythemas, fever, and arthralgia who subsequently developed neutrophil infiltration into the cartilage of the bilateral auricularis, consistent with relapsing polychondritis. A skin biopsy of the erythema on his right arm showed dense neutrophilic infiltration into the dermis, while a bone marrow aspirate revealed myelodysplastic syndromes with characteristic vacuoles in myeloid precursor cells. Although the patient achieved remission with high-dose oral prednisolone, the inflammatory symptoms relapsed, and he was resistant to colchicine and cyclosporine. The patient spontaneously developed left leg oedema and high-output cardiac failure caused by an arteriovenous fistula with a common iliac artery aneurysm. We successfully performed a two-stage surgery using internal iliac artery coil embolisation and endovascular aortic repair of the iliac aneurysm. We assumed the patient was suffering from large-vessel vasculitis such as giant cell arteritis or Takayasu's arteritis. We treated him with tocilizumab in addition to prednisolone, and the febrile events and elevated C-reactive protein levels improved. One year later, sequencing of ubiquitylation-initiating E1 enzyme using peripheral blood leucocytes revealed somatic variants (c.121A>C p.Met41Leu), confirming the diagnosis of vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome. This case suggests that arteriovenous fistula could be a complication of VEXAS syndrome with large-vessel vasculitis, and adequate surgical intervention and prompt diagnosis are essential for rescue. Although arteriovenous fistula is a rare complication of VEXAS syndrome, physicians should be aware of this complication to ensure prompt diagnosis and timely surgical intervention.

Case Report: Tocilizumab Treatment for VEXAS Syndrome With Relapsing Polychondritis: A Single-Center, 1-Year Longitudinal Observational Study In Japan.

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is an autoinflammatory disease caused by somatic variants in the UBA1 gene that lead to severe systemic inflammation and myelodysplastic syndrome. Although no standard therapy has been established yet, azacitidine and bone marrow transplantation have been reported to be promising possibilities; however, the indications for these treatments are problematic and not necessarily applicable to all patients. We previously reported the results of short-term treatment with tocilizumab (TCZ) and glucocorticoids in three patients with VEXAS syndrome. In this paper, we report that the combination of TCZ and glucocorticoids allowed the patients to continue treatment for at least one year without significant disease progression. Glucocorticoids were able to be reduced from the start of TCZ. Adverse events were herpes zoster, skin ulceration after cellulitis, and decreased blood counts. The results suggest the significance of this treatment as a bridge therapy for the development of future therapies.

Case Report: Coexistence of Multiple Myeloma and Auricular Chondritis in VEXAS Syndrome.

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is an inflammatory disorder caused by somatic UBA1 variants, which are sometimes associated with hematological disorders, including myelodysplastic syndrome (MDS). VEXAS syndrome often overlaps with rheumatic diseases, including relapsing polychondritis. Here, we describe a case of VEXAS syndrome with auricular chondritis and exceptional multiple myeloma (MM). An 83-year-old man was diagnosed with MM, which was treated once by lenalidomide hydrate obtaining a partial response, but the patient did not desire further aggressive therapy. Although the treatment was effective, progressive macrocytic anemia and inflammation of both the ears emerged over the following 2 months. The histological examination of the auricle skin revealed that the perichondrial area was infiltrated by inflammatory cells, leading to the diagnosis of auricular chondritis. He was treated with oral prednisolone 40 mg/day, and his symptoms rapidly resolved. The re-evaluation of the histopathological bone marrow findings revealed vacuoles in the myeloid precursor cells without myelodysplasia-related changes. Sanger sequencing of UBA1 was performed using genomic DNA from peripheral blood leukocytes and revealed a somatic variant (c.122T>C:p.Met41Thr) consistent with VEXAS syndrome. This demonstrates that patients with chondritis can have complications with MM despite the absence of underlying MDS. A strong association exists between UBA1 variants and the risk of MDS; however, it remains elusive whether somatic UBA1 variants contribute to the development of plasma cell dyscrasia without MDS. Hence, we discuss the possible relationship between auricular chondritis and MM on a background of VEXAS syndrome.

The Roles of Monocytes and Macrophages in Behçet's Disease With Focus on M1 and M2 Polarization.

Behçet's disease (BD) is a systemic inflammatory disease characterized by recurrent oral ulcers, genital ulcers, cutaneous inflammation, and uveitis. In addition, other potentially life-threatening lesions may occur in the intestinal tract, blood vessels, and central nervous system. This heterogeneity of the BD phenotype hampers development of a targeted treatment strategy. The pathogenesis of BD is not fully elucidated, but it is likely that genetically susceptible people develop BD in response to environmental factors, such as microbiome factors. Genetic analyses have identified various BD susceptibility loci that function in HLA-antigen presentation pathways, Th1 and Th17 cells, and autoinflammation related to monocytes/macrophages, or that increase levels of pro-inflammatory cytokines, reduce levels of anti-inflammatory cytokines, or act in dysfunctional mucous barriers. Our functional analyses have revealed that impairment of M2 monocyte/macrophage-mediated anti-inflammatory function through IL-10 is crucial to BD pathogenesis. We, therefore, propose that BD is an M1-dominant disease. In this review, we describe the roles of monocytes and macrophages in BD and consider the potential of these cells as therapeutic targets.

Anti-interferon-γ Antibody-seropositive Disseminated Nontuberculous Mycobacterial Infection Mimicking POEMS and TAFRO Syndromes.

Disseminated nontuberculous mycobacterial infection (DNTM) is typically observed in immunocompromised hosts. Recently, it has been reported that healthy individuals with serum neutralizing autoantibodies for interferon (IFN)-γ can also develop DNTM. We herein report a case of anti-IFN-γ antibody-seropositive DNTM caused by Mycobacterium kansasii with symptoms mimicking TAFRO or POEMS syndrome, including anasarca, organomegaly, skin pigmentation, polyneuropathy, osteosclerotic change, thrombocytopenia, serum M protein, high C-reactive protein level, and reticulin fibrosis. The combination of antimicrobial chemotherapy with glucocorticoid and intravenous immunoglobulin improved his symptoms. Glucocorticoids may be an effective method of suppressing the production of anti-IFN-γ antibodies in DNTM.

Incidence and Distinct Features of Immune Checkpoint Inhibitor-Related Myositis From Idiopathic Inflammatory Myositis: A Single-Center Experience With Systematic Literature Review and Meta-Analysis.

Immune checkpoint inhibitor (ICI)-related myositis is a rare, potentially fatal condition that warrants further studies. Its incidence, clinical features, and prognosis remain poorly understood. To address these gaps, we conducted a systematic review and meta-analysis to evaluate the risk of myositis associated with ICI for solid tumors by analyzing phase III randomized controlled trials of anti-programmed death-1/ligand-1 (PD-1/PD-L1) and anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4). To complement this analysis with clinical data, we evaluated published ICI case reports along with cases from our institutional registry. This registry comprised 422 patients treated with ICIs alone or in combination from September 2014 to June 2021. The analysis revealed an incidence of ICI-related myositis in 6,838 patients in 18 randomized controlled trials of 0.38% (odds ratio 1.96; 95% confidence interval 1.02-3.75) for patients receiving ICIs compared with controls. Detailed analysis of 88 cases from the literature search and our registry showed that myositis induced by PD-1 inhibitors was more frequent than that induced by anti-CTLA-4 agents, revealing a clinically diverse trend including myasthenia gravis and myocarditis. Importantly, having ptosis at the time of onset was significantly associated with the development of concomitant myocarditis (odds ratio 3.81; 95% CI 1.48-9.83), which is associated with poor prognosis. Regarding treatment, most patients received glucocorticoids, and some received immunosuppressants. Our study revealed the incidence of ICI-mediated myositis and the clinical features of myocarditis, highlighting the need for recognition and early intervention.