Efficacy of ravulizumab in patients with generalized myasthenia gravis by time from diagnosis: A post hoc subgroup analysis of the CHAMPION MG study

INTRODUCTION/AIMS

The CHAMPION MG study demonstrated that ravulizumab significantly improved Myasthenia Gravis-Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) total scores versus placebo in adults with acetylcholine receptor antibody-positive generalized myasthenia gravis (AChR+ gMG). This post hoc analysis aimed to assess these outcomes by time from MG diagnosis.

METHODS

Changes from baseline to week 26 in MG-ADL and QMG total scores were analyzed by time from MG diagnosis to study entry (≤2 vs. >2 years). Within each subgroup, least-squares (LS) mean changes for ravulizumab and placebo were compared using mixed models for repeated measures.

RESULTS

In ravulizumab-treated patients, differences in LS mean (standard error of the mean) changes from baseline to week 26 were not statistically significant in the ≤2-years subgroup versus the >2-years subgroup for MG-ADL (-4.3 [0.70] vs. -2.9 [0.37]; p = .0511) or QMG (-4.3 [0.94] vs. -2.5 [0.50]; p = .0822) scores. No clear trends were observed in the placebo group. LS mean changes from baseline were significantly greater for ravulizumab versus placebo in both the ≤2 and >2 years from diagnosis subgroups for MG-ADL and QMG scores (all p < .05). The difference in treatment effect between the ≤2-years and >2-years subgroups was not statistically significant. No clinically meaningful between-subgroup differences in treatment-emergent adverse events were observed in ravulizumab-treated patients.

DISCUSSION

Ravulizumab treatment improved clinical outcomes for patients with AChR+ gMG regardless of time from diagnosis. A numerical trend was observed favoring greater treatment effect with earlier versus later treatment after diagnosis. Further studies are required for confirmation.

Taste disorders and alopecia in myasthenia gravis

BACKGROUND

Non-motor symptoms in myasthenia gravis (MG) are rarely confirmed. Although there are some small cohort studies, a large-systemic survey has not yet been performed.

METHODS

We investigated the incidence and clinical characteristics of patients with MG who had taste disorders and alopecia using data of 1710 patients with MG enrolled in the Japan MG Registry 2021.

RESULTS

Among them, 104 (6.1%) out of 1692 patients and 138 (8.2%) out of 1688 patients had histories of taste disorders and alopecia, respectively. Among the patients with MG, taste disorders were significantly more common in women, those with severe symptoms, refractory MG, or thymoma-associated MG, and were less common in those with ocular MG. The taste disorders often occurred after the onset of MG and often responded to MG treatments. Alopecia was more common in MG patients with a history of bulbar palsy and thymoma, and it often occurred before the onset of MG and sometimes responded to MG treatments. Multivariate logistic regression analysis revealed taste disturbance was associated with worst quantitative MG score and thymoma-associated MG; and alopecia was associated with thymoma-associated MG.

CONCLUSION

Clinicians should be aware of the non-motor symptoms in MG, especially in patients with severe myasthenic symptoms and thymoma-associated MG.

Pathologic Features of Anti-Ku Myositis

OBJECTIVE

Characteristics of myositis with anti-Ku antibodies are poorly understood. The purpose of this study was to elucidate the pathologic features of myositis associated with anti-Ku antibodies, compared with immune-mediated necrotizing myopathy (IMNM) with anti-signal recognition particle (SRP) and anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibodies, in muscle biopsy-oriented registration cohorts in Japan and Germany.

METHODS

We performed a retrospective pathology review of patients with anti-Ku myositis samples diagnosed in the Japanese and German cohorts. We evaluated histologic features and performed HLA phenotyping.

RESULTS

Fifty biopsied muscle samples in the Japanese cohort and 10 in the German cohort were obtained. After exclusion of myositis-specific autoantibodies or other autoimmune connective tissue diseases, 26 samples (43%) of anti-Ku antibody-positive myositis were analyzed. All the samples shared some common features with IMNM, whereas they showed expression of MHC class II and clusters of perivascular inflammatory cells more frequently than the anti-SRP/HMGCR IMNM samples (71% vs 7%/16%; p < 0.005/<0.005; 64% vs 0%/0%; p < 0.005/<0.005). Anti-Ku myositis biopsies could be divided into 2 subgroups based on the extent of necrosis and regeneration. The group with more abundant necrosis and regeneration showed a higher frequency of MHC class II expression and perivascular inflammatory cell clusters. HLA phenotyping in the 44 available patients showed possible associations of HLA-DRB1*03:01, HLA-DRB1*11:01, and HLA-DQB1*03:01 (p = 0.0045, 0.019, and 0.027; odds ratio [OR] 50.2, 4.6, and 2.8; 95% CI 2.6-2942.1, 1.1-14.5, and 1.0-7.0) in the group with less conspicuous necrosis and regeneration. On the contrary, in the group of more abundant necrosis and regeneration, the allele frequencies of HLA-A*24:02, HLA-B*52:01, HLA-C*12:02, and HLA-DRB1*15:02 were lower than those of healthy controls (p = 0.0036, 0.027, 0.016, and 0.026; OR = 0.27, 0, 0, and 0; 95% CI 0.1-0.7, 0-0.8, 0-0.8, and 0-0.8). However, these HLA associations did not remain significant after statistical correction for multiple testing.

DISCUSSION

While anti-Ku myositis shows necrotizing myopathy features, they can be distinguished from anti-SRP/HMGCR IMNM by their MHC class II expression and clusters of perivascular inflammatory cells. The HLA analyses suggest that anti-Ku myositis may have different subsets associated with myopathologic subgroups.

B-cell immune dysregulation with low soluble CD22 levels in refractory seronegative myasthenia gravis

Myasthenia gravis (MG), primarily caused by acetylcholine receptor (AChR) autoantibodies, is a chronic autoimmune disorder causing severe muscle weakness and fatigability. In particular, seronegative MG constitutes 10%-15% of MG cases and presents diagnostic challenges especially in early-onset female patients who often show severe disease and resistance to immunosuppressive therapy. Furthermore, the immunopathology of seronegative MG remains unclear. Thus, in this study, we aimed to elucidate the pathogenic mechanism of seronegative MG using scRNA-seq analysis and plasma proteome analysis; in particular, we investigated the relationship between immune dysregulation status and disease severity in refractory seronegative MG. Employing single-cell RNA-sequencing and plasma proteome analyses, we analyzed peripheral blood samples from 30 women divided into three groups: 10 healthy controls, 10 early-onset AChR-positive MG, and 10 refractory early-onset seronegative MG patients, both before and after intravenous immunoglobulin treatment. The disease severity was evaluated using the MG-Activities of Daily Living (ADL), MG composite (MGC), and revised 15-item MG-Quality of Life (QOL) scales. We observed numerical abnormalities in multiple immune cells, particularly B cells, in patients with refractory seronegative MG, correlating with disease activity. Notably, severe MG cases had fewer regulatory T cells without functional abnormalities. Memory B cells were found to be enriched in peripheral blood cells compared with naïve B cells. Moreover, plasma proteome analysis indicated significantly lower plasma protein levels of soluble CD22, expressed in the lineage of B-cell maturation (including mature B cells and memory B cells), in refractory seronegative MG patients than in healthy donors or patients with AChR-positive MG. Soluble CD22 levels were correlated with disease severity, B-cell frequency, and RNA expression levels of CD22. In summary, this study elucidates the immunopathology of refractory seronegative MG, highlighting immune disorders centered on B cells and diminished soluble CD22 levels. These insights pave the way for novel MG treatment strategies focused on B-cell biology.

Serious Bacterial Infections Associated with Eculizumab: A Pharmacovigilance Study

Objective Molecular-targeted agents, including eculizumab and rituximab, are considered treatment options for refractory myasthenia gravis (MG), but bacterial infections can occur as serious adverse events when using these agents. The present study elucidated the relative risks of bacterial infections associated with eculizumab and rituximab using a pharmacovigilance database. Methods We analyzed eculizumab- and rituximab-associated adverse events reported between 2007 and 2021 in the US Food and Drug Administration Adverse Event Reporting System (FAERS) and herein report a refractory MG patient who developed streptococcal toxic shock syndrome during eculizumab treatment. Patients We evaluated a 74-year-old Japanese woman with refractory MG who developed severe bacteremia after receiving eculizumab. Results A total of 44,215 and 108,485 adverse events were reported with eculizumab and rituximab, respectively, from among 13,742,321 individual case safety reports in the FAERS database after data cleaning. We found a strong association between eculizumab and Neisseria infections. In contrast, we found only one case of meningococcal meningitis treated with rituximab. Both eculizumab and rituximab were weakly associated with streptococcal infections. Two cases of streptococcal toxic shock syndrome were associated with rituximab. Conclusion Careful monitoring of serious bacterial infections associated with eculizumab treatment is warranted.

Real-world experience with eculizumab and switching to ravulizumab for generalized myasthenia gravis

OBJECTIVE

Eculizumab and ravulizumab are complement protein C5 inhibitors, showing efficacy and tolerability for patients with anti-acetylcholine receptor-positive (AChR+) generalized myasthenia gravis (gMG) in phase 3 clinical trials and subsequent analyses. The purpose of the present study was to evaluate the clinical significance of eculizumab and switching to ravulizumab for refractory AChR+ gMG patients in the real-world experience.

METHODS

Among the database of Japan MG registry survey 2021, we studied AChR+ gMG patients who received eculizumab. We also evaluated these patients who switched from eculizumab to ravulizumab. Responder was defined as an improvement of at least 3 points in MG-ADL. We performed a questionnaire of preference between eculizumab and ravulizumab.

RESULTS

Among 1,106 patients with AChR+ gMG, 36 patients (3%) received eculizumab (female 78%, mean age 56.0 years). Eculizumab was preferentially used in severe and refractory MG patients. The duration of eculizumab treatment was 35 months on average. MG-ADL improved from 9.4 ± 4.9 to 5.9 ± 5.1, and 25 (70%) of the 36 gMG patients were responders. Postintervention status was markedly improved after the eculizumab treatment. Of 13 patients who did not continue eculizumab, 6 showed insufficiencies. Early onset MG was most effective. However, 15 patients switching from eculizumab to ravulizumab kept favorable response and tolerability. Questionnaire surveys showed preference for ravulizumab over eculizumab.

INTERPRETATION

Eculizumab and switching to ravulizumab showed to be effective for refractory AChR+ gMG patients in clinical settings.

Clinicopathological predictors of postoperative long-term myasthenic status in resected thymoma with myasthenia gravis

PURPOSE

Surgical patients with thymoma and myasthenia gravis (MG) must have their MG status and oncological outcomes critically monitored. We aimed to identify clinicopathological predictors of the postoperative MG status.

METHODS

We conducted a retrospective review of 40 consecutive surgical patients with MG-related thymomas between 2002 and 2020. The quantitative myasthenia gravis score (QMGS) and Myasthenia Gravis Foundation of America post-intervention status (MGFA-PIS) were used to evaluate postoperative MG status.

RESULTS

All patients underwent extended total thymectomy. The most common WHO type was type B2 (32%), while 65% of patients had type B1-B3 and 35% had type A-AB thymomas. Eleven patients (28%) achieved controlled MG status in MGFA-PIS 6 months after surgery. This controlled status was observed more frequently in type A-AB than in B1-B3 (57% vs. 12%, p = 0.007). In a multivariate analysis, WHO type (A-AB or B1-B3) was an independent predictor of worsening episodes of MG based on the QMGS (Type B1-B3, hazard ratio: 3.23, 95% confidence interval: 1.12-9.25). At the last follow-up, 23 patients (58%) achieved controlled MG status. The 5-year overall survival rate of all patients was 93.7%.

CONCLUSION

The WHO type of thymoma is an informative predictor of postoperative MG status in patients with MG-related thymoma.

[Clinical Features of Myasthenia Gravis as an Immune-related Adverse Event]

Neurological and muscular immune-related adverse events (irAEs) associated with cancer treatment using immune checkpoint inhibitors (ICIs) may show a diverse clinical presentation. Myasthenia gravis (MG) represents a serious irAE associated with the aforementioned therapy. Recent studies have discussed the clinical features of MG that occurs as an irAE (irAE-MG). The incidence of irAE-MG is estimated to be 1%. This complication occurs during the early phase of ICI treatment and rapidly worsens, resulting in severe bulbar muscle involvement and myasthenic crisis and significantly elevated serum creatine kinase levels. MG and myositis, which may occur concomitantly as irAEs are often indistinguishable. Myocarditis is occasionally observed in patients with irAE-MG and can cause severe heart failure and lethal arrhythmias, with a fatal outcome. Kv1.4 antibodies serve as biomarkers of severe irAE-MG and myocarditis. Immunotherapy with corticosteroids is effective for management of irAE-MG and should be initiated promptly. Collaboration between consulting neurologists is necessary for safe management of cancer immunotherapy.

Clinical features and outcomes of patients with muscle-specific kinase antibody-positive myasthenia gravis in Japan

This study included 51 patients with muscle-specific kinase antibody-positive myasthenia gravis (MuSK-MG) from a Japanese multicenter survey to examine clinical features and outcomes. Median onset age was 37 years and female predominance was observed. All patients developed generalized symptoms and almost all (50/51) patients had bulbar symptoms. About half of the patients met the criteria for refractory MG. The refractory group had a lower age of onset, higher severity scores, and higher maximum daily doses of oral prednisolone compared to the nonrefractory group. The outcomes for MuSK-MG patients in Japan are not favorable, indicating the need for more aggressive treatment.

Erratum: Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande [Phys. Rev. Lett. 130, 031802 (2023)]

This corrects the article DOI: 10.1103/PhysRevLett.130.031802.

Multi-ancestry genome-wide analysis identifies shared genetic effects and common genetic variants for self-reported sleep duration

Both short (≤6 h per night) and long sleep duration (≥9 h per night) are associated with increased risk of chronic diseases. Despite evidence linking habitual sleep duration and risk of disease, the genetic determinants of sleep duration in the general population are poorly understood, especially outside of European (EUR) populations. Here, we report that a polygenic score of 78 European ancestry sleep duration single-nucleotide polymorphisms (SNPs) is associated with sleep duration in an African (n = 7288; P = 0.003), an East Asian (n = 13 618; P = 6 × 10-4) and a South Asian (n = 7485; P = 0.025) genetic ancestry cohort, but not in a Hispanic/Latino cohort (n = 8726; P = 0.71). Furthermore, in a pan-ancestry (N = 483 235) meta-analysis of genome-wide association studies (GWAS) for habitual sleep duration, 73 loci are associated with genome-wide statistical significance. Follow-up of five loci (near HACD2, COG5, PRR12, SH3RF1 and KCNQ5) identified expression-quantitative trait loci for PRR12 and COG5 in brain tissues and pleiotropic associations with cardiovascular and neuropsychiatric traits. Overall, our results suggest that the genetic basis of sleep duration is at least partially shared across diverse ancestry groups.

Association Between HLA Alleles and Autoantibodies in Dermatomyositis Defined by Sarcoplasmic Expression of Myxovirus Resistance Protein A

OBJECTIVE

The diagnosis in the studies analyzing HLA of dermatomyositis (DM) was based on a combined clinical category of polymyositis/DM. This retrospective study investigated the associations of HLA with 5 DM-specific autoantibodies in Japanese patients diagnosed by muscle pathology.

METHODS

We diagnosed Japanese patients with DM based on sarcoplasmic expression of myxovirus resistance protein A. These patients underwent investigation for 5 DM-specific autoantibodies and HLA genotyping.

RESULTS

Of 175 patients (83 males and 92 females; range 1-86 yrs; mean 46 yrs), 173 (98.9%) had 1 of the 5 autoantibodies. Seven alleles-A*02:07, B*46:01, DRB1*04:07, DRB1*07:01, DRB1*08:03, DQB1*06:01, and DPB1*02:02-were more frequently detected in the patients with DM than healthy controls, but these associations were not significant after multiple testing correction. Stratifying by DM-specific autoantibodies, we found the associations of 6 already known and 7 new alleles-B*48:01, B*52:01, C*12:02, DRB1*04:05, DRB1*15:02, DPB1*05:01, and DPB1*09:01-with subsets of DM. Moreover, significant associations of 5 alleles with antinucleosome remodeling deacetylase complex (Mi-2) remained after multiple testing correction. In particular, the DRB1*04:07 (odds ratio [OR 28.9]; corrected P = 2.7 × 10-6) and DQB1*06:01 (OR 4.0; corrected P = 1.6 × 10-4) alleles were significantly more prevalent in patients with anti-Mi-2 antibody than in controls.

CONCLUSION

This study demonstrates DM-specific autoantibodies defined immunogenetic subsets of DM.

Dysautonomia associated with immune checkpoint inhibitors

OBJECTIVE

The purpose of this study is to report the clinical characteristics of dysautonomia associated with immune checkpoint inhibitors (ICIs).

METHODS

We reported two patients with autoimmune autonomic ganglionopathy (AAG) occurring as immune-related adverse events (irAEs). We also performed a review of previous case reports presenting dysautonomia during ICI therapy. Moreover, we conducted pharmacovigilance analyses using the US Food and Drug Administration Adverse Events Reporting System (FAERS) to investigate dysautonomia associated with ICI.

RESULTS

Two patients in our care developed both AAG and autoimmune encephalitis following ICI therapy for lung cancers. We comprehensively reviewed 13 published cases (M:F = 11:2, mean onset age of 53 years) with ICI-associated dysautonomia including AAG (n = 3) and autonomic neuropathy (n = 10). Of these, ICI monotherapy was performed in seven and combination ICI use in six. In 6 of 13 patients, dysautonomia appeared within one month after the start of ICIs. Orthostatic hypotension was observed in 7 and urinary incontinence or retention in five. All patients except three showed gastrointestinal symptoms. Anti-ganglionic acetylcholine receptor antibodies were undetectable. All but two patients received immune-modulating therapy. Immuno-modulating therapy was effective in three patients with AAG and two patients with autonomic neuropathy, but ineffective in the others. Five patients died, of either the neurological irAE (n = 3) or cancer (n = 2). The pharmacovigilance analyses using FAERS showed that ipilimumab monotherapy and the combination of nivolumab and ipilimumab constituted significant risks for developing dysautonomia, consistent with the review of literature.

CONCLUSION

ICIs can cause dysautonomia including AAG, and autonomic neuropathy is a neurological irAE.

Search for the Pair Production of Dark Particles X with K_{L}^{0}→XX, X→γγ

We present the first search for the pair production of dark particles X via K_{L}^{0}→XX with X decaying into two photons using the data collected by the KOTO experiment. No signal was observed in the mass range of 40-110  MeV/c^{2} and 210-240  MeV/c^{2}. This sets upper limits on the branching fractions as B(K_{L}^{0}→XX)<(1-4)×10^{-7} and B(K_{L}^{0}→XX)<(1-2)×10^{-6} at the 90% confidence level for the two mass regions, respectively.

Muscle pathology of antisynthetase syndrome according to antibody subtypes

Identification of antisynthetase syndrome (ASS) could be challenging due to inaccessibility and technical difficulty of the serology test for the less common non-Jo-1 antibodies. This study aimed to describe ASS antibody-specific myopathology and evaluate the diagnostic utility of myofiber HLA-DR expression. We reviewed 212 ASS muscle biopsies and compared myopathologic features among subtypes. Additionally, we compared their HLA-DR staining pattern with 602 non-ASS myositis and 140 genetically confirmed myopathies known to have an inflammatory component. We used t-test and Fisher's exact for comparisons and used sensitivity, specificity, positive and negative predictive values to assess the utility of HLA-DR expression for ASS diagnosis. RNAseq performed from a subset of myositis cases and histologically normal muscle biopsies was used to evaluate interferon (IFN)-signaling pathway-related genes. Anti-OJ ASS showed prominent myopathology with higher scores in muscle fiber (4.6 ± 2.0 vs. 2.8 ± 1.8, p = 0.001) and inflammatory domains (6.8 ± 3.2 vs. 4.5 ± 2.9, p  = 0.006) than non-OJ ASS. HLA-DR expression and IFN-γ-related genes upregulation were prominent in ASS and inclusion body myositis (IBM). When dermatomyositis and IBM were excluded, HLA-DR expression was 95.4% specific and 61.2% sensitive for ASS with a positive predictive value of 85.9% and a negative predictive value of 84.2%; perifascicular HLA-DR pattern is common in anti-Jo-1 ASS than non-Jo-1 ASS (63.1% vs. 5.1%, p < 0.0001). In the appropriate clinicopathological context, myofiber HLA-DR expression help support ASS diagnosis. The presence of HLA-DR expression suggests involvement of IFN-γ in the pathogenesis of ASS, though the detailed mechanisms have yet to be elucidated.

Proteolytic ectodomain shedding of muscle-specific tyrosine kinase in myasthenia gravis

Autoantibodies to muscle-specific tyrosine kinase (MuSK) proteins at the neuromuscular junction (NMJ) cause refractory generalized myasthenia gravis (MG) with dyspnea more frequently than other MG subtypes. However, the mechanisms via which MuSK, a membrane protein locally expressed on the NMJ of skeletal muscle, is supplied to the immune system as an autoantigen remains unknown. Here, we identified MuSK in both mouse and human serum, with the amount of MuSK dramatically increasing in mice with motor nerve denervation and in MG model mice. Peptide analysis by liquid chromatography-tandem-mass spectrometry (LC-MS/MS) confirmed the presence of MuSK in both human and mouse serum. Furthermore, some patients with MG have significantly higher amounts of MuSK in serum than healthy controls. Our results indicated that the secretion of MuSK proteins from muscles into the bloodstream was induced by ectodomain shedding triggered by neuromuscular junction failure. The results may explain why MuSK-MG is refractory to treatments and causes rapid muscle atrophy in some patients due to the denervation associated with Ab-induced disruption of neuromuscular transmission at the NMJ. Such discoveries pave the way for new MG treatments, and MuSK may be used as a biomarker for other neuromuscular diseases in preclinical studies, clinical diagnostics, therapeutics, and drug discovery.

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.

Impact of Early Treatment with Intravenous High-Dose Methylprednisolone for Ocular Myasthenia Gravis

The efficacy of intravenous high-dose methylprednisolone (IVMP) in ocular myasthenia gravis (MG) has not been fully established. This study aimed to elucidate the effects of early intervention with IVMP for achieving the therapeutic targets (minimal manifestations [MM] or MM or better status with prednisolone ≤ 5 mg/day [MM5mg]) in ocular MG. In this observational study, we included a total of 1710 consecutive patients with MG enrolled in the Japan MG Registry in 2021. Of these, 204 patients with ocular MG who received immunotherapy were analyzed. The clinical course and time to first achieve MM or MM5mg after starting immunotherapy were compared between the early IVMP group (treated with IVMP within 3 months of treatment initiation) and the non-early IVMP group. Despite having greater clinical severity before immunotherapy and lower oral prednisolone doses throughout the course, the early IVMP group (n = 55) showed a higher rate of achievement of MM (P = 0.0040, log-rank test; hazard ratio 1.58, 95% confidence interval [CI] 1.13-2.20, P < 0.0001) and MM5mg (P = 0.0005, log-rank test; hazard ratio 1.78, 95% CI 1.27-2.51, P < 0.0001) compared with the non-early IVMP group (n = 149). In conclusion, an early intervention with IVMP is likely to increase the probability of achieving a better long-term outcome and reducing the total dose of corticosteroids in ocular MG.

Risk factors for persistent positive anticardiolipin antibodies in women with recurrent pregnancy loss

Antiphospholipid syndrome (APS) is an established cause of recurrent pregnancy loss (RPL). It is necessary to detect persistently positive antiphospholipid antibodies to diagnose APS. This study aimed to explore risk factors for persistent anticardiolipin (aCL) positivity. Women with a history of RPL or with a history of one or more intrauterine fetal deaths after 10 weeks underwent examinations to determine the causes of RPL, including antiphospholipid antibodies. If aCL-IgG or aCL-IgM antibodies were positive, retests were performed at least 12 weeks apart. Risk factors for persistent aCL antibody positivity were retrospectively investigated. The number and percentage of cases above the 99th percentile were 74/2399 (3.1%) for aCL-IgG, and 81/2399 (3.5%) for aCL-IgM. Of the initially tested cases, 2.3% (56/2399) for aCL-IgG and 2.0% (46/2289) for aCL-IgM were ultimately positive above the 99th percentile in retests. Retest values after 12 weeks were significantly lower than the initial values for both IgG and IgM immunoglobulin classes. Initial aCL antibody titers were significantly higher in the persistent-positive group than in the transient-positive group for both IgG and IgM immunoglobulin classes. The cut-off values for predicting persistent positivity of aCL-IgG antibodies and aCL-IgM antibodies were 15 U/mL (99.1 percentile) and 11 U/mL (99.2 percentile), respectively. The only risk factor for persistently positive aCL antibodies is a high antibody titer during the initial test. When the aCL antibody titer in the initial test exceeds the cut-off value, therapeutic strategies can be defined in subsequent pregnancies without waiting for 12 weeks.

Regression of venous thrombus after trans-sphenoidal hypophysectomy for pituitary-dependent hyperadrenocorticism in a dog

An 8.0-kg 8-year-old male dachshund was presented for surgical treatment of suspected pituitary-dependent hyperadrenocorticism with portal vein thrombosis. Advanced diagnostic imaging revealed a thrombus in the splenic and portal veins. For the portal vein thrombus, CT angiography showed an enhanced timing delay in the lateral right and caudate liver lobes. Blood tests showed a marked increase in the liver panel, including total bile acid. Brain MRI revealed a pituitary mass, suggesting pituitary-dependent hyperadrenocorticism. The mass was completely resected. The preoperative antithrombotic therapy of rivaroxaban (0.66 mg/kg, PO, once per day) and clopidogrel sulphate (1.66 mg/kg, PO, once per day) was continued postoperatively. Six months after resection of the pituitary mass, the thrombus had disappeared. Further studies are required to prove a causal association between the disappearance of the thrombus and the treatments provided.

Effectiveness of early cycles of fast-acting treatment in generalised myasthenia gravis

BACKGROUND

Early fast-acting treatment (EFT) is the aggressive use of fast-acting therapies such as plasmapheresis, intravenous immunoglobulin and/or intravenous high-dose methylprednisolone (IVMP) from the early phases of treatment. EFT is reportedly beneficial for early achievement of minimal manifestations (MM) or better status with ≤5 mg/day prednisolone (MM5mg), a practical therapeutic target for myasthenia gravis (MG).

OBJECTIVE

The current study aimed to clarify which specific EFT regimen is efficacious and the patient characteristics that confer sensitivity to EFT.

METHODS

We recruited a total of 1710 consecutive patients with MG who enrolled in the Japan MG Registry for this large-cohort study. Among them, 1066 with generalised MG who had received immunotherapy were analysed. Prognostic background factors were matched in a 1:1 ratio using propensity score matching analysis between patients treated with EFT (n=350) and those treated without EFT (n=350). The clinical course and time to first achieve MM5mg after starting immunotherapy was analysed in relation to treatment combinations and patient characteristics.

RESULTS

Kaplan-Meier analyses showed that EFT had a significant effect on the achievement of MM5mg (p<0.0001, log-rank test; HR 1.82, p<0.0001). Notably, EFT was efficacious for any type of MG, and the inclusion of IVMP resulted in earlier and more frequent achievement of MM5mg (p=0.0352, log-rank test; HR 1.46, p=0.0380). In addition, early administration of calcineurin inhibitors also promoted MM5mg achievement.

CONCLUSION

Early cycles of intervention with EFT and early use of calcineurin inhibitors provides long-term benefits in terms of achieving therapeutic targets for generalised MG, regardless of clinical subtype.

Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande

We report a search for cosmic-ray boosted dark matter with protons using the 0.37  megaton×years data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross section between 10^{-33}cm^{2} and 10^{-27}cm^{2} for dark matter mass from 1  MeV/c^{2} to 300  MeV/c^{2}.

Association of immune-mediated necrotizing myopathy with HLA polymorphisms

Immune-mediated necrotizing myopathy (IMNM) is a type of autoimmune myositis typically characterized clinically by proximal muscle weakness with elevated creatine kinase levels, pathologically by myofiber necrosis and regeneration with paucity of lymphocytic cell infiltration, and serologically by the presence of either of two myositis-specific autoantibodies, anti-SRP, and anti-HMGCR antibodies. However, the HLA loci and alleles associated with IMNM are still not fully understood at least partly because IMNM was a relatively recently established condition. In this study, we genotyped the six HLA loci (HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1) in 250 patients (237 patients over age 18 years and 13 juvenile patients) diagnosed with IMNM based on clinicopathological features and autoantibody information and performed a case control study with Japanese healthy subjects. In the adult patients, specific HLA alleles associated with IMNM were identified at all HLA loci, with DRB1*08:03 showing the strongest association (OR = 2.5; p = 0.00000017). Furthermore, subgroup analysis with various clinical information showed that C*03:04 (OR = 3.7; p = 0.00012) was a higher risk allele for collagen disease in adult patients, and B*13:01 (OR = 23.2; p = 0.021) and C*03:04 (OR = 5.8; p = 0.0074) were higher risk for juvenile patients with anti-HMGCR antibody-positive IMNM. These findings will help to better understand the HLA genetic background and features of IMNM in designing future studies.

Efgartigimod for generalized myasthenia gravis with or without anti-acetylcholine receptor antibodies: a worldwide and Japanese perspective

INTRODUCTION

The management of myasthenia gravis (MG) has been improved due to immunotherapy advances, but 20% of individuals with MG are refractory to the conventional therapy, and the need for novel biological drugs remains.

AREA COVERED

The Japanese clinical guidelines for MG published in May 2022 include the concept that treatment is often lifelong and should aim to maintain a sufficient quality of life and mental health. We provide an overview of the therapeutic strategy for generalized MG in Japan, in comparison with the international consensus. We summarize the clinical efficacy, safety, and tolerability of efgartigimod, the first approved anti-neonatal Fc receptor inhibitor for MG. A phase III study showed that efgartigimod was well-tolerated and efficacious in patients with generalized MG.

EXPERT OPINION

Efgartigimod is a promising biological drug for patients with moderate to severe generalized MG with or without anti-acetylcholine receptor antibodies in Japan.

Mass-resolved ion measurement by particle counting analysis for characterizing relativistic ion beams driven by lasers

Particle counting analysis is a possible way to characterize GeV-scale, multi-species ions produced in laser-driven experiments. We present a multi-layered scintillation detector to differentiate multi-species ions of different masses and energies. The proposed detector concept offers potential advantages over conventional diagnostics in terms of (1) high sensitivity to GeV ions, (2) realtime analysis, and (3) the ability to differentiate ions with the same charge-to-mass ratio. A novel choice of multiple scintillators with different ion stopping powers results in a significant difference in energy deposition between the scintillators, allowing accurate particle identification in the GeV range. Here, we report a successful demonstration of particle identification for heavy ions, performed at the Heavy Ion Medical Accelerator in Chiba. In the experiment, the proposed detector setup showed the ability to differentiate particles with similar atomic numbers, such as C⁶⁺ and O⁸⁺ ions, and provided an excellent energy resolution of 0.41%-1.2% (including relativistic effect, 0.51%--1.6%).

Usefulness of echocardiographic parameters in predicting the incidence of ischemic stroke in Japanese patients with non-valvular atrial fibrillation

Background

Atrial fibrillation (AF) is a risk factor for ischemic stroke (IS). We developed a novel risk score of IS (HELT-E2S2 score) in non-valvular atrial fibrillation (NVAF) patients from the combined database of 5 major AF registries in Japan. However, this score does not include echocardiographic (Echo) parameters that have been reported to be risk factors of IS, such as left atrial diameter (LAD) enlargement or increased relative wall thickness (RWT) of left ventricle (LV).

Purpose

To investigate the predictive value of Echo parameters in Japanese patients with NVAF.

Methods

After excluding patients without the Echo data, 6,032 NVAF patients were analyzed in the present study. LAD was measured in the parasternal long axis view at the end-ventricular systole. RWT was calculated as (2x posterior wall thickness)/ LV end-diastolic dimension. We compared clinical characteristics and the incidence of IS between NVAF patients divided by LAD level (High/Low LAD group) and RWT level (High/Low RWT group). To balance the follow-up period among the registries, event data from individuals whose follow-up period exceeded 730 days were excluded from the analysis.

Results

The optimal cut-off value of LAD and RWT to predict the incidence of IS with the receiver operating characteristic analysis was 43.3 mm and 0.4167, respectively. Between the High/Low LAD groups (High LAD: n=2,640 vs. Low LAD: n=3,392), age (70.3±12.1 vs. 68.3±12.5 years; p&lt;0.001), CHA2DS2-VASc score (3.02±1.84 vs. 2.57±1.78; p&lt;0.001), HELT-E2S2 score (2.20±1.31 vs. 1.55±1.33; p&lt;0.001), the prescription of oral anticoagulants (OACs) (69.5 vs. 51.5%; p&lt;0.001), LV ejection fraction (60.4±13.4 vs. 64.4±10.7%; p&lt;0.001) and RWT (0.401±0.091 vs. 0.396±0.082; p=0.02) were significantly different. Between the High/Low RWT groups (High RWT: n=2,293 vs. Low RWT: n=3,739), percentage of female (35.6 vs. 27.8%; p&lt;0.001), age (71.2±12.1 vs. 68.0±12.4 years; p&lt;0.001), CHA2DS2-VASc score (3.08±1.82 vs. 2.58±1.79; p&lt;0.001), HELT-E2S2 score (2.10±1.39 vs. 1.67±1.31; p&lt;0.001), the prescription of OACs (62.6 vs. 57.4%; p&lt;0.001), LV ejection fraction (65.5±9.9 vs. 60.9±13.0%; p&lt;0.001) and LAD (43.0±8.1 vs. 42.4±8.3; p=0.004) were significantly different. In Kaplan-Meier analysis, the incidence of IS was different between the groups during the median follow-up period of 730 days (High LAD vs. Low LAD; 1.82 vs. 1.00 per 100 person-years; p&lt;0.001, by log-rank test, High RWT vs. Low RWT; 1.86 vs. 1.06; p&lt;0.001) (Figure). Both High LAD (hazard ratio: 1.65, 95% CI: 1.12–2.46; p=0.01) and High RWT (hazard ratio: 1.43, 95% CI: 1.01–2.04; p=0.045) were independent predictors of the incidence of IS after adjustment by the components of the HELT-E2S2 score and other clinically relevant variables including co-existing diseases, gender, and the prescription of OACs (Table).

Conclusion

Echo parameters, LAD and RWT, were independently associated with the incidence of IS among Japanese patients with NVAF.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical Research and Development

Prediction of recurrence after catheter ablation for atrial fibrillation using left atrial morphology on preprocedural computed tomography: application of radiomics

Background

Radiomics is a comprehensive analysis methodology of medical image and involves the extraction of numerous features from standard imaging. Its usefulness has been reported mainly in the field of cancer for diagnosis and prediction of prognosis. In the territory of cardiac imaging, several reports have investigated the utility of radiomics for classifying the risk of prognosis in coronary artery disease, and few practical applications have been reported for patients with atrial fibrillation (AF) who underwent pulmonary vein isolation (PVI). Although the left atrial morphology can affect the clinical course after the PVI procedure, it is unclear whether the radiomics feature values of the left atrial morphology on cardiac computed tomography (CT) is useful for predicting the AF recurrence after PVI.

Purpose

To predict the recurrence of AF after PVI using the radiomics feature values of the left atrial morphology on cardiac computed tomography (CT).

Methods

We analyzed 525 consecutive three-dimensional cardiac CT in patients with atrial fibrillation who underwent PVI from 2018 to 2019 in our institute. After marking the region of interest on left atrium (including the root of pulmonary veins) semiautomatically, 107 radiomics feature values were obtained by Python program. After excluding the parameters having collinearity or with low predictive capability for the recurrence of AF after PVI, 42 parameters were applied to the final prediction model. Two prediction models were constructed by multivariate Cox regression analysis and machine learning model by support vector machine algorithm.

Results

The area under the curve (AUC) for predicting the recurrence of AF was 0.815 for the multivariate Cox regression model and 0.826 for the machine learning model by support vector machine.

Conclusion

The radiomics feature values on preprocedural cardiac CT could be helpful for predicting the recurrence of AF after PVI. Since radiomics feature analysis yields a huge number of numerical values representing the left atrial morphology in a reproducible manner, it would provide a new direction to construct a good prediction model using machine learning including artificial intelligence out of a routine cardiac CT scan.

Funding Acknowledgement

Type of funding sources: None.

Derivation and validation of a machine learning-based risk prediction model for in-hospital mortality in patients with acute heart failure

Background

Although risk stratification is important in patients with acute heart failure (AHF) to predict patient prognosis, pre-existing risk models have not often been used due to its complexity. Recently, machine learning methods have been presented as an alternative approach to analyzing the predictive probability of large clinical datasets.

Purpose

The aim of this study is to develop a user-friendly risk score developed by one of machine learning methods and compare the performance of the new risk score to the existing conventional risk models.

Methods

A machine-learning-based risk model was developed using least absolute shrinkage and selection operator (LASSO) regression by identifying predictors of in-hospital mortality in the derivation cohort (REALITY-AHF) and externally validating and comparing its performance with two pre-existing risk models: the Get With The Guidelines risk score incorporating brain natriuretic peptide and hypochloremia (GWTG-BNP-Cl-RS) and the acute decompensated heart failure national registry (ADHERE) risk model.

Results

In-hospital deaths in the derivation and validation (NARA-HF) cohorts were 76 (5.1%) and 61 (4.9%), respectively. The risk score comprised four variables (systolic blood pressure, blood urea nitrogen, serum chloride, and C-reactive protein) and was developed according to the results of the LASSO regression weighting the coefficient for selected variables using a logistic regression model (4V-RS). Even though 4V-RS comprised fewer variables, In the validation cohort, it showed a higher area under the receiver operating characteristic curve (AUC) than the ADHERE risk model (AUC, 0.783 vs. 0.740; P=0.059) and a significant improvement in net reclassification (0.359; 95% CI, 0.10–0.67; p=0.006). 4V-RS performed similarly to GWTG-BNP-Cl-RS in terms of discrimination (AUC, 0.783 vs. 0.759; p=0.426) and net reclassification (0.176; 95% CI, −0.08–0.43; p=0.178).

Conclusions

The 4V-RS model comprising only four readily available data points at the time of admission performed similarly to the more complex pre-existing risk model in patients with AHF.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Cardiovascular Research Fund

Clinical phenotypes of older adults with non-valvular atrial fibrillation not treated with oral anticoagulants by hierarchical cluster analysis in the ANAFIE registry

Background and purpose

The All Nippon AF In the Elderly (ANAFIE) registry evaluated the current status of anticoagulant therapy in older adult patients (aged ≥75 years) with non-valvular atrial fibrillation (NVAF) in Japan. Although older adult NVAF patients requires anticoagulation therapy, some of them do not receive it and the reasons would be diverse. Therefore, we aimed to identify the phenotypes of older adult NVAF patients not treated with oral anticoagulants using data from the ANAFIE registry.

Methods

In this sub-analysis of the ANAFIE registry, the phenotypes of patients who were not receiving anticoagulants at baseline were evaluated by cluster analysis using Ward's linkage hierarchical algorithm. We used 20 categorical variables and 6 continuous variables for the cluster analysis which were used as the risk factors in the main analysis of the ANAFIE registry [1].

Results

Of 33,275 enrolled patients, 2445 (7.3%) were not receiving anticoagulants. Two clusters were identified: (1) elderly paroxysmal AF (PAF) patients with a low prevalence of comorbidities (58%) and (2) very elderly patients with a high previous major bleeding prevalence (42%). For each cluster, mean ages were 79.9 and 85.7 years, mean CHADS2 scores were 2.3 and 3.1, PAF prevalences were 83% and 54%, heart failure prevalences were 18% and 48%, the proportions of patients with a history of major bleeding were 0% and 25%, the proportions of patients with a history of catheter ablation were 21% and 8%, respectively. Annual incidence rates of each cluster were 2.62% and 9.08% for all-cause death, 1.72% and 5.83% for major adverse cardiovascular or neurological events, 1.22% and 3.14% for stroke or systemic embolism, and 0.53% and 1.43% for major bleeding.

Conclusions

In this cohort of elderly NVAF patients not receiving anticoagulants, more than half (∼60%) were PAF patients and had a low incidence of adverse outcomes. The remaining ∼40% were characterized as very elderly patients with a high prevalence of previous major bleeding and a high incidence of adverse outcomes.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Daiichi Sankyo Co., Ltd.

Prediction of persistent form of atrial fibrillation using left atrial morphology on preprocedural computed tomography: application of radiomics

Background

Radiomics is a comprehensive analysis methodology of medical image and involves the extraction of numerous features from standard imaging. Its usefulness has been reported mainly in the field of cancer for diagnosis and prediction of prognosis. In the territory of cardiac imaging, several reports have investigated the utility of radiomics for classifying the risk of prognosis in coronary artery disease, and few practical applications have been reported for patients with atrial fibrillation (AF) who underwent catheter ablation (CA).

Purpose

The objective of this study was to evaluate the utility of radiomics analysis applying to the preprocedural cardiac computerized tomography (CT) in AF patients.

Methods

We analyzed 525 consecutive three-dimensional CT in patients with AF who underwent CA. After marking the region of interest on left atrium (LA) (including the root of pulmonary veins) semiautomatically, 107 radiomics feature values were obtained by Python program. We calculated the amount of representative statistics for each radiomics feature for prediction of persistent AF (PeAF) (Wald statistic in logistic regression analysis) and LA diameter (LAD) (coefficient correlation), respectively. To compare the distribution of the two statistics, the relative importance (calculated as the ratio of statistic to the maximum statistics among 107 radiomics features [%]) was calculated for each statistic. Further, we compared the area under the curve (AUC) in receiver operation characteristic (ROC) curve analysis for predicting PeAF between radiomics features (multivariate model) and LAD (single parameter).

Results

In 525 study patients (age 63±10 years old and male 80%), 253 (48%) were PeAF and remaining were paroxysmal AF (PAF). LAD was 43±6 mm and 38±6 mm in patients with PeAF and PAF, respectively. The relative importance of the two statistics (Wald statistic for PeAF and coefficient correlation for LAD) of 107 radiomics features are displayed in Figure 1, which shows similar distribution of two statistics. It means the close relationship between LA morphology and the form of PeAF in AF patients and the radiomics features possibly well explain the relationship. In Figure 2, the predictive capability for PeAF was compared between radiomics feature values and LAD, where the AUC was 0.85 (95% confidence interval [CI], 0.82–0.88) and 0.73 (95% CI, 0.69–0.78) for radiomics feature values and LAD, respectively (Delong test, P&lt;0.001).

Conclusion

We applied the radiomics features for the evaluation of LA morphology. The predictive capability for PeAF in the prediction model with the radiomics feature values was much better than that with LAD alone. Since radiomics feature analysis yields a huge number of numerical values representing the LA morphology in a reproducible manner, it would provide a new direction to construct a good prediction model using machine learning including artificial intelligence out of a routine cardiac CT scan.

Funding Acknowledgement

Type of funding sources: None.

Anemia in female patients with myasthenia gravis

Myasthenia gravis (MG) is the most common autoimmune neuromuscular disorder, and is more common in women than in men. Anemia is also more common in women. The purpose of this study was to investigate factors associated with anemia and the negative impact of anemia in female MG patients. We investigated factors related to MG and anemia in 215 female patients with MG, who were attending the MG clinic of Keio Hospital between January and December 2021. We statistically evaluated clinical factors related to anemia in patients with and without anemia. Eighty-five patients (40%) had anemia in the past, and 130 patients did not have anemia in the past. There were no significant differences in age at study, age at MG onset, body mass index, or frequency of autoantibodies between the anemia and non-anemia groups. MG severity evaluated by the MG Foundation of America classification was greater in the anemia group than in the non-anemia group. History of anemia was associated with immunosuppressive treatment, such as prednisolone and calcineurin inhibitor treatment. There was a correlation between hemoglobin levels and the MG-quality of life score. Long term immunosuppressive therapy can cause anemia in female MG patients. Anemia may negatively affect the quality of life of female MG patients.

Effects of tourism promotion on COVID-19 spread: The case of the "Go To Travel" campaign in Japan

Introduction

On July 22, 2020, the Japanese government launched the "Go to Travel" campaign that subsidizes 50% of personal travel expenditure to support the tourism industry under the COVID-19 pandemic. This policy was controversial from the viewpoint of infection spread and was temporarily cancelled in December 2020, though there was no statistical evidence.

Methods

This is the first study that measures the extent to which this campaign increased COVID-19 cases. This study regards the campaign as a natural experiment: although Tokyo and its commuting areas experienced the same time-series trends of COVID-19 cases before the "Go To Travel" campaign, this campaign was implemented in areas outside Tokyo, but not in Tokyo. Then, the comparison (difference-in-differences) yields the campaign's effect.

Results

The estimation shows that the "Go To Travel" campaign significantly raised the increment rate of cases by 23.7%-34.4% during July 30-August 4. There is no significant effect after August 5. In addition, our simulation identified the number of campaign-related cases in each city.

Conclusions

Although the campaign significantly spread COVID-19, the effect was not continuous to permanently change the time-series trend.

Immunodeficiency in patients with thymoma-associated myasthenia gravis

Thymoma with immunodeficiency is sometimes accompanied by myasthenia gravis (MG), but the clinical characteristics have not been elucidated. This study aimed to characterize its clinical and immunological features. Of the 132 thymoma-associated MG patients, 9 patients presented with immunodeficiency. All suffered from severe pneumonia, and most had invasive thymoma and autoimmune disorders. DRB1*08:03 and DQB1*06:01 alleles were frequently detected. Compared to group without immunodeficiency, they showed no significant differences in the severity of MG, significantly lower IgG concentrations and higher mortality rate. Thymoma-associated MG with immunodeficiency is a distinct subset requiring special attention to prevent infection during the follow-up period.

Immunohistochemical Phenotype of T Cells Invading Muscle in Inclusion Body Myositis

Inclusion body myositis (IBM) is an inflammatory myopathy of aged people with poor response to therapy. To characterize muscle-invading inflammatory cells, we performed immunohistochemical and ultrastructural studies on muscle biopsies from 10 patients with IBM with durations of illness from 3 to 84 months. At the surface of muscle fibers, 79% and 48% of CD8+ cells were positive for killer cell lectin-like receptor subfamily G, member 1 (KLRG1) and CD57, respectively. CD8+KLRG1+ cells are highly differentiated cytotoxic cells. On an average, 27% of CD8-CD57+KLRG1+ cells at the surface were CD4+. Proportions of CD28+ cells among KLRG1+ cells showed a negative correlation with duration of illness (r = -0.68). These changes indicated progressive differentiation of CD8+ T cells. Moreover, PD-1 expression on CD57+ and CD8+ cells increased early, then fluctuated, and reincreased in later stages. PD ligand-1 (PD-L1) and PD-L2 were expressed on adjacent cells including muscle fibers. T cell large granular lymphocytes (LGLs) are potent effector cells and cells with ultrastructure indistinguishable from LGLs were seen in the sarcoplasm along with lymphocytes undergoing degeneration. Together, along the course of IBM, some inflammatory cells retained the potential for cytotoxicity whereas others indicated suppression by exhaustion, senescence, or through the PD-1 pathway.

P-131 The fate of irregularly divided blastomeres: why does “Direct cleavage” reduce blastocyst development rate but not blastocyst euploid rate?

Study question

How do the blastomeres formed by direct cleavage (dynamics of one cell dividing into three or more cells) subsequently develop?

Summary answer

About half of the blastomeres by direct cleavage did not form blastocysts.

What is known already

There are many reports that embryos with direct cleavage in the early development have a lower blastocyst development rate because direct cleavage produces chromosomal abnormal cells. However, when such embryos develop into blastocysts, there have been some reports that the transfer pregnancy rate and euploid rate did not decrease, but the reasons for this have not been clarified.

Study design, size, duration

This is a retrospective study of 89 blastocysts obtained during 2013-18. These embryos were those that patients requested to be discarded and consented to be used in this study. All target embryos were time-lapse monitored by EmbryoScope (Vitrolife, Sweden), and several trophectoderms were biopsied and examined for euploidy.

Participants/materials, setting, methods

The target embryos were classified into three groups: embryos with normal first and second cleavage (NC group), embryos with irregular division (one cell dividing into three or more cells) called direct cleavage at the first cleavage (DC1 group), and embryos with direct cleavage of one blastomere at the second cleavage (DC2 group). It was recorded whether the blastomeres of the embryos subsequently developed into blastocysts or not. NGS analysis was performed on the embryos.

Main results and the role of chance

The target embryos were classified as 48 in the NC group, 32 in the DC1 group, and 9 in the DC2 group. Whether the blastomeres in the target embryos subsequently formed blastocysts or not was recorded one by one by time-lapse images, resulting in the blastomeres’ blastocyst formation rate was 95.1% in the NC group and 55.9% in the DC1 group, which was significantly lower in the DC1 group (P &lt; 0.01). In the DC2 group, blastomeres formed by normal division and those by direct cleavage at the second cleavage were recorded separately, and the blastocyst formation rate was 90.8% for normal cleavage blastomeres and 46.0% for direct cleavage blastomeres, with significantly lower rates for direct cleavage blastomeres (P &lt; 0.01). Therefore, about half of the blastomeres generated by direct cleavage at the first or second cleavage did not form blastocysts. The results of NGS analysis were as follows: NC group: 35.4% euploid, 45.8% aneuploid, and 18.8% mosaic; DC1 group: 37.5%, 53.1%, and 9.4%, respectively; and DC2 group: 55.6%, 33.3%, and 11.1%, respectively. There was no significant difference in any of the items, suggesting that direct cleavage does not affect the euploidy of blastocysts.

Limitations, reasons for caution

For the purpose of NGS analysis, all the target embryos in this study were blastocysts, but if all the cultured embryos were included, arrested embryos would be included, which would probably result in more blastomeres formed by direct cleavage not developing into blastocysts.

Wider implications of the findings

The blastomeres generated by direct cleavage were often excluded from blastocyst formation. This may be an exclusion of chromosomally abnormal cells and may be one of the reasons why direct cleavage decreases blastocyst development rate but does not decrease blastocyst euploid rate.

Trial registration number

not applicable

First Application of Mass Measurements with the Rare-RI Ring Reveals the Solar r-Process Abundance Trend at A=122 and A=123

The Rare-RI Ring (R3) is a recently commissioned cyclotronlike storage ring mass spectrometer dedicated to mass measurements of exotic nuclei far from stability at Radioactive Isotope Beam Factory (RIBF) in RIKEN. The first application of mass measurement using the R3 mass spectrometer at RIBF is reported. Rare isotopes produced at RIBF-^{127}Sn, ^{126}In, ^{125}Cd, ^{124}Ag, ^{123}Pd-were injected in R3. Masses of ^{126}In, ^{125}Cd, and ^{123}Pd were measured whereby the mass uncertainty of ^{123}Pd was improved. This is the first reported measurement with a new storage ring mass spectrometry technique realized at a heavy-ion cyclotron and employing individual injection of the preidentified rare nuclei. The latter is essential for the future mass measurements of the rarest isotopes produced at RIBF. The impact of the new ^{123}Pd result on the solar r-process abundances in a neutron star merger event is investigated by performing reaction network calculations of 20 trajectories with varying electron fraction Y_{e}. It is found that the neutron capture cross section on ^{123}Pd increases by a factor of 2.2 and β-delayed neutron emission probability, P_{1  n}, of ^{123}Rh increases by 14%. The neutron capture cross section on ^{122}Pd decreases by a factor of 2.6 leading to pileup of material at A=122, thus reproducing the trend of the solar r-process abundances. The trend of the two-neutron separation energies (S_{2n}) was investigated for the Pd isotopic chain. The new mass measurement with improved uncertainty excludes large changes of the S_{2n} value at N=77. Such large increase of the S_{2n} values before N=82 was proposed as an alternative to the quenching of the N=82 shell gap to reproduce r-process abundances in the mass region of A=112-124.

Loss of IκBζ Drives Dentin Formation via Altered H3K4me3 Status

Enforced enrichment of the active promoter marks trimethylation of histone H3 lysine 4 (H3K4me3) and acetylation of histone H3 lysine 27 (H3K27ac) by inhibiting histone demethylases and deacetylases is positively associated with hard tissue formation through the induction of osteo/odontogenic differentiation. However, the key endogenous epigenetic modulator of odontoblasts to regulate the expression of genes coding dentin extracellular matrix (ECM) proteins has not been identified. We focused on nuclear factor (NF)-κB inhibitor ζ (IκBζ), which was originally identified as the transcriptional regulator of NF-κB and recently regarded as the NF-κB-independent epigenetic modulator, and found that IκBζ null mice exhibit a thicker dentin width and narrower pulp chamber, with aged mice having more marked phenotypes. At 6 mo of age, dentin fluorescent labeling revealed significantly accelerated dentin synthesis in the incisors of IκBζ null mice. In the molars of IκBζ null mice, marked tertiary dentin formation adjacent to the pulp horn was observed. Mechanistically, the expression of COL1A2 and COL1A1 collagen genes increased more in the odontoblast-rich fraction of IκBζ null mice than in wild type in vivo, similar to human odontoblast-like cells transfected with small interfering RNA for IκBζ compared with cells transfected with control siRNA in vitro. Furthermore, the direct binding of IκBζ to the COL1A2 promoter suppressed COL1A2 expression and the local active chromatin status marked by H3K4me3. Based on whole-genome identification of H3K4me3 enrichment, ECM and ECM organization-related gene loci were selectively activated by the knockdown of IκBζ, which consistently resulted in the upregulation of these genes. Collectively, this study suggested that IκBζ is the key negative regulator of dentin formation in odontoblasts by inhibiting dentin ECM- and ECM organization-related gene expression through an altered local chromatin status marked by H3K4me3. Therefore, IκBζ is a potential target for epigenetically improving the clinical outcomes of dentin regeneration therapies such as pulp capping.

Precise Measurement of Differential Cross Sections of the Σ^{-}p→Λn Reaction in Momentum Range 470-650 MeV/c

The differential cross sections of the Σ^{-}p→Λn reaction were measured accurately for the Σ^{-} momentum (p_{Σ}) ranging from 470 to 650  MeV/c at the J-PARC Hadron Experimental Facility. Precise angular information about the Σ^{-}p→Λn reaction was obtained for the first time by detecting approximately 100 reaction events at each angular step of Δcosθ=0.1. The obtained differential cross sections show a slightly forward-peaking structure in the measured momentum regions. The cross sections integrated for -0.7≤cosθ≤1.0 were obtained as 22.5±0.68 [statistical error(stat.)] ±0.65 [systematic error(syst.)] mb and 15.8±0.83(stat)±0.52(syst)  mb for 470<p_{Σ}(MeV/c)<550 and 550<p_{Σ}(MeV/c)<650, respectively. These results show a drastic improvement compared with past measurements of the hyperon-proton scattering experiments. They will play essential roles in updating the theoretical models of the baryon-baryon interactions.

A Comparison of Line Blots, Enzyme-linked Immunosorbent, and RNA-immunoprecipitation Assays of Antisynthetase Antibodies in Serum Samples from 44 Patients

Objective To determine the differences between anti-aminoacyl tRNA synthetase (ARS) antibodies among line blots, enzyme-linked immunosorbent assay (ELISA) anti-ARS tests, and RNA-immunoprecipitation (IP) assays. Methods Sera from patients with confirmed or suspected antisynthetase syndrome (ASS) that were positive for either the anti-ARS test or the line-blot assay were used to perform an RNA-IP assay and ELISA to detect individual anti-ARS antibodies. Results Among the 44 patients, 10 were positive only in line-blot assays, 6 were positive only in the anti-ARS test, and 28 were positive in both assays. We compared the accuracy of these assays against the gold standard RNA-IP assay. The κ coefficient was 0.23 in the line-blot assay, but this increased to 0.75 when the cut-off was increased from 1+ to 2+. The κ coefficient was 0.73 in the anti-ARS test. The κ coefficient was 0.85 for positivity in both assays. Patients with ASS that was positive in an RNA-IP assay more frequently had mechanic's hand (62.1% vs. 20%: p=0.031), myositis (51.7 vs. 10%: p=0.028) and more ASS symptoms than those who were positive only in line-blot assays (3.48 vs. 2.2: p=0.019). Conclusions Clinicians need to understand the features of each assay and determine diagnoses by also considering clinical presentations. Diagnoses should not be judged based only on the results of line-blot assays due to the risk of a misdiagnosis from false positives.

Recent progress and future prospects of hyperon nucleon scattering experiment

A new hyperon-proton scattering experiment, dubbed J-PARC E40, was performed to measure differential cross sections of the Σ+p, Σ−p elastic scatterings and the Σ−p → Λn scattering by identifying a lot of Σ particles in the momentum ranging from 0.4 to 0.8 GeV/c produced by the π±p → K+Σ± reactions. We successfully measured the differential cross sections of these three channels with a drastically improved accuracy with a fine angular step. These new data will become important experimental constraints to improve the theories of the two-body baryon-baryon interactions. Following this success, we proposed a new experiment to measure the differential cross sections and spin observables by using a highly polarized Λ beam for providing quantitative information on the ΛN interaction. The results of three Σp channels and future prospects of the Λp scattering experiment are described.

Cardio-renal protective effects of SGLT2 inhibitors in patients with type 2 diabetes mellitus and severely impaired renal function

Background

Prognostic impact of Sodium-Glucose Cotransporter 2 (SGLT2) inhibitors on cardiovascular and renal outcome was unknown in patients with type-2 diabetes mellitus (DM) and severely impaired renal function.

Methods

From July 2015 to December 2020, patients with type-2 DM who were taken SGLT2 inhibitors for more than six months were retrospectively screened. Patients with estimated glomerular filtration rate (eGFR) over 60ml/min/1.73m2 were excluded. We divided those patients into two groups by eGFR; less than 45ml/min/1,73m2 were group A and 46–60ml/min/m2 were group B. Randomly selected patients with DM not taking SGLT2 inhibitors and having severe renal dysfunction: eGFR less than 45ml/min/m2 (Group C) were set as controls. The primary outcome was a composite of cardiovascular/renal death, initiation of dialysis, doubling of the serum creatine level, decline in the eGFR more than 30%, nonfatal myocardial infraction, nonfatal stroke, and hospitalization for heart failure.

Results

Totally 418 patients were enrolled. Median age was 71 years (group A, n=106), 64 years (group B, n=115), and 77 years (group C, n=201) (p&lt;0.001). After median 24 months follow-up, primary endpoints were observed 24.5% in group A, 4.3% in group B, 36.8% in group C (p&lt;0.001). In Kaplan-Meier analysis, significantly lower incidence of primary endpoints were observed in SGLT2 groups (group A and B) than controls (p&lt;0.001, Figure 1). In patients with severe renal dysfunction, taking SGLT2 inhibitors tended to decrease future renal event (Figure 2). The incidence of SGLT2 related adverse events was not different between 2 groups (A and B).

Conclusions

Even in patients with severe renal dysfunction, SGLT2 inhibitors would have cardio-renal protective effects without drug-related adverse effects.

Funding Acknowledgement

Type of funding sources: None.