POS1183 RISK FACTORS FOR CYTOMEGALOVIRUS INFECTION IN PATIENTS WITH RHEUMATIC DISEASE; SINGLE-CENTER PROSPECTIVE COHORT STUDY

Background

Cytomegalovirus (CMV) infection is one of serious opportunistic infections for immunosuppressed patients, therefore, identifying patients at risk for CMV infection is of importance. However, no prospective study about CMV infection in systemic rheumatic disease has been reported.

Objectives

To identify risk factors relevant with CMV infection in patients with systemic rheumatic disease during intensive remission induction therapy.

Methods

Consecutive systemic rheumatic disease cases who started intensive immunosuppressive therapy from February 2017 until February 2019 were enrolled. Serum CMV-IgG was measured before the induction therapy, and subsequently, CMV pp65 antigen was monitored weekly. Patients were divided into 2 groups according to the presence or absence of CMV infection, and risk factors for CMV infection were analyzed.

Results

157 patients consisting of 136 CMV-IgG positive and 21 CMV-IgG negative patients were enrolled in the study. Mean age was 60.8 ± 17.4 y/o, and female was 70.7%. The underlying diseases were following; vasculitides 54, systemic lupus erythematosus 27, polymyositis/dermatomyositis 25, rheumatoid arthritis 14, IgG4-related disease 13, mixed connected tissue disease 6, Behçet disease 5, adult-onset Still’s disease 4, and others 9. The initial dose of glucocorticoid (GC) was 48.4 ± 11.5 mg/day (0.91 ± 0.16 mg/kg/day) as prednisolone (PSL) with additional methylprednisolone (mPSL) pulse therapy being conducted in 44 (28.0%). Concomitant immunosuppressive therapies were intravenous cyclophosphamide (IVCY) in 55, calcineurin inhibitor 27, mycophenolate mofetil 16, hydroxychloroquine 5, and methotrexate 4. Concomitant biological agents were rituximab 12, tocilizumab 6, infliximab 2, golimumab 1, and abatacept 1. CMV infection occurred in 52 patients (33.1%), and all of them were CMV-IgG positive before induction therapy (38.2% in the CMV-IgG positive patients). Univariable analysis revealed initial PSL dose >0.91 mg/kg/day (odds ratio [OR] 5.2, p<0.01), IVCY (OR 3.4, p<0.01), diabetes mellitus (OR 5.2, p<0.01), and a history of malignancy (OR 2.9, p=0.02) were independent risk factors for CMV infection. CMV antiviral drugs were administered in 22 patients (42.3%). At the first detection of CMV pp65 antigen, PSL dose ≥37.5 mg/day (OR 5294.8, p<0.01), CMV pp65 antigen-positive cells ≥2 cells/2 slides (OR 16.0, p = 0.04), and serum albumin levels <3.0 g/dL (OR 26.3, p=0.01) were associated with subsequent CMV antiviral drug administration.

Conclusion

CMV infection occurred only in CMV-IgG positive patients with systemic rheumatic diseases who were undergoing intensive remission induction therapy. CMV infection was related with treatment regimen and comorbidities, and the necessity of CMV antiviral treatment was predicted with prednisolone dose, the number of CMV pp65 antigen positive cells, and albumin levels at the first detection of CMV pp65 antigen.

Disclosure of Interests

None declared

POS0257 COMPARISON OF SARS-CoV-2 VACCINE RESPONSE IN PATIENTS WITH INFLAMMATORY RHEUMATIC DISEASE; mRNA-1273 VACCINE INDUCES HIGHER HUMORAL IMMUNOGENICITY THAN BNT162b2

Background

The SARS-CoV-2 messenger RNA (mRNA) vaccines BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) have benefitted all countries amid the coronavirus disease 2019 (COVID-19) crisis. Whereas both of them have shown efficacy in preventing COVID-19 illness in healthy participants, there is paucity of data about immunogenicity and safety of mRNA COVID-19 vaccines in patients with autoimmune, inflammatory rheumatic disease. Recent observational studies evaluated mainly BNT162b2, suggesting that glucocorticoids, immunosuppressive agents impair SARS-CoV-2 vaccine responses. However, difference in immune reactions and safety between BNT162b2 and mRNA-1273 have not been clarified in patients with inflammatory rheumatic diseases.

Objectives

To assess humoral and T cell immune responses and safety profiles after two doses of different mRNA vaccine against SARS-CoV-2; BNT162b2 and mRNA-1273.

Methods

We enrolled consecutive, previously uninfected patients with inflammatory rheumatic diseases receiving mRNA vaccine including BNT162b2 and mRNA-1273. Healthy participants receiving BNT162b2 were also recruited as control. Blood samples were obtained 3weeks, 2 months, 3 months, 4 months, and 6 months after second dose of vaccines. We measured titres of neutralizing antibodies against SARS-CoV-2 and calculated seroconversion rates to evaluate humoral responses. We also assessed T-cell immunity responses by using interferon releasing assay against SARS-CoV-2 in a part of the patients. Answers to questionnaires about adverse reactions were obtained from participants.

Results

A total of 974 patients with inflammatory rheumatic diseases and healthy 630 control participants were enrolled. Among them, 796 patients received BNT162b2, 178 patients received mRNA-1273, and all control participants received BNT162b2. Seroconversion rates and neutralizing antibody titres 3 weeks after vaccination were significantly higher in patients with mRNA-1273 and healthy participants with BNT162b2 compared with patients with BNT162b2; seroconversion rates, 97.2% vs 99.5% vs 83.3%, p<0.001; titers of neutralizing antibodies, 29.4±33.9 IU/mL vs 23.9±14.2 IU/mL vs 10.8±16.5 IU/mL, p<0.001, respectively. On another front, T cell reaction against SARS-CoV-2 was similar in both patients with mRNA-1273 and BNT162b2; interferon gamma levels for antigen 1, 1.2±2.1 IU/mL vs 0.8±2.5 IU/mL, p=0.23; and for antigen 2, 1.4±1.9 IU/mL vs 1.0±2.1 IU/mL, p=0.11, respectively. Regarding adverse reaction of each mRNA vaccine, the frequency of systemic adverse reactions including fever and general fatigue are also significantly higher in patients with mRNA-1273 and healthy controls than patients with BNT162b2; fever, 48.0% vs 44.9% vs 10.2%, p<0.001; general fatigue, 70.4% vs 61.8% vs 31.2%, p<0.001, respectively). In longitudinal measurement, neutralizing antibody titres in patients with BNT162b2 were decreased more rapidly than those in healthy controls; 3.3±3.2 IU/mL in patients with BNT162b2 at 4 months and 3.2±4.7 IU/mL in healthy controls with BNT162b2 at 6 months. We identified age, glucocorticoid dose (prednisolone > 7.5mg), use of immunosuppressants including methotrexate, mycophenolate, cyclophosphamide, and tacrolimus are associated with rapid attenuation of humoral responses in patients with BNT162b2.

Conclusion

Our results demonstrated a significant higher humoral immunogenicity and frequency of systemic adverse reaction of the SARS-CoV-2 mRNA-1273 (Moderna) compared with the BNT162b2 (Pfizer-BioNTech) in inflammatory rheumatic disease patients. Glucocorticoid and immunosuppressive agents impaired induction and sustention of neutralizing antibody, and earlier third booster vaccination may be required within 4 months, especially for those receiving BNT162b2.

References

[1]Steensels D, Pierlet N, Penders J et al. JAMA. 2021;326(15):1533–1535.

[2]Friedman MA, Curtis JR and Winthrop KL. Ann Rheum Dis 2021;80:1255–1265.

Disclosure of Interests

None declared

AB0443 LONG-TERM OUTCOMES OF MULTITARGET THERAPY OF MYCOPHENOLATE MOFETIL AND TACROLIMUS IN LUPUS NEPHRITIS: A SINGLE CENTER RETROSPECTIVE ANALYSIS

Background

Recent studies showed the efficacy of multitarget therapy with mycophenolate mofetil (MMF) and calcineurin inhibitor for induction therapy for lupus nephritis (LN)1. However, long-term outcomes have not been well elucidated.

Objectives

We retrospectively analyzed the long-term outcomes of multitarget therapy of MMF and tacrolimus.

Methods

We examined 27 LN patients (4 male, 23 female) treated with multitarget therapy for induction therapy between Oct. 2009 and Nov. 2018 in our department. Complete remission (CR) was defined as 1) UPCR<0.5 g/gCr, and 2) serum creatinine (S-Cr) normal or if abnormal, within 15% of baseline; 1) and 2) were observed in 2 consecutive visits. Relapse was defined as UPCR>1.0 g/gCr or intensification of immunosuppressive treatment after achievement of CR.

Results

The mean age was 38.6±11．6 years old. 17 patients were new-onset LN, and 10 patients were relapse LN. UPCR and eGFR before treatment were 4.42±2.98 g/gCr and 71.5±32.9 mL/min/1.73m2, respectively. Renal histology was Class III in 1, III+V in ４, IV in 12. IV+V in 9 and V in 1 by ISN/RPS 2003 classification. CR at 6 and 12 months were 59% and 74%, respectively. Patients were treated by multitarget therapy for median of 25 months (IQR, 5.5-37). Finally, 26 (96%) patients achieved CR. During multitarget therapy, there were 15 serious adverse events: deep vein thrombosis in 2, myocardial infarctions in 2, cervical intraepithelial neoplasia in 2, heart failure in 1, herpes zoster in 1, viral myocarditis in 1, cytomegalovirus gastroenteritis in 1, cholecystitis in 1, pyelonephritis in 1, bacterial enteritis in 1, sepsis in 1, and breast cancer in 1. During the median observation period of 94 months (IQR, 63-111.5) after the initiation of multitarget therapy, 1 patient died due to sudden death. No patient reached end-stage kidney disease or doubling S-Cr. 16 patients relapsed at median of 32 months (IQR,13.8-64.5) after CR; 8 patients relapsed on multitarget therapy, and 8 patients relapsed after cessation of multitarget therapy. Relapse was associated with chronic lesions in renal biopsy and normal or higher C4 levels at treatment initiation by Kaplan Meier analysis (Log-rank, P=0.006, P<0.001, respectively).

Conclusion

Multitarget therapy effectively induced CR and maintained renal function in long-term period. However, relapse was often observed during or after withdrawal of multitarget therapy.

References

[1]Liu Z, Zhang H, Liu Z, et al. Multitarget therapy for induction treatment of lupus nephritis: a randomized trial. Ann Int Med 2015; 162: 18-26.

Disclosure of Interests

Yoichi Imai: None declared, Hidekazu Ikeuchi: None declared, Junya Suwa: None declared, Yuko Ohishi: None declared, Mitsuharu Watanabe: None declared, Masao Nakasatomi: None declared, Hiroko Hamatani: None declared, Toru Sakairi: None declared, Yoriaki Kaneko: None declared, Keiju Hiromura Speakers bureau: Chugai, Astellas., Grant/research support from: Chugai, Astellas.

A new method for right ventricular lead implantation into the intraventricular septum

Funding Acknowledgements

Type of funding sources: None.

Background

Right ventricular (RV) lead placement into the interventricular septum is only accurate in 16–48% of cases under conventional fluoroscopic guidance. A previous report showed the importance of individualized left anterior oblique (LAO) projection to improve the success rate of RV lead placement into the interventricular septum. However, this procedure is complicated. We sought to investigate the preprocedural predictors of individualized LAO projection.

Methods

We assessed the relationship between preoperative electrocardiographic parameters and the angle of the interventricular septum obtained using thoracic computed tomography (CT).

Results

In the retrospective derivation cohort group (n=39), the mean angle of individualized LAO assessed by thoracic CT was 53.1±8.9°, and the preoperative electrocardiogram QRS axis was strongly correlated with the interventricular septum axis detected by thoracic CT (R2 = 0.490). In contrast, the preoperative electrocardiographic transitional zone was not associated with the interventricular septum axis (R2 = 0.041, P = 0.78). Using individual LAO projection derived from the preoperative electrocardiogram QRS axis, it was confirmed that the RV lead was placed in the interventricular septum during the pacemaker procedure in the prospective internal validation group (n=30). The success rate for placing the RV lead into the interventricular septum was significantly improved in the internal validation cohort group (93% vs. 64%, P &lt; 0.05). In addition, the N-terminal pro-brain natriuretic peptide level decreased significantly after surgery in the interventricular septal indwelling group.

Conclusions

Individualized LAO angle derived from the preoperative electrocardiogram QRS axis is a new useful and simple method for RV lead implantation into the interventricular septum.

Safety verification of carbon-ion radiotherapy for patients with cardiac implantable electronic devices (CIEDs)

According to guidelines, carbon-ion beam therapy is considered to carry a high safety risk for patients with cardiac implantable electronic devices (CIEDs), although the actual impacts remain unclear. In this study, we investigated the safety of carbon-ion beam therapy in patients with CIEDs. Patients with CIEDs who underwent carbon-ion therapy at Gunma University Heavy Ion Medical Center between June 2010 and December 2019 were identified and investigated for abnormalities in the operation of their CIEDs, such as oversensing and resetting during irradiation, and abnormalities in operation after treatment. In addition, the risk of irradiation from carbon-ion beam therapy was evaluated by model simulations. Twenty patients (22 sites) with CIEDs were identified, 19 with pacemakers and one with an implantable cardioverter-defibrillator (ICD). Treatments were completed without any problems, except for one case in which the treatment was discontinued because of worsening of the primary disease. Monte Carlo simulation indicated that the carbon beam irradiation produced neutrons at a constant and high level in the irradiation field. Nevertheless, with the distances between the CIEDs and the irradiation fields in the analyzed cases, the quantity of neutrons at the CIEDs was lower than that within the irradiation. Although carbon-ion beam therapy can be safely administered to patients with CIEDs, it is advisable to perform the therapy with sufficient preparation and backup devices because of the risks involved.

Acute Myocarditis Associated with COVID-19 Vaccination: A Case Report

Recently, new vaccine platforms-including mRNA vaccines for coronavirus disease 2019 (COVID-19) have been given emergency use authorization in Japan. Here, we present a rare case of myocarditis following a COVID-19 vaccine. In this case, myocarditis was confirmed by cardiac magnetic resonance imaging, endomyocardial biopsy, and troponin levels. The degree of myocardial inflammation in the endomyocardial biopsy samples was mild and the patient's clinical course was not severe. Although the pathology of myocarditis in this case was mild, further investigation would be needed.

<Learning objective: Vaccination for coronavirus disease 2019 is advancing worldwide, but post-vaccination myocarditis is getting attention as a rare side effect. Although the myocarditis in this case was mild, the pathogenesis of the disease is unclear and needs to be thoroughly investigated in the vaccination.>

Fast-slow atrioventricular nodal reentrant tachycardia phenotype mimicking the slow-slow type

Background

Fast-slow (F/S-) atrioventricular (AV) nodal reentrant tachycardia (AVNRT) is characterized by a short atrio-His (AH) interval and the earliest site of atrial activation (EAA) in the proximal coronary sinus (EAA-CS), while slow-slow (S/S-) AVNRT presents a long AH interval and EAA-CS. Those intracardiac appearances are initial indicators for making a diagnosis.

Purpose

To identify an unknown phenotype of F/S-AVNRT.

Methods

Among 46 consecutive patients with F/S-AVNRT, 6 patients (1 man, age 59±9) had an apparent but not typical (pseudo-) S/S-AVNRT during an electrophysiologic study. In 2 patients, pseudo-S/S-AVNRT was clinically documented.

Results

In all 6 patients, the diagnosis of F/S-AVNRT was made by an exclusion of atrial tachycardia with findings of 1) a V-A-V response following ventricular entrainment or 2) termination without atrial capture by ventricular pacing, and an exclusion of AV reentrant tachycardia with a ventriculoatrial dissociation during an initial (so-called QRS transition) zone of ventricular entrainment. An initial A-A-V activation sequence on atrial induction of F/S-AVNRT observed in 1 patient and Wenckebach-type AV block during ongoing F/S-AVNRT developing in 3 patients suggested the presence of the lower common pathway (LCP). Like the typical S/S-AVNRT, pseudo-S/S-AVNRT was induced with atrial stimulation after a jump in the AH interval or double ventricular response. However, in all patients, the pseudo-S/S-AVNRT transited to F/S-AVNRT following AV block in a single cycle and/or pseudo-S/S-AVNRT transited from spontaneously or triggered by atrial contractions. Importantly, on these transitions, the atrial cycle length (CL) and EAA-CS remained unchanged, that is, the atrial CL of S/S-AVNRT was almost identical to that of F/S-AVNRT, suggesting that the essential circuit of both tachycardias was identical. Actually, both tachycardias were cured by ablation at a single site in the traditional slow pathway (SP). Collectively, the pseudo-S/S-AVNRT was diagnosed as another phenotype of F/S-AVNRT accompanied by sustained antegrade conduction via another bystander (likely the left-sided or superior) SP breaking through the His bundle owing to the repetitive antegrade block at the LCP occurring by linking phenomenon, thus representing a long AH interval during the ongoing F/S-AVNRT. When the antegrade conduction is blocked at the bystander SP during the pseudo-S/S-AVNRT, releasing the linking phenomenon, the subsequent antegrade conduction reach the His-bundle via the fast pathway, thus returning to F/S-AVNRT.

Conclusions

An unknown, but not rare F/S-AVNRT phenotype exists that apparently mimics the typical S/S-AVNRT and is also an unknown subtype of apparent S/S-AVNRT. The presence of this pseudo-S/S-AVNRT suggests the limitation of classifying types of AVNRT based on AH and HA intervals during tachycardia. Understandings of this phenotype can advance a diagnosis of atypical AVNRT with multiple phenotypes.

Funding Acknowledgement

Type of funding sources: None.

Pacing site- and rate-dependent shortening of retrograde conduction time over the slow pathway after atrial entrainment of fast-slow atrioventricular nodal reentrant tachycardia

Introduction

We tested our hypothesis that atrial entrainment pacing (EP) of a) the common‐type (com‐) fast‐slow (F/S‐) atypical atrioventricular nodal reentrant tachycardia (AVNRT) using a typical slow pathway (SP), or b) the superior‐type (sup‐) F/S‐AVNRT using a superior SP, both modify the retrograde conduction time across the SP immediately after termination of EP (retro‐SP‐time).

Methods

We measured the difference in the His‐atrial interval (HA difference) immediately after cessation of EP, performed at 2 ± 2 rates from the high right atrium (HA[1]‐HRA) versus from the proximal coronary sinus (HA[1]‐CS) in 17 patients with com‐F/S‐AVNRT and 11 patients with sup‐F/S‐AVNRT. We also measured the atrial‐His and HA intervals of the first and second cycles immediately after cessation of EP and during stable tachycardia.

Results

Unequal responses, defined as a ≥ 20‐ms HA difference at ≥1 EP rates, were observed in 16 patients (57%), including 7 with com‐ and 9 with sup‐F/S‐AVNRT. Irrespective of the EP rate, all unequal responses of com‐F/S‐AVNRT were due to a shorter HA[1]‐CS than HA[1]‐HRA, with a mean 34 ± 11 ms HA difference, whereas all unequal responses of sup‐F/S‐AVNRT were due to a longer HA[1]‐CS than HA[1]‐HRA, with a mean 49 ± 25 ms HA difference. The unequal responses resolved within two cycles after the cessation of EP.

Conclusions

We have identified a little‐known pacing site‐ and pacing rate‐dependent shortening of the retro‐SP‐time.

Unilateral Lung Congestion During Exercise in a Patient With a Single Pulmonary Vein Stenosis

A 55-year-old man underwent exercise stress echocardiography for evaluation of left inferior pulmonary vein stenosis. During exercise, ultrasound B-lines developed in the left lung only. Unilateral pulmonary congestion did not lead to forward or backward failure. The patient was followed up conservatively. (Level of Difficulty: Beginner.).

AB0145 SMARTPHONE- AND SMARTWATCH-ACQUIRED DAILY STEPS, ACTIVITY, AND BAROMETRIC PRESSURES ASSOCIATED WITH SUBJECTIVE MEASURES OF RHEUMATOID ARTHRITIS: A PROSPECTIVE STUDY FOR RA DIGITAL PHENOTYPING

Background:

Symptoms in patients with rheumatoid arthritis (RA) are potentially influenced by exercise load and meteorological change, and often vary from day to day, especially in unstable condition of RA. Patients with RA not infrequently experience worsening of joint symptoms when the load on the joint, such as walking and doing housework, exceeds a moderate range. However, the worsening of joint symptoms is often not observed in the midst of the loading of the joint, but often becomes apparent after a few hours or days.

Objectives:

To elucidate the relationship between smartphone- and smartwatch-acquired daily objective data (barometric pressures, steps, and activity) and daily subjective patient reported outcomes of RA.

Methods:

A smartphone (iPhone 8) and a wristband-type smartwatch (Fitbit Versa 2) were lent to each patient for free. A mobile app was developed and installed into the smartphones to collect patients’ daily subjective RA symptoms including Pt-P-VAS (patient-pain-visual analogue scale), Pt-G-VAS (pt-general-VAS), PtTJCount(68)(patient self-determined tender joint count among 68 joints), PtTJCount(28), PtSJCount(66)(patient self-determined swollen joint count among 66 joints), PtSJCount(28). Also, the smartwatch data and physicians’ assessment were collected from the same subject. Physicians’ and patients’ assessment of TJC, SJC, and G-VAS was independently performed without seeing each other’s assessment.

We conducted a simple linear regression analysis with outcome variables of Pt-P-VAS, Pt-G-VAS, PtTJCount(68), PtTJCount(28), PtSJCount(66), and PtSJCount(28). The independent variables included smartphone-acquired daily steps and barometric pressure of the reported day and the previous day, and smartwatch-acquired minutes of “lightly active (1-3 METs equivalent)”, “fairly active(3-6 METs equivalent)”, and “very active(>6 METs equivalent)” of the reported day and previous day. We defined low barometric pressure as below 1000 hPa. The level of activity was measured by the smartwatch. Patients were blinded to daily barometric pressure data and their daily active time when the patients answered daily symptom questions on the smartphones.

Results:

A total of five patients were enrolled. At baseline, mean (± standard deviation (SD)) age was 50.8±14.8 years; all patients were females; mean disease duration was 6.6±4.9 years; mean SDAI was 18.6±25.5; mean DAS28-CRP was 3.23±1.85; mean morning stiffness was 134±116 min; mean HAQ-DI was 0.7±0.9. Mean observation period was 77.8 days. Because of the missing data, the sample size (N) for the regression analysis varies with the outcomes: Pt-P-VAS and Pt-G-VAS are 250 while PtTJCount and PtSJCount are 260.

The table 1 showed that the patients’ assessment of TJC, SCJ, and G-VAS was correlated well with the physicians’ assessment.

Table 1.Evaluation itemCorrelation between physicians and patients (ρ)Tender Joint Count (68)0.909Tender Joint Count(28)0.913Swollen Joint Count(66)0.896Swollen Joint Count(28)0.890General VAS0.688

The figure 1 showed the change associated with one SD increment in each independent variable with 90% confidence intervals. Low barometric pressure was associated with bad health conditions (high Pt-G-VAS, Pt-P-VAS, and SJCount). Moreover, longer very active time in the previous day (“veryactive_1” in the Figure 1) was associated with bad health condition (high SJCount). Many steps were associated with good health conditions (low Pt-G-VAS, Pt-P-VAS, and SJCount).

Figure 1.

Conclusion:

High barometric pressure was associated with good health conditions, and longer very active time in the previous day was associated with bad health condition. Barometric pressure data and physical activity data acquired by mobile digital devices may predict the change in RA symptoms. Further investigation in larger patient numbers is warranted.

Acknowledgements:

The authors would like to thank Harumi Kondo for her assistance.

Disclosure of Interests:

Keisuke Izumi Speakers bureau: Abbvie, Asahi Kasei Pharma, Bristol Myers Squibb, Chugai Pharmaceutical, Eli-Lily, Mochida Pharmaceutical, Ono Pharmaceutical, Grant/research support from: Abbvie, Asahi Kasei Pharma, Daisuke Moriwaki Employee of: CyberAgent, Inc., Takamichi Toda Employee of: AI Shift, Inc., Misako Higashida-Konishi: None declared, Manami Koyama: None declared, Hisaji Oshima: None declared, yutaka okano Speakers bureau: Asahi Kasei Pharma, Yuko Kaneko Speakers bureau: AbbVie, Astellas, Ayumi, Bristol–Myers Squibb, Chugai, Eisai, Eli Lilly, Hisamitsu, Jansen, Kissei, Kirin, Novartis, Pfizer, Sanofi, Takeda, Taisho, Tanabe-Mitsubishi, and UCB, Shigeru Ko: None declared, Tsutomu Takeuchi Speakers bureau: Abbott Japan Co, Ltd, Bristol–Myers KK, Chugai Pharmaceutical Co, Ltd, Eisai Co, Ltd, Janssen Pharmaceutical KK, Mitsubishi Tanabe Pharma Co, Pfizer Japan Inc, Takeda Pharmaceutical Co, Ltd, Astellas Pharma and Daiichi Sankyo Co, Ltd., Consultant of: Astra Zeneca KK, Eli Lilly Japan KK, Novartis Pharma KK, Mitsubishi Tanabe Pharma Co, Asahi Kasei Medical KK, Abbvie GK and Daiichi Sankyo Co, Ltd., Grant/research support from: Abbott Japan Co, Ltd, Astellas Pharma, Bristol-Myers KK, Chugai Pharmaceutical Co, Ltd, Daiichi Sankyo Co, Ltd, Eisai Co, Ltd, Janssen Pharmaceutical KK, Mitsubishi Tanabe Pharma Co, Pfizer Japan Inc, Sanofi–Aventis KK, Santen Pharmaceutical Co, Ltd, Takeda Pharmaceutical Co, Ltd, Teijin Pharma Ltd, Abbvie GK, Asahikasei Pharma Corp and Taisho Toyama Pharmaceutical Co, Ltd.

AB0253 COMPARISON OF PHARMACODYNAMICS OF METHOTREXATE AS METHOTREXATE-POLYGLUTAMATES CONCENTRATIONS IN RHEUMATOID ARTHRITIS; INTERIM DATA EVALUATION OF MIRACLE STUDY CONDUCTED IN JAPAN, KOREA AND TAIWAN

Background:

Methotrexate (MTX) is the first-line therapy for rheumatoid arthritis (RA). The concentrations of MTX-polyglutamates (PG) in erythrocytes, an active form of MTX, are useful markers for the optimal usage of MTX in patients with RA. The concentrations of MTX-PG have been reported to be different between Japanese and Caucasians. However, the difference among Asian ethnicity remains unclear.

Objectives:

To examine MTX-PG concentrations in association with MTX dose during the first 24 weeks after the initiation of MTX for newly diagnosed RA patients in Japan, Korea and Taiwan.

Methods:

MIRACLE study is a multicenter, open-label, randomized, 48 weeks interventional study conducted in Japan, Korea and Taiwan to evaluate non-inferiority of low dose to high dose of MTX as an add-on therapy to adalimumab in 300 patients with RA who do not achieve remission after 24 weeks MTX monotherapy in stipulated dosage. In the first 24 weeks, MTX was started at 6 to 8 mg/week for newly diagnosed RA patients, and promptly escalated to the maximum tolerable dose in 12 weeks in principle. This interim data evaluation was intended to investigate the differences among countries in the relationship between MTX dose, safety and MTX-PG concentrations in erythrocytes during the first 24 weeks. The efficacy of the treatment is not included at this point.

Results:

A total of 166 patients (106 in Japan, 35 in Korea, 25 in Taiwan) were included in this interim data. The age at treatment initiation was 57.2 years old on average and female was 79.5%. The time course changes in total and individual MTX-PG levels differed in the three countries. At 24 weeks, whereas the mean total MTX-PG concentrations were comparable (112.9 nmol/L in Japan, 104.4 nmol/L in Korea, and 115.7 nmol/L in Taiwan) with a dose of MTX of 12.3 mg/week, 14.1 mg/week, and 12.2 mg/week, respectively, the individual MTX-PG concentrations were different. The MTX-PG1 and MTX-PG2 concentrations were lower in Korea than Japan and Taiwan whereas MTX-PG3, MTX-PG4 and MTX-PG5 concentrations were the highest in Korea.

Conclusion:

The distribution of short-chain and long-chain MTX-PG concentrations were various among Asian countries despite similar dose of MTX administration: NCT03505008.

Disclosure of Interests:

Hiroya Tamai: None declared, Yuko Kaneko Speakers bureau: AbbVie, Astellas, Ayumi, Bristol–Myers Squibb, Chugai, Eisai, Eli Lilly, Hisamitsu, Jansen, Kissei, Kirin, Pfizer, Sanofi, Takeda, Tanabe-Mitsubishi, and UCB., Grant/research support from: Sanofi, Hideto Kameda Speakers bureau: AbbVie, Pfizer, Consultant of: AbbVie, Grant/research support from: AbbVie, Eisai, Masataka Kuwana Speakers bureau: Astellas, Asahi Kasei Pharma, Boehringer- Ingelheim, Chugai, Eisai, Janssen, Mochida, Nippon Shinyaku, Ono Pharmaceuticals, Pfizer, Mitsubishi-Tanabe, Consultant of: Corbus, Grant/research support from: AbbVie, Asahi Kasei Pharma, Boehringer- Ingelheim, Chugai, Eisai, MBL, Nippon Shinyaku, Ono Pharmaceuticals, Mitsubishi-Tanabe, Yutaka Okano: None declared, Tomonori Ishii Speakers bureau: Chugai, Mitsubishi- Tanabe, Glaxo Smith Kline, Pfizer, Eli Lilly, Janssen, AbbVie, Eisai, Astellas, Kei Ikeda Speakers bureau: AbbVie, Eli Lilly, Novartis, Mitsubishi-Tanabe, Eisai, BMS, Grant/research support from: Mitsubishi-Tanabe, Hiroaki Taguchi: None declared, Shinji Sato: None declared, Toshiaki Miyamoto: None declared, Shintaro Hirata Speakers bureau: AbbVie, Asahi Kasei Pharma, Astellas, Ayumi, Bristol Myers Squibb, Chugai, Eisai, Eli Lilly, Janssen, Glaxo Smith Kline, Kissei, Pfizer, Sanofi, Mitsubishi- Tanabe, UCB, Paid instructor for: AbbVie, Mitsubishi- Tanabe, Consultant of: AbbVie, Eisai, Gilead, Grant/research support from: AbbVie, Chugai, Mitsubishi-Tanabe, UCB, Hidekata Yasuoka Speakers bureau: AbbVie, Asahi Kasei Pharma, Astellas, Daiichi- Sankyo, Eisai, Kissei, Takeda, Mitsubishi- Tanabe, Chugai, Novartis, Eli Lilly, Pfizer, Janssen, Sanofi, Teijin, Boehringer- Ingelheim, Bayer, Glaxo Smith Kline, Paid instructor for: AbbVie, Consultant of: AbbVie, Asahi Kasei, Grant/research support from: Mitsubishi-Tanabe, Takeda, Daiichi-Sankyo, Chugai, Bristol-Myers, MSD, Astellas, Toshihisa Kojima Speakers bureau: AbbVie, Pfizer, Eisai, Grant/research support from: AbbVie, Sung-Hwan Park: None declared, Kichul Shin: None declared, Han Joo Baek: None declared, Yun Jong Lee Grant/research support from: research fund, In Ah Choi Speakers bureau: Abbvie, Eizai, Grant/research support from: Abbvie, Eizai, Jinhyun Kim: None declared, Ping-Ning Hsu: None declared, Chang-Fu Kuo: None declared, Chun-Ming Huang Paid instructor for: AbbVie, Pfizer, Meng-Yu Weng Consultant of: AbbVie, Wan-Yu Sung: None declared, Wen-Chan Tsai: None declared, Tien-Tsai Cheng Paid instructor for: AbbVie, Grant/research support from: AbbVie, Takehiro Taninaga Shareholder of: Eisai Co., Ltd., Employee of: Eisai Co., Ltd., Masahiko Mori Shareholder of: Eisai Co., Ltd., Employee of: Eisai Co., Ltd., Hideaki Miyagishi Employee of: Eisai Co., Ltd., Yasunori Sato: None declared, Tsutomu Takeuchi Speakers bureau: Astellas, Abbvie, Daiichi Sankyo, Ayumi, Eisai, GlaxoSmithKline, Mitsubishi Tanabe, Chugai, Novartis, Eli Lilly, Pfizer, Bristol Myers Squibb, Janssen, UCB, TaishoToyama, Sanofi–Aventis, Nipponkayaku, Taiho, Gilead, Boehringer Ingelheim, Grant/research support from: Asahikasei, Astellas, Abbvie, Daiichi Sankyo, Ayumi, Eisai, Takeda, Mitsubishi Tanabe, Chugai, Eli Lilly, UCB, Sanofi–Aventis, Nipponkayaku, Boehringer Ingelheim

POS0975 CLINICAL CHARACTERISTICS OF NONRADIOGRAPHIC AXIAL SPONDYLOARTHRITIS IN ASIAN COUNTRIES COMPARED TO OTHER REGIONS: RESULTS OF THE INTERNATIONAL CROSS-SECTIONAL ASAS-COMOSPA STUDY

Background:

Clinical characteristics of nonradiographic axial spondyloarthritis (nr-ax-SpA) are highly variable across patients, and may potentially vary across patient populations, particularly due to differing distributions of human leukocyte antigens (HLA) and other genetic factors. The majority of nr-ax-SpA studies have been conducted in Europe, the United States, and small studies are reported from Asia [1].

Objectives:

To delineate clinical characteristics of patients with nr-ax-SpA in Asian countries in comparison to other areas of the world.

Methods:

Utilizing the ASAS-COMOSPA data, an international cross-sectional observational study of SpA patients, we analyzed information on demographics, disease characteristics, comorbidities, and risk factors. Patients were classified by region: Asia (China, Japan, Singapore, South Korea, and Taiwan), and non-Asian countries (Europe, Americas, and Africa); patient characteristics, including diagnosis and treatment, were compared.

Results:

Among 3984 SpA patients included in the study, 1094 were from centers in Asian countries, and 2890 from other regions. 112/780 (14.4%) of axial SpA patients in Asian countries were nr-ax-SpA, substantially less than in other countries (486/1997, 24.3%). Nr-ax-SpA patients in Asian countries compared to nr-ax-SpA in other countries were more likely male (75.9 vs 47.1%), have onset (22.8 vs 27.8 years) and diagnosis (27.2 vs 34.5 years) at younger age, and experience less diagnostic delay (1.88 vs 2.92 years) (Table 1). Nr-ax-SpA patients in Asian countries have higher prevalence of positive HLA-B27 (90.6% vs 61.9%) and fewer peripheral signs such as arthritis, enthesitis, or dactylitis (53.6% vs 66.3%) but have similar rate of extra-articular manifestations (psoriasis, IBD, or uveitis) and co-morbidities. Disease activity, functional impairment, and inflammation on MRI were less in nr-ax-SpA patients in Asian countries. NSAIDs response was higher and use of methotrexate and b-DMARDs were lower among nr-ax-SpA in Asian countries.

Conclusion:

Among axial SpA patients, substantially lower frequency of nr-ax-SpA was observed in Asian countries compared to other regions of the world. Nr-ax-SpA patients in Asian countries were predominantly male, and had younger disease onset with higher HLA-B27 positivity rate and less peripheral signs, and better response to NSAIDs. These results offer an opportunity to improve both early diagnosis and treatment of nr-ax-SpA patients in Asian countries.

Table 1.

Characteristics of nonradiographic axial SpA in Asia versus non-Asian regions

VariablesAsianon-Asian regionsp valueN112486Age at disease diagnosis, yrs27.2 [21.1, 39.6]34.5 [27.7, 41.7]<0.001Diagnostic delay, yrs1.88 [0.27, 5.56]2.92 [0.59, 9.58]0.011Male (%)85 (75.9)229 (47.1)<0.001Sacroiliitis on MRI among tested (%)49 (67.1)341 (82.2)0.005HLA B27 positivity among measured (%)96 (90.6)273 (61.9)<0.001Inflammatory Back Pain (%)107 (95.5)478 (98.4)0.076Arthritis, enthesitis, or dactylitis (%)60 (53.6)322 (66.3)0.016Psoriasis (%)12 (10.7)82 (16.9)0.142Uveitis (%)20 (17.9)81 (16.7)0.870Inflammatory bowel disease (%)5 (4.5)27 (5.6)0.817Elevated CRP (%)37 (33.0)213 (43.8)0.048Physician global assessment (0-10)2.0 [1.0, 5.0]2.0 [1.0, 4.0]0.741Patient global assessment (0-10)3.0 [1.0, 6.0]4.0 [2.0, 6.0]0.012ASDAS-CRP1.40 [0.95, 2.08]1.97 [1.21, 2.78]<0.001BASFI0.8 [0.05, 2.65]2.9 [0.8, 5.6]<0.001Good response to NSAIDs (%)80 (71.4)272 (56.0)0.004Methotrexate use (%)18 (16.1)134 (27.6)0.016Biological DMARDs use (%)27 (24.1)191 (39.3)0.004

References:

[1]López-Medina C, Ramiro S, van der Heijde D, et al. Characteristics and burden of disease in patients with radiographic and non-radiographic axial Spondyloarthritis: a comparison by systematic literature review and meta-analysis. RMD Open. 2019 Nov 21;5(2): e001108.

Acknowledgements:

This study was conducted under the umbrella of the International Society for Spondyloarthritis Assessment (ASAS) and COMOSPA study was supported by unrestricted grants from Pfizer, AbbVie and UCB.

Disclosure of Interests:

Keisuke Ono: None declared, Mitsumasa Kishimoto Speakers bureau: AbbVie, Amgen-Astellas BioPharma, Asahi-Kasei Pharma, Astellas, Ayumi Pharma, BMS, Chugai, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Janssen, Kyowa Kirin, Novartis, Ono Pharma, Pfizer, Tanabe-Mitsubishi, Teijin Pharma, and UCB Pharma, Consultant of: AbbVie, Amgen-Astellas BioPharma, Asahi-Kasei Pharma, Astellas, Ayumi Pharma, BMS, Chugai, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Janssen, Kyowa Kirin, Novartis, Ono Pharma, Pfizer, Tanabe-Mitsubishi, Teijin Pharma, and UCB Pharma, Sho Fukui: None declared, Satoshi Kawaai: None declared, Gautam A. Deshpande: None declared, Kazuki Yoshida Consultant of: OM1, Inc., Grant/research support from: Corrona, LLC, Naomi Ichikawa: None declared, Yuko Kaneko Speakers bureau: AbbVie, Astellas, Ayumi, Bristol-Myers Squibb, Chugai, Eisai, Eli Lilly, Hisamitsu, Jansen, Kissei, Pfizer, Sanofi, Takeda, Tanabe-Mitsubishi, and UCB, Taku Kawasaki: None declared, Kazuo Matsui: None declared, Mitsuhiro Morita: None declared, Kurisu Tada: None declared, Naoho Takizawa: None declared, Naoto Tamura: None declared, Atsuo Taniguchi: None declared, Yoshinori Taniguchi: None declared, Shigeyoshi Tsuji: None declared, Shigeto Kobayashi: None declared, Masato Okada: None declared, Clementina López-Medina: None declared, Anna Moltó Consultant of: AbbVie, Pfizer, MSD, Novartis, Gilead, Lilly and UCB, Grant/research support from: AbbVie, Pfizer, MSD, Novartis, Gilead, Lilly and UCB, Désirée van der Heijde Consultant of: AbbVie, Amgen, Astellas, AstraZeneca, Bayer, BMS, Boehringer Ingelheim, Celgene, Cyxone, Daiichi, Eisai, Eli-Lilly, Galapagos, Gilead, Glaxo-Smith-Kline, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sanofi, Takeda, UCB Pharma, Employee of: Imaging Rheumatology bv. (Director), Maxime Dougados: None declared, Yoshinori Komagata: None declared, Tetsuya Tomita: None declared, Shinya Kaname: None declared.

AB0660 COVID-19 SHARES CLINICAL FEATURES WITH ANTI-MELANOMA DIFFERENTIATION ASSOCIATED PROTEIN 5 POSITIVE DERMATOMYOSITIS AND ADULT STILL’S DISEASE

Background:

The coronavirus disease 2019 (COVID-19), caused by a novel corona virus named SARS-CoV-2, has emerged as a global pandemic. Severe inflammatory process is one of main pathogenesis of COVID-19 and this involves cytokine storm along with overactivation of macrophage. On another front, cytokine storm with macrophage activation is frequently observed in various connective tissue diseases including dermatomyositis with positive antimelanoma differentiation-associated protein 5 (anti-MDA5) autoantibodies and adult Still’s disease. Macrophage activation during inflammatory states is partially characterized by an increased serum ferritin levels and hyperferritinaemia and characteristics shared by the three diseases are a topic of interest to rheumatologists, however, no study has evaluated anti-MDA5-positive dermatomyositis and adult Still’s disease in comparison to COVID-19.

Objectives:

The aim of this study was to highlight the homology and heterogeneity of COVID-19, anti-MDA5 dermatomyositis, and adult Still’s disease by comparing clinical pictures of each disease in order to discuss their respective pathogeneses.

Methods:

We reviewed consecutive, newly diagnosed, untreated patients with COVID-19, anti-MDA5 dermatomyositis, or adult Still’s disease. We compared their clinical, laboratory, and radiological characteristics, including the prevalence of macrophage activation syndrome and lung involvement in each disease.

Results:

The numbers of patients with COVID-19, anti-MDA5 dermatomyositis, and adult-onset Still’s disease with hyperferritinaemia (serum ferritin ≥ 500ng/dL) who were included for main analysis were 22, 14, and 59, respectively. COVID-19 and adult Still’s disease both featured hyperinflammatory status, such as high fever and elevated serum C-reactive protein, whereas COVID-19 and anti-MDA5 dermatomyositis both presented with severe interstitial lung disease and hypoxaemia. While two-thirds of the patients in each group met the criteria for macrophage-activated syndrome that is used in systemic juvenile idiopathic arthritis, the HScore, an indicator of haemophagocytic lymphohistiocytosis, was low in anti-MDA5 dermatomyositis and COVID-19 even in severe or critical cases. The findings of chest computed tomography were similar between COVID-19 and anti-MDA5 dermatomyositis (Figure 1).

Conclusion:

COVID-19 shared clinical features with rheumatic diseases characterised by hyperferritinaemia, including anti-MDA5 dermatomyositis and adult Still’s disease. These findings should be investigated further in order to shed light on the pathogenesis of not only COVID-19 but also the aforementioned rheumatic diseases.

References:

[1]Mehta P, McAuley DF, Brown M, et al. COVID-19: consider cytokine storm syndromes and immunosuppression. Lancet. (2020) 395: 1033-4.

[2]Gono T, Sato S, Kawaguchi Y, et al. Anti-MDA5 antibody, ferritin and IL-18 are useful for the evaluation of response to treatment in interstitial lung disease with anti-MDA5 antibody-positive dermatomyositis. Rheumatology (Oxford). 2012; 51(9):1563-70.

Figure 1.

Imaging characteristics of chest CT scans in patients with COVID-19, anti-MDA5 dermatomyositis, and adult Still’s disease A)Bilateral ground-glass and consolidative opacities with peripheral distribution in COVID-19. B)Bilateral ground-glass opacities with peripheral consolidations in anti-MDA5 dermatomyositis. C)Pleural effusion with pleural thickening on the left side in adult Still’s disease.

Disclosure of Interests:

Yasushi Kondo: None declared., Yuko Kaneko: None declared., Hisoshi Takei: None declared., Hiroya Tamai: None declared., Tsutomu Takeuchi Grant/research support from: received research grants outside the submitted work from Abbvie, Astra Zeneca, Bristol Myers Squibb, Chugai Pharmaceutical, Eisai Pharmaceutical, Janssen Pharmaceutical, Mitsubishi Tanabe Pharma Corporation, Novartis, Takeda Pharmaceutical, Abbott Japan Co., Ltd., Astellas Pharma, Ltd., Daiichi Sankyo, Pfizer, Sanofi–Aventis, Santen Pharmaceutical, Teijin Pharma Ltd., Asahikasei Pharma Corp., SymBio Pharmaceuticals Ltd., Celtrion, Nipponkayaku Co. Ltd., Eli Lilly Japan, and Taisho Toyama Pharmaceutical.

Towards Mutation-Specific Precision Medicine in Atypical Clinical Phenotypes of Inherited Arrhythmia Syndromes

Most causal genes for inherited arrhythmia syndromes (IASs) encode cardiac ion channel-related proteins. Genotype-phenotype studies and functional analyses of mutant genes, using heterologous expression systems and animal models, have revealed the pathophysiology of IASs and enabled, in part, the establishment of causal gene-specific precision medicine. Additionally, the utilization of induced pluripotent stem cell (iPSC) technology have provided further insights into the pathophysiology of IASs and novel promising therapeutic strategies, especially in long QT syndrome. It is now known that there are atypical clinical phenotypes of IASs associated with specific mutations that have unique electrophysiological properties, which raises a possibility of mutation-specific precision medicine. In particular, patients with Brugada syndrome harboring an SCN5A R1632C mutation exhibit exercise-induced cardiac events, which may be caused by a marked activity-dependent loss of R1632C-Nav1.5 availability due to a marked delay of recovery from inactivation. This suggests that the use of isoproterenol should be avoided. Conversely, the efficacy of β-blocker needs to be examined. Patients harboring a KCND3 V392I mutation exhibit both cardiac (early repolarization syndrome and paroxysmal atrial fibrillation) and cerebral (epilepsy) phenotypes, which may be associated with a unique mixed electrophysiological property of V392I-Kv4.3. Since the epileptic phenotype appears to manifest prior to cardiac events in this mutation carrier, identifying KCND3 mutations in patients with epilepsy and providing optimal therapy will help prevent sudden unexpected death in epilepsy. Further studies using the iPSC technology may provide novel insights into the pathophysiology of atypical clinical phenotypes of IASs and the development of mutation-specific precision medicine.

Multiple arrhythmic and cardiomyopathic phenotypes associated with an SCN5A A735E mutation

BACKGROUND

SCN5A mutations are associated with multiple arrhythmic and cardiomyopathic phenotypes including Brugada syndrome (BrS), sinus node dysfunction (SND), atrioventricular block, supraventricular tachyarrhythmias (SVTs), long QT syndrome (LQTS), dilated cardiomyopathy and left ventricular noncompaction. Several single SCN5A mutations have been associated with overlap of some of these phenotypes, but never with overlap of all the phenotypes.

OBJECTIVE

We encountered two pedigrees with multiple arrhythmic phenotypes with or without cardiomyopathic phenotypes, and sought to identify a responsible mutation and reveal its functional abnormalities.

METHODS

Target panel sequencing of 72 genes, including inherited arrhythmia syndromes- and cardiomyopathies-related genes, was employed in two probands. Cascade screening was performed by Saner sequencing. Wild-type or identified mutant SCN5A were expressed in tsA201 cells, and whole-cell sodium currents (I_Na) were recorded using patch-clamp techniques.

RESULTS

We identified an SCN5A A735E mutation in these probands, but did not identify any other mutations. All eight mutation carriers exhibited at least one of the arrhythmic phenotypes. Two patients exhibited multiple arrhythmic phenotypes: one (15-year-old girl) exhibited BrS, SND, and exercise and epinephrine-induced QT prolongation, the other (4-year-old boy) exhibited BrS, SND, and SVTs. Another one (30-year-old male) exhibited all arrhythmic and cardiomyopathic phenotypes, except for LQTS. One male suddenly died at age 22. Functional analysis revealed that the mutant did not produce functional I_Na.

CONCLUSIONS

A non-functional SCN5A A735E mutation could be associated with multiple arrhythmic and cardiomyopathic phenotypes, although there remains a possibility that other unidentified factors may be involved in the phenotypic variability of the mutation carriers.

Reduced current density, partially rescued by mexiletine, and depolarizing shift in activation of SCN5A W374G channels as a cause of severe form of Brugada syndrome

BACKGROUND

SCN5A-related Brugada syndrome (BrS) can be caused by multiple mechanisms including trafficking defects and altered channel gating properties. Most SCN5A mutations at pore region cause trafficking defects, and some of them can be rescued by mexiletine (MEX).

OBJECTIVE

We recently encountered symptomatic siblings with BrS and sought to identify a responsible mutation and reveal its biophysical defects.

METHODS

Target panel sequencing was performed. Wild-type (WT) or identified mutant SCN5A was transfected into tsA201 cells. After incubation of transfected cells with or without 0.1 mM MEX for 24-36 hr, whole-cell sodium currents (I_Na ) were recorded using patch-clamp techniques.

RESULTS

The proband was 29-year-old male who experienced cardiopulmonary arrest. Later, his 36-year-old sister, who had been suffering from recurrent episodes of syncope since 12 years, was diagnosed with BrS. An SCN5A W374G mutation, located at pore region of domain 1 (D1 pore), was identified in both. The peak density of W374G-I_Na was markedly reduced (WT: 521 ± 38 pA/pF, W374G: 60 ± 10 pA/pF, p < .01), and steady-state activation (SSA) was shifted to depolarizing potentials compared with WT-I_Na (V_1/2 -WT: -39.1 ± 0.8 mV, W374G: -30.9 ± 1.1 mV, p < .01). Incubation of W374G-transfected cells with MEX (W374G-MEX) increased I_Na density, but it was still reduced compared with WT-I_Na (W374G-MEX: 174 ± 19 pA/pF, p < .01 versus W374G, p < .01 versus WT). The SSA of W374G-MEX-I_Na was comparable to W374G-I_Na (V_1/2 -W374G-MEX: -31.6 ± 0.7 mV, P = NS).

CONCLUSIONS

Reduced current density, possibly due to a trafficking defect, and depolarizing shift in activation of SCN5A W374G are underlying biophysical defects in this severe form of BrS. Trafficking defects of SCN5A mutations at D1 pore may be commonly rescued by MEX.

Novel Diagnostic Observations of Nodoventricular/Nodofascicular Pathway-Related Orthodromic Reciprocating Tachycardia Differentiating From Atrioventricular Nodal Re-Entrant Tachycardia

OBJECTIVES

This study sought to assess the performance of current diagnostic criteria and identify additional electrophysiological features differentiating orthodromic reciprocating tachycardia (ORT) with a concealed nodoventricular/nodofascicular (NV/NF) pathway from atrioventricular nodal re-entrant tachycardia (AVNRT).

BACKGROUND

Diagnosing sustained supraventricular tachycardia (SVT) despite the occurrence of ventriculoatrial block (VAB) is challenging.

METHODS

We analyzed electrograms of 25 sustained SVTs (9 NV/NF-ORTs [n = 7/2] and 16 AVNRTs) with VAB and 91 AVNRTs without VAB (for reference).

RESULTS

More than 1 SVT, each with a different ventriculoatrial interval, was commonly induced in AVNRT cases (75%) but not in NV/NF-ORT cases (0%; p = 0.0005). Wenckebach VAB was common in NV/NF-ORTs (78%), but VAB patterns varied in AVNRTs. The His-His interval transiently prolonged in the following beat after the VAB in most AVNRTs but rarely did in NV/NF-ORTs (79% vs. 22%; p = 0.01). NV/NF-ORT was diagnosed by His-refractory premature ventricular contractions (n = 5) and the findings during right ventricular overdrive pacing showing an uncorrected/corrected post-pacing interval (PPI)-tachycardia cycle length (TCL) ≤115/110 ms (n = 5/5), orthodromic His capture (n = 6), and V-V-A (ventricle-ventricle-atrial response) response (n = 3). A single form of induced SVT (positive predictive value [PPV]: 69%; negative predictive value [NPV]: 100%), Wenckebach VAB (PPV: 70%; NPV: 87%), stable His-His interval despite VAB (PPV: 70%; NPV: 85%), orthodromic His capture (PPV: 100%; NPV: 97%), and V-V-A response (PPV: 100%; NPV: 95%) characterized NV/NF-ORT, and a PPI-TCL of ≤125 ms (PPV: 100%; NPV: 100%) characterized NV-ORT.

CONCLUSIONS

Induction of a single SVT form, Wenckebach VAB, stable His-His interval despite VAB, orthodromic His capture, and V-V-A response appeared to discriminate NV/NF-ORT from AVNRT, with a PPI-TCL of ≤125 ms discriminating NV-ORT from NF-ORT and AVNRT.

Topological Kagome Magnet Co3Sn2S2 Thin Flakes with High Electron Mobility and Large Anomalous Hall Effect

Magnetic Weyl semimetals attract considerable interest not only for their topological quantum phenomena but also as an emerging materials class for realizing quantum anomalous Hall effect in the two-dimensional limit. A shandite compound Co₃Sn₂S₂ with layered kagome-lattices is one such material, where vigorous efforts have been devoted to synthesize the two-dimensional crystal. Here, we report a synthesis of Co₃Sn₂S₂ thin flakes with a thickness of 250 nm by chemical vapor transport method. We find that this facile bottom-up approach allows the formation of large-sized Co₃Sn₂S₂ thin flakes of high-quality, where we identify the largest electron mobility (∼2600 cm² V^-1 s^-1) among magnetic topological semimetals, as well as the large anomalous Hall conductivity (∼1400 Ω^-1 cm^-1) and anomalous Hall angle (∼32%) arising from the Berry curvature. Our study provides a viable platform for studying high-quality thin flakes of magnetic Weyl semimetal and stimulate further research on unexplored topological phenomena in the two-dimensional limit.

Superior-Type Fast-Slow Atrioventricular Nodal Reentrant Tachycardia Phenotype Mimicking the Slow-Fast Type

BACKGROUND

Superior-type fast-slow (sup-F/S-) atrioventricular nodal reentrant tachycardia (AVNRT) is a rare AVNRT variant using a superior slow pathway (SP) as the retrograde limb. Its intracardiac appearance, characterized by a short atrio-His (AH) interval and the earliest site of atrial activation in the His-bundle, is an initial indicator for making a diagnosis.

METHODS

Among 22 consecutive patients with sup-F/S-AVNRT, 3 (age, 68-81 years) patients had an apparent slow-fast (S/F-) AVNRT characterized by a long AH interval and the earliest site of atrial activation in or superior to the His-bundle region (tachy-long-AH).

RESULTS

The diagnosis of sup-F/S-AVNRT was based on the standard criteria in 2 patients and on the occurrence of Wenckebach-type atrioventricular block during tachycardia, which was attributable to a block at the lower common pathway (LCP) below the circuit of the AVNRT, detected owing to the lower common pathway potentials, in one patient. As with the typical S/F-AVNRT, tachy-long-AH was induced after a jump in the AH interval. In contrast to typical S/F-AVNRT, fluctuation in the ventriculoatrial interval was observed during the tachy-long-AH. Ventricular overdrive pacing was unable to entrain or terminate the tachy-long-AH. Moreover, the tachy-long-AH reciprocally transited to/from sup-F/S-AVNRT spontaneously or was triggered by ventricular contractions while the atrial cycle length and earliest site of atrial activation remained unchanged. Both tachycardias were cured by ablation at a single site in the right-side para-Hisian region of 2 patients and the noncoronary aortic cusp of one patient. Collectively, the essential circuit of both tachycardias was identical, and the tachy-long-AH was diagnosed as another phenotype of sup-F/S-AVNRT accompanied by sustained antegrade conduction via another bystander slow pathway breaking through the His-bundle owing to the repetitive antegrade block at the lower common pathway, thus representing a long AH interval during the ongoing sup-F/S-AVNRT.

CONCLUSIONS

An unknown sup-F/S-AVNRT phenotype exists that apparently mimics the typical S/F-AVNRT and is also an unknown subtype of apparent S/F-AVNRT.

Giant magneto-optical responses in magnetic Weyl semimetal Co3Sn2S2

The Weyl semimetal (WSM), which hosts pairs of Weyl points and accompanying Berry curvature in momentum space near Fermi level, is expected to exhibit novel electromagnetic phenomena. Although the large optical/electronic responses such as nonlinear optical effects and intrinsic anomalous Hall effect (AHE) have recently been demonstrated indeed, the conclusive evidence for their topological origins has remained elusive. Here, we report the gigantic magneto-optical (MO) response arising from the topological electronic structure with intense Berry curvature in magnetic WSM Co₃Sn₂S₂. The low-energy MO spectroscopy and the first-principles calculation reveal that the interband transitions on the nodal rings connected to the Weyl points show the resonance of the optical Hall conductivity and give rise to the giant intrinsic AHE in dc limit. The terahertz Faraday and infrared Kerr rotations are found to be remarkably enhanced by these resonances with topological electronic structures, demonstrating the novel low-energy optical response inherent to the magnetic WSM.

Novel Cardiocerebral Channelopathy Associated with a KCND3 V392I Mutation

While a KCND3 V392I mutation uniquely displays a mixed electrophysiological phenotype of Kv4.3, only limited clinical information on the mutation carriers is available. We report two teenage siblings exhibiting both cardiac (early repolarization syndrome and paroxysmal atrial fibrillation) and cerebral phenotypes (epilepsy and intellectual disability), in whom we identified the KCND3 V392I mutation. We propose a link between the KCND3 mutation with a mixed electrophysiological phenotype and cardiocerebral phenotypes, which may be defined as a novel cardiocerebral channelopathy.

Role of the voltage sensor module in Nav domain IV on fast inactivation in sodium channelopathies: The implication of closed-state inactivation

The segment 4 (S4) voltage sensor in voltage-gated sodium channels (Na_vs) have domain-specific functions, and the S4 segment in domain DIV (DIVS4) plays a key role in the activation and fast inactivation processes through the coupling of arginine residues in DIVS4 with residues of putative gating charge transfer center (pGCTC) in DIVS1-3. In addition, the first four arginine residues (R1-R4) in Na_v DIVS4 have position-specific functions in the fast inactivation process, and mutations in these residues are associated with diverse phenotypes of Na_v-related diseases (sodium channelopathies). R1 and R2 mutations commonly display a delayed fast inactivation, causing a gain-of-function, whereas R3 and R4 mutations commonly display a delayed recovery from inactivation and profound use-dependent current attenuation, causing a severe loss-of-function. In contrast, mutations of residues of pGCTC in Na_v DIVS1-3 can also alter fast inactivation. Such alterations in fast inactivation may be caused by disrupted interactions of DIVS4 with DIVS1-3. Despite fast inactivation of Na_vs occurs from both the open-state (open-state inactivation; OSI) and closed state (closed-state inactivation; CSI), changes in CSI have received considerably less attention than those in OSI in the pathophysiology of sodium channelopathies. CSI can be altered by mutations of arginine residues in DIVS4 and residues of pGCTC in Na_vs, and altered CSI can be an underlying primary biophysical defect of sodium channelopathies. Therefore, CSI should receive focus in order to clarify the pathophysiology of sodium channelopathies.