Nintedanib-Induced Renal Thrombotic Microangiopathy

Nintedanib is a unique tyrosine kinase inhibitor used to suppress fibrosis in patients with idiopathic pulmonary fibrosis (IPF). Nintedanib has been shown to suppress multiple processes of fibrosis, thereby reducing the rate of lung function decline in patients with IPF. Since vascular endothelial growth factor is one of this agent's targets, nephrotoxicity, including renal thrombotic microangiopathy (TMA), is a possible major adverse effect. However, only 2 previous cases of nintedanib-induced renal TMA have been published. Our patient was an 83-year-old man with IPF. As adverse effects including liver enzyme level elevation, diarrhoea, anorexia, and nephrotoxicity developed, the nintedanib dosage was reduced after 9 months. The digestive symptoms resolved promptly, but the proteinuria and reduced kidney function remained. Although the kidney injury had improved to some extent, we performed a percutaneous renal biopsy. The biopsy revealed typical TMA findings such as microaneurysms filled with pale material, segmental double contours of glomerular basement membranes, and intracapillary foam cells. After discontinuation of nintedanib, the patient's nephrotoxicity improved. Nintedanib-induced renal TMA is reversible and is possibly dose-dependent. Here, we report the clinical course of our case and review the characteristics of nintedanib-induced renal TMA.

Angiotensin-converting enzyme inhibitor prevents skeletal muscle fibrosis in diabetic mice

NEW FINDINGS

What is the central question of this study? We questioned whether an angiotensin-converting enzyme (ACE) inhibitor prevents skeletal muscle fibrosis in diabetic mice. What is the main finding and its importance? Administration of ACE inhibitor prevents the increase in skeletal muscle fibrosis during the early phase after induction of diabetes by streptozotocin. Our findings might provide a new therapeutic target for skeletal muscle abnormalities in diabetes.

ABSTRACT

Fibrosis is characterized by the excessive production and accumulation of extracellular matrix components, including collagen. Although the extracellular matrix is an essential component of skeletal muscle, fibrosis can have negative effects on muscle function. Skeletal muscle fibrosis was shown to be increased in spontaneously hypertensive rats and to be prevented by an angiotensin-converting enzyme (ACE) inhibitor, an antihypertensive drug, in dystrophic mice or a mouse model of myocardial infarction. In this study, we therefore analysed whether (1) there is increased skeletal muscle fibrosis in streptozotocin (STZ)-induced diabetic mice, and (2) a preventive effect on skeletal muscle fibrosis by administration of an ACE inhibitor. Skeletal muscle fibrosis was significantly increased in STZ-induced diabetic mice compared with control mice from 2 to 14 days post-STZ. The ACE inhibitor prevented both skeletal muscle fibrosis and the reduction in muscle function in STZ-treated mice. Our study demonstrated that administration of an ACE inhibitor prevents the increase in skeletal muscle fibrosis during the early phase after onset of diabetes. Our findings might provide a new therapeutic target for skeletal muscle abnormalities in diabetes. Future studies are required to clarify whether skeletal muscle fibrosis is also linked directly to physical activity.

POS0824 THE LONG-TERM CLINICAL COURSE OF MUSCULAR VASCULITIS DEPENDING ON THE ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY STATUS: A RETROSPECTIVE OBSERVATIONAL STUDY

Background:

Skeletal muscle is known as one of the organ involvements of primary systemic vasculitis.1,2 Muscle inflammation is detected by magnetic resonance imaging, and necrotizing vasculitis is proved by muscle biopsy.3 As with systemic vasculitis or single organ vasculitis, glucocorticoid (GC) and immunosuppressants are used in its treatment.4 There are not many reports about muscular vasculitis, and its long-term clinical course after initial treatment, including the rates of relapse and mortality, remains unclear.

Objectives:

To identify the predictors of relapse and mortality in patients with muscular vasculitis, especially focusing on the status of anti-neutrophil cytoplasmic antibody (ANCA).

Methods:

We retrospectively reviewed patients diagnosed with necrotizing vasculitis with muscle involvements in our hospital between 2004 and 2020. In all cases, muscular vasculitis was identified by muscle biopsy or magnetic resonance imaging. To focus on the clinical features of muscular vasculitis, we excluded patients with such severe organ involvements as cardiovascular, abdominal, cerebral, severe renal, and severe pulmonary involvements. We compared the 5-year cumulative incidence of relapse, the overall survival rate, and the dose of GC over 5 years between the ANCA-positive and ANCA-negative groups. A relapse was defined as any new or worsened state of disease activity requiring an escalation of GC dose. Gray’s method was used for assessing the cumulative incidence of relapse. The log-rank test was used for assessing overall survival. The Mann-Whitney U test was used for assessing the dose of GC. The possible factors for relapse in 5 years in a univariate analysis were selected for a multivariate analysis using the Cox proportional hazards model.

Results:

Forty-nine patients were enrolled. The median age of onset was 77 (69-82) years and 71.4% were women. There were 30 ANCA-positive patients (90.0% with anti-myeloperoxidase) and 19 ANCA-negative patients. The median age and the number of patients with renal involvements were higher in the ANCA-positive group than in the ANCA-negative group (73.0 ± 9.29 years vs. 79.5 ± 20.28 years, p=0.0062 and 7/30 [23.3%] vs. 0/19 [0.0%], p=0.034, respectively). The Birmingham Vasculitis Activity Score (ver. 3), the induction dose of GC, and the rate of immunosuppressants use were not significantly different between the two groups. During the observational period, 24 patients relapsed. The 5-year cumulative incidence of relapse was significantly higher in the ANCA-positive group than in the ANCA-negative group (p=0.026) (Figure 1). The Cox proportional hazards model revealed that the presence of ANCA was an independent risk factor for relapse (hazard ratio: 3.15; 95% confidence interval 1.06–9.38; p=0.040). During the observational period, 9 patients died (3 died from cancer, 1 from interstitial pneumonia, 1 from cerebral hemorrhage, 1 from infection, and 3 from unknown reasons). The ANCA-positive group exhibited a higher mortality rate than the ANCA-negative group without a statistical significance (p=0.12). The 5-year cumulative dose of GC was larger in the ANCA-positive group than in the ANCA-negative group without a statistical significance (14786 [11246–19138] mg vs. 10088 [7129–12634] mg, p=0.12).

Conclusion:

In muscular vasculitis, the presence of ANCA is an independent risk factor for long-term relapse. Stratified treatment depending on the ANCA status may reduce the relapse rate and the occurrence of side effects of GC in patients with muscular vasculitis.

References:

[1]Kitching AR et al. Nat Rev Dis Primers 2020; 6(1): 71.

[2]Hernández-Rodríguez J et al. J Autoimmun 2014; 48-49: 84-9.

[3]Ushiyama S et al. Rheumatol Int 2020; 40(10): 1667-74.

[4]Ganeshanandan LR et al. Semin Arthritis Rheum 2020; 50(3): 503-8.

Disclosure of Interests:

None declared

Premedication with pioglitazone prevents doxorubicin-induced left ventricular dysfunction in mice

BACKGROUND

Doxorubicin (DOX) is widely used as an effective chemotherapeutic agent for cancers; however, DOX induces cardiac toxicity, called DOX-induced cardiomyopathy. Although DOX-induced cardiomyopathy is known to be associated with a high cumulative dose of DOX, the mechanisms of its long-term effects have not been completely elucidated. Pioglitazone (Pio) is presently contraindicated in patients with symptomatic heart failure owing to the side effects. The concept of drug repositioning led us to hypothesize the potential effects of Pio as a premedication before DOX treatment, and to analyze this hypothesis in mice.

METHODS

First, for the hyperacute (day 1) and acute (day 7) DOX-induced dysfunction models, mice were fed a standard diet with or without 0.02% (wt/wt) Pio for 5 days before DOX treatment (15 mg/kg body weight [BW] via intraperitoneal [i.p.] administration). The following 3 treatment groups were analyzed: standard diet + vehicle (Vehicle), standard diet + DOX (DOX), and Pio + DOX. Next, for the chronic model (day 35), the mice were administrated DOX once a week for 5 weeks (5 mg/kg BW/week, i.p.).

RESULTS

In the acute phase after DOX treatment, the percent fractional shortening of the left ventricle (LV) was significantly decreased in DOX mice. This cardiac malfunction was improved in Pio + DOX mice. In the chronic phase, we observed that LV function was preserved in Pio + DOX mice.

CONCLUSIONS

Our findings may provide a new pathophysiological explanation by which Pio plays a role in the treatment of DOX-induced cardiomyopathy, but the molecular links between Pio and DOX-induced LV dysfunction remain largely elusive.

Impact of Inadequate Calorie Intake on Mortality and Hospitalization in Stable Patients with Chronic Heart Failure

Malnutrition is highly prevalent in patients with heart failure (HF), but the precise impact of dietary energy deficiency on HF patients' clinical outcomes is not known. We investigated the associations between inadequate calorie intake and adverse clinical events in 145 stable outpatients with chronic HF who had a history of hospitalization due to worsening HF. To assess the patients' dietary pattern, we used a brief self-administered diet-history questionnaire (BDHQ). Inadequate calorie intake was defined as <60% of the estimated energy requirement. In the total chronic HF cohort, the median calorie intake was 1628 kcal/day. Forty-four patients (30%) were identified as having an inadequate calorie intake. A Kaplan-Meier analysis revealed that the patients with inadequate calorie intake had significantly worse clinical outcomes including all-cause death and HF-related hospitalization during the 1-year follow-up period versus those with adequate calorie intake (20% vs. 5%, p < 0.01). A multivariate logistic regression analysis showed that inadequate calorie intake was an independent predictor of adverse clinical events after adjustment for various factors that may influence patients' calorie intake. Among patients with chronic HF, inadequate calorie intake was associated with an increased risk of all-cause mortality and rehospitalization due to worsening HF. However, our results are preliminary and larger studies with direct measurements of dietary calorie intake and total energy expenditure are needed to clarify the intrinsic nature of this relationship.

Inhibition of xanthine oxidase in the acute phase of myocardial infarction prevents skeletal muscle abnormalities and exercise intolerance

AIMS

Exercise intolerance in patients with heart failure (HF) is partly attributed to skeletal muscle abnormalities. We have shown that reactive oxygen species (ROS) play a crucial role in skeletal muscle abnormalities, but the pathogenic mechanism remains unclear. Xanthine oxidase (XO) is reported to be an important mediator of ROS overproduction in ischaemic tissue. Here, we tested the hypothesis that skeletal muscle abnormalities in HF are initially caused by XO-derived ROS and are prevented by the inhibition of their production.

METHODS AND RESULTS

Myocardial infarction (MI) was induced in male C57BL/6J mice, which eventually led to HF, and a sham operation was performed in control mice. The time course of XO-derived ROS production in mouse skeletal muscle post-MI was first analysed. XO-derived ROS production was significantly increased in MI mice from Days 1 to 3 post-surgery (acute phase), whereas it did not differ between the MI and sham groups from 7 to 28 days (chronic phase). Second, mice were divided into three groups: sham + vehicle (Sham + Veh), MI + vehicle (MI + Veh), and MI + febuxostat (an XO inhibitor, 5 mg/kg body weight/day; MI + Feb). Febuxostat or vehicle was administered at 1 and 24 h before surgery, and once-daily on Days 1-7 post-surgery. On Day 28 post-surgery, exercise capacity and mitochondrial respiration in skeletal muscle fibres were significantly decreased in MI + Veh compared with Sham + Veh mice. An increase in damaged mitochondria in MI + Veh compared with Sham + Veh mice was also observed. The wet weight and cross-sectional area of slow muscle fibres (higher XO-derived ROS) was reduced via the down-regulation of protein synthesis-associated mTOR-p70S6K signalling in MI + Veh compared with Sham + Veh mice. These impairments were ameliorated in MI + Feb mice, in association with a reduction of XO-derived ROS production, without affecting cardiac function.

CONCLUSION

XO inhibition during the acute phase post-MI can prevent skeletal muscle abnormalities and exercise intolerance in mice with HF.

Cardiac-specific loss of mitoNEET expression is linked with age-related heart failure

Heart failure (HF) occurs frequently among older individuals, and dysfunction of cardiac mitochondria is often observed. We here show the cardiac-specific downregulation of a certain mitochondrial component during the chronological aging of mice, which is detrimental to the heart. MitoNEET is a mitochondrial outer membrane protein, encoded by CDGSH iron sulfur domain 1 (CISD1). Expression of mitoNEET was specifically downregulated in the heart and kidney of chronologically aged mice. Mice with a constitutive cardiac-specific deletion of CISD1 on the C57BL/6J background showed cardiac dysfunction only after 12 months of age and developed HF after 16 months; whereas irregular morphology and higher levels of reactive oxygen species in their cardiac mitochondria were observed at earlier time points. Our results suggest a possible mechanism by which cardiac mitochondria may gradually lose their integrity during natural aging, and shed light on an uncharted molecular basis closely related to age-associated HF.

Brain-Derived Neurotrophic Factor Improves Impaired Fatty Acid Oxidation Via the Activation of Adenosine Monophosphate-Activated Protein Kinase-ɑ - Proliferator-Activated Receptor-r Coactivator-1ɑ Signaling in Skeletal Muscle of Mice With Heart Failure

BACKGROUND

We recently reported that treatment with rhBDNF (recombinant human brain-derived neurotrophic factor) improved the reduced exercise capacity of mice with heart failure (HF) after myocardial infarction (MI). Since BDNF is reported to enhance fatty acid oxidation, we herein conducted an in vivo investigation to determine whether the improvement in exercise capacity is due to the enhancement of the fatty acid oxidation of skeletal muscle via the AMPKα-PGC1α (adenosine monophosphate-activated protein kinase-ɑ-proliferator-activated receptor-r coactivator-1ɑ) axis.

METHODS

MI and sham operations were conducted in C57BL/6J mice. Two weeks postsurgery, we randomly divided the MI mice into groups treated with rhBDNF or vehicle for 2 weeks. AMPKα-PGC1α signaling and mitochondrial content in the skeletal muscle of the mice were evaluated by Western blotting and transmission electron microscopy. Fatty acid β-oxidation was examined by high-resolution respirometry using permeabilized muscle fiber. BDNF-knockout mice were treated with 5-aminoimidazole-4-carboxamide-1-beta-d-riboruranoside, an activator of AMPK.

RESULTS

The rhBDNF treatment significantly increased the expressions of phosphorylated AMPKα and PGC1α protein and the intermyofibrillar mitochondrial density in the MI mice. The lowered skeletal muscle mitochondrial fatty acid oxidation was significantly improved in the rhBDNF-treated MI mice. The reduced exercise capacity and mitochondrial dysfunction of the BDNF-knockout mice were improved by 5-aminoimidazole-4-carboxamide-1-beta-d-riboruranoside.

CONCLUSIONS

Beneficial effects of BDNF on the exercise capacity of mice with HF are mediated through an enhancement of fatty acid oxidation via the activation of AMPKα-PGC1α in skeletal muscle. BDNF may become a therapeutic option to improve exercise capacity as an alternative or adjunct to exercise training.

Clinical impact of complete atrioventricular block in patients with ST-segment elevation myocardial infarction

Complete atrioventricular block (CAVB) is a common complication of ST-segment elevation myocardial infarction (STEMI). Although STEMI patients complicated with CAVB had a higher mortality in the thrombolytic era, little is known about the impact of CAVB on STEMI patients who underwent primary percutaneous coronary intervention (PCI). The study aimed at evaluating the clinical impact of CAVB on STEMI patients in the primary PCI era. We consecutively enrolled 1295 STEMI patients undergoing primary PCI within 24 hours from onset. Patients were divided into two groups according to the infarct location: anterior STEMI (n = 640) and nonanterior STEMI (n = 655). The outcomes were all-cause death and major adverse cardiocerebrovascular events (MACCE) with a median follow-up period of 3.8 (1.7-6.6) years. Eighty-one patients (6.3%) developed CAVB. The incidence of CAVB was lower in anterior STEMI patients than in nonanterior STEMI (1.7% vs 10.7%, p < .05). Anterior STEMI patients with CAVB had a higher incidence of all-cause deaths (82% vs 20%, p < .05) and MACCE (82% vs 25%, p < .05) than those without CAVB. Although higher incidence of all-cause deaths was found more in nonanterior STEMI patients with CAVB compared with those without CAVB (30% vs 18%, p < .05), there was no significant difference in the incidence of MACCE (24% vs 19%). Multivariate analysis showed that CAVB was an independent predictor for all-cause mortality and MACCE in anterior STEMI patients, but not in nonanterior STEMI. CAVB is rare in anterior STEMI patients, but remains a poor prognostic complication even in the primary PCI era.

Clinical Outcomes of Acute Myocardial Infarction Patients With a History of Malignant Tumor

BACKGROUND

Little is known about the clinical outcomes of acute myocardial infarction (AMI) in patients with a history of malignant tumor (MT).

PATIENTS AND METHODS

We retrospectively studied 1,295 consecutive patients with AMI who underwent primary percutaneous coronary intervention within 24 hours of onset. The patients were divided into two groups: those with a history of MT (MT group, n=50) and those without (non-MT group, n=1,245).

RESULTS

The MT group was older, and had lower hemoglobin, total protein, and albumin levels. All-cause mortality and re-admission rates due to acute decompensated heart failure (ADHF) were significantly higher in the MT group. Multivariate analysis showed that a history of MT was an independent predictor for all-cause mortality and re-admission due to ADHF.

CONCLUSION

The clinical outcomes of patients with AMI with a history of MT are poor, and a history of MT is an independent predictor for all-cause mortality and re-admission due to ADHF. These patients may need careful risk management for heart failure to avoid re-admissions due to ADHF.

Activation of invariant natural killer T cells ameliorates doxorubicin-induced cardiotoxicity in mice

Objective

Doxorubicin (DOX) is one of the most important anticancer agents and widely used to treat cancers but clinical utility of DOX is limited for its dose-dependent cardiotoxicity. The precise mechanism of DOX-induced cardiotoxicity is still not fully understood but it has been reported that cardiac inflammation is involved in the cardiotoxicity. Invariant natural killer T (iNKT) cells, a unique subset of T lymphocytes that recognize glycolipid antigens and secrete a large amount of both Th1 and Th2 cytokines on activation, have been shown to play crucial roles in the regulation of immune responses. However, it remains unclear whether iNKT cells are involved in DOX-induced cardiotoxicity.

Methods and results

Male C57BL/6J mice were administered DOX (20mg/kg body weight; n=28) or vehicle (Vehicle; n=6). DOX-administered mice were further divided into 2 groups; those treated with α-galactosylceramide (αGC, 0.1μg/g body weight; DOX-αGC; n=14), which specifically activates iNKT cells, or those treated with PBS (DOX-PBS; n=14) by intraperitoneal injections (twice; 4 days before and 3 days after DOX administration).An echocardiography conducted at 14 days after DOX/Vehicle administration revealed that LV fractional shortening was significantly reduced in the DOX-PBS compared to the Vehicle (49.3±0.8% vs. 59.2±1.7%, P&lt;0.05), and this decrease was completely attenuated in the DOX-αGC (57.7±1.3%, P&lt;0.05 vs. DOX-PBS)without affecting LV end-diastolic diameter. Flow cytometric analysis revealed that the ratio of iNKT cells to mononuclear cells infiltrated into the heart tissue was significantly increased in the DOX+αGC compared to the Vehicle and the DOX+PBS (1.00±0.09% vs. 0.54±0.09% and 0.71±0.07%, P&lt;0.05). Immuno-histochemistry revealed that the infiltration number of Iba1+macrophages in the heart tissue was significantly elevated in the DOX+αGC compared to the Vehicle and the DOX+PBS (55.4±3.2 cells/mm2 vs. 21.7±2.0 cells/mm2 and 37.5±5.9 cells/mm2, P&lt;0.05) The ratio of fibrosis area to the heart tissue was markedly higher in the DOX-PBS than in Vehicle (4.3±0.5% vs. 2.2±0.1%, P&lt;0.05), and this increase was completely attenuated in the DOX-αGC (2.8±0.1%, P&lt;0.05 vs.DOX-PBS).Real-time PCR analysis revealed that mRNA expressions of M2 macrophage markers (Arginase 1 and Retnla) and IL-4 were significantly enhanced in the DOX+αGC compared to the DOX+PBS (Arginase 1: 2.5±0.4 vs. 1.6±0.3 [relative ratio to the Vehicle], P=0.08; Retnla: 2.4±0.5 vs. 1.1±0.2 [relative ratio to the Vehicle], P&lt;0.05; IL-4: 1.0±0.3 vs. 8.94±2.8 [relative ratio to the DOX+PBS], P&lt;0.05), while those of M1 macrophage markers (iNOS and MCP-1) did not change among all groups.

Conclusions

Activation of iNKT cells ameliorates DOX-induced cardiotoxicity in mice via enhanced M2 macrophage polarization with the upregulation of IL-4 and reducing cardiac fibrosis. iNKT cell activation can be a novel preventive strategy against DOX-induced cardiotoxicity.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Japan Agency for Medical Research and Development (18lm0203001j0002) and JSPS KAKENHI (18K15834).

Characterizing genetic variants for DAG and IP3 signalling pathways in severe cases of coronary spastic angina

Background

We previously reported that the activity of phospholipase C (PLC), a key molecule for intracellular calcium signaling, was enhanced in patients with coronary spastic angina (CSA). Furthermore, we found PLC-δ1 864 G to A mutation in about 10% of the male CSA patients. However, comprehensive understanding of genetic role in the pathogenesis of CSA remains to be elucidated.

Purpose

We tested the hypothesis that variants in the genes responsible for contraction signaling, especially a Ca2+-dependent mechanism, plays an important role in the pathogenesis of CSA.

Methods and results

Exome sequencing was performed to genotype comprehensively CSA cohort, enabling investigation of 258 gene network for diacylglycerol (DAG) and inositol trisphosphate (IP3) signallings, which are responsible for contraction signaling in the vascular smooth muscle cell (VSMC) by a Ca2+-dependent mechanism.

The study population included 30 Japanese patients with severe cases of CSA (18 men and 12 women with a mean age of 62.2±10.1 years). In 23 patients, ST segment elevation was recorded on the electrocardiogram during a spontaneous attack. In other 3 patients, ventricular fibrillation occurred following CSA attacks. The rests were diagnosed by ECG changes and elevated cardiac enzymes following CSA attacks. Genetic information from these CSA patients were compared with those from 914 healthy controls.

Frequencies of 17 common, functional polymorphisms of DAG and IP3 signallings were statistically similar to those of healthy controls. By high-quality (Call Quality ≥20, Read Depth ≥10), and predicted-deleterious (CADD score ≥20) filterings, the number of the candidate genes were narrowed from 234,445 to 17,738, and by selecting genes for DAG and IP3 signallings, further narrowed to 208 genes. Compared with 914 healthy controls, DAG and IP3 signalling genes revealed 26 variants in 15 genes in CSA cases, and by further filtering for rare (914 healthy control frequency &lt;1%), 21 variants in 12 genes were found. They shared variants in G protein subunit alpha q (GNAQ), phospholipase C beta 3 (PLCB3), inositol 1,4,5-trisphosphate receptor type 3 (ITPR3), glutamate ionotropic receptor NMDA type subunit 2D (GRIN2D) in ≥5 cases. By filtering for high-quality, predicted-deleterious, and rare, genetic variants related with DAG and IP3 signalling were more found in severe CSA patients compared with healthy controls (CSA 4.33/person vs healthy controls 2.60 /person).

Conclusions

These findings indicate genetic heterogeneity in CSA susceptibility and a likely polygenic basis, giving a cumulative effect on DAG and IP3 signalling pathways in a subset of individual CSA patients. Study of larger cohorts is warranted to define genetic risk factors for CSA.

Funding Acknowledgement

Type of funding source: None

Retrospective analysis of risk factors for liposomal amphotericin B-associated nephrotoxicity

In this study, we examined patients who received liposomal amphotericin B (L-AMB) to determine the risk factors associated with nephrotoxicity before and during L-AMB treatment. In this retrospective, single-center, observational cohort study, we examined 37 patients who received L-AMB treatment between April 2018 and December 2019. Nephrotoxicity was observed in 11 (29.7%) patients. We focused on the baseline albumin level and body surface area (BSA) before L-AMB treatment. Univariate analysis showed that the BSA and baseline albumin levels in patients with nephrotoxicity were significantly higher than those in patients without nephrotoxicity. Moreover, univariate analysis showed that albumin supplementation was significantly associated with the frequency of nephrotoxicity during L-AMB treatment. Multiple logistic regression analysis revealed the following independent risk factors for nephrotoxicity before or during L-AMB treatment: baseline albumin level (odds ratio [OR] = 16.000; 95% CI 1.480-172.000; P = 0.022) and albumin supplementation (OR = 40.800; 95% CI 2.210-753.000; P = 0.013). In conclusion, we identified baseline albumin level and albumin supplementation as novel risk factors for L-AMB-induced nephrotoxicity.

Golodirsen for Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a life-shortening X-linked genetic disorder characterized by progressive wasting and weakening of muscles in boys. Loss-of-function mutations in the DMD gene, which codes for dystrophin, lead to this disease. The majority of mutations in this gene result in the exclusion of one or more exons from the transcript, eventually causing the remaining exons not to fit together correctly (i.e., out-of-frame mutations). Antisense oligonucleotides, e.g., phosphorodiamidate morpholino oligomers (PMOs), can induce therapeutic exon skipping during pre-mRNA processing to restore the reading frame of the primary transcript of DMD. As a result, truncated but partially functional dystrophin is produced, potentially slowing down the disease progression. Golodirsen is a provisionally approved PMO-based drug for approx. 8% of all DMD patients amenable to exon 53 skipping. This article summarizes golodirsen's pharmacology, efficacy and safety information. It also discusses some controversies that golodirsen met after the approval.

THU0324 CYTOMEGALOVIRUS REACTIVATION AND HIGH INITIAL SERUM CREATININE ARE SIGNIFICANT PROGNOSTIC FACTORS FOR SUBSEQUENT SEVERE INFECTIONS IN PATIENTS WITH ANCA-ASSOCIATED VASCULITIS

Background:

There are several reports that cytomegalovirus (CMV) reactivation resulted in more co-infections affecting survival in rheumatic disease, and CMV reactivation can lead to infections in granulomatosis with polyangiitis patients by inducing CD4+CD28- T cell and depressing naïve T cell populations.1-4Despite this evidence, the prognostic value of CMV reactivation for severe infections in patients with connective tissue disease are still unknown.

Objectives:

The aim of this study was to examine prognostic factors for severe infection during the early phase of treatment, especially in CMV reactivation, in patients with antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) who received initial high dose corticosteroid therapy (prednisolone > 0.8mg/kg/day).

Methods:

We analyzed the data of 88 consecutive hospitalized patients newly diagnosed with AAV at our hospital from January 2006 to March 2019 in this retrospective cohort study. There were 32 patients with CMV reactivation during remission induction therapy compared to 56 patients without CMV reactivation. CMV reactivation was defined by the detection of CMV pp65 antigen in blood samples, and CMV positive cells ≥ 5 per 3.0 × 105polymorphonuclear neutrophils (PMNs). The variable for severe infections within 180 days with apvalue < 0.1 in univariate analysis were selected for multivariate analysis using the Cox regression model. The positive predictive value (PPV) and positive likelihood ratio (PLR) of CMV reactivation for subsequent severe infections were also analyzed.

Results:

Patients with CMV reactivation, compared to those without, had a higher prevalence of MPO-ANCA, renal manifestation and renal impairment at diagnosis, received hemodialysis (HD), higher revised five factor score (FFS), older age, higher Birmingham Vasculitis Activity Score at diagnosis, and higher initial doses of corticosteroids (CS) at baseline. Revised FFS ≥ 2, renal involvement, high initial serum creatinine (≥ 1.5 mg/dl) at diagnosis, received HD, and CMV reactivation were associated with severe infections in the univariate analysis, although receiving cyclophosphamide or rituximab was not. Among these variables, CMV reactivation (Hazard ratio [HR] 3.50; 95% confidence interval [CI]: 1.22-10.10;p= 0.02) and high initial serum creatinine at diagnosis (HR 8.09; 95%CI: 2.00-32.73;p< 0.01) were independent risk factors for severe infections within 180 days. (Table 1) The PPV and PLR of CMV reactivation for subsequent severe infections were 35% and 1.91. When including higher initial serum creatinine, PPV and PLR for subsequent severe infections was 67% and 7.26.

Table 1.

Cox regression analysis for severe infections within 180 days.

Univariate analysisMultivariate analysisPotential prognostic factorsHR (95% CI)P valueHR (95% CI)P valueAge ≥ 651.36 (0.48-3.71)0.580Male1.23 (0.50-3.04)0.648Past history of lung disease0.39 (0.11-1.36)0.140Past history of diabetes mellitus0.64 (0.15-2.77)0.550Lung involvement1.76 (0.67-4.62)0.254Renal involvement†3.68 (1.22-11.10)0.021Serum Cr ≥ 1.5 at diagnosis9.50 (3.40-26.49)< 0.0018.09 (2.00-32.73)0.003Hemodialysis4.85 (1.73-13.54)0.0030.96 (0.31-2.97)0.950BVAS ≥ 201.50 (0.59-3.81)0.393Revised FFS ≥ 24.40 (1.28-15.13)0.0180.83 (0.16-4.27)0.818MPSL pulse therapy1.16 (0.47-2.86)0.746Received CYC or RTX1.54 (0.55-4.27)0.409CMV reactivation5.10 (1.93-13.48)0.0013.50 (1.22-10.06)0.020

† “Renal involvement” was excluded in the multivariate analysis to avoid multicollinearity.

Conclusion:

Our study shows that there should be focus on subsequent severe infections when CMV reactivation is detected during early phase of treatment, especially in renal-impaired patients with ANCA-associated vasculitis.

References:

[1]Gardiner BJ et al. Rheumatol Int. 2019;39:1229-40

[2]Hung M et al. J Microbiol Immunol Infect. 2019;52:114-21.

[3]Hanaoka R et al. Mod Rheumatol. 2012;22:438-45.

[4]Morgan MD et al. Arthritis Rheum. 2011;63:2127-37.

Disclosure of Interests:

Daisuke Waki Speakers bureau: Mitsubishi Tanabe Pharma, AbbVie Inc, eisai Co,. Ltd, ONO PHARMACEUTICAL CO., LTD,, Keisuke Nishimura Speakers bureau: Mitsubishi Tanabe Pharma Corporation. Pfizer Inc. Kyowa Kirin Co., Ltd. Chugai Pharmaceutical Co., Ltd. ONO PHARMACEUTICAL CO., LTD. Japan Blood Products Organization. Kissei Pharmaceutical Co., Ltd. Astellas Pharma Inc. AYUMI Pharmaceutical Corporation. Eisai Co., Ltd. DAIICHI SANKYO COMPANY. Norvartis AG. Bayer AG. Sanofi K.K.

, Tomohiro Yoshida: None declared, Keiichiro Kadoba: None declared, Nozomi Tanaka: None declared, Hiroyuki Murabe: None declared, Toshihiko Yokota: None declared

Responder Analysis of Daikenchuto Treatment for Constipation in Poststroke Patients: A Subanalysis of a Randomized Control Trial

A traditional Japanese medicine, daikenchuto (DKT), is used for treating abdominal bloating and pain with coldness. In modern medicine, it is used to treat postoperative intestinal dysfunction and ileus. We previously showed the effective improvement in functional constipation with DKT in poststroke patients. However, response prediction for the treatment has not been elucidated. We investigated the data from the prior trial (UMIN000007393) to predict the DKT treatment response. We assessed the efficacy of DKT for chronic constipation in poststroke patients. Neurogenic bowel dysfunction score (NBDS) and the Gastrointestinal Symptom Rating Scale–constipation subscale (GSRS-C) score were newly analyzed comparing the pre- and postintervention data after intake of 15 g of DKT extract granule daily for 4 weeks. Single and multiple regression analyses were performed to examine the correlations between the changes in NBDS, GSRS-C score, patient characteristics, clinical symptom score, gas volume in the gut, and serum calcitonin gene–related peptide level. The total NBDS and GSRS-C score were significantly reduced after DKT administration. The total NBDS, GSRS-C score, and gas volume score at baseline were significantly correlated with the change in these scores. Higher NBDS and GSRS-C scores and more gas volume in the gut may be possible predictors of response to DKT when treating constipation.

Soft sensors for a sensing-actuation system with high bladder voiding efficiency

Sensing-actuation systems can assist a bladder with lost sensation and weak muscle control. Here, we advance the relevant technology by integrating a soft and thin capacitive sensor with a shape memory alloy-based actuator to achieve a high-performance closed-loop configuration. In our design, sensors capable of continuous bladder volume detection and actuators with strong emptying force have been used. This integration has previously hindered performance due to large bladder volume changes. Our solution integrates sensing-actuation elements that are bladder compatible but do not interfere with one another, achieving real-time bladder management. The system attains a highly desirable voiding target of 71 to 100% of a rat's bladder with a volume sensitivity of 0.7 μF/liter. Our system represents an efficient voiding solution that avoids overfilling and represents a technological solution to bladder impairment treatment, serving as a model for similar soft sensor-actuator integration with other organs.

Angiotensin-converting-enzyme inhibitor prevents skeletal muscle fibrosis in myocardial infarction mice

BACKGROUND

Transforming growth factor beta (TGF-β)-Smad2/3 is the major signaling pathway of fibrosis, which is characterized by the excessive production and accumulation of extracellular matrix (ECM) components, including collagen. Although the ECM is an essential component of skeletal muscle, fibrosis may be harmful to muscle function. On the other hand, our previous studies have shown that levels of angiotensin II, which acts upstream of TGF-β-Smad2/3 signaling, is increased in mice with myocardial infarction (MI). In this study, we found higher skeletal muscle fibrosis in MI mice compared with control mice, and we investigated the mechanisms involved therein. Moreover, we administered an inhibitor based on the above mechanism and investigated its preventive effects on skeletal muscle fibrosis.

METHODS

Male C57BL/6 J mice with MI were created, and sham-operated mice were used as controls. The time course of skeletal muscle fibrosis post-MI was analyzed by picrosirius-red staining (days 1, 3, 7, and 14). Mice were then divided into 3 groups: sham + vehicle (Sham + Veh), MI + Veh, and MI + lisinopril (an angiotensin-converting enzyme [ACE] inhibitor, 20 mg/kg body weight/day in drinking water; MI + Lis). Lis or Veh was administered from immediately after the surgery to 14 days postsurgery.

RESULTS

Skeletal muscle fibrosis was significantly increased in MI mice compared with sham mice from 3 to 14 days postsurgery. Although mortality was lower in the MI + Lis mice than the MI + Veh mice, there was no difference in cardiac function between the 2 groups at 14 days. Skeletal muscle fibrosis and hydroxyproline (a key marker of collagen content) were significantly increased in MI + Veh mice compared with the Sham + Veh mice. Consistent with these results, protein expression of TGF-β and phosphorylated Smad2/3 in the skeletal muscle during the early time points after surgery (days 1-7 postsurgery) and blood angiotensin II at 14 days postsurgery was increased in MI mice compared with sham mice. These impairments were improved in MI + Lis mice, without any effects on spontaneous physical activity, muscle strength, muscle weight, and blood pressure.

CONCLUSIONS

ACE inhibitor administration prevents increased skeletal muscle fibrosis during the early phase after MI. Our findings indicate a new therapeutic target for ameliorating skeletal muscle abnormalities in heart diseases.

Validation of Gene Therapy for Mutant Mitochondria by Delivering Mitochondrial RNA Using a MITO-Porter

Here, we report on validating a mitochondrial gene therapy by delivering nucleic acids to mitochondria of diseased cells by a MITO-Porter, a liposome-based carrier for mitochondrial delivery. We used cells derived from a patient with a mitochondrial disease with a G625A heteroplasmic mutation in the tRNA^Phe of the mitochondrial DNA (mtDNA). It has been reported that some mitochondrial gene diseases are caused by heteroplasmic mutations, in which both mutated and wild-type (WT) genes are present, and the accumulation of pathological mutations leads to serious, intractable, multi-organ diseases. Therefore, the decrease of the mutated gene rate is considered to be a useful gene therapy strategy. To accomplish this, wild-type mitochondrial pre-tRNA^Phe (pre-WT-tRNA^Phe), prepared by in vitro transcription, was encapsulated in the MITO-Porter. The pre-WT-tRNA^Phe encapsulated in the MITO-Porter was transfected into diseased mitochondrial cells, and the resulting mutant levels were examined by an amplification refractory mutation system (ARMS)-quantitative PCR. The mutation rate of tRNA^Phe was decreased, and this therapeutic effect was sustained even on the 8th day after transfection. Furthermore, mitochondrial respiratory activity of the disease cells was increased after the transfection of therapeutic pre-WT-tRNA^Phe. These results support the conclusion that the mitochondrial delivery of therapeutic nucleic acids represents a viable strategy for mitochondrial gene therapy.