Subclinical left atrial dysfunction profiles for prediction of cardiac outcome in the general population

Background

Echocardiographic screening for subclinical left atrial (LA) dysfunction might enhance the prediction of cardiac diseases such as atrial fibrillation (AFib) in the community. To date, however, outcome-driven definitions of early-stage LA dysfunction remain scarce.

Purpose

In a large population sample, we sought to extract outcome-driven thresholds for echocardiographic indexes of LA function to define subclinical left atrial (LA) dysfunction and assess the prognostic value of these echocardiographic criteria for prediction of cardiac events.

Methods

In 1306 community-dwelling individuals (mean age, 50.7 years; 51.6% women), we assessed LA function and left ventricular (LV) global longitudinal strain (LS) by echocardiography. Using receiver-operating curve threshold analysis, we derived outcome-driven cut-offs for LA emptying fraction (LAEF) and LA reservoir strain (LARS) that best balanced the cardiac event prediction (i.e. cut-offs yielding the highest Youden index (=sensitivity+specificity-1)). Next, we constructed LA dysfunction profiles and integrative LA/LV strain profiles based on the extracted cut-offs for LAEF and LARS and a validated definition of impaired LV global LS. We assessed the prognostic performance of these profiles in predicting the incidence of cardiac events and AFib (mean follow-up, 8.5 years).

Results

During follow-up, 93 participants experienced a cardiac event (8.3 events/1000 person-years) and 27 developed AFib (2.3 events/1000 person-years). LAEF<55% and LARS<23% yielded the highest Youden indexes and thus provided the most balanced prediction of incident AFib. When applying these cut-offs, abnormal LAEF and LARS were respectively present in 27.0% and 18.1% of the cohort. Abnormal LARS was independently associated with higher risk for cardiac events (hazard ratio (HR) versus normal LA phenotype: 2.11, P=0.0021). Both abnormal LAEF (HR: 2.57) and abnormal LARS (HR: 3.28) predicted incident AFib (P≤0.029). As compared to subjects free from any LA dysfunction, those with both LAEF<55% and LARS<23% had a significantly higher risk to develop cardiac events (HR: 2.10; P=0.014) and AFib (HR: 6.45; P=0.0036). Of the integrative LA/LV strain profiles, the concomitant presence of an impaired LARS and LV global LS independently elevated the risk for cardiac events (HR: 2.81; P=0.0012) and AFib (HR: 4.36, P=0.0071) as compared to normal counterparts. Both the degree of LA dysfunction and the integrative LA/LV strain profiles improved the prognostic accuracy beyond clinical risk models and risk scores.

Conclusions

We validated population-based and outcome-driven definitions of subclinical LA dysfunction predicting cardiac events independent of conventional risk factors. Echocardiographic screening for subclinical LA and LV systolic dysfunction might enhance the prediction of cardiac diseases such as AFib in the community, empowering clinicians to timely intervene with the disease development.

Prediction of cardiac events

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Research Foundation Flanders, Internal Funds KU Leuven

The lower the renal function in patients with chronic renal disease, the greater the improvement in the renal function cardiac rehabilitation provides

Background

Our previous study suggested that cardiac rehabilitation (CR) resulted in a significant improvement in the renal function in cardiac vascular disease (CVD) patients with chronic renal disease (CKD), using cystatin C. However, whether the difference in the severity of the renal impairment at the beginning of the CR affects the degree of the improvement in the renal function after CR is unknown.

Methods

We studied 203 CVD patients (155 males; 73 y/o) with CKD (15≤estimated glomerular filtration rate based on the serum cystatin C concentration [eGFRcys]<60 ml/min/1.73m2) who participated in our 3-month CR program. The eGFRcys was examined at the beginning and end of the CR. In addition, the patients were divided into 3 groups according to the severity of the renal impairment at the beginning of the CR: CKD G3a group (45≤eGFRcys<60 ml/min/1.73m2, n=122), CKD G3b group (30≤eGFRcys<45 ml/min/1.73m2, n=60), and CKD G4 group (15≤eGFRcys<30 ml/min/1.73m2, n=21). We compared the renal function at the beginning and end of the CR in each of the 3 groups. Moreover, we evaluated the correlation between the eGFRcys at the beginning of the CR and the change in the eGFRcys (%ΔeGFRcys).

Results

In all the study patients, the eGFRcys improved after the CR (45.5 to 47.7 ml/min/1.73m2, p<0.001). In the CKD G3b and G4 groups, the eGFRcys also improved (38.4 to 41.5 ml/min/1.73m2, p=0.001; 23.2 to 28.0 ml/min/1.73m2, p=0.016). However, in the CKD G3a group, the eGFRcys did not improve after the CR (52.9 to 54.2 ml/min/1.73m2, p=0.074) (Figure 1). The univariate analysis results showed that the %ΔeGFRcys was significantly negatively correlated with the eGFRcys at the beginning of the CR (p=0.016, r=−0.26, Figure 2).

Conclusion

The greater the renal dysfunction in the CVD patients with CKD was, the greater the improvement in the renal function after participating in the CR program.

Funding Acknowledgement

Type of funding source: None

Prognosis and cause of death in patients with left atrial appendage thrombus treated with or without anticoagulation therapy

Background

Thrombus in left atrial appendage (LAA) is associated with cardiogenic ischemic stroke; however, little is known about prognosis of patients with LAA thrombus detected by transoesophageal echocardiography (TOE).

Purpose

This study is to investigate the prognosis of patients with LAA thrombus and their cause of death.

Methods

Between 2005 and 2016, the patients who were performed TOE in our hospital were enrolled in this retrospective observational study. Five-year stroke free and survival curves were constructed by Kaplan-Meir method and cause of death were assessed.

Results

Among the 1263 study patients, LAA thrombus was detected in 146 (12%) patients. The patients with LAA thrombus were elder (74 y [66–79 y] vs. 70 y [62–76 y], P<0.001), than those without LAA thrombus, respectively. The prevalence of male sex (67% vs. 69%, P=0.63) were similar between the 2 groups. The prevalence of CHA2DS2-VASc score ≥2, d-dimer (1.7 mcg/ml [0.9–3.5 mcg/ml] vs. 0.8 mcg/ml [0.5–2.2 mcg/ml], P<0.001), and plasma brain natriuretic peptide (315 pg/ml [128–515 pg/ml] vs. 126 pg/ml [47–284 pg/ml], P<0.001) were higher in the patients with LAA thrombus than those without (89% vs. 78%, P=0.003). The LAA velocity was slower in the patients with LAA thrombus than those without (23 cm/s [15–34 cm/s] vs. 51 cm/s [35–72 cm/s], P<0.001). The prevalence of receiving anticoagulation therapy before (34% vs. 24%, P=0.01) and after (98% vs. 66%, P<0.001) TOE 1 month were higher in the patients with LAA thrombus than those without. The 5-year stroke free rate was lower in the patients with LAA thrombus than those without (82% vs. 93%, P<0.001); however, the 5-year survival were similar between the 2 groups (84% vs. 84%, P=0.93) (Figure). The cause of death as ischemic stroke was only 7% (1/14) and 3% (3/94), (P=0.43); the cardiac cause (14% vs. 43%, P=0.07) and the malignancy (35% vs. 29%, P=0.75) were the frequent cause of death in the patient with LAA thrombus and those without, respectively.

Conclusions

The patients who were detected thrombus in the LAA had higher incidence of ischemic stroke; however, the 5-y survival were similar. The ischemic stroke was not major cause of death in the patients with and without LAA thrombus. The higher rate of receiving anticoagulation therapy may be one of the causes of the discrepancy.

Figure 1

Funding Acknowledgement

Type of funding source: None

Short-term risk stratification using CADILLAC risk score in patients with ST elevation myocardial infarction

Background

The recent reperfusion therapy for ST-elevation myocardial infarction (STEMI) has made the length of hospital stay shorter without adverse events. CADILLAC risk score is reportedly one of the risk scores predicting the long-term prognosis in STEMI patients.

Purpose

To invenstigate the usefulness of CADILLAC risk score for predicting short-term outcomes in STEMI patients.

Methods

Consecutive patients admitted to our university hospital and our medical center with STEMI (excluding shock, arrest case) who underwent primary PCI between January 2012 and April 2018 (n=387) were enrolled in this study. The patients were classified into 3 groups according to the CADILLAC risk score: low risk (n=176), intermediate risk (n=87), and high risk (n=124). Data on adverse events within 30 days after hospitalization, including in-hospital death, sustained ventricular arrhythmia, recurrent myocardial infarction, heart failure requiring intravenous treatment, stroke, or clinical hemorrhage, were collected.

Results

In the low risk group, adverse events within 30 days were significantly less observed, compared to the intermediate and high risk groups (n=13, 7.4% vs. n=13, 14.9% vs. n=58, 46.8%, p<0.001). In particular, all adverse events occurred within 3 days in the low risk group, although adverse events, such as heart failure (n=4), recurrent myocardial infarction (n=1), stroke (n=1), and gastrointestinal bleeding (n=1), were substantially observed after day 4 of hospitalization in the intermediate and high risk groups.

Conclusions

In STEMI patients with low CADILLAC risk score, better short-term prognosis was observed compared to the intermediate and high risk groups, and all adverse events occurred within 3 days of hospitalization, suggesting that discharge at day 4 might be safe in this study population. CADILLAC risk score may help stratify patient risk for short-term prognosis and adjust management of STEMI patients.

Initial event occurrence timing

Funding Acknowledgement

Type of funding source: None

Long-term prognostic significance of dispersion of ventricular repolarization in patients with cardiac sarcoidosis

Background

Although the presence of cardiac involvement is recognised as a determinant of worse clinical outcomes in sarcoidosis patients, the determinants of adverse outcomes in patients with cardiac sarcoidosis (CS) have not been well understood. T-peak to T-end interval (TpTe) on the surface electrocardiogram (ECG) was proposed as a marker of dispersion of ventricular repolarisation. Prolonged TpTe to QT interval ratio (TpTe/QT) represents a period of potential vulnerability to reentrant ventricular arrhythmias. Notably, prolonged TpTe/QT has been associated with increased risk of mortality in hypertrophic cardiomyopathy, congenital long-QT syndrome, and Brugada syndrome. However, its prognostic implication in patients with CS is unclear.

Purpose

We sought to investigate whether TpTe/QT was associated with long-term clinical outcomes in patients with CS.

Methods

A total of 108 consecutive CS patients between August 1986 and March 2019 in two academic hospitals who had ECG data before initiation of immunosuppressive therapy were examined. We excluded patients who received pacemaker (n=15) or cardiac resynchronization therapy (n=3) at the time of ECG. Ultimately, 90 CS patients were included in this study. All standard 12-lead ECGs were recorded at 25 mm/s with an amplification of 10 mm/mV. TpTe was measured from the peak of T wave to the end of T wave which defined as the intersection of the tangent to the down slope of the T wave and the isoelectric line. Lead V5 was selected for the analyses. If V5 is not suitable for analyses, V4 was selected. The primary outcome was the composite of advanced atrioventricular block (AVB), ventricular tachycardia or ventricular fibrillation (VT/VF), heart failure hospitalisation and all-cause death.

Results

During a median follow-up period of 4.70 (interquartile range [IQR] 2.06–7.23) years, adverse events occurred in 21 patients (23.3%), including 2 advanced AVB, 12 VT/VF, 4 heart failure hospitalisation and 3 all-cause death. Events group had higher TpTe/QT compared to no events group (0.231 [IQR 0.193–0.261] vs. 0.282 [IQR 0.263–0.304] P<0.001). Kaplan-Meier analyses revealed that the primary outcome, especially VT/VF or sudden cardiac death more frequently occurred in patients with higher TpTe/QT (≥0.242, the median) compared to those with lower TpTe/QT (Figure 1). Multivariable Cox regression analysis showed that higher TpTe/QT was independently associated with increased subsequent risk of adverse events (hazard ratio 1.09, 95% confidence interval [CI] 1.02–1.17, P=0.014) even after adjustment for age, sex and left ventricular ejection fraction. Furthermore, the optimal cut-off value of TpTe/QT for the discriminatory of primary outcome was 0.257, and c-index was 0.77 (95% CI 0.64–0.89).

Conclusions

Higher TpTe/QT was associated with worse long-term clinical outcomes in patients with CS. Our findings indicate the importance of assessing TpTe/QT for risk stratification in patients with CS.

Figure 1

Funding Acknowledgement

Type of funding source: None

Age-related differences and vascular function test findings in patients with vasospastic angina

Background

Vasospastic angina (VSA) accounts for the majority of angina cases with no epicardial stenosis and develops amongawide range of age, which is reportedly induced by coronary functional abnormalities including endothelial dysfunction and smooth muscle hypercontraction. However, the relation of noninvasive vascular function tests to VSA remains to be fully elucidated.

Purpose

The aim of this study was to assess differences in clinical characteristics and findings from noninvasive vascular function tests among groups by age in patients with VSA.

Methods

We enrolled a total of 732 patients with angina who underwent intracoronary acetylcholine provocation test. VSA was defined as total or subtotal occlusion of epicardial coronary arteries accompanied by chest pain and/or ischemic electrocardiographic changes in response to acetylcholine administration. Patients with VSA were divided into 3 groups by age (young [<50 years], intermediate [50–64 years], and elderly group [≥65 years]). Noninvasive vascular function test findings such as ankle-brachial index (ABI), brachial-ankle pulse wave velocity (baPWV), andpercentage of mean arterial pressure (%MAP) were compared among groups by age in patients with VSA.

Results

Of all patients, 367 (50.1%) were diagnosed as VSA with intracoronary acetylcholine test, including 66 (18.0%), 113 (30.8%), and 188 (51.2%) patients in the young, intermediate, and elderly groups. Among groups by age, there was no significant difference in gender (female, 31.8% vs. 40.7% vs. 44.7%, P=0.19). Patients in the young group were more often smokers and alcohol drinkers than those in the intermediate and elderly groups, while the prevalence of hypertension, dyslipidemia, and diabetes were lower in younger patients. A history of percutaneous coronary intervention was less frequently found in the young group compared tothe intermediate and elderly groups (7.6% vs. 16.8% vs. 20.7%, P=0.033). The baPWV was higher in the elderly group (1424±232 vs. 1537±247 vs. 1774±358 cm/s, P<0.0001), while there was no difference in ABI between the 3 groups. %MAP at arms was significantly and progressively decreased with an increase in age (54.0±4.5% vs. 53.0±2.6% vs. 51.2±2.8%, P<0.0001).

Conclusion

Our study demonstrated that there were distinct age-related differences in clinical characteristics of patients with VSA. The higher %MAP in younger patients suggests that more impaired endothelial dysfunction may play a role in the development of VSA in this age group.

Funding Acknowledgement

Type of funding source: None

Estimation model for lower extremity strength using gait movement measured with inertial sensor considering differences of sex and environment

In this study, we propose a method for estimating lower extremity strength from daily gait movement. Gait movement is affected by sex and gait environment. Therefore, we examined correlation coefficient between lower extremity strength and gait movement based on sex and environment and created models for estimating lower extremity strength. As a result, when only male or female data were used for model constructing, the correlation coefficient between estimates and actual measurements of lower extremity strength were approximately 0.7 and the precision had a mean absolute error of approximately 0.1 N/kg. The accuracy of the estimates was higher than that when sex was considered.

Risk Factors for Major Bleeding During Anticoagulation Therapy in Cancer-Associated Venous Thromboembolism - From the COMMAND VTE Registry

BACKGROUND

Patients with cancer-associated venous thromboembolism (VTE) are at high risk for recurrent VTE and are recommended to receive prolonged anticoagulation therapy if they are at a low risk for bleeding. However, there are no established risk factors for bleeding during anticoagulation therapy.Methods and Results:The COMMAND VTE Registry is a multicenter retrospective registry enrolling 3,027 consecutive patients with acute symptomatic VTE among 29 Japanese centers. The present study population consisted of 592 cancer-associated VTE patients with anticoagulation therapy. We constructed a multivariable Cox proportional hazard model to estimate the hazard ratio (HR) and 95% confidence interval (CI) of the potential risk factors for major bleeding. During a median follow-up period of 199 days, major bleeding occurred in 72 patients. The cumulative incidence of major bleeding was 5.8% at 3 months, 13.8% at 1 year, 17.5% at 2 years, and 28.1% at 5 years. The most frequent major bleeding site was gastrointestinal tract (47%). Terminal cancer (adjusted HR, 4.17; 95% CI, 2.22-7.85, P<0.001), chronic kidney disease (adjusted HR, 1.89; 95% CI 1.06-3.37, P=0.031), and gastrointestinal cancer (adjusted HR, 1.78; 95% CI, 1.04-3.04, P=0.037) were independently associated with an increased risk of major bleeding.

CONCLUSIONS

Major bleeding events were common during anticoagulation therapy in real-world cancer-associated VTE patients. Terminal cancer, chronic kidney disease, and gastrointestinal cancer were the independent risk factors for major bleeding.

Neural-network-assisted in situ processing monitoring by speckle pattern observation

We propose a method to monitor the progress of laser processing using laser speckle patterns. Laser grooving and percussion drilling were performed using femtosecond laser pulses. The speckle patterns from a processing point were monitored with a high-speed camera and analyzed with a deep neural network. The deep neural network enabled us to extract multiple information from the speckle pattern without a need for analytical formulation. The trained neural network was able to predict the ablation depth with an uncertainty of 2 μm, as well as the material under processing, which will be useful for composite material processing.

Relationship between Histological Grade and Histopathological Appearance in Canine Mammary Carcinomas

Canine mammary carcinomas are common tumours in female dogs and histopathological examination has an important role in identifying whether they are benign or malignant. The latest and most commonly used histological grading system was established by Peña et al. (2013) and is based on the extent of tubule formation, nuclear pleomorphism and number of mitoses. Before the establishment of this grading system, tumour size and classical histological indicators of malignancy such as lymphovascular invasion, infiltration into surrounding tissue, necrosis and presence of a micropapillary pattern were important predictors of biological behaviour. However, the system of Peña et al. does not consider tumour size or these histological features. Clarifying the association of these features and histological grade, especially in grade II and III carcinomas, is important. In this study, we confirmed that the system of Peña et al. is effective for predicting biological behaviour and that evaluation of histological features of malignancy reinforced histological grade, as determined by the system of Peña et al., especially in grade II carcinomas.

Bifidobacterium Breve A1 Supplementation Improved Cognitive Decline in Older Adults with Mild Cognitive Impairment: An Open-Label, Single-Arm Study

OBJECTIVES

We previously reported the therapeutic potential of Bifidobacterium breve A1 (B. breve A1) for preventing cognitive impairment in Alzheimer's disease model mice, which suggested that supplementation of the probiotics could be an effective therapeutic strategy for managing cognitive function in mild cognitive impairment (MCI).

DESIGN AND SETTINGS

We conducted an open-label, single-arm study to examine the effects of 24-week supplementation of B. breve A1 on elderly with MCI in Aki Orthopedics Rehabilitation Clinic in Japan.

PARTICIPANTS

27 participants were screened by their Mini Mental State Examination (MMSE) scores.

MEASUREMENTS

Cognitive function was assessed using MMSE and Digit Symbol Substitution Test (DSST) at baseline and every 8 weeks. Mental condition and quality of life for gastrointestinal symptoms were measured using the Profile of Mood States 2nd Edition (POMS2), and the Gastrointestinal Symptom Rating Scale (GSRS).

RESULTS

Of the 27 participants enrolled, 19 completed the study. MMSE scores were significantly increased during the intervention by mixed model Dunnett's test and Wilcoxon signed-rank tests (+1.7, P < 0.01). POMS2 and GSRS scores were significantly improved during intervention when analyzed by Wilcoxon signed-rank tests.

CONCLUSION

The present study showed that oral supplementation of B. breve A1 in participants with MCI improved cognitive function, thus suggesting the potential of B. breve A1 for improving cognitive function and maintaining quality of life of the elderly. Further randomized, double-blind placebo-controlled studies are worth conducting to examine the beneficial effect of B. breve A1.

Nivolumab and ipilimumab immunotherapy for hemodialysis patients with advanced renal cell carcinoma

Combined immune checkpoint blockade with nivolumab and ipilimumab is standard therapy for the treatment of patients with previously untreated advanced renal cell carcinoma who are at intermediate or poor risk. However, data about the safety and efficacy of combined immune checkpoint blockade with nivolumab and ipilimumab in patients on hemodialysis are limited. Renal function has no known clinically important effects on the pharmacokinetics and clearance of nivolumab and ipilimumab. Further, most immune-related adverse events in patients on hemodialysis are thought to be manageable with the same treatments applied in patients with normal renal function. We present a case of advanced clear-cell renal cell carcinoma in a patient on hemodialysis who received combined immune checkpoint blockade with nivolumab and ipilimumab and who showed no evident signs of immune-related adverse events. Here, we confirm the safety and efficacy of combined immune checkpoint blockade with nivolumab and ipilimumab in a patient on hemodialysis.

Bounds on Lorentz Invariance Violation from MAGIC Observation of GRB 190114C

On January 14, 2019, the Major Atmospheric Gamma Imaging Cherenkov telescopes detected GRB 190114C above 0.2 TeV, recording the most energetic photons ever observed from a gamma-ray burst. We use this unique observation to probe an energy dependence of the speed of light in vacuo for photons as predicted by several quantum gravity models. Based on a set of assumptions on the possible intrinsic spectral and temporal evolution, we obtain competitive lower limits on the quadratic leading order of speed of light modification.

Platelet-rich plasma (PRP) accelerates murine patellar tendon healing through enhancement of angiogenesis and collagen synthesis

PURPOSE

Although platelet-rich plasma (PRP) therapy has become an increasingly popular treatment for sports-related injuries, the molecular mechanisms of PRP on tissue healing process remain poorly understood. The aim of the present study was to develop an experimental method quantifying the efficacy of PRP with murine patellar tendon injury model, leading to future elucidation of the mechanisms of PRP on healing processes.

METHODS

Full-thickness defects were created in the central third of the murine patellar tendon. The prepared allogenic PRP gel was applied on the defect of the patellar tendon (PRP group), while the remaining mice served as the untreated control group. Mice were sacrificed at 2, 4, 6, 8, and 10 weeks after the operation, with histological sections obtained in each time point (n = 4 / time point / group). Semi-quantitative histological evaluation was performed in accordance with the Bonar score. The variables included in this scoring system were cell morphology, ground substance, collagen arrangement, and vascularity, with higher grades indicating worse tendon structures. In addition, the ratio of the collagen fibers to the entire tendon tissue (FT ratio) was measured using KS400 software as a quantitative histological evaluation.

RESULTS

The total Bonar score in the PRP group was significantly lower than in control group. With regard to the variables in the Bonar score, the vascularity score was significantly higher in the PRP group at 2 and 4 weeks, while the collagen arrangement score was significantly lower in the PRP group at 8 weeks. Based on a quantitative evaluation, the recovery speed of the patellar tendon determined by FT ratio was significantly faster in the PRP group than in the control group at 6 and 8 weeks.

CONCLUSIONS

We have developed an experimental method for histological and quantitative evaluation of the effects of PRP on tissue healing using murine patellar tendon injury model. The results of this study suggest that the local application of PRP could enhance the tissue-healing process both directly through action on localized cells and indirectly through the recruitment of reparative cells through the blood flow. Further investigations will be needed to confirm the mechanisms of PRP in tissue-healing processes with the development of this experimental model.

Impact of the school lunch program on overweight and obesity among junior high school students: a nationwide study in Japan

BACKGROUND

Japan has experienced a low prevalence of childhood obesity. The Japanese nationwide school lunch program is suggested to have helped this phenomenon, but it has not been proven.

METHODS

From official statistics, we combined annual data for 2006-15 about the prefecture-level school lunch coverage rate for public junior high school students and the prefecture-level nutritional indicators calculated by randomly selected age-sex groups of 13-15-year olds: the percentage of overweight, obese or underweight children, who are 20% heavier, 30% heavier or 20% lighter than the standard weight by sex, age and height; and mean body weight (kg) or height (cm). We estimated the impact of the school lunch coverage rate on the nutritional indicators in subsequent years, adjusting for the lagged dependent variable and dummies for prefecture, age and year.

RESULTS

A 10 percentage point increase in the prefecture-level school lunch coverage rate significantly decreased the percentage of overweight (0.37%, 95% CI: 0.18-0.56) and obesity (0.23%, 0.10-0.37) in subsequent years among boys, but not among girls. No significant effect on the percentage of underweight or mean body weight/height was observed for either sex.

CONCLUSIONS

Appropriate nutritional intake through school lunch may be effective to reduce childhood obesity.

Platelet-rich plasma promotes recruitment of macrophages in the process of tendon healing

INTRODUCTION

Researchers have investigated the use of platelet-rich plasma (PRP) therapy. However, the mechanisms through which PRP affects tissue repair remain unclear. We hypothesize that PRP promotes tissue repair through not only via direct manner on the local cells but also via indirect manner that encourage the recruitment of reparative cells such as macrophages (MPs), and it depends on the quality of PRP including the concentration of leukocytes. The aim of this study is to elucidate the actions of the MPs in the mechanisms of PRP on tissue repair processes.

METHODS

Leukocyte-rich (LR) PRP and leukocyte-poor (LP) PRP were prepared from 12-week-old C57BL6 mice. Full-thickness defects were created in central third of patellar tendons of 12-week-old C57BL/6 mice for histologic analysis (n = 36) and 12-week-old B6.129P-Cx3cr1tm1Litt/J mice for flow cytometry analysis (n = 108). B6.129P-Cx3cr1tm1Litt/J mouse is GFP-positive only in the MP-linage cells thus MPs recruited to the repair tissue can be distinguished whether it had originated from administrated PRP or recruited from host mouse. Mice were treated either with LR-PRP, LP-PRP, or without PRP (control group). Histological analyses were performed to evaluate the tendon healing using Bonar score as semi-quantitative histological scoring system. Flow cytometric analyses were performed to count the number of GFP-positive cells around repaired patellar tendon. In addition, the ratio of pro-inflammatory MPs (M1)/anti-inflammatory MPs (M2) were analyzed in those GFP-positive cells. The statistical analysis was performed using GraphPad Prism ver6. P values < 0.05 were considered statistically significant.

RESULTS

In LR-PRP and LP-PRP groups, all variables in Bonar score such as cell morphology, cellularity, vascularity, and collagen arrangement were significantly improved in comparison with control group, indicating that both PRPs promote tendon hearing. LP-PRP promoted the tendon healing significantly faster than that of LR-PRP on postoperative day 28 (P < 0.001). LR-PRP enhanced angiogenesis (vascularity: P < 0.001), while LP-PRP improved the collagen arrangement on postoperative day 28 (collagen arrangement: P < 0.01). In other variables such as cell morphology and cellularity score, there were no significant differences between LR-PRP and LP-PRP groups in any time points. Flow cytometric findings showed that recruitment of GFP-positive MPs in the LR and LP-PRP groups were significantly increased from postoperative day 4 compared with control group without PRP treatment (P < 0.001). The majority of GFP-positive MPs were M1 at the initiation of tendon healing phase, and M2 were gradually increased from postoperative day 4. The number of M1 was significantly high both in the LP- and LR-PRP groups (day 4 and 7, p < 0.001), but the number of M2 was high only in the LP-PRP group (day 7 and 14, P < 0.05) when it compared with control group. The M1/M2 ratio on postoperative day 7 was significantly lower in the LP-PRP group than those in the control group (P < 0.05).

CONCLUSIONS

This study demonstrated that PRP enhanced the tendon healing and promoted the recruitment of MPs to the injured tissue. The subtypes of MPs were different depends on the types of PRPs, suggesting that leukocytes in PRP influence the effect of PRP therapy.

THU0221 EVIDENCE FOR A PATHOGENIC ROLE OF EXTRA-FOLLICULAR, IL-10 PRODUCING CCR6+B-HELPER T-CELLS IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

IL-10 plays a key role in systemic lupus erythematosus (SLE) pathogenesis, promoting B-cell response. IL10 is mainly secreted by regulatory T-cells, but follicular helper T-cells (TFH), also produce it. We previously identified a subset of CCR6+IL-7R+T-cells in human tonsils providing IL-10-dependent B-cell help. These CCR6+T-cells were able to produce IL-10, inducing IgG production.

Objectives:

to investigate a possible role of CD4+CCR6+IL7R+T-cells in SLE pathogenesis.

Methods:

37 patients fulfilling the ACR criteria for SLE have been included. Disease activity was assessed by 2k-SLEDAI. PBMC were analyzed by flow cytometry, using specific lineage markers. CCR6+IL7R+T-cells purified from total PBMC of SLE patients or healthy donors (HD) were co-cultured with autologous CD20+B-cells. IL-10, Il-17, total IgG and anti-dsDNA antibodies titers in patients serum and culture supernatants were assessed by ELISA. Embedded sections of lymph nodes from 8 SLE patients were analyzed by immunofluorescence (IF).

Results:

IL10 levels were significantly higher in SLE patients (Fig 1A). CD4+CCR6+IL7R+T-cells were significantly increased in SLE, in particular in those with higher disease activity and higher IL10 levels. CD4+CCR6+IL7R+T-cells levels associated with anti-dsDNA positivity. CCR6+IL7R+T-cells of SLE patients induced production of IgG and anti-dsDNA IgG (in anti-dsDNA + patients) from autologous B-cells, providing spontaneous help for autoantibody productionex vivo(Fig 1B-C). The IF study of lymph nodes of SLE patients showed that IL-10-producing CCR6+T-cells were highly abundant and co-localized with B-cells at follicle margins.

Fig 1

Conclusion:

our study revealed a novel population of extra-follicular B-helper T-cells, which produce IL-10 and could play a prominent pathogenic role in SLE. Further studies will clarify if this potentially pathogenic cell population might represent a possible future therapeutic target.

References:

[1]Facciotti F. J Allergy Clin Immunol. 2016; Geginat J. Semin Immunol. 2019; Tsokos GC. Nat Rev Rheumatol. 2019

Tab 1:

SLE patients characteristics

(n=37)DemographicsFemale/Male, n37/5Age, years, median (IQR)44 (38-49)Disease duration, years, median (IQR)19 (11-26)Lab testsANA86%*anti-dsDNA (%)46% medium/high titre41%Disease activity and clinical manifestations SLEDAI-2K, median (min-max)3.5 (0-24) Moderate/high activity19%Ongoing therapyPrednisone dose mg/day, median (IQR)7,5 mg (2,5 – 20)hydroxychloroquine78%Immunosuppressants87%Fig 2

Disclosure of Interests: :

Maria Gerosa: None declared, Federica Facciotti: None declared, Paola Larghi: None declared, Roberto Bosotti: None declared, Chiara Vasco: None declared, Nicola Gagliani: None declared, Chiara Cordiglieri: None declared, Elsa Rottoli: None declared, Alessandra Emiliana Penatti: None declared, Lorenza Maria Argolini: None declared, Bhavna Karnani: None declared, Yasushi Kobayashi: None declared, Mauro Bombaci: None declared, Jan Piet Van Hamburg: None declared, Roberta Gualtierotti: None declared, Stefano Gatti: None declared, Sara Torretta: None declared, Lorenzo Pignataro: None declared, Sander W. Tas: None declared, Roberto Caporali Consultant of: AbbVie; Gilead Sciences, Inc.; Lilly; Merck Sharp & Dohme; Celgene; Bristol-Myers Squibb; Pfizer; UCB, Speakers bureau: Abbvie; Bristol-Myers Squibb; Celgene; Lilly; Gilead Sciences, Inc; MSD; Pfizer; Roche; UCB, Sergio Abrignani: None declared, Massimiliano Pagani: None declared, Fabio Grassi: None declared, Pier Luigi Meroni: None declared, Richard Flavell: None declared, Jens Geginat: None declared

Piezo-electric transducer actuated mirror with a servo bandwidth beyond 500 kHz

We demonstrate a novel system that uses a piezoelectric transducer (PZT)-actuated mirror for laser stabilization. A combination of a simple mechanical design and electronic circuits is used to realize an ultra-flat frequency response, which enables an effective feedback bandwidth of 500 kHz. The PZT also performed well when used in a mode-locked laser with a GHz repetition rate, to which it is difficult to apply an electro-optic modulator (EOM).

g Factor of the ^{99}Zr (7/2^{+}) Isomer: Monopole Evolution in the Shape-Coexisting Region

The gyromagnetic factor of the low-lying E=251.96(9)  keV isomeric state of the nucleus ^{99}Zr was measured using the time-dependent perturbed angular distribution technique. This level is assigned a spin and parity of J^{π}=7/2^{+}, with a half-life of T_{1/2}=336(5)  ns. The isomer was produced and spin aligned via the abrasion-fission of a ^{238}U primary beam at RIKEN RIBF. A magnetic moment |μ|=2.31(14)μ_{N} was deduced showing that this isomer is not single particle in nature. A comparison of the experimental values with interacting boson-fermion model IBFM-1 results shows that this state is strongly mixed with a main νd_{5/2} composition. Furthermore, it was found that monopole single-particle evolution changes significantly with the appearance of collective modes, likely due to type-II shell evolution.

Validation of the VTE-BLEED score's long-term performance for major bleeding in patients with venous thromboembolisms: From the COMMAND VTE registry

BACKGROUND

The recently proposed VTE-BLEED score to predict the risk of major bleeding in patients with venous thromboembolisms (VTEs) on prolonged anticoagulation therapy was validated externally in randomized controlled trials and in a selected cohort, but not applied in non-selective cohorts.

OBJECTIVES

The present study aimed to evaluate the generalizability of the VTE-BLEED score in a non-selective cohort.

PATIENTS/METHODS

The COMMAND VTE Registry is a multicenter retrospective registry enrolling consecutive patients with acute symptomatic VTEs among 29 centers in Japan. The present study population consisted of 2124 patients with prolonged anticoagulation therapy beyond 30 days, including 2008 (95%) patients with a first VTE episode and 1075 (51%) with unprovoked VTEs, who were divided into 1445 patients (68%) with a VTE-BLEED score of ≥2 (high-risk group) and 679 (32%) with a VTE-BLEED score of <2 (low-risk group).

RESULTS

During a median follow-up period of 672 days, major bleeding events occurred in 121 patients. The cumulative 5-year incidence of major bleeding beyond 30 days was significantly higher in the high-risk group than low-risk group (13.2% versus 5.4%, P < .001). The hazard function curves demonstrated that the hazards of the high-risk group were consistently higher over time compared with the low-risk group, which suggested the long-term predictive ability of the score.

CONCLUSIONS

In the present real-world VTE registry, the VTE-BLEED score had  a long-term predictive ability for high-risk patients with major bleeding during prolonged anticoagulation therapy, which could be useful in determining the optimal duration of anticoagulation therapy in individual patients.