Effect of lockdown amid second wave of COVID-19 on environmental noise scenario of the megacity Delhi, India

This paper analyzes the impact of second wave of COVID-19 lockdown on environmental noise levels of 25 sites in Delhi city and compares the noise scenario during pre-lockdown, lockdown, and post-lockdown periods. The study utilized the noise monitoring data acquired from 25 real-time ambient noise monitoring stations, installed by the Delhi Pollution Control Committee, Delhi, at various sites throughout Delhi city. A significant reduction of up to 10 and 3 dB(A) in day and night equivalent noise levels, respectively, had been observed during the lockdown period as compared to the pre-lockdown and post-lockdown periods. The study also revealed that only nine sites, including four industrial and five commercial zone sites, complied with the ambient noise standards during lockdown period, and no silence or residential zone sites complied with the ambient noise standards even during the lockdown period. A roadmap for environmental noise management and control is suggested. The study also reports the community's perception toward the change in acoustic environment of Delhi city during the lockdown period by conducting an environmental noise perception survey. The present study should be helpful in devising noise control action plans and policy interventions for environmental noise management and control in the metropolitan city Delhi, India.

ML-Based Texture and Wavelet Features Extraction Technique to Predict Gastric Mesothelioma Cancer

Microsatellites are small, repetitive sequences found all across the human genome. Microsatellite instability is the phenomenon of variations in the length of microsatellites induced by the insertion or deletion of repeat units in tumor tissue (MSI). MSI-type stomach malignancy has distinct genetic phenotypes and clinic pathological characteristics, and the stability of microsatellites influences whether or not patients with gastric mesothelioma react to immunotherapy. As a result, determining MSI status prior to surgery is critical for developing treatment options for individuals with gastric cancer. Traditional MSI detection approaches need immunological histochemistry and genetic analysis, which adds to the expense and makes it difficult to apply to every patient in clinical practice. In this study, to predict the MSI status of gastric cancer patients, researchers used image feature extraction technology and a machine learning algorithm to evaluate high-resolution histopathology pictures of patients. 279 cases of raw data were obtained from the TCGA database, 442 samples were obtained after preprocessing and upsampling, and 445 quantitative image features, including first-order statistics of impressions, texture features, and wavelet features, were extracted from the histopathological images of each sample. To filter the characteristics and provide a prediction label (risk score) for MSI status of gastric cancer, Lasso regression was utilized. The predictive label's classification performance was evaluated using a logistic classification model, which was then coupled with the clinical data of each patient to create a customized nomogram for MSI status prediction using multivariate analysis.

Application of lean management after audit of Medical Records Department in a COVID19 dedicated center during the COVID pandemic

Background

The Medical Record (MR) contains the information which is needed to plan, provide, and evaluate the care given to the individual. It also serves as a pivotal tool for communicating information to all the health personnel who manage the patient, and it contributes to the continuity of patient care. There is an unmet need of identifying and correcting the issues faced with MR and Medical Records Departments (MRDs) so that higher efficiency can be achieved. This study was conducted to study the deficiencies and discrepancies found in MRD files during COVID management and to correlate the deficiencies with the facilities available and the workflow. Later Lean Management (LM) was applied to ensure compliance and efficiency in the system.

Methods

An observational study was done on the audit of COVID 19 patient files and facilities in the care centres. Process mapping was done. The data for LM were collected by brainstorming, observation, interview, and workflow review of several processes, values, number of wastes, and suggestions were documented the MRD staff.

Results

Area available was 400 m2 which is adequate against the norm of 350 m2. The existing staff of 30 was adequate as per norms. Deficiencies were observed in physical examination, history, radiology, and laboratory reports. The findings showed that the MRD units had 13 current processes, 26 wastes, and 10 values were identified. In addition, they were offered a total of 25 comments on eliminating the waste.

Conclusion

Staff and equipment were adequate. Recommendations include regular staff training and usage of electronic medical records, focus on deficiency check by specific MRD staff on regular basis monitored by the administration and supported by the medical audit committee. The study also recommends that suggestions applied after LM should be implemented in letter and spirit and a repeat study of LM is advisable after regular intervals to maintain the quality standards and to maintain or further improve the efficiency.

POS0945 IMPROVEMENT OF ENDOTHELIAL DYSFUNCTION AND INFLAMMATION IN ANKYLOSING SPONDYLITIS: IMPROVE-AS STUDY

Background

Cardiovascular (CV) disease is the leading cause of death in Ankylosing Spondylitis (AS)1. The chronic inflammatory-driven endothelial dysfunction and accelerated atherosclerosis contribute to the enhanced CV risk in AS. However, the therapeutic options to treat the enhanced CV risk are limited.

Objectives

To investigate the impact of Olmesartan and Rosuvastatin on endothelial dysfunction and inflammation in AS.

Methods

60 consequtive AS patients were randomized to receive 24-weeks of treatment with Olmesartan (OLME) (10 mg/day, n=20), Rosuvastatin (Rvs) (10 mg/day, n=20), or placebo (PL) (n=20) as an adjunct to existing stable csDMARDs. Endothelial function was assesed by brachial artery flow-mediated dilatation (FMD) using AngioDefender. EPCs (CD34+/CD133+) were estimated by flow cytometry. Serum nitrite, TBARS, ICAM-1, VCAM-1 and lipids levels estimated at baseline and after treatment. Inflammatory measures included: ASDAS, BASDAI, BASFI, ESR and CRP, pro-inflammatory cytokines. Quality of life and CV 10-year risk (SCORE high risk charts) were estimated using standard tools.

Results

Baseline levels of FMD and EPC population were impaired indicating endothelial dysfunction. Basal concentrations of inflammatory markers, pro-inflammatory cytokines and markers of endothelial dysfunction were elevated among three groups. After 24-weeks of treatment, FMD improved significantly in the rosuvastatin and olmesartan group as compared to placebo from their baseline levels: {OLME vs. PL (p≤0.01), Rvs vs. PL (p<0.01), Rvs vs. OLME (p=0.10) (Figure 1A). EPCs and nitrite (Figure 1B) levels improved significantly in both rosuvastatin and olmesartan groups. A significant reduction found in ICAM-1 after rosuvastatin treatment (p<0.01) where as olmesartan significantly decreased VCAM-1 (p=0.04) levels. Both rosuvastatin and olmesartan resulted in significant reductions of ASDAS, BASDAI, BASFI, ESR, CRP, IL-6 (Figure 1C) and TNF-α (Figure 1D) as compared to placebo. A significant reduction found in TBARS concentration after olmesartan treatment (p<0.01) as compared with rosuvastatin and placebo. There was a significant reduction in SCORE, HAQ-DI & SF-36 (PH) after treatment with rosuvastatin and olmesartan.

Conclusion

Olmesartan and rosuvastatin improve endothelial dysfunction and vascular inflammation and QoL in AS patients. Olmesartan and Rosuvastatin lower the proinflammatory cytokines, especially TNF-α, that upregulate eNOS and downregulates the production of adhesion molecules, CRP and nitric oxide which, in turn, improves endothelial dysfunction. Both drugs also decrease nitrite concentration and improve the EPC population in AS patients. The augmentation of EPCs by olmesartan and rosuvastatin represents a fascinating new approach for the management of AS. However, Rosuvastatin in addition also favorably impacted ICAM-1 and lipid abnormalities. In contrast, olmesartan has beneficial effect on blood pressure. Thus, both rosuvastatin and olmesartan have anti-inflammatory, immunomodulatory, vasculoprotective and cardioprotective effects in AS mediated through anti-proinflammatory cytokine action. These findings suggests that both drugs could mediate modest but clinically apparent anti-inflammatory effects with modification of CV risk in the context of high-grade autoimmune inflammation of AS and may provide a novel strategy to prevent cardiovascular events in these patients.

References

[1]Azevedo VF, Pecoits-Filho R. Atherosclerosis and endothelial dysfunction in patients with ankylosing spondylitis. Rheumatol Int 2010;30(11):1411–1416

Disclosure of Interests

None declared

Randomized comparison of proximal and distal radial access for coronary angiography and interventions

Funding Acknowledgements

Type of funding sources: None.

Introduction

Vascular access for coronary procedures is of paramount important not only for successful procedure but also to prevent complications. In comparison to femoral access, proximal radial artery (PRA) access at wrist is associated with decreased bleeding complications and mortality.  The most important complication of PRA access is radial artery occlusion Use of the proximal radial artery (PRA) approach at wrist has several limitations:  the need to supinate the hand, which can exacerbate chronic joint pain, the depth of the radial artery in large arms, which could make arterial puncture challenging even under ultrasound guidance, the risk of sporadic bleeding in the forearm, and the risk of radial artery occlusion. All above limitations can be overcome by distal radial artery (DRA) access in anatomical snuff box.  Randomized Studies are lacking for the comparison between DRA and PRA approach in coronary procedures.

Aims and objective

To compare safety, efficacy and feasibility between PRA and DRA approach in randomized fashion.

Material and methods

This was single center randomized controlled trial. 320 patients were randomized in PRA and DRA groups. PRA approach was in wrist and DRA approach was in anatomical snuff box. Primary endpoint was cannulation failure (failure to achieve radial access) and transradial failure (failure to complete procedure after successful access). Secondary safety outcome includes major (compartment syndrome, need for vascular surgery, hand dysfunction, nerve palsy ,arteriovenous fistula, hematoma requiring blood transfusion, proximal radial artery occlusion) and minor (radial artery spasm, hematoma not requiring transfusion or causing compartment syndrome, ecchymosis, local edema, paresthesia, pseudoaneurysm) complications; secondary efficacy outcome were puncture attempts, cannulation time, procedure time, radiation dose, hemostasis time  and quality of life endpoint  was pain score .

Results

 Each group was having 160 patients. In DRA group 73.9 % were CAG and 26.1 % were PCI; in PRA group and 75.7 were CAG and 24.3 were PCI. Cannulation failure was more in DRA group (7.5 % vs 2.5 %, P &lt; 0.001) without difference in transradial failure (n = 3 vs 4, p =0.764). There were no major complications in both groups except PRAO which was significantly less in DRA group (0 % vs 5.2 %, p= 0.007). Puncture attempts, cannulation time, pain score were more in DRA (1.65 vs 1.29, P &lt; 0.001;3.23 vs 2.62 minutes, p &lt; 0.001;25.5 vs 21.6 minutes, p = 0.039 respectively). There was no significant difference for minor complications in both groups.

Conclusion

DRA approach is as safe and feasible as PRA approach and causes significantly less PRAO. DRA approach may be advocated as default approach where radial access is chosen for coronary procedures. Abstract Figure. primary outcome  Abstract Figure. Procedural characteristic

Clinical significance of epicardial fat in suspected angina pectoris: an observational study

Funding Acknowledgements

Type of funding sources: None.

Background

Epicardial adipose tissue (EAT) is the visceral fat between pericardium and visceral epicardium and is the source of several endocrine and inflammatory mediators. It also has paracrine affects in the neighboring coronary arteries.

Objective

 To evaluate the association of EAT with subclinical atherosclerosis (carotid intima media thickness & flow mediated vasodilation), ultrasonic and anthropometric measures of abdominal fat, metabolic syndrome and coronary artery disease (CAD) concurrently.

Material and methods

Patients who underwent computed tomography (CT) coronary angiography for suspected CAD were prospectively included. All underwent anthropometric measurements, laboratory investigations, ultrasonic measurement of liver fat grade & B-mode hepatorenal ratio, carotid intima media thickness (CIMT), flow mediated vasodilation (FMD), CT measurement of epicardial fat thickness (EFT) & epicardial fat volume (EFV) along with CT coronary angiography. Study population was divided into 2 groups on the basis of presence or absence of CAD and were compared. The relationship between risk factors and presence of CAD was assessed by logistic regression analysis. To define EFT and EFV value predictive of the presence of significant CAD, the area under (AUC) the receiver operating characteristic (ROC) curve was calculated. Correlation between EFT as well as EFV with anthropometric and laboratory parameters, CIMT and FMD were assessed by Pearson correlation coefficient.

Results

Total 54 patients were included in study. Mean age was 54 years, 66% were diabetic and 33% were hypertensive. Mean CIMT, FMD, EFT and EFV were 0.70 + 0.27 cm; 5.64 + 2.64%; 5.51 + 2.50 mm and 60.6 + 28.6 cc, respectively. Total 34 (62.96%) patients were detected to have CAD. EFT as well as EFV were significantly higher in CAD group (3.31 + 2.34 vs 6.24 + 1.91mm; p= &lt;0.001, 72.5 + 22.3 vs 40.4 + 27.1cc; p= &lt;0.001); in patients with metabolic syndrome (83.3 + 18.4 vs 49.2 + 26.1cc; p &lt; 0.001, 7.13 + 1.49 vs 4.16 + 2.32mm; p &lt; 0.001). Both, EFV & EFT were significantly correlated with the abdominal fat, CIMT and FMD. Smoking, age and EFV were the independent predictors for CAD.  EFV &gt;31.65cc predicted the presence of CAD (sensitivity 91.25%, specificity 60%, AUC = 0.798, 95% CI = 0.665-0.930) and EFT &gt;2.85mm predicted the presence of CAD (sensitivity 94.1%, specificity 65%, AUC= 0.820, 95% CI= 0.687-0.953).

Conclusions

Epicardial fat is significantly associated with presence of CAD, metabolic syndrome, visceral fat, CIMT and FMD. CT measured epicardial fat may be included with CT based CAD lesion assessment and CT coronary calcium score to screen the patients of suspected angina pectoris. Abstract Figure. Epicardial adipose tissue  Abstract Figure. EFV and CAD

Pharmacological targeting of MTHFD2 suppresses acute myeloid leukemia by inducing thymidine depletion and replication stress

The folate metabolism enzyme MTHFD2 (methylenetetrahydrofolate dehydrogenase/cyclohydrolase) is consistently overexpressed in cancer but its roles are not fully characterized, and current candidate inhibitors have limited potency for clinical development. In the present study, we demonstrate a role for MTHFD2 in DNA replication and genomic stability in cancer cells, and perform a drug screen to identify potent and selective nanomolar MTHFD2 inhibitors; protein cocrystal structures demonstrated binding to the active site of MTHFD2 and target engagement. MTHFD2 inhibitors reduced replication fork speed and induced replication stress followed by S-phase arrest and apoptosis of acute myeloid leukemia cells in vitro and in vivo, with a therapeutic window spanning four orders of magnitude compared with nontumorigenic cells. Mechanistically, MTHFD2 inhibitors prevented thymidine production leading to misincorporation of uracil into DNA and replication stress. Overall, these results demonstrate a functional link between MTHFD2-dependent cancer metabolism and replication stress that can be exploited therapeutically with this new class of inhibitors.

Impact of COVID-19 lockdown on ambient noise levels in seven metropolitan cities of India

The paper analyzed the impact of lockdown on the ambient noise levels in the seventy sites in the seven major cities of India and ascertained the noise scenario in lockdown period, and on the Janta Curfew day in comparison to the pre-lock down period and year 2019 annual average values. It was observed that the majority of the noise monitoring sites exhibited a decrement in ambient day and night equivalent noise levels on the national Janta Curfew day and Lockdown period as compared with the normal working days attributed to the restricted social, economical, industrial, urbanization activity and reduced human mobility. A mixed pattern was observed at a few sites, wherein the ambient day and night equivalent noise levels during Janta curfew day and Lockdown period had been reported to be higher than that on the normal working days. The study depicts the noise scenario during the lockdown and pre-lockdown period for seventy sites in India and shall be instrumental in analyzing the consequences and implications of imposing lockdowns in future on the environmental noise pollution in Indian cities.

A Rare Case of Isolated Intraventricular Primary Central Nervous System Lymphoma in an 85-Year-Old Man

Primary CNS lymphoma (PCNSL) is rare malignant B cell lymphoid tumor of brain which predominantly occurs in supratentorial region in periventricular location. Majority of PCNSL are of DLBCL type and idiopathic in etiology. Here we are reporting a case of primary CNS lymphoma, DLBCL involving extremely uncommon intraventricular location. Central neurocytoma, subependymal giant cell astrocytoma, choroid plexus tumors and meningiomas are the common diagnosis at this site. Aim of reporting this case is to bring awareness of unusual intraventricular location of primary CNS lymphoma which should be kept in mind before considering gross total excision of lesion.

In hospital outcomes of orbital/rotational coronary atherectomy in diabetic vs non-diabetic population: insights from the nationwide inpatient sample

Background

Atherectomy (AT) using an orbital/rotational system is useful in altering calcified plaque thereby facilitating stent placement and optimal stent expansion. Patients with diabetes mellitus (DM) are known to have a higher rate of complications after percutaneous coronary intervention. We aimed to assess the incidence of major adverse cardiovascular events after atherectomy in the diabetic population using a nationwide inpatient sample (NIS).

Methods

NIS-HCUP database from 2015–2017 was used to identify patients who underwent atherectomy. A cohort of patients with and without diabetes was identified. Demographics, in-hospital outcomes, complications in both groups were compared. Statistical significance was assigned at p&lt;0.05.

Results

Out of 6184 patients who underwent AT, 3134 (50.6%) patients had DM. Baseline characteristics have been outlined in the table below. Complications were comparable between the two groups except for higher incidence of post-procedure VTE in Diabetic patients. In-hospital mortality was lower among patients with DM (2.24% vs 3.29%, p-0.27), while the mean length of stay (5.92 vs 4.91 days, p-0.002) and the hospitalization charges ($165118.4 vs 151226, p-0.04) were higher, but this difference in length of stay and hospitalization charges were nullified on multivariate regression.

Conclusion

Our study suggests that an AT for severely calcified plaque in the coronary artery is a safe option in patients with DM with comparable in-hospital complications and outcomes to non-DM patients.

Funding Acknowledgement

Type of funding sources: None. Demographics and Outcomes of Atherectomy

Distal radial access in the right anatomical snuffbox for coronary angiography and interventions: a prospective observational study

Background

Distal radial access in the anatomical snuffbox is a novel technique for vascular access. However, limited clinical data is available, mainly limited to the left distal radial access. In view of the paucity of data on right distal radial access; this study was conducted to assess the feasibility, efficacy and safety of the right distal radial approach as a default access route for transradial catheterization.

Methods

We enrolled 159 consecutive patients with a palpable right distal radial pulse prospectively at a single center. A detailed clinical evaluation, laboratory tests and echocardiographic examination was done. Doppler examination of distal radial artery for its patency and size was done before puncture attempt. The right distal radial artery was punctured using the back wall technique. Primary outcome was successful puncture of distal right radial artery. Secondary outcomes were number of puncture attempts, pain score, radial artery spasm, forearm and distal radial hematoma, proximal and distal radial artery occlusion, bleeding and other vascular complications, access site crossover due to distal radial access failure, contrast volume used, and radiation dose.

Results

Distal radial puncture was successful in 144/159 (90.1%) patients. The mean distal radial artery diameter was 2.2±0.25 mm. Mean pain score by visual analogue scale was 2.36±1.9. There were no bleeding events. Snuffbox hematoma was seen in 11 (7.6%) patients and forearm hematoma occurred in 5 (3.5%) patients. There were 9 (6.3%) cases of radial spasm, 4 (2.8%) cases of radial occlusion at distal access site and 1 (0.7%) forearm radial artery occlusion.

Conclusions

The right distal radial access is a feasible, safe and efficacious alternative approach for coronary angiogram and interventions.

Funding Acknowledgement

Type of funding sources: None.

Attaining a British consensus statement on managing idiopathic congenital talipes equinovarus (CTEV) through a Delphi process: a study protocol

INTRODUCTION

Idiopathic congenital talipes equinovarus (CTEV) is the most common congenital limb deformity. Non-operative intervention using the Ponseti method has shown to be superior to soft tissue release and has become the gold standard for first-line treatment. However, numerous deviations from the Ponseti protocol are still reported following incomplete correction or deformity relapse. Significant variation in treatment protocols and management is evident in the literature. Reducing geographical treatment variation has been identified as one of The James Lind Alliance priorities in children's orthopaedics. For this reason, the British Society of Children's Orthopaedic Surgery (BSCOS) commissioned a consensus document to form a benchmark for practitioners and ensure consistent high quality care for children with CTEV.

METHODS AND ANALYSIS

The consensus will follow an established Delphi approach aiming at gaining an agreement on the items to be included in the consensus statement for the management of primary idiopathic CTEV up to walking age. The process will include the following steps: (1) establishing a steering group, (2) steering group meetings, (3) a two-round Delphi survey aimed at BSCOS members, (4) final consensus meeting and (5) dissemination of the consensus statement. Degree of agreement for each item will be predetermined. Descriptive statistics will be used for analysis of the Delphi survey results.

ETHICS AND DISSEMINATION

No patient involvement is required for this project. Informed consent will be assumed from participants taking part in the Delphi survey. Study findings will be published in an open access journal and presented at relevant national and international conferences. Charities and associations will be engaged to promote awareness of the consensus statement.

Radial EBUS-Guided Cryobiopsy of Peripheral Lung Lesions With Flexible Bronchoscopy Without Using Guide-Sheath

BACKGROUND

A guide-sheath (GS) is conventionally used as a conduit for biopsy forceps under the guidance of radial endobronchial ultrasound (REBUS) for sampling the peripheral pulmonary lesions (PPLs). As compared with forceps, the cryoprobe has the advantage of obtaining larger samples. There is a paucity of literature on the use of cryobiopsy for PPL. We evaluated the diagnostic yield and safety of the REBUS-guided cryobiopsy (REBUS-CB) without using GS for the diagnosis of PPL.

METHODS

We retrospectively analyzed the database of 126 patients with PPL between November 2015 and December 2019. The REBUS-CB was performed using a flexible bronchoscopy without GS. Multidisciplinary consensus diagnostic yield was determined and procedural complications were recorded.

RESULTS

The histopathologic diagnosis by REBUS-CB, which is the primary objective of the study was obtained in 99 (78.6%) of total 126 cases. Yield was significantly higher in central lesions as compared to adjacent lesions visualized by the REBUS probe (81.4% versus 53.8%, P=0.021) but not significantly different between large (≥30 mm) and small (<30 mm) lesions (81.6% versus 71.8%, P=0.214). The average largest diameter of biopsy specimens was 6.9 mm (range 1-12, SD 2.132). We witnessed moderate bleeding in 7 (5.6%) and post procedure hypoxic respiratory failure in 4 (3.2%) cases which could be managed without escalation of care.

CONCLUSION

The REBUS-CB from peripheral lung lesions are feasible even without using GS and significantly large samples can be obtained.

POS0205 AMELIORATION OF ENDOTHELIAL DYSFUNCTION WITH JAK INHIBITION IN RHEUMATOID ARTHRITIS: JAK CV-RISK REDUCTION STUDY

Background:

Cardiovascular (CV) disease is the leading cause of premature mortality and sudden death in Rheumatoid Arthritis (RA). Conventional CV risk factors and disease specific risk factors are responsible for endothelial dysfunction (ED) in RA. ED is the barometer of CV health and key initial event in atherosclerosis. Tofacitinib, a JAK inhibitor, is in clinical use since 2012 and has had the most extensive development program in RA, but its impact on ED has not yet been explored in humans.

Objectives:

To investigate the impact of tofacitinib on endothelial dysfunction in RA

Methods:

40 RA patients fulfilling the 2010 Rheumatoid Arthritis classification criteria with active disease (DAS28>3.2) were randomized to receive 24 weeks of treatment with Tofacitinib (5mg bd, n=20) and placebo (n=20) as an adjunct to existing stable antirheumatic drugs. Primary endpoints included endothelial dysfunction assessed by FMD using Angiodefender and lipids were estimated at baseline and after 12 weeks of treatment. The secondary end points included: DAS28, ESR, CRP, HAQ-DI and cardiovascular risk using SCORE chart assessed at week 0 and 12.

Results:

At baseline, endothelial function was impaired and levels of inflammatory measures were elevated in both groups. CV risk SCORE was high and HAQ-DI was impaired at baseline. After treatment, FMD improved significantly in the tofacitinib group from (8.16±1.38% to 10.98±2.33%, p≤0.05) as compared to placebo (7.12±0.25% to 8.04±0.30%, p=0.35) (Fig. 1A). DAS28 (Fig. 1B), ESR and CRP (Fig. 1C) levels improved significantly in tofacitinib group as compared to placebo (p≤0.05). Tofacitinib significantly decreased HAQ-DI and SCORE (Fig. 1D) values as compared to placebo. There was significant increase in HDL (p≤0.05) after treatment with tofacitinib as compared to placebo. After 12 weeks of treatment, FMD and HDL increased by 34.55% and 13.58% respectively where as DAS28, ESR and CRP decreased by 37.40%, 36.10% and 76.59% respectively in the tofacitinib group. Significant negative correlation was observed between FMD and DAS28 (r= -0.50, p≤0.05) and CRP (r= -52, p≤0.05) after treatment with tofacitinib where as no such correlation was found in placebo group.

Figure 1.

Impact of Tofacitinib on FMD, DAS 28, CRP & SCORE

Conclusion:

First study to show that tofacitinib, apart from its anti inflammatory activity, improves endothelial dysfunction and cardiovascular risk in RA. Thus, JAK inhibition with tofacitinib has vasculoprotective and cardioprotective effect mediated through anti-inflammatory and probably other mechanisms. This study would stimulate further research in exploring the vasculoprotective and cardioprotective potential of tofacitinib in RA.

References:

[1]Tofacitinib reversed endothelial dysfunction in rheumatoid arthritis: mechanistic insights from the rat adjuvant-induced arthritis model. http://dx.doi.org/10.1136/annrheumdis-2020-eular.2747

Disclosure of Interests:

None declared

POS1011 PREDICTORS OF ENDOTHELIAL DYSFUNCTION IN ANKYLOSING SPONDYLITIS

Background:

Cardiovascular (CV) disease is the leading cause of death in Ankylosing Spondylitis (AS). Chronic systemic inflammation driven endothelial dysfunction leading to accelerated atherosclerosis results in premature mortality. Endothelial dysfunction is potentially treatable hence a therapeutic target. Predictive biomarkers for endothelial dysfunction would allow tailoring therapy to the individual.

Objectives:

To assess the endothelial dysfunction in AS in context of markers of inflammation and oxidative stress in AS patients.

Methods:

Sub group–analysis of our previous studies of AS1-3 was carried out and 80 AS patients were compared with 40 healthy controls matched for age and sex that were also part of these studies.2,3 Such analysis had so far not been performed in this cohort. Patients with traditional CV risk factors had been excluded in these studies. Flow-mediated dilatation (FMD), as a measure of endothelial function, was assessed by AngioDefender (Everist Health, Ann Arbor, MI). Inflammatory measures included: Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Ankylosing Spondylitis Disease Activity Score (ASDAS) in AS. We also assayed markers of inflammation, including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), proinflammatory cytokines (interleukin [IL]-1, IL-6, and tumor necrosis factor [TNF]-α), and endothelial dysfunction, including lipids and nitrite and marker of oxidative stress, TBARS.

Results:

FMD was significantly lower in AS patients compared with controls [(5.80±0.35% vs. 9.09±0.35%, p≤0.05) reduced by approximately 36%] whereas serum nitrite, TBARS, total cholesterol and LDL levels were significantly higher in AS compared with controls (p≤0.05). Compared with controls, AS patients had significantly high BASDAI, ASDAS and increased concentrations of ESR, CRP, TNF-α, and IL-6. In AS, FMD inversely correlated with ASDAS, CRP (Figure 1A), TNF-α (Figure 1B), nitrite (Figure 1C) and TBARS (Figure 1) and positively correlated with HDL (p≤0.05).

Figure 1.

Correlation of FMD with CRP, TNF-α, Nitrite and TBARS

Conclusion:

In AS, FMD was impaired, indicating endothelial dysfunction. ASDAS, CRP, TNF-α, nitrite, and TBARS were independent predictors of FMD in AS. AS-related inflammatory mechanisms (TNF-α, IL-6) and markers of vascular function and oxidative stress (CRP, nitrite and TBARS) may all be involved in the development of cardiovascular disease in AS and these predictors could serve as a novel therapeutic targets for preventing CV risk in AS.

References:

[1]Garg N, Krishan P, Syngle A. Rosuvastatin improves endothelial dysfunction in ankylosing spondylitis. Clin Rheumatol. 2015;34:1065-1071.

[2]Verma I, Syngle A, Krishan P, Garg N. Endothelial Progenitor Cells as a Marker of Endothelial Dysfunction and Atherosclerosis in Ankylosing Spondylitis. International Journal of Angiology. 2017;26:36–42.

[3]Verma I, Krishan P, Syngle A. Predictors of Atherosclerosis in Ankylosing Spondylitis. Rheumatol Ther. 2015;2(2): 173–182.

Disclosure of Interests:

None declared.

Safety and diagnostic yield of transbronchial lung cryobiopsy by flexible bronchoscopy using laryngeal mask airway in diffuse and localized peripheral lung diseases: A single-center retrospective analysis of 326 cases

Background

Intubation with either an endotracheal tube or a rigid bronchoscope is generally preferred to provide airway protection as well as to manage unpredictable complications during transbronchial lung cryobiopsy (TBLC). The laryngeal mask airway has been described as a safe and convenient tool for airway control during bronchoscopy.

Aims and Objectives

In this study, we evaluated the safety and outcome of using a laryngeal mask airway (LMA) as a conduit for performing TBLC by flexible video bronchoscopy (FB).

Methods

We retrospectively analyzed the database of the patients who underwent TBLC between November 2015 and September 2019. The procedure was performed using FB through LMA under general anesthesia. Prophylactic occlusion balloon was routinely used starting January 2017 onwards. Radial endobronchial ultrasound (R-EBUS) guidance was used for TBLC in the localized lung lesions when deemed necessary. Multidisciplinary consensus diagnostic yield was determined and periprocedural complications were recorded.

Results

A total of 326 patients were analysed. The overall diagnostic yield was 81.60% (266/326) which included a positive yield of 82.98% (161/194) in patients with diffuse lung disease and 79.54% (105/132) in patients with localized disease. Serious bleeding complication occurred in 3 (0.92%) cases. Pneumothorax was encountered in 8 (2.45%) cases. A total of 9 (2.76%) cases had at least 1 major complication.

Conclusion

This study demonstrates that the use of LMA during TBLC by flexible bronchoscopy allows for a convenient port of entry, adequate airway support and effective endoscopic management of intrabronchial haemorrhage especially with the use of occlusion balloon.

Challenges in Sensors Technology for Industry 4.0 for Futuristic Metrological Applications

The current advances and innovations in sensor technologies attributed to Industry 4.0 serve as the backbone for the inclusive growth of industry and ramping up the economy of any country. Industry 4.0 was basically conceptualized by introducing the Internet of Things (IoT) and Information and Communication technologies (ICT) that serve as an interface between digital and physical world through the fusion of smart sensors. The role of smart sensors and IoT-enabled industrial infrastructure is pivotal for adapting to the advanced technologies based on fusion of smart sensors. Digital meteorological traceability and uses of intelligent sensors, instrumentation and machinery in Industry 4.0, Smart Cities, Digital India and AtmaNirbhar Bharat missions of the government of India, are not only highly important but also in huge demand, which is going to increase manifolds in the years to come. The present paper is an attempt to provide a terse review and perspectives related to the advanced technological developments in this field and the challenges therein.

Violence against health care workforce in COVID and non COVID times: Analysis of predisposing factors

Background: The prevalence of violence against Health Care Workers (HCW) is showing a rising trend. Various studies have been done in the recent past shows that the prevalence of violence against HCW s ranged from 27.4% to 67%. The present study was done to compare and analyze the underlying causes of violence against HCW in a Non COVID and COVID situation to identify the commonality if any, and to suggest any remedial measures. Methodology: This was cross-sectional analytical design and was carried out in inpatient care areas of a tertiary care hospital. The study subjects comprised of Doctors, Nurses, Group C employees. Data was collected using direct interview method on a standard questionnaire. In addition, various media reports were collected and analyzed through internet. Results: Maximum incidents were experienced in emergency and OPD, where staff patient’s ratio is less. 39.4% incidents were experienced by the staff who were providing care to the Terminally ill patients, Mentally and Physically disabled persons & Psychiatric patients. Suggestion which emerged to reduce WPV are, triage in casualty, availability of trained security guards, CCTV, restricted visiting hours and limited attendants with the patients, improvement in patient amenities etc. Whereas in COVID situation the major reason is the religious and social belief, poor dietary services and lack of hygiene and sanitation. Conclusion: There is an urgent and inescapable requirement that the healthcare administrators should address the underlying precipitating factors of violence, for delivery of quality healthcare services to the patients in a safe environment.

AB0577 ENDOTHELIAL DYSFUNCTION AND ATHEROSCLEROSIS IN SYSTEMIC SCLEROSIS: A MULTIPARAMETRIC ANALYSIS USING IMAGING TECHNIQUE AND LABORATORY MARKERS OF INFLAMMATION AND VASCULAR FUNCTION: SCLERODERMA CV RISK STUDY

Background:

Systemic sclerosis (SSc) patients have an increased risk for atherosclerotic cardiovascular disease (CVD), possibly mediated by inflammatory and fibrotic mechanisms1. However, pathogenesis of accelerated atherosclerosis in SSc remains to be elucidated. Endothelial dysfunction is the key initial event in atherosclerosis. Predictors for rapid evolution of cardiovascular complications would be highly desirable for CV risk stratification. This study aims to assess endothelial function and atherosclerosis in SSc, in context of markers of inflammation and vascular function in SSc patients.

Objectives:

To assess endothelial function and atherosclerosis in SSc in context of markers of inflammation and vascular function in SSc patients.

Methods:

A cross-sectional study was performed in 20 SSc patients meeting the 2013 European League Against Rheumatism (EULAR) and American College of Rheumatology (ACR) classification criteria and 18 healthy controls matched for age and sex. Flow-mediated dilatation (FMD) assessed by AngioDefender and CIMT measured ultrasonographically. Disease-specific measures included: Disease duration, Modified Rodnan Skin Score (mRSS), EUSTAR activity score in SSc. We also assayed markers of inflammation, including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), proinflammatory cytokines (interleukin IL-1, IL-6, and IL-17), and endothelial dysfunction including lipids, serum nitrite and TBARS (marker of oxidative stress). Quality of life measured by Scleroderma Health Assessment Questionnaire (SHAQ).

Results:

FMD is significantly lower in SSc patients compared with controls (6.13±0.35% vs. 9.12±0.25%, p≤0.05). CIMT is significantly higher in SSc patients compared with controls (0.071±0.04cm vs. 0.035±0.02cm p≤0.05). Compared with controls, SSc patients had significantly (p≤0.05) elevated mRSS, EUSTAR score, ESR, CRP, IL-1, IL-6, IL-17, nitrite, TBARS and SHAQ whereas HDL levels are significantly reduced in SSc compared with controls (p≤0.05). In SSc, FMD inversely correlated with EUSTAR score, mRSS, IL-6 (Fig. 1A), serum nitrite (Fig. 1B), TBARS (Fig. 1C) and CIMT (Fig. 1D). CIMT positively correlated with age (Fig. 2A), disease duration, CRP (Fig. 2B) and IL-17 (Fig. 2C) and inversely correlated with HDL (Fig. 2D) (p< 0.05).

Conclusion:

In the present study, FMD and CIMT are impaired in SSc, indicating endothelial dysfunction and accelerated atherosclerosis, respectively. EUSTAR score, mRSS, IL-6, serum nitrite, CIMT and TBARS predicted endothelial dysfunction. Age, disease duration, CRP, IL-17, HDL and impaired FMD predicted accelerated atherosclerosis. SSc-related inflammatory mechanisms (IL-6, IL-17) and markers of vascular function (CRP, serum nitrite and TBARS) may all be involved in the development of vascular disease in SSc. Cytokine-triggered inflammation mediated by nitrite and TBARS is associated with endothelial dysfunction and accelerated atherosclerosis in SSc. These markers would possibly serve as predictors of endothelial dysfunction and atherosclerosis and more importantly therapeutic targets to prevent premature atherosclerosis and cardiovascular disease in SSc.

References:

[1]Pagkopoulou E, Poutakidou M, Garyfallos A, Kitas G, Dimitroulas T. Cardiovascular risk in systemic sclerosis: Micro- and Macro-vascular involvement. Indian Journal of Rheumatology 2017;12:S211-7.

Acknowledgments:

None

Disclosure of Interests:

None declared

AB0613 AUTONOMIC NEUROPATHY AND ITS PREDICTORS IN SYSTEMIC SCLEROSIS

Background:

Systemic sclerosis (SSc), a chronic autoimmune disease, is associated with autonomic neuropathy1. Autonomic neuropathy, especially cardiovascular autonomic neuropathy (CAN) is significant risk predictor of sudden cardiac death. However, its relationship with disease specific measures remains unexplored in SSc.

Objectives:

To assess cardiovascular autonomic neuropathy and sudomotor function and its predictors in systemic sclerosis.

Methods:

In this cross-sectional study, 16 SSc patients meeting the 2013 European League Against Rheumatism (EULAR) and American College of Rheumatology (ACR) classification criteria and 15 age and sex-matched healthy controls were recruited. Cardiovascular autonomic function assessed by five cardiovascular reflex tests according to Ewing. Peripheral sympathetic autonomic function assessed by FDA approved Sudoscan (Impeto Medical, Paris) through measurement of electrochemical skin conductance. Disease-specific measures (Disease duration, Modified Rodnan Skin Score (mRSS), EUSTAR activity score), and inflammatory measures (ESR, CRP) were determined. Quality of life measured by Scleroderma Health Assessment Questionnaire (SHAQ).

Results:

Systemic sclerosis patients had significantly impaired parasympathetic [Heart rate response to deep breath (HRD) (Fig. 1A), Heart rate response to standing (HRS) (Fig. 1B) and Heart rate response to valsalva manoeuvre (Fig. 1C)] and symapathetic [BP response to hand grip (BPH) (Fig. 1D)] function as compared to healthy controls. Scleroderma patients had significantly impaired sudomotor function (p<0.05) as compared to healthy controls. Levels of mRSS, EUSTAR score, ESR, CRP and SHAQ were significantly higher in SSc patients as compared to healthy controls (p≤0.05). Parasympathetic (HRD & HRS) dysfunction inversely correlated with ESR, CRP and mRSS. Sudomotor function positively correlated with mRSS, disease duration and CRP.

Conclusion:

CAN and Sudomotor function are significantly impaired in SSc. Parasympathetic dysfunction is more pronounced than sympathetic dysfunction in SSc. CAN and Sudomotor dysfunction are associated with disease-duration, skin-score, ESR and CRP. These could serve as potential predictors of Cardiovascular Autonomic neuropathy and sudomotor dysfunction in SSc.

References:

[1]Dessein PH, Joffe BI, Metz RM, Millar DL, Lawson M, Stanwix AE. Autonomic dysfunction in systemic sclerosis: sympathetic overactivity and instability. The American journal of medicine. 1992;93(2):143-50.

Acknowledgments:

None

Disclosure of Interests:

None declared

Seeded droplet microfluidic system for small molecule crystallization

A microfluidic approach to seeded crystallization has been demonstrated using abacavir hemisulfate, a nucleoside analog reverse transcriptase inhibitor, in droplet reactors to control polymorphism and produce particles with a low particle size distribution. Two techniques are introduced: (1) the first technique involves an emulsion system consisting of a dispersed phase solvent and a continuous phase, which holds slight solubility of the dispersed phase solvent. The dispersed phase contains both a dissolved active pharmaceutical ingredient (API) and seeds of the desired polymorph. While the continuous phase enables solvent extraction, the negligible solubility of the API allows for growth of seeds inside droplets via extraction and subsequent API saturation. This technique demonstrates the ability to crystallize the API in spherical agglomerates via slow extraction of droplets. (2) The second technique utilizes a combined dispersed phase by joining in-flow a seed suspension stream with a supersaturated active pharmaceutical ingredient (API) stream. The combined dispersed phase is emulsified in a continuous phase for which the dispersed phase solvent and the API are both insoluble - droplets are incubated at temperatures below their saturation limit to induce crystal growth. Decreasing the concentration of seeds in its input stream resulted in a decreased number of crystals per droplet, increase in crystal size, and decrease in PSD. Temperature cycling was utilized as a proof of concept to demonstrate the ability to reduce the number of seeds per droplet where the optimal goal is to obtain a single seed per droplet for all droplets. Utilizing this approach in conjunction with the ability to produce monodispersed droplet reactors allows for enhanced control of particle size distribution (PSD) by precisely controlling the available mass for each individual seed crystal. The development of this technique as a proof-of-concept for crystallization can be expanded to manufacturing scales in a continuous manner using parallelized droplet generators and flow reactors to precisely control the temperature and crystal growth kinetics of individual droplets.

Optimization of Tetrahydroindazoles as Inhibitors of Human Dihydroorotate Dehydrogenase and Evaluation of Their Activity and In Vitro Metabolic Stability

Human dihydroorotate dehydrogenase (DHODH), an enzyme in the de novo pyrimidine synthesis pathway, is a target for the treatment of rheumatoid arthritis and multiple sclerosis and is re-emerging as an attractive target for cancer therapy. Here we describe the optimization of recently identified tetrahydroindazoles (HZ) as DHODH inhibitors. Several of the HZ analogues synthesized in this study are highly potent inhibitors of DHODH in an enzymatic assay, while also inhibiting cancer cell growth and viability and activating p53-dependent transcription factor activity in a reporter cell assay. Furthermore, we demonstrate the specificity of the compounds toward the de novo pyrimidine synthesis pathway through supplementation with an excess of uridine. We also show that induction of the DNA damage marker γ-H2AX after DHODH inhibition is preventable by cotreatment with the pan-caspase inhibitor Z-VAD-FMK. Additional solubility and in vitro metabolic stability profiling revealed compound 51 as a favorable candidate for preclinical efficacy studies.

P41 Correlation of doppler ultrasound assessment of carotid femoral pulse wave velocity with coronary artery disease

Funding Acknowledgements

self

Background

Arterial stiffness is an important cardiovascular risk factor. Carotid femoral pulse wave velocity (cfPWV) is simple noninvasive  method to determine aortic stiffness. Arterial stiffness measures, cfPWV in particular,  have been found to be correlate with stroke and peripheral artery disease. Usually SphygmoCor or Complior are used to calculate cfPWV. Doppler ultrasound can serve as an alternative to these methods. 

Purpose

To assess cfPWV using doppler ultrasound and study its correlation with coronary artery disease and its severity. 

Methods

cfPWV was assessed by ultrasound Doppler in patient aged 20-70 years undergoing coronary angiography.  cfPWV was measured by sequential recordings of arterial pressure waveform at the carotid and femoral arteries with a Doppler ultrasound with ECG gating and calculated as the distance between the carotid and the femoral sampling site divided by the time interval. 

Result

Of the 358 subjects studied, 243 had coronary artery disease(CAD) (&gt;50% diameter stenosis) and were further divided into single, double or triple vessel disease groups. 115 patients  had mild CAD (&lt; 50% stenosis) or no CAD and served as controls. Baseline characteristics were similar except diabetes (more common in CAD group)(39.09% v/s 27.82%). cfPWV was found to increase with age in all groups. cfPWV was not significantly affected  by sex, diabetes, dyslipidemia, BMI, smoking or hypothyroidism. Mean cfPWV was significantly higher in patients with CAD (8.99 v/s 6.51 m/s, p &lt; 0.001) and hypertensives (8.71 v/s 7.83 m/s, p &lt; 0.001). Patients with triple vessel disease(TVD) had significantly higher cfPWV (10.12 m/s) than those with double(DVD)(8.84 m/s) or single vessel disease(SVD)(8.28m/s)(p &lt; 0.001). Multinomial logistic regression revealed an odds ratio of 2.00, 2.375 and 3.368 respectively for SVD, DVD and TVD groups in comparison to controls (p &lt; 0.001). cfPWV value &gt; 7.25 m/s predicted CAD with sensitivity 78.6 % and specificity 74.8% (AUC =0.848, P &lt; 0.001). 

Conclusion

Carotid femoral pulse wave velocity can be measured noninvasively by ultrasound Doppler. cfPWV increases with age and hypertension and has strong correlation with coronary artery disease and its severity. The cfPWV can be an independent risk factor and may be utilized for cardiovascular risk prediction.

Abstract P41 Figure. cfPWV in various subgroups.

Association between multiple respiratory viral infections and pediatric intensive care unit admission among infants with bronchiolitis

Background

It is unclear whether multiple respiratory viral infections are associated with more severe bronchiolitis requiring pediatric intensive care unit (PICU) admission. We aimed to identify the association between multiple respiratory viral infections and PICU admission among infants with bronchiolitis.

Methods

We performed a 1:1 case-control study enrolling previously healthy full-term infants (≤12 months) with bronchiolitis admitted to the PICU as cases and those to the general pediatric ward as controls from 2015 to 2017. Multiplex polymerase chain reaction (PCR) was used for detection of the respiratory viruses. We summarized the characteristics of infants admitted to the PICU and the general pediatric unit. Multivariable logistic regression analysis was used to fit the association between multiple respiratory viral infections (≥2 strains) and PICU admission.

Results

A total of 135 infants admitted to the PICU were compared with 135 randomly selected control infants admitted to the general pediatric unit. The PICU patients were younger (median: 2.2 months, interquartile range: 1.3–4.2) than the general ward patients (median: 3.2 months, interquartile range: 1.6–6.4). Respiratory syncytial virus (74.1%), rhinovirus (28.9%), and coronavirus (5.9%) were the most common viruses for bronchiolitis requiring PICU admission. Patients with bronchiolitis admitted to the PICU tended to have multiple viral infections compared with patients on the general ward (23.0% vs. 10.4%, P < 0.001). In the multivariable logistic regression analysis, bronchiolitis with multiple viral infections was associated with higher odds of PICU admission (adjusted odds ratio: 2.56, 95% confidence interval: 1.17–5.57, P = 0.02).

Conclusion

Infants with multiviral bronchiolitis have higher odds of PICU admission compared with those with a single or nondetectable viral infection.

P1496Use of strain, strain rate, tissue velocity imaging and endothelial function for early detection of cardiovascular involvement in young diabetics

Background

Subtle structural and functional changes may precede the onset of overt global left ventricular dysfunction and obvious reduction of ejection fraction (EF), especially in young diabetics. Data pertaining to tissue velocity indices (TVI) and strain imaging to assess regional myocardial function and flow mediated vasodilatation is limited in young patients with diabetes.

Purpose

To evaluate conventional echocardiography parameters, tissue doppler indices, global and regional strain, carotid intimal medial thickness (CIMT), endothelial dependent (FMD) and independent function (NMD) of brachial artery in young patients (age <18 years) with type 1 diabetes and compare them with matched controls.

Methods

Conventional echocardiography parameters, tissue velocity indices (TVI) parameters along with strain (S), and strain rate (SR) in basal and mid left ventricular (LV) lateral wall, right ventricular (RV) lateral wall and septum were measured in 50 young diabetics (age 15.16±2.95 years, mean HBA1c 8.15±1.37 gm %) and 25 controls (age 15.60±2.51 years). Flow-mediated dilatation (FMD), nitrate mediated dilatation and carotid intimal media thickness (CIMT) were also estimated.

Results

Conventional echocardiography parameters were similar in patients and controls however deceleration time of the mitral inflow velocity (EDT) was significantly shorter in patients when compared with controls (149.06±31.66 vs. 184.56±19.27 ms, p<0.05). Lateral early diastolic myocardial velocity (LV-Em) was significantly lower (10.30±0.99 vs. 11.67±3.21, p<0.05) whereas lateral late diastolic myocardial velocity (LV-Am) was significantly higher than controls (11.73±1.44 vs. 8.82±1.69, p<0.05), thus a significantly lower ratio of early/late diastolic velocity at the basal segment of lateral LV (LV-Em/Am). Lower strain values at the basal lateral LV (21.39±4.12 vs. 23.78±2.02; p<0.05), mid lateral LV (21.43±4.27 vs. 23.17±1.92; p<0.05), basal septum (20.59±5.28 vs. 22.91±2.00; p<0.05), and mid septum (22.06±4.75 vs. 24.10±1.99; p<0.05) as compared to controls. SR at the basal and mid segments of the lateral LV wall and at the basal septum were also significantly lower in diabetic subjects. Strain rate (SR) in mid septal, basal and mid RV were lower than controls although not statistically significant. Patients also had significantly lower flow mediated dilatation (FMD) (8.36±4.27 vs. 10.57±4.12, p<0.05) implying endothelial dysfunction.

Strain rate in diabetic patient

Conclusion

Left ventricular strain indices are impaired in asymptomatic children and adolescents with type 1 DM despite absence of overt heart failure and normal ejection fraction. Early detection of subclinical regional myocardial dysfunction by deformation analysis including strain and strain rate may be useful in the asymptomatic diabetic population. In addition, evidence of endothelial dysfunction in the form of impaired flow mediated vasodilatation was observed in the diabetic children.

Acknowledgement/Funding

None

Chemoselective probe for detailed analysis of ketones and aldehydes produced by gut microbiota in human samples

New strategies are required for the discovery of unknown bioactive molecules produced by gut microbiota in the human host. Herein, we utilize a chemoselective probe immobilized to magnetic beads for analysis of carbonyls in human fecal samples. We identified 112 metabolites due to femtomole analysis and an increased mass spectrometric sensitivity by up to six orders of magnitude.

Conduction block in immune-mediated neuropathy: paranodopathy versus axonopathy

BACKGROUND AND PURPOSE

Conduction block is a pathognomonic feature of immune-mediated neuropathies. The aim of this study was to advance understanding of pathophysiology and conduction block in chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN).

METHODS

A multimodal approach was used, incorporating clinical phenotyping, neurophysiology, immunohistochemistry and structural assessments.

RESULTS

Of 49 CIDP and 14 MMN patients, 25% and 79% had median nerve forearm block, respectively. Clinical scores were similar in CIDP patients with and without block. CIDP patients with median nerve block demonstrated markedly elevated thresholds and greater threshold changes in threshold electrotonus, whilst those without did not differ from healthy controls in electrotonus parameters. In contrast, MMN patients exhibited marked increases in superexcitability. Nerve size was similar in both CIDP groups at the site of axonal excitability. However, CIDP patients with block demonstrated more frequent paranodal serum binding to teased rat nerve fibres. In keeping with these findings, mathematical modelling of nerve excitability recordings in CIDP patients with block support the role of paranodal dysfunction and enhanced leakage of current between the node and internode. In contrast, changes in MMN probably resulted from a reduction in ion channel density along axons.

CONCLUSIONS

The underlying pathologies in CIDP and MMN are distinct. Conduction block in CIDP is associated with paranodal dysfunction which may be antibody-mediated in a subset of patients. In contrast, MMN is characterized by channel dysfunction downstream from the site of block.

CT Texture Analysis of Cervical Lymph Nodes on Contrast-Enhanced [18F] FDG-PET/CT Images to Differentiate Nodal Metastases from Reactive Lymphadenopathy in HIV-Positive Patients with Head and Neck Squamous Cell Carcinoma

BACKGROUND AND PURPOSE

Differentiating nodal metastases from reactive adenopathy in HIV-infected patients with [¹⁸F] FDG-PET/CT can be challenging because lymph nodes in HIV-positive patients often show increased [¹⁸F] FDG uptake. The purpose of this study was to assess CT textural analysis characteristics of HIV-positive and HIV-negative lymph nodes on [¹⁸F] FDG-PET/CT to differentiate nodal metastases from disease-specific nodal reactivity.

MATERIALS AND METHODS

Nine HIV-positive patients with head and neck squamous cell carcinoma (7 men, 2 women; 29-62 years of age; median age, 48 years) with 22 lymph nodes (≥1 cm) who underwent contrast-enhanced CT with [¹⁸F] FDG-PET followed by pathologic evaluation of cervical lymph nodes were retrospectively reviewed. Twenty-six HIV-negative patients with head and neck squamous cell carcinoma with 61 lymph nodes were evaluated as a control group. Each lymph node was manually segmented, and an in-house-developed Matlab-based texture analysis program extracted 41 texture features from each segmented volume. A mixed linear regression model was used to compare the pathologically proved malignant lymph nodes with benign nodes in the 2 enrolled groups.

RESULTS

Thirteen (59%) lymph nodes in the HIV-positive group and 22 (36%) lymph nodes in the HIV-negative control group were confirmed as positive for metastases. There were 7 histogram features (P = .017-0.032), 3 gray-level co-occurrence features (P = .009-.025), and 9 gray-level run-length features (P < .001-.033) that demonstrated a significant difference in HIV-positive patients with either benign or malignant lymph nodes.

CONCLUSIONS

CT texture analysis may be useful as a noninvasive method of obtaining additional quantitative information to differentiate nodal metastases from disease-specific nodal reactivity in HIV-positive patients with head and neck squamous cell carcinoma.

Anti-EGFR-resistant clones decay exponentially after progression: implications for anti-EGFR re-challenge

BACKGROUND

Colorectal cancer (CRC) has been shown to acquire RAS and EGFR ectodomain mutations as mechanisms of resistance to epidermal growth factor receptor (EGFR) inhibition (anti-EGFR). After anti-EGFR withdrawal, RAS and EGFR mutant clones lack a growth advantage relative to other clones and decay; however, the kinetics of decay remain unclear. We sought to determine the kinetics of acquired RAS/EGFR mutations after discontinuation of anti-EGFR therapy.

PATIENTS AND METHODS

We present the post-progression circulating tumor DNA (ctDNA) profiles of 135 patients with RAS/BRAF wild-type metastatic CRC treated with anti-EGFR who acquired RAS and/or EGFR mutations during therapy. Our validation cohort consisted of an external dataset of 73 patients with a ctDNA profile suggestive of prior anti-EGFR exposure and serial sampling. A separate retrospective cohort of 80 patients was used to evaluate overall response rate and progression free survival during re-challenge therapies.

RESULTS

Our analysis showed that RAS and EGFR relative mutant allele frequency decays exponentially (r2=0.93 for RAS; r2=0.94 for EGFR) with a cumulative half-life of 4.4 months. We validated our findings using an external dataset of 73 patients with a ctDNA profile suggestive of prior anti-EGFR exposure and serial sampling, confirming exponential decay with an estimated half-life of 4.3 months. A separate retrospective cohort of 80 patients showed that patients had a higher overall response rate during re-challenge therapies after increasing time intervals, as predicted by our model.

CONCLUSION

These results provide scientific support for anti-EGFR re-challenge and guide the optimal timing of re-challenge initiation.