POS0249 FIBROBLAST ACTIVATION PROTEIN AS A LINK BETWEEN INFLAMMATION AND VASCULAR REMODELING IN GIANT CELL ARTERITIS

Background

Giant cell arteritis (GCA) can present with serious complications such as blindness, stroke and aortic aneurysm that are related to both inflammation and remodeling of the vessel wall. GCA frequently overlaps with polymyalgia rheumatica (PMR). The pathogenesis of GCA starts in the adventitia where fibroblasts are the major stromal cell population. A preliminary study [1] reported the migration of adventitial fibroblasts to the intima, contributing to intimal hyperplasia in GCA. Fibroblast activation protein (FAP) is a non-classical serine protease which can be present in both a membrane-bound form and a soluble form and has been demonstrated to promote inflammation and fibrosis in coronary artery disease and rheumatoid arthritis [2-3]. We hypothesize that FAP is involved in GCA vasculopathy due to its pro-inflammatory and pro-fibrotic effects.

Objectives

As a first step to unravel the contribution of FAP to the vasculopathy in GCA, we determined FAP plasma levels and FAP protein expression at the site of vascular inflammation in GCA.

Methods

In our prospective cohort of GCA, PMR and healthy elderly (GPS), we measured the plasma FAP levels with ELISA in new-onset, treatment-naïve GCA (N=62), and PMR (N=63) patients and 42 age-matched healthy controls (HC). In addition, we measured the plasma FAP levels at follow-up (3-months, 1-year, 1.5-year and treatment-free remission (TFR)). Temporal artery biopsies (TAB) from treatment-naïve GCA patients (n=9) and non-GCA patients (n=9), aorta samples from GCA-related aneurysm (n=9) and atherosclerosis (n=11) were stained for FAP using immunohistochemistry. Immunofluorescence staining for CD90, CD68, αSMA and FAP was performed to detect FAP expression in fibroblasts, macrophages and vascular smooth muscle cells (VSMC), respectively.

Results

Baseline plasma FAP levels were significantly lower in GCA patients (52.72±2.93 ng/ml) than in PMR patients (66.42±2.86 ng/ml) and HC (80.47±3.38 ng/ml). FAP levels at baseline correlated inversely with C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), interleukin (IL)-6, macrophage-associated protein YKL-40 (Chitinase 3-like 1/CHI3L1) levels and monocyte counts. Plasma FAP levels in GCA patients decreased even further at 3 months (37.23±2.10 ng/ml) upon glucocorticoid-induced remission, and gradually increased to the level of HC (76.84±5.43 ng/ml) when patients were in TFR. Increased FAP expression in GCA TAB (adventitia, media, intima) and aorta (media) compared with tissues from non-GCA was documented. FAP was abundantly expressed in fibroblast- and macrophage-rich areas but not in VSMC-rich areas in TAB and aorta of GCA patients.

Conclusion

FAP expression is clearly modulated both in plasma and at the site of vascular inflammation in GCA and may represent a pathogenic link between the inflammatory and remodeling processes in GCA. As such, FAP may have utility as a biomarker and should be further investigated as target for therapeutic intervention.

References

[1]Parreau Simon VN, Regent Alexis, et al. (2019). Adventitial fibroblast, an important player in giant cell arteritis. Annual European Congress of Rheumatology, EULAR 2019: Annals of the Rheumatic Diseases), pp. 434.2-5.

[2]Brokopp CE, Schoenauer R, Richards P, et al. Fibroblast activation protein is induced by inflammation and degrades type I collagen in thin-cap fibroatheromata. Eur Heart J. 2011; 32: 2713-22.

[3]Croft AP, Campos J, Jansen K, et al. Distinct fibroblast subsets drive inflammation and damage in arthritis. Nature. 2019; 570: 246-51.

Acknowledgements

No.

Disclosure of Interests

None declared

Transfusable neutrophil progenitors as cellular therapy for the prevention of invasive fungal infections

The use of mature neutrophil (granulocyte) transfusions for the treatment of neutropenic patients with invasive fungal infections (IFIs) has been the focus of multiple clinical trials. Despite these efforts, the transfusion of mature neutrophils has resulted in limited clinical benefit, likely owing to problems of insufficient numbers and the very short lifespan of these donor cells. In this report, we employed a system of conditionally immortalized murine neutrophil progenitors that are capable of continuous expansion, allowing for the generation of unlimited numbers of homogenous granulocyte-macrophage progenitors (GMPs). These GMPs were assayed in vivo to demonstrate their effect on survival in 2 models of IFI: candidemia and pulmonary aspergillosis. Mature neutrophils derived from GMPs executed all cardinal functions of neutrophils. Transfused GMPs homed to the bone marrow and spleen, where they completed normal differentiation to mature neutrophils. These neutrophils were capable of homing and extravasation in response to inflammatory stimuli using a sterile peritoneal challenge model. Furthermore, conditionally immortalized GMP transfusions significantly improved survival in models of candidemia and pulmonary aspergillosis. These data confirm the therapeutic benefit of prophylactic GMP transfusions in the setting of neutropenia and encourage development of progenitor cellular therapies for the management of fungal disease in high-risk patients.

[Analysis of clinical phenotype and genotype of Chinese children with disorders of sex development]

Objective: To explore the heterogeneity and correlation of clinical phenotypes and genotypes in children with disorders of sex development (DSD). Methods: A retrospective study of 1 235 patients with clinically proposed DSD in 36 pediatric medical institutions across the country from January 2017 to May 2021. After capturing 277 DSD-related candidate genes, second-generation sequencing was performed to analyzed the heterogeneity and correlation combined with clinical phenotypes. Results: Among 1 235 children with clinically proposed DSD, 980 were males and 255 were females of social gender at the time of initial diagnosis with the age ranged from 1 day of age to 17.92 years. A total of 443 children with pathogenic variants were detected through molecular genetic studies, with a positive detection rate of 35.9%. The most common clinical phenotypes were micropenis (455 cases), hypospadias (321 cases), and cryptorchidism (172 cases) and common mutations detected were in SRD5A2 gene (80 cases), AR gene (53 cases) and CYP21A2 gene (44 cases). Among them, the SRD5A2 mutation is the most common in children with simple micropenis and simple hypospadias, while the AMH mutation is the most common in children with simple cryptorchidism. Conclusions: The SRD5A2 mutation is the most common genetic variant in Chinese children with DSD, and micropenis, cryptorchidism, and hypospadias are the most common clinical phenotypes. Molecular diagnosis can provide clues about the biological basis of DSD, and can also guide clinicians to perform specific clinical examinations. Target sequence capture probes and next-generation sequencing technology can provide effective and economical genetic diagnosis for children with DSD.

The Yin and Yang of Pneumolysin During Pneumococcal Infection

Pneumolysin (PLY) is a pore-forming toxin produced by the human pathobiont Streptococcus pneumoniae, the major cause of pneumonia worldwide. PLY, a key pneumococcal virulence factor, can form transmembrane pores in host cells, disrupting plasma membrane integrity and deregulating cellular homeostasis. At lytic concentrations, PLY causes cell death. At sub-lytic concentrations, PLY triggers host cell survival pathways that cooperate to reseal the damaged plasma membrane and restore cell homeostasis. While PLY is generally considered a pivotal factor promoting S. pneumoniae colonization and survival, it is also a powerful trigger of the innate and adaptive host immune response against bacterial infection. The dichotomy of PLY as both a key bacterial virulence factor and a trigger for host immune modulation allows the toxin to display both "Yin" and "Yang" properties during infection, promoting disease by membrane perforation and activating inflammatory pathways, while also mitigating damage by triggering host cell repair and initiating anti-inflammatory responses. Due to its cytolytic activity and diverse immunomodulatory properties, PLY is integral to every stage of S. pneumoniae pathogenesis and may tip the balance towards either the pathogen or the host depending on the context of infection.

Preparation of magnesium Ferrite-Doped magnetic biochar using potassium ferrate and seawater mineral at low temperature for removal of cationic pollutants

Magnetic biochar has captured a great interest for remediation of environment as an easily separable carbonous adsorbent. Herein, a highly adsorptive magnetic biochar was manufactured through seawater mineral and K₂FeO₄ co-promoted pyrolysis of jackfruit peel at 300 °C for removal of different cationic pollutants, and characterized by element analysis, FTIR, SEM-EDS, XRD, XPS and so on. MgFe₂O₄ was generated without external base and a 19.42 emu/g saturation magnetization was achieved. Simultaneously, iron oxides and oxygen containing groups were introduced. The magnetic biochar exhibited 61.30 mg/g, 129.61 mg/g, and 1238.30 mg/g adsorption capacities for Cu²⁺, methylene blue (MB), and malachite green (MG) at 25 °C, respectively, and remarkably surpassed the corresponding pristine biochar. The adsorption of MB and MG was mainly realized by electrostatic interaction, hydrogen bonding, complexation, and π-π electron-donor-acceptor interaction, and that of Cu²⁺ was attributed to electrostatic interaction, hydrogen bonding, and complexation.

Investigation of seawater mineral promoted pyrolysis at low temperature for improving the adsorption capabilities of biochar

Naturally abundant seawater mineral was employed to engineer banana pseudostem and bamboo biochars through pyrolysis at different low temperatures for improving their adsorption capabilities for methylene blue (MB) and tetracycline (TC). The adsorption capabilities were greatly enhanced as the biochars were pyrolyzed at 300 °C with 50/1 (mL/g) dosage of seawater to biomass. For instance, the engineered banana pseudostem biochar exhibited 8.00 and 6.54 times higher adsorption capabilities than the corresponding pristine biochar for MB (447.79 mg/g vs 55.96 mg/g) and TC (100.59 mg/g vs 16.75 mg/g) at 25 °C, respectively. The characterization results indicated that a large number of carboxylates, lactone acid salts, and alkoxides were generated on the engineered biochar and a high cation exchange capacity was gained. The adsorption of MB was mainly attributed to cation exchange complying with hydrogen bonding and electrostatic interaction, whereas the adsorption of TC was realized by hydrogen bonding and complexation.

Knee symptom but not radiographic knee osteoarthritis increases the risk of falls and fractures: results from the Osteoarthritis Initiative

OBJECTIVE

To describe the effect of knee symptoms and radiographic osteoarthritis (ROA) on the risk of falls, recurrent falls, and fractures.

DESIGN

Participants from the Osteoarthritis Initiative were classified as having 'no', 'unilateral' or 'bilateral' knee symptoms (≥19 on a 0-96 Western Ontario and McMaster Universities Osteoarthritis Index) and ROA (Kellgren-Lawrence grade ≥2) for each visit. Self-reported falls and fractures in the past 12 months were extracted at baseline and follow-up visits until month 96. Recurrent falls were defined as having ≥2 falls in the past 12 months. Hazard ratios (HR) with 95% confidence intervals (CI) were estimated using mixed-effects complementary log-log regression.

RESULTS

Of 4465 participants, 3145 (70%), 1681 (38%), and 806 (18%) experienced at least one fall, recurrent fall, and fracture, respectively, over 96 months. Compared to participants without symptomatic knee, unilateral and bilateral knee symptoms were associated with a 17% increased risk of falls and a 36-46% increased risk of recurrent falls, and bilateral knee symptoms increased the risk of fractures (HR 1.45, 95%CI 1.17 to 1.81). Compared to participants with no ROA in either knee, bilateral ROA was associated with a reduced risk of falls (HR 0.87, 95%CI 0.77 to 0.99) and fractures (HR 0.78, 95%CI 0.64 to 0.96). No statistically significant interactions between knee symptoms and ROA were observed.

CONCLUSIONS

This large population-based study showed that knee symptoms but not ROA increased the risk of falls, recurrent falls, and fractures, and that adults with bilateral ROA may have a lower risk of falls and fractures.

222 Robotic Surgery: Public Perceptions and Current Misconceptions

Aim

While surgeons and robotic companies are key stakeholders involved in the adoption of Robotic Surgery (RS), the public's role is often overlooked. However, given that patients hold ultimate power over their healthcare decisions, public acceptance of RS is crucial. This study aims to identify public understanding, opinions and misconceptions on RS and present solutions to facilitate its wider integration.

Method

An online questionnaire distributed via social media platforms between February and May 2021 identified the views of UK adults on RS. The data was evaluated using thematic analysis, descriptive statistics, and statistical analysis. Statistical differences in age, gender, education level, and presence in the medical field were also sought.

Results

263 responses were obtained, with 216 (82.1%) analysed. Demographic differences provided significantly different results. Participants were relatively uninformed about RS, with a median knowledge score of 4.00(2.00–6.00) on a 10-point likert scale. Fears surrounding increased risk, reduced precision and technological failure were identified, alongside misconceptions on what RS entails, including it being autonomous. However, providing factual information in the survey about RS statistically increased participant comfort (p=<0.0001). Most (61.8%) participants believed robot manufacturers were responsible for malfunctions, but doctors were held accountable more by older, less educated, and non-medical participants.

Conclusions

This study highlights the role of negative and inaccurate public perceptions surrounding RS in impeding its widespread adoption. Greater emphasis must be placed on patient education in RS to mitigate misconceptions and ensure greater diffusion of its benefits

219 The Opportunities and Challenges of Robotic Surgery: A Surgeon and Robotic Company Perspective

Introduction

As an increasing number of specialties have begun to adopt robotic surgery (RS), its prevalence within the NHS is continually rising. This study aims to establish stakeholders’ opinions on the opportunities and challenges of the widespread adoption of RS.

Method

Participants were recruited through social media platforms such as LinkedIn or via university affiliations and current RS research. Semi-structured interviews of eight surgeons and five company representatives were conducted online. Transcripts were analysed to formulate themes surrounding the opportunities and challenges of RS.

Results

This study identified six common themes amongst shareholders: Perspective, Ethics, Impact of Robotics, Training, Adoption and Finances. The success rates and quality of results offered by RS make it a recognised future surgical staple amongst interviewees. However, the technology remains a contentious subject amongst surgeons, with many doubting whether the benefits outweigh the costs associated with implementation. Such reservations are further exacerbated by the absence of a formal training pathway. National guidelines are necessary to embed RS within the NHS infrastructure, allowing greater standardisation for patients and surgeons. The importance of patient education to address misconceptions was emphasised. Despite current high costs, robotic technology is forecasted to become cheaper with greater use and increased market competition. Interviewees stressed that responsibility for errors lies with the surgeon, but with the manufacturer for instrument malfunctions.

Conclusions

This study highlights stakeholders’ views on the opportunities and challenges of RS. The identified themes should form the basis of the proposed recommendations to facilitate a more widespread adoption of RS.

[Epidemiological characteristics of imported Plasmodium ovale malaria in Jiangsu Province from 2012 to 2020]

OBJECTIVE

To analyze the epidemiological characteristics of imported cases with Plasmodium ovale infections in Jiangsu Province from 2012 to 2020, so as to provide insights into the development of the imported malaria control strategy in the province.

METHODS

All data pertaining to cases with definitive diagnosis of P. ovale malaria in Jiangsu Province from 2012 to 2020 were captured from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China, including the date of going abroad and returning to China, time of malaria infections overseas, date of malaria onset, initial diagnosis and definitive diagnosis. All data pertaining to epidemic status were descriptively analyzed.

RESULTS

A total of 347 cases of P. ovale malaria were reported in Jiangsu Province from 2012 to 2020, with the highest number seen in 2015 (71 cases). All cases were laboratory-confirmed overseas imported malaria cases, accounting for 14.32% of all reported malaria cases in Jiangsu Province during the period from 2012 to 2020. The 5 cities with the highest number of imported P. ovale malaria cases included Lianyungang City (53 cases, 15.27%), Nantong City (44 cases, 12.68%), Huai'an (44 cases, 12.68%), Taizhou City (44 cases, 12.68%) and Yangzhou City (36 cases, 10.37%). The highest number of imported P. ovale malaria cases was reported in October (39 cases, 11.24%), and the lowest number was seen in December (21 cases, 6.05%). P. ovale infections mainly occurred in were Equatorial Guinea (97 cases, 37.95%), Angola (60 cases, 17.29%) and Nigeria (40 cases, 11.53%). The median duration between returning to China and malaria onset was 64 (144) days, and 7.49% (26/347) of all cases developed malaria one year after returning to China. The initial diagnosis of P. ovale malaria was mainly made at county-level medical institutions (117 cases, 33.72%), and the definitive diagnosis was mainly made at city-level medical institutions (122 cases, 35.16%). The correct rate of initial diagnosis of P. ovale malaria increased from 0 in 2012 to 78.26% in 2020, appearing a tendency towards a rise year by year (χ² = 50.90, P < 0.01).

CONCLUSIONS

Imported P. ovale malaria cases were reported in Jiangsu Province each year from 2012 to 2020, and P. ovale infections predominantly occurred in Africa. Initial and definitive diagnoses of P. ovale malaria were mainly made at city- and county-level medical institutions. Training on the detection ability of malaria parasites is recommended among grassroots microscopists to improve the diagnostic ability of P. ovale malaria, and consolidate the achievements of malaria elimination in Jiangsu Province.

[Adult myofibroma: a clinicopathological analysis of 15 cases]

Objective: To investigate the clinicopathological features and immunophenotype of adult myofibroma with emphasis on its differential diagnosis. Methods: The clinical, pathologic data and immunohistochemical profiles were analyzed in 15 cases of adult myofibroma diagnosed between 2014 and 2020 in Department of Pathology, Fudan University Shanghai Cancer Center. The literature was reviewed. Results: There were seven males and eight females, with age at presentation ranging from 22 to 74 years (mean 54 years; median 57 years). Tumor occurred principally in the extremities (n=9), less frequently involved the head and neck region (n=3) and trunk (n=2); one case was located in the vertebral canal of C6-7. Fourteen cases were solitary; one case was multifocal. Most patients presented with a slowly growing painless subcutaneous nodule, about 1 to 2 cm in size. One patient with multifocal disease and the patient with spinal lesion complained of intermittent pain. The duration of symptoms ranged from 2 months to 10 years. Microscopically, they were well circumscribed. All cases showed biphasic growth pattern, consisting of relatively well-differentiated eosinophilic nodules alternating with dark-staining primitive-appearing areas. The light-staining hypocellular nodules were composed of myofibroblast-like plump spindle cells within an eosinophilic stroma, which assumed pale blue myxochondroid appearance and hyalinization of varying degree. The dark-staining areas were composed of compact short spindled to ovoid cells with hyperchromatic nuclei and low mitotic activity, frequently showing a distinctive hemangiopericytoma-like architecture. By immunohistochemistry, the myoid spindled cells and the primitive cells stained variably for α-SMA, MSA and calponin, but were consistently negative for desmin and β-catenin. Conclusions: Adult myofibroma tends to occur in the middle to old aged patients with a predilection for the dermis or subcutis of the extremities. It is a benign neoplasm which can be cured by excision in most cases. Familiarity with its distinctive clinicopathological features helps in the distinction from other myofibroblastic neoplasms.

Knockdown of Sirt1 Gene in Mice Results in Lipid Accumulation in the Liver Mediated via PGC-1α-Induced Mitochondrial Dysfunction and Oxidative Stress

The study demonstrated the crucial role of Sirt1 gene in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) related to the influence of Sirt1 on oxidative stress and glycolipid metabolism. The 16-week-old genetically diabetic db/db mice were characterized with downregulated expression of Sirt1 in the liver accompanied by hepatomegaly and a larger size of fat vacuoles in hepatocytes. In db/m mice, silencing Sirt1 gene induced hepatic steatosis and significantly increased serum AST. Additionally, the levels of triglycerides in blood and liver of these mice were elevated. However, all pathological changes in the liver of Sirt1-knockdown db/m mice were less pronounced than in 16-week-old db/db mice. Further experiments showed that oxidative stress and PGC-1α-mediated mitochondrial dysfunction are implicated in pathological changes of lipid metabolism in T2DM-induced NAFLD provoked by Sirt1 silencing. This study showed that down-regulation of Sirt1 expression plays the key role in pathological processes developed during T2DM-induced abnormalities of lipid metabolism in the liver. Thus, up-regulation of Sirt1 expression seems to be a promising strategy in early prevention of T2DM-induced NAFLD.

Efficacy of Bifidobacterium animalis subsp. lactis, BB-12® on infant colic - a randomised, double-blinded, placebo-controlled study

To evaluate the administration of Bifidobacterium animalis subsp. lactis, BB-12^® (BB-12) on infant colic in breastfed infants, a double-blind, placebo-controlled randomised study was conducted in Chengdu, China from April 2016 to October 2017 with 192 full-term infants less than 3 months of age and meeting the ROME III criteria for infant colic. After a 1-week run-in the infants were randomly assigned to receive daily BB-12 (1×10⁹ cfu/day) or placebo for 3 weeks. Crying/fussing time were recorded using a 24 h structured diary. The primary endpoint was the proportion of infants achieving a reduction in crying and fussing time of ≥50% from baseline. Parent's/caregiver's health related quality of life was measured using a modified PedsQL^™ 2.0 Family Impact Module and immunological biomarkers were evaluated from faecal samples at baseline and after the 21-day intervention. The percentage of infants achieving a reduction in the daily crying/fussing time ≥50% after the 21-day intervention was significantly higher in the infants supplemented with BB-12 (P<0.001). The mean number of crying episodes was significantly reduced in the BB-12 group compared to the placebo group (10.0±3.0 to 5.0±1.87 vs 10.5±2.6 to 7.5±2.8, respectively) (P<0.001) and the mean daily sleep duration was markedly increased from baseline to end of intervention in the BB-12 group compared to the infants in the placebo group (60.7±104.0 vs 31.9±102.7 min/day, respectively) (P<0.001). The faecal levels of human beta defensin 2, cathelicidin, slgA, calprotectin and butyrate were statistically higher in the BB-12 group compared to the placebo group after the 21-day intervention. At the end of the intervention the parent's/caregiver's physical, emotional and social functioning scores were significantly higher for the BB-12 group compared to the placebo group (all P<0.05). Supplementation of BB-12 is effective in reducing crying and fussing in infants diagnosed with infant colic.

[Application of Hydrashift 2/4 daratumumab assay in eliminating interference of daratumumab on serum immunofixation electrophoresis]

Objective: To investigate the interference of daratumumab on immunofixation electrophoresis after treating plasma cell diseases and methods to eliminate the interference. Methods: Serum samples of eight patients with plasma cell diseases treated with daratumumab in Peking University People's Hospital from April 2020 to March 2021 were collected for standard immunofixation electrophoresis and Hydrashift 2/4 daratumumab assay. Results: After treatment, 81.3% (13/16) of the samples showed drug-induced monoclonal antibodies (IgG-κ) . The samples without drug-induced monoclonal bands were related to individual differences, administration intervals, and immunoglobulin levels. Among the samples with IgG-κ monoclonal bands, 76.9% (10/13) could be directly identified as endogenous or exogenous monoclonal bands by immunofixation electrophoresis, and the others (3/13) could be identified by Hydrashift 2/4 daratumumab assay. Conclusion: Hydrashift 2/4 daratumumab assay can remove the band of daratumumab on the immunofixation electrophoresis and help with efficacy evaluation.

[Establishment and application of a multilocus sequence typing assay for Corynebacterium striatum]

Objective: To establish a multilocus sequence typing (MLST) assay for Corynebacterium (C.) striatum, explore the population structure and evolution relationship of clinical isolates of C. striatum. Methods: Seven housekeeping genes (gyrA, gyrB, hsp65, sodA, secA1, rpoB, 16S rRNA) were amplified with PCR by using self-designed specific primers and sequenced. Then, the sequences were assembled with software SeqMan. The gene diversity and gene recombination characteristics were evaluated by using software DnaSP 5.10.01 and Splits tree 4.14.2. The phylogenetic tree and the minimum spanning tree were constructed based on the sequence types (ST) characteristics by using software MEGA 7.0.14 and BioNumerics, respectively. In addition, the genetic evolutionary relationship among STs were analyzed by using software eBURST 3.0. Results: The expected amplification products of seven sites selected in all the test strains were obtained. Splits tree showed that the clustering of all C. striatum strains was consistent, suggesting that gene recombination is the potential driving force for the evolution of C. striatum. All of the 344 C.striatum strains were divided into 72 STs by MLST and 85.7% of the strains formed clonal complexes. CC19 was the predominant clonal complex, whereas ST16 in the clonal complex was detected in the most strains. ST had a certain geographic clustering and a certain correlation with the isolation time. Conclusions: C. striatum showed high genetic diversity in China and CC19 was the predominant clonal complex. The MLST assay established in this study can be used for the typing of C. striatum, but further improvement is needed.