Systematic profiling of Taxol resistance and sensitivity to tubulin missence mutations at molecular and cellular levels

Taxol (paclitaxel) is the first approved microtubule-stabilizing agent (MSA) by binding stoichiometrically to tubulin, which is considered to be one of the most significant advances in first-line chemotherapy against diverse tumors. However, a large number of residue missence mutations harboring in the tubulin have been observed to cause acquired drug resistance, largely limiting the clinical application of Taxol and its analogs in chemotherapy. A systematic investigation of the intermolecular interactions between the Taxol and various tubulin mutants would help to establish a comprehensive picture of drug response to tubulin mutations in clinical treatment of cancer, and to design new MSA agents with high potency and selectivity to overcome drug resistance. In this study, we described an integration of in silico analysis and in vitro assay (iSiV) to profile Taxol against a panel of 149 clinically observed, cancer-associated missence mutations in β-tubulin at molecular and cellular levels, aiming to a systematic understanding of molecular mechanism and biological implication underlying drug resistance and sensitivity conferring from tubulin mutations. It is revealed that the Taxol-resistant mutations can be classified into three types: (I) nonbonded interaction broken due to mutation, (II) steric hindrance caused by mutation, and (III) conformational change upon mutation. In addition, we identified three new Taxol-resistant mutations (C239Y, T274I, and R320P) that can largely reduce the binding affinity of Taxol to tubulin at molecular level, in which the T274I and R320P were observed to considerably impair the antitumor activity of Taxol at cellular level. Moreover, a novel drug-susceptible mutation (M363T) was also identified, which improves Taxol affinity by 2.6-fold and decreases Taxol antitumor EC50 values from 29.4 to 18.7 μM.

[Current status of diagnosis and treatment of chronic lymphocytic leukemia in China: A national multicenter survey research]

Objective: To understand the current status of diagnosis and treatment of chronic lymphocytic leukemia (CLL) /small lymphocytic lymphoma (SLL) among hematologists, oncologists, and lymphoma physicians from hospitals of different levels in China. Methods: This multicenter questionnaire survey was conducted from March 2021 to July 2021 and included 1,000 eligible physicians. A combination of face-to-face interviews and online questionnaire surveys was used. A standardized questionnaire regarding the composition of patients treated for CLL/SLL, disease diagnosis and prognosis evaluation, concomitant diseases, organ function evaluation, treatment selection, and Bruton tyrosine kinase (BTK) inhibitor was used. Results: ①The interviewed physicians stated that the proportion of male patients treated for CLL/SLL is higher than that of females, and the age is mainly concentrated in 61-70 years old. ②Most of the interviewed physicians conducted tests, such as bone marrow biopsies and immunohistochemistry, for patient diagnosis, in addition to the blood test. ③Only 13.7% of the interviewed physicians fully grasped the initial treatment indications recommended by the existing guidelines. ④In terms of cognition of high-risk prognostic factors, physicians' knowledge of unmutated immunoglobulin heavy-chain variable and 11q- is far inferior to that of TP53 mutation and complex karyotype, which are two high-risk prognostic factors, and only 17.1% of the interviewed physicians fully mastered CLL International Prognostic Index scoring system. ⑤Among the first-line treatment strategy, BTK inhibitors are used for different types of patients, and physicians have formed a certain understanding that BTK inhibitors should be preferentially used in patients with high-risk factors and elderly patients, but the actual use of BTK inhibitors in different types of patients is not high (31.6%-46.0%). ⑥BTK inhibitors at a reduced dose in actual clinical treatment were used by 69.0% of the physicians, and 66.8% of the physicians had interrupted the BTK inhibitor for >12 days in actual clinical treatment. The use of BTK inhibitors is reduced or interrupted mainly because of adverse reactions, such as atrial fibrillation, severe bone marrow suppression, hemorrhage, and pulmonary infection, as well as patients' payment capacity and effective disease progression control. ⑦Some differences were found in the perceptions and behaviors of hematologists and oncologists regarding the prognostic assessment of CLL/SLL, the choice of treatment options, the clinical use of BTK inhibitors, etc. Conclusion: At present, a gap remains between the diagnosis and treatment of CLL/SLL among Chinese physicians compared with the recommendations in the guidelines regarding the diagnostic criteria, treatment indications, prognosis assessment, accompanying disease assessment, treatment strategy selection, and rational BTK inhibitor use, especially the proportion of dose reduction or BTK inhibitor discontinuation due to high adverse events.

[Correlation between polycyclic aromatic hydrocarbons component phenanthrene and clinical indicators in patients on peritoneal dialysis]

Objective: To explore the correlation between polycyclic aromatic hydrocarbons (PAHs) component phenanthrene and clinical indicators in patients on continuous ambulatory peritoneal dialysis (CAPD). Methods: A total of 22 patients who underwent peritoneal dialysis catheterization and regular dialysis in the First Affiliated Hospital of Zhengzhou University from June to August 2018 were selected. Meanwhile, 18 healthy adults who underwent physical examination were also selected as the control group. Fasting blood samples were taken to detect the concentration of PAHs components for comparison, and the correlation between PAHs components and clinical indicators was further analyzed. Results: There were 22 cases in CAPD group (13 males and 9 females), and aged (45±13) years, while there were 18 cases in control group (6 males and 12 females), and aged (41±13) years. The concentration of blood phenanthrene (PHE) was the highest in CAPD group [0.449 (0.254, 0.581) mg/L], and it was only lower than acenaphthene in the control group [0.081 (0.050, 0.444) mg/L], with a statistically significant difference between the two groups (P=0.008). The analysis of PHE and clinical indicators showed that the concentration of PHE in CAPD patients was negatively correlated with weekly urea clearance index (Kt/V), weekly creatinine clearance (Ccr) and leukocyte level, but positively correlated with triglyceride level (r=-0.743, -0.749, -0.655 and 0.610, respectively, all P<0.05). Simple linear regression analysis demonstrated that for every 0.1 mg/L increase in PHE concentration, weekly Kt/V, weekly Ccr and white blood cell count decreased by 0.226, 3.050 L/1.73 m² and 0.512×10⁹/L, respectively, but triglyceride level increased by 0.152 mmol/L (all P<0.05). Multiple linear regression analysis revealed that the blood PHE concentration of CAPD patients was negatively correlated with weekly Kt/V and Ccr levels (t=-2.402 and -2.368, respectively, both P<0.05). All CAPD patients were followed up for 3 years, during which 8 patients (36.4%) withdrew from peritoneal dialysis due to technical failure, and the baseline PHE concentration was higher than that of patients who did not quit peritoneal dialysis [0.572 (0.416, 0.662) vs 0.268 (0.120, 0.475) mg/L, P=0.003]. Eight patients (36.4%) had cardiovascular events, and the baseline blood PHE concentration was higher than that of patients without cardiovascular events [0.542 (0.389, 0.741) vs 0.373 (0.157, 0.545) mg/L, P=0.045]. Conclusion: PHE correlates with clinical indicators of CAPD patients, including Kt/v, Ccr, leukocyte and triglyceride.

[Associations between early onset of puberty and obesity types in children: Based on both the cross-sectional study and cohort study]

OBJECTIVE

To explore and analyze the relationship between early onset of puberty and different types of obesity in children, by combining large sample cross-sectional survey data with long-term longitudinal cohort data, so as to provide clues for further clarifying the health hazards of early onset of puberty and obesity prevention and control.

METHODS

The research data were from the cross-sectional survey data of seven provinces(autonomous regions, municipalities) in China and the cohort data of adolescent development in Xiamen. The study first found the association between early onset of puberty and obesity by Logistic regression on the cross-sectional data, and then used Poisson regression to analyze the association between early puberty initiation and various types of obesity risk.

RESULTS

In the study, 43 137 and 1 266 children were included in the cross-sectional survey and cohort survey respectively. The cross-sectional study found that among the girls aged 10-13 years, compared with the girls of the same age who did not start puberty, the body mass index (BMI)-Z score of the girls in the puberty start group was 0.5-0.8 higher, and the waist circumference Z score was 0.4-0.7 higher, and the risk of various types of obesity was higher. At the same time, the early onset of puberty was positively correlated with simple obesity, central obesity and compound obesity, the OR (95%CI) were 1.86 (1.42-2.44), 1.95 (1.65-2.32) and 1.86 (1.41-2.45), respectively. No significant association was found in boys. According to the cohort data, in girls, the risk of simple obesity was 6.00 times [RR (95%CI): 6.00 (1.07-33.60)], the risk of central obesity was 3.30 times [RR (95%CI): 3.30 (1.22-8.92)], and the risk of compound obesity was 5.76 times [RR (95%CI): 5.76 (1.03-32.30)], compared with the group without early puberty initiation, while no association between early puberty initiation and obesity was found in boys.

CONCLUSION

Based on the cross-sectional survey and longitudinal cohort survey, it is confirmed that the early onset of puberty in girls may increase the risk of simple obesity, central obesity and compound obesity, while there is no significant correlation between puberty onset and obesity in boys.

POS0599 IMPACT OF TREAT-TO-TARGET THERAPY ON BONE MINERAL DENSITY LOSS IN PATIENTS WITH RHEUMATOID ARTHRITIS: A PROSPECTIVE COHORT STUDY

Background

Osteoporosis is a common comorbidity of rheumatoid arthritis (RA). Although RA disease activity has been demonstrated to be associated with bone loss in previous studies, most of them were cross-sectional studies and not in the context of treat-to-target (T2T) strategies.

Objectives

To evaluate the association of disease activity with bone mineral density (BMD) changes in the context of T2T strategies in a prospective RA cohort.

Methods

RA patients were enrolled from a prospective CENTRA cohort of Peking University First Hospital. BMD was repeated at baseline, 1-year and then every other year. Time-adjusted mean disease activity scores were adopted to reflect the overall disease activity during follow-up. The influence of univariable associations between predictors and BMD was investigated using linear regression.

Results

A total of 268 patients were included in our analysis. Their mean age was 50 (12.9) years old. At enrollment, the mean (SD) DAS28-ESR was 3.70 (1.17), and the median (IQR) CDAI and SDIA was 10 (14.45) and 10.30 (16.53), respectively. Osteoporosis at lumbar spine was observed in 23.1% patients and 9.3% at femoral neck at enrollment. Older age, higher SDAI score and lower BMI were found to be associated with osteoporosis at baseline. Reevaluations of BMD at 1 year was applied in 144 patients. Mean decreases of BMDs were 1.75 % at the lumbar spine and 1.40 % at femoral neck at 1 year form baseline, respectively. Patients who achieved remission had less yearly bone loss at lumbar spine (p=0.036). Female gender was identified as a risk factor in the multiple linear regression analyses, and lower disease activity and bisphosphonates were protective factors of continuous bone loss.

Conclusion

Disease activity is associated with bone loss in RA patients in the context of T2T strategies, and those who achieved remission had less yearly bone loss.

Disclosure of Interests

None declared

POS0720 LOW-DOSE GLUCOCORTICOIDS WITHDRAWN IN SYSTEMIC LUPUS ERYTHEMATOSUS: A DESIRABLE AND ATTAINABLE GOAL

Background

Prolonged use of GC may cause irreversible organ damage, leading to impaired quality of life and even increased mortality. However, many physicians are worried about severe flares after GC withdrawal in daily practice.

Objectives

To assess the risk of flare in systemic lupus erythematosus (SLE) patients after low dose glucocorticoids (GC) discontinuation and evaluate the risk factors of flare.

Methods

SLE patients who ever discontinued GC were identified from PKUFHS cohort. The disease flare profile after GC discontinuation were analyzed. Flare rate was analyzed using Kaplan-Meier analysis. COX regression was used to determine the effect of variables on SLE flare. A prognostic nomogram using Cox proportional hazards regression modeling were developed.

Results

132 SLE patients were eligible for the final analysis. They were followed up for a median (IQR) period of 21.8 (9.01, 36.7) months. The cumulative probability of flare after GC discontinuation was 8.3 % at 6 months, 16.8% at year 1 and 27.5% at year 2 (Figure 1A). In multivariate COX analysis, hypocomplementemia and serologically active clinically quiescent (SACQ) were independent risk factors of flare [HR 2.53, 95% CI (1.32, 4.88); HR 3.17, 95% CI (1.44, 6.97), respectively]. Age ≥ 40y at GC withdrawal and hydroxychloroquine usage were independent protective factors of flare [HR 0.53, 95% CI (0.29, 0.99); HR 0.32, 95% CI (0.17, 0.62), respectively] (Table 1). The protective effect of hydroxychloroquine was dosage related. From the prospective of different tapering strategies embodied as duration from prednisone 5mg/d to complete discontinuation, slower tapering strategy (12-24 months) significantly reduced the risk of flare compared to faster tapering strategy (< 3 months) [HR 0.30, 95% CI (0.11, 0.82), p=0.019]. The prognostic nomogram including aforementioned factors effectively predicted 1- and 2-year probability of flare-free (Figure 1B).

Table 1.

Predictors of flare by univariate and multivariate COX analysis.

UnivariatepMultivariatepMultivariatepModel 1Model 2age≥40y at GC withdrawal0.59 (0.33,1.07)0.0840.53 (0.29, 0.99)0.0490.63 (0.33, 1.18)0.147Age at onset ≥18y2.03 (0.62, 6.66)0.2442.75 (0.77, 9.85)0.1212.88 (0.81, 10.2)0.103Remission duration≥60 months since the last flare0.66 (0.35, 1.27)0.2170.81 (0.41, 1.57)0.5260.73 (0.38, 1.41)0.346history of thrombocytopenia1.73 (0.94, 3.18)0.0771.36 (0.70, 2.65)0.3591.45 (0.74, 2.83)0.278history of lupus nephritis0.86 (0.47, 1.55)0.610////Hypocomplementemia1.97 (1.06, 3.66)0.0312.53 (1.32, 4.88)0.005//anti-dsDNA positive1.25 (0.70, 2.23)0.456////SACQ (both)2.91 (1.38, 6.15)0.005//3.17 (1.44, 6.97)0.004SACQ (or)1.29 (0.73, 2.30)0.380////Hydroxychloroquine or not0.29 (0.16, 0.53)<0.0010.29 (0.15, 0.56)<0.0010.32 (0.17, 0.62)0.001Immunosuppressant or not0.77 (0.40, 1.48)0.426////

There was strong collinearity between hypocomplementemia and SACQ, so the two parameters were separated into two models. SACQ (both): anti-dsDNA positive and hypocomplementemia; SACQ (or): anti-dsDNA positive or hypocomplementemia; GC: glucocorticoids. Data were shown as HR (95% CI).

Figure 1.

Conclusion

Low-dose GC is feasibly discontinued with infrequent flare in real-life setting. SACQ and younger age are potential risk factors of SLE flare, while hydroxychloroquine usage and slow GC tapering to withdrawal can reduce relapse. The visualized model we developed may help to predict risk of flare among SLE patients who discontinued GC.

Disclosure of Interests

None declared

AB0030 THE BIOLOGICAL FUNCTION AND MECHANISM EXPLORATION OF TACI IN SJOGREN’S SYNDROME

Background

primary Sjogren’s syndrome (pSS) is a chronic autoimmune disease that affects the lacrimal, salivary and other exocrine glands. More and more studies have shown that B cells play a central role in the pathogenesis of SS.

Objectives

We intended to explore the expression of the transmembrane activator, calcium modulator and cyclophilin ligand interactor (TACI) on the B cells, its role in pSS, and possible signal transduction pathways.

Methods

We included 34 naive pSS patients who visited the rheumatology department of Peking University First Hospital, and 37 gender- and age-distribution matched healthy controls (HCs). (1) To compare the B cell subsets, expression of TACI and relevant receptors in pSS patients, peripheral blood mononuclear cells were separated to analyze the ratio of B subsets, TACI, and BAFF-R by flow cytometry; ELISA was applied to detect the serum BAFF and soluble TACI (sTACI) concentration. (2) As for functional research of TACI, CD19+ B cells separated by magnetic sorting were treated under in vitro culture circumstances with raw TACI, TACI knocked down by siRNA, and sTACI analog (telitacicept) intervention with varing doses. The apoptosis, proliferation, differentiation and regulatory capacity on T cells were analyzed by flow cytometry, inflammatory cytokines and immunoglobulin levels in the culture supernatants were detected by CBA. (3) As for TACI-associated signaling pathway exploration, based on our previous miRNA data and relevant report of high quality, miRNA associated with TACI with significantly biased expression was confirmed by RT-qPCR. Screening the target gene of the candidate miRNA, and miRNA overexpression and inhibition experiments were conducted to validate the targeted relationship in B cells. And TACI-associated signaling pathway was explored via overexpressing and inhibiting the target gene.

Results

(1) Compared to HC, peripheral blood B subsets of pSS patients exhibited a significant bias, manifesting as increased proportion of CD19+CD24hiCD38hi Breg and decreased ratio of CD19+CD24+CD38- memory B cells. The expression of TACI in all B subsets was down-regulated, while that of BAFF-R was up-regulated. Both the serum concentration of BAFF and sTACI in pSS patients increased significantly. (2) As for functional research of TACI, in the setting of raw TACI, B cells in the pSS group showed higher apoptosis rate than HC under culture in vitro, where the ligand of TACI (APRIL or BAFF) addition turned the rate comparable; more active proliferation, and impaired capacity of inducing Treg cells to secrete IL-10. When TACI was knocked down by 50%, B cells performed less late apoptosis, significantly increased proliferation, impaired differentiation, significant dysfunction of Breg itself and impaired induction of Treg cells to secrete IL-10. While telitacicept intervention increased early apoptosis rate of B cells, significantly inhibited proliferation in 500ng/mL group and impaired ability of Breg and Treg cells to secrete IL-10. Besides, increased TACI on B cells treated with telitacicept, decreased IgG and increased IgA in the culture supernatants were observed. (3) As for TACI-associated signaling pathway exploration, hsa-miR-30b-5p showed satisfactory correlation between both transmembrane and sTACI. Besides, the expression of hsa-miR-30b-5p was significantly down-regulated, and inhibition its expression in vitro could lead to differentiation retard, impaired secretion of IL-10 by Breg cells. SMAD1 was screened based on database and validated as its target gene by overexpressing and inhibiting hsa-miR-30b-5p in B cell. After targeted up- or down-regulating the transcription of SMAD1 further, the transcription of ID2 downstream the TGF-β/Hippo signaling pathway changed accordingly.

Conclusion

The expression of TACI on peripheral blood B cells was deficient in pSS patients. TACI deficiency was closely associated with the downregulation of hsa-miR-30b-5p, activating TGF-β/Hippo pathway mediated by its target gene SMAD1 and taking part in the pathogenesis of pSS.

Disclosure of Interests

None declared

[The impact of occupational aluminum exposure on workers' overall cognitive function and various cognitive fields]

Objective: To evaluate the effects of occupational aluminum exposure on workers' overall cognitive function and cognitive fields. Methods: From July to August 2019, using the method of cluster sampling, 101 and 117 workers were selected from the electrolytic aluminum workshop of an aluminum plant in a region and the maintenance workshop of a plant in the same region. The venous blood of the subjects was collected, the plasma was extracted, and the blood aluminum concentration was measured by ICP-MS. According to the blood aluminum concentration and type of work, 93 workers who were lower than the median blood aluminum concentration and in the maintenance workshop of a factory were divided into low aluminum exposure group, and 85 workers who were higher than the median blood aluminum concentration and in the electrolytic aluminum workshop of an aluminum factory were divided into high aluminum exposure group. The basic information of the respondents, was collected through the employee physical examination form. The overall cognitive function of workers was evaluated by Beijing Montreal Cognitive Assessment Scale (MoCA) . Multiple linear regression analysis and logistic regression analysis were used for multiple statistical analysis. Results: Compared with the low aluminum exposure group (25.42±1.808) , the total score of MoCA in the high aluminum exposure group (23.84±2.919) was significantly lower, and the scores of visual space, executive function, abstract and delayed recall were significantly lower (P<0.05) . Linear regression analysis showed that the total score of MoCA, visual space and executive function, naming and delayed recall were negatively correlated with blood aluminum concentration (β=-0.018、-0.008、-0.003、-0.008, P<0.05) .MOCA total score, visual space and executive function, attention, language, abstraction, orientation were positively correlated with educational level (β=0.853、0.310、0.216、0.171、0.412、0.122, P<0.05) . Logistic regression analysis showed that adjusting for age, smoking, drinking and education, blood aluminum was a risk factor for mild cognitive impairment (OR=1.017, P<0.05) ; Education level was the protective factor of mild cognitive impairment (OR=0.419, P<0.05) . Conclusion: Occupational aluminum exposure can affect the overall cognitive function of workers, and occupational aluminum exposure increases the risk of MCI.

[Application of traction metal clip with fishhook-like device in endoscopic resection]

From July 2020 to June 2021, patients in Jiangyin Hospital Affiliated to Nantong University who met the enrollment criteria were treated with the fishhook-like device during the operation to suture the postoperative wound (group A). Patients with similar conditions and similar size wounds who were treated with a "purse-string suture" to suture the wounds were retrospectively analyzed as the control group (group B). Difference in the suture rate, adverse events, time required for suturing, and number of metal clips were compared between the two groups. The time required for suturing was (7.83±2.41) min in group A and (11.00±3.31) min in group B. The difference was statistically significant (P=0.002). The number of metal clamps used in group A averaged 7.17 pieces/case, and the number of metal clamps used in group B averaged 7.06 pieces/case. The difference was not statistically significant (P>0.05).The traction metal clip with the fishhook-like device is ingeniously designed and easy to operate. It has a good suture effect on the wound after endoscopic resection and effectively prevents postoperative adverse events.

Knockdown of circ‑PVT1 inhibits the progression of lung adenocarcinoma and enhances the sensitivity to cisplatin via the miR‑429/FOXK1 signaling axis

Lung cancer is one of the most prevalent cancers in China, and its incidence and morbidity remain high due to various independent factors. Lung adenocarcinoma (ADC) is the most common type of non‑small cell lung carcinoma. Circular RNA plasmacytoma variant translocation 1 (circ‑PVT1) plays an oncogenic role in various types of cancer, but the specific role of circ‑PVT1 in lung ADC has not yet been reported. In the present study, circ‑PVT1 was knocked down in A549 cells and the cell viability, proliferation, migration and invasion were measured via MTT, colony formation, wound healing and Transwell assays, respectively. Then, the cell viability of A549 cells with circ‑PVT1‑knockdown or ‑overexpression was detected after exposure to cisplatin (DDP). After confirming the associations among circ‑PVT1, microRNA (miR)‑429 and forkhead box k1 (FOXK1) using various tools and assays, the cellular functions of A549 cells treated with combined short hairpin (sh)RNA‑circ‑PVT1 and miR‑429 inhibitor/pcDNA3.1‑FOXK1 were tested again. The expression of circ‑PVT1 was found to be increased in lung ADC cells, and shRNA‑circ‑PVT1 led to decreased cell viability, proliferation, migration and invasion. The expression of circ‑PVT1 was higher in A549/DDP cells than that in A549 cells, and the activity of caspase‑3 was also activated by DDP in A549/DDP cells transfected with shRNA‑circ‑PVT1, whereas it was inactivated by DDP in A549 cells transfected with circ‑PVT1 overexpression plasmid. Furthermore, the decreased cell viability, proliferation, invasion and migration induced by shRNA‑circ‑PVT1 could be abated by transfection with miR‑429 inhibitor and pcDNA3.1‑FOXK1. In conclusion, interference of circ‑PVT1 inhibits the progression of lung ADC and enhances its sensitivity to DDP via miR‑429/FOXK1, which may provide a theoretical basis for the use of novel targets in the treatment of lung ADC.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

AB0280 THE INFLUENCE OF TARGET THERAPY AS WELL AS GLUCOCORTICOIDS TAPERING ON DISEASE FLARE IN SYSTEMIC LUPUS ERYTHEMATOSUS: RESULTS FROM A PROSPECTIVE CHINESE COHORT

Background:

Treat-to-target in systemic lupus erythematosus (SLE) has been proposed for 7 years and several recommendations were developed [1]. In these recommendations, prevention of flares should be a realistic target. Meanwhile, ‘remission’ or ‘low disease activity’ was recommended as the treatment target and minimizing glucocorticoids (GC) dose or withdrawal if possible was suggested in the maintenance treatment. However, would target therapy and GC tapering/withdrawal influence disease flare?

Objectives:

To investigate the frequency and determinants of disease flare, especially the influence of target therapy as well as GC tapering on flare in Chinese lupus patients.

Methods:

The baseline and follow-up data of all consecutive patients in a prospective longitudinal lupus cohort from January 2017 to June 2020 were collected. The lupus low disease activity state (LLDAS) was defined as in Golder et al., 2019[2]. The criteria for remission were from DORIS definitions [3]. Flare was assessed using the SELENA-SLEDAI flare index [4].

Results:

We enrolled 185 patients with disease duration at recruitment of 2.3 (0.8–7.7) years. During the 26.2 (12.5-34.5) months of follow-up, 73 (39.5%) patients experienced 95 flares, including 70 mild/moderate and 25 severe flares. The incidence of flare per patient-year was 0.27. Kaplan-Meier analyses showed that compared with those who never achieved LLDAS or DORIS, the patients who achieved the target at least once had a higher flare free survival rate; meanwhile, the patients with prednisone withdrawn had significantly lower flare free rate compared with those with small dose of GC maintained (≤7.5mg/d) (Figure 1A), but among the patients with different prednisone maintain doses (7.5~5mg, 5~2.5mg, and ≤2.5mg) there was not significant difference (Figure 1B). Cox regression analysis showed that younger age at disease onset and lower Complement 3 (C3) level at recruitment were independent risk factors for flare and achieving LLDAS or DORIS ≥50% of visits was independent protective factor (Table 1).

Conclusion:

In this Chinese prospective SLE cohort, age at disease onset, C3 level at recruitment and therapeutic target achieving influenced disease flare independently and significantly. GC tapering in appropriate patients and with appropriate pace did not increase the flare rate, but prednisone withdrawal may induce more disease exacerbation, which needs to be confirmed by large prospective studies.

References:

[1]Van Vollenhoven R F, et al. Treat-to-target in systemic lupus erythematosus: recommendations from an international task force. Ann Rheum Dis, 2014. 73(6): 958-967

[2]Golder, V., et al. Lupus low disease activity state as a treatment endpoint for systemic lupus erythematosus: a prospective validation study. The Lancet Rheumatology, 2019. 1(2): p. e95-e102.

[3]van Vollenhoven R, et al. A framework for remission in SLE: consensus findings from a large international task force on definitions of remission in SLE (DORIS). Ann Rheum Dis. 2017. 76(3): 554–561.

[4]Petri M, et al. Classification and definition of major flares in SLE clinical trials. Lupus. 1999. 8(8): 685-691.

Table 1.

Determinants of disease flare by multivariate Cox regression analyses

Model 1(LLDAS) ΔModel 2(RONT) ΔModel 3(Complete RONT) ΔHR95%CIP valueHR95%CIP valueHR95%CIP valueAge at disease onset (years)†0.970.95-0.990.0040.970.95-0.990.0030.970.95-0.990.003Anti-dsDNA positive at recruitment1.340.82-2.180.2171.120.68-1.850.6491.190.73-1.960.486C3 (mg/L) at recruitment0.9980.997-0.9990.0040.9980.997-0.9990.0070.9980.997-1.0000.010Minimum prednisone dose during follow- up (mg/d)0.980.90-1.080.7161.010.94-1.080.7471.040.97-1.110.243Therapeutic target achieved≥50% of observationsΔ0.600.39-0.940.0010.540.34-0.870.0110.680.51-0.920.011

Δ In the three hazard models, the different target achievement status were included respectively.

RONT: Clinical remission on treatment; Complete RONT: Complete remission on treatment.

Disclosure of Interests:

None declared

POS1481-HPR SEXUAL EXPERIENCE IN MALE PATIENTS WITH ANKYLOSING SPONDYLITIS: RESULTS FROM A CROSS-SECTIONAL STUDY OF 113 PATIENTS

Background:

The expression and experience of sexuality is a key part of an individual self-identity1, so it is essential for both healthy individuals and patients. Patients with ankylosing spondylitis (AS) may be susceptible to sexual issues due to disease activity, dysfunction and comorbid emotional problems. However, sexuality, especially sexual experience, are rarely paid attention in patients with AS.

Objectives:

Our study aims to assess sexual experience in male patients with AS, and analyze the factors affecting sexual experience.

Methods:

This is a cross-sectional study. A total of 113 patients with AS and 46 healthy people were investigated, matched according to age and body mass index. The Sexual Experience Questionnaire is used to assess male sexual experience. Linear regression analysis is used to explore the contributions of clinical variables to worse sexual experience.

Results:

There is a significant difference in the total sexual experience score between AS patients and healthy controls (41.92±8.83 vs 46.98±8.10, P=0.0013). Also, patients with AS have a worse score in all dimensions of sexual experience, including erectile function, individual satisfaction and couple satisfaction, comparing to healthy people. In the regression model after controlling for the effects of age, disease duration and body mass index, disease activity (BASDAI), function (BASFI), mobility (BASMI, chest expansion and finger-floor distance), health index (ASAS HI), sleep quality (PSQI) and psychological status (HADS, HADS-A and HADS-D) are significant determinants of sexual experience, including erectile function (except for chest expansion), individual satisfaction (except for BASMI) and couple satisfaction (except for BASMI). See Table 1 for details.

Table 1.

Multivariable regression analysis of association between sexual experience and clinical outcomes

IndependentSexual experience total scoreErectile functionIndividual satisfactionCouple satisfactionβ (95%CI)Pβ (95%CI)Pβ (95%CI)Pβ (95%CI)PPain total-0.09 (-0.25, 0.07)0.28-0.27 (-0.58, 0.03)0.073-0.51 (-0.91, -0.100.014-0.15 (-0.32, 0.02)0.077BASDAI1.35 (-2.24, -0.45)0.003-0.42 (-0.75, -0.09)0.014-0.72 (-1.16, -0.28)0.001-0.21 (-0.40, -0.02)0.028BASFI-1.80 (-2.59, -1.01)<0.001-0.62 (-0.91, -0.32)<0.001-0.89 (-1.28, -0.50)<0.001-0.30 (-0.47, -0.13)0.001BASMI-1.04 (-2.01, -0.07)0.036-0.47 (-0.82, -0.12)0.008-0.48 (-0.96, 0.001)0.051-0.09 (-0.29, 0.12)0.413Chest expansion1.60 (0.24, 2.96)0.0210.50 (-0.004, 0.99)0.0520.74 (0.07, 1.42)0.0320.36 (0.08, 0.64)0.011Finger-floor distance-0.20 (-0.33, -0.07)0.003-0.07 (-0.11, -0.02)0.009-0.10 (-0.17, -0.03)0.003-0.04 (-0.06, -0.01)0.011ASAS HI-1.27 (-1.64, -0.91)<0.001-0.42 (-0.55, -0.28)<0.001-0.62 (-0.80, -0.43)<0.001-0.24 (-0.32, -0.16)<0.001PSQI-0.60 (-1.11, -0.09)0.021-0.19 (-0.38, -0.004)0.045-0.28 (-0.54, -0.03)0.03-0.13 (-0.23, -0.02)0.019HADS-0.53 (-0.76, -0.29)<0.001-0.18 (-0.27, -0.09)<0.001-0.24 (-0.36, -0.13)<0.001-0.10 (-0.15, -0.05)<0.001HADS-A-0.86 (-1.30, -0.42)<0.001-0.28 (-0.44, -0.12)0.001-0.42 (-0.63, -0.20)<0.001-0.17 (-0.26, -0.07)<0.001HADS-D-0.99 (-1.45, -0.53)<0.001-0.35 (-0.52, -0.19)<0.001-0.44 (-0.67, -0.21)<0.001-0.20 (-0.29, -0.10)<0.001

Conclusion:

Worse sexual experience is associated with increased disease activity, decreased function, poor mobility, decreased health index, poor sleep quality and psychological status. Therefore, special attention to worse sexual experience in patients with AS is essential to assess disease-related suffering and develop new patient management strategies.

References:

[1]Hill J, Bird H, Thorpe R. Effects of rheumatoid arthritis on sexual activity and relationships. Rheumatology (Oxford), 2003. 42(2):280-6.

Disclosure of Interests:

None declared

[Sex Estimation of Typical Adult Vertebrae Morphology in Central China Based on CT Technique]

Abstract

Objective The morphological data of the second thoracic vertebra and the third lumbar vertebra were measured by computerized tomography （CT）. The sex differences were analyzed and the discrimination equation was obtained. Methods The data of 274 adults （203 cases from experimental group and 69 cases from validation group） from central China were collected. Four linear data （maximum transverse length of vertebral body, maximum longitudinal length of vertebral body, maximum transverse length of vertebral foramen, maximum longitudinal length of vertebral foramen）, one angle data （angle between spinous processes） and two area （vertebral foramen area, total cross-sectional area of vertebral body） data of the second thoracic vertebra and the third lumbar vertebra were collected, respectively. Then three ratios ［maximum transverse length/　maximum longitudinal length of vertebral body, maximum transverse length/ maximum longitudinal length of vertebral foramen, vertebral foramen area/ （total cross-sectional area of vertebral body-vertebral foramen area）］ and one angle （angle between spinous processes） were obtained. The discriminant equation was established for sexual discriminant analysis. Results The morphology of the second thoracic vertebra and the third lumbar vertebra was related with gender. Four single index discriminant formulae and eleven multi-index discriminant formulae were established. The 69 validation group samples were substituted into the formula for testing, and the maximum discriminant accuracy rate of the single-index discriminant formula was 75%. The maximum discriminant accuracy rate of multi-index discriminant formula was 83%. Conclusion It is feasible to conduct individual sex analysis by the morphological indexes of second thoracic vertebra and the third lumbar vertebra. The indexes have important application values in practice.

Effects of IL-1β and IL-18 induced by NLRP3 inflammasome activation on myocardial reperfusion injury after PCI

OBJECTIVE

To investigate the effect of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in the serum levels of interleukin-1β (IL-1β) and interleukin-18 (IL-18) in patients with myocardial reperfusion injury after the percutaneous coronary intervention (PCI).

PATIENTS AND METHODS

Twenty healthy controls (control group) and forty patients (treatment group) were recruited in this study. The enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels of IL-1β and IL-18 at various time points in both the control and treatment groups. Data processing and analysis were performed using the Statistical Product and Service Solution (SPSS) 22.0 software (IBM Corp, Armonk, NY, USA). Pearson's correlation coefficient test was applied in all data analyses. A difference was statistically significant when p<0.05.

RESULTS

The levels of IL-1β and IL-18 in the treatment group were significantly higher than those in the control group (p<0.05). The IL-1β level in the treatment group peaked at 0.5 h after PCI and then, gradually decreased. The multiple regression analysis showed that IL-1β level was positively correlated with levels of LDL-C and IL-18 (p<0.05, r=0.527 and 0.955 respectively), and negatively correlated with the HDL-C level (p<0.05, r=-0.34).

CONCLUSIONS

The levels of IL-1β and IL-18 significantly rose in patients with myocardial ischemia-reperfusion injury after PCI.