Multi-ancestry genome-wide association analyses identify novel genetic mechanisms in rheumatoid arthritis

Rheumatoid arthritis (RA) is a highly heritable complex disease with unknown etiology. Multi-ancestry genetic research of RA promises to improve power to detect genetic signals, fine-mapping resolution and performances of polygenic risk scores (PRS). Here, we present a large-scale genome-wide association study (GWAS) of RA, which includes 276,020 samples from five ancestral groups. We conducted a multi-ancestry meta-analysis and identified 124 loci (P < 5 × 10-8), of which 34 are novel. Candidate genes at the novel loci suggest essential roles of the immune system (for example, TNIP2 and TNFRSF11A) and joint tissues (for example, WISP1) in RA etiology. Multi-ancestry fine-mapping identified putatively causal variants with biological insights (for example, LEF1). Moreover, PRS based on multi-ancestry GWAS outperformed PRS based on single-ancestry GWAS and had comparable performance between populations of European and East Asian ancestries. Our study provides several insights into the etiology of RA and improves the genetic predictability of RA.

P-763 effect of duration of cryo-storage of vitrified embryos on obstetric and perinatal outcomes

Study question

Does the duration of cryo-storage of vitrified embryos affect obstetric and perinatal outcomes?

Summary answer

Duration of cryo-storage with an open vitrification system did not affect obstetric and perinatal outcomes.

What is known already

Frozen-thawed blastocyst transfer has been performed widely with improvement of embryo culture conditions and cryopreservation techniques. Although blastocyst vitrification has become an essential method to improve clinical outcomes of IVF, there has been little study into the relationship between a long duration of cryo-storage in liquid nitrogen and obstetric and perinatal outcomes.

Study design, size, duration

This retrospective study was conducted at Kyono ART Clinic from January 2007 to December 2020. This study includes a total of 1053 singletons derived from 2461 frozen-thawed blastocyst transfers in 2461 patients. Steel’s multiple comparison test was performed for clinical and perinatal outcomes with cases of cryo-storage of less than 3 months as a control group. P &lt; 0.05 was considered statistically significant.

Participants/materials, setting, methods

The subjects are patients who underwent their first single frozen-thawed blastocyst transfer (FBT) with an open vitrification system. Females &gt;40 years old at cryopreservation and those who underwent preimplantation genetic testing were excluded. According to cryo-storage duration, patients were grouped as follows: group A, 0-3 months (1255 cycles); group B, 3-6 months (1008 cycles); group C, 6-12 months (162 cycles), group D, 12-24 months (36 cycles).

Main results and the role of chance

Both the mean maternal age at blastocyst cryopreservation (A: 33.7±3.6, B: 34.1±3.5, C: 34.8±3.2, D: 35.1±3.3) and the mean maternal age at FBT (A: 33.8±3.6, B: 34.4±3.5, C: 35.5±3.1, D: 36.4±3.3) in groups B, C, and D were significantly higher compared to those in group A.. There was no significant difference in the survival rate after blastocyst thawing [A: 97.4% (1256/1290), B: 98.3% (1010/1027), C: 99.4% (163/164), D: 97.2% (35/36)]. The pregnancy rate in group C was significantly lower compared to group A [A: 60.0% (752/1254), B: 61.4% (619/1008), C: 48.1% (78/162), D: 63.9% (23/36)] The gestational age of group C was significantly lower compared to group A (A: 39.5±1.8, B: 39.4±1.8, C: 38.4±3.1, D: 39.8±1.6), but there were no significant differences in live birth weight or height. There were no significant differences in congenital abnormality rate [A: 1.3% (7/541), B: 2.5% (11/440), C: 1.8% (1/56), D: 0.0% (0/16)], placental abnormalities such as placenta previa [A: 1.3% (7/541), B: 1.6% (7/440), C: 1.8% (1/56), D: 0.0% (0/16)], perinatal abnormalities such as hypertensive disorders of pregnancy or gestational diabetes [A: 6.1% (33/541), B: 8.6% (38/440), C: 1.8% (1/56), D: 6.3% (1/16)] among the four groups.

Limitations, reasons for caution

We could not provide sufficient information on confounding factors such as smoking habits, and the sample size was too small for multivariate analysis. The safety of longer storage will need to be verified as this has not been clarified in this study.

Wider implications of the findings

The pregnancy rate in group C was significantly lower than that in group A, but the effect was small: 0.065, power of 0.78. Our data suggested that the duration of cryopreservation with an open vitrification system in liquid nitrogen did not affect obstetric or perinatal outcomes.

Trial registration number

not applicable

Genome-Wide Association Study of Intracranial Artery Stenosis Followed by Phenome-Wide Association Study

The genetic background of intracranial artery stenosis (ICAS), a major cause of ischemic stroke, remains elusive. We performed the world's first genome-wide association study (GWAS) of ICAS using DNA samples from Japanese subjects, to identify the genetic factors associated with ICAS and their correlation with clinical features. We also conducted a phenome-wide association study (PheWAS) of the top variant identified via GWAS to determine its association with systemic disease. The GWAS involved 408 patients with ICAS and 349 healthy controls and utilized an Asian Screening Array of venous blood samples. The PheWAS was performed using genotypic and phenotypic data of the Biobank Japan Project, which contained information on 46 diseases and 60 quantitative trait data from > 150,000 Japanese individuals. The GWAS revealed that the East Asian-specific functional variant of RNF213, rs112735431 (c.14429G > A, p.Arg4810Lys), was associated with ICAS (odds ratio, 12.3; 95% CI 5.5 to 27.5; P = 7.8 × 10^-10). Stratified analysis within ICAS cases demonstrated that clinical features of those with and without the risk allele were different. PheWAS indicated that high blood pressure and angina were significantly associated with RNF213 rs112735431. The first GWAS of ICAS, which stratifies subpopulations within the ICAS cases with distinct clinical features, revealed that RNF213 rs112735431 was the most significant variant associated with ICAS. Thus, RNF213 rs112735431 shows potential as an important clinical biomarker that characterizes pleiotropic risk in various vascular diseases, such as blood pressure and angina, thereby facilitating personalized medicine for systemic vascular diseases in East Asian populations.

The bacteriostatic effect of erythritol on canine periodontal disease-related bacteria

Erythritol helps both prevent and improve periodontal disease and is therefore widely used for dental care in humans. However, only a few studies have investigated the effects of erythritol on periodontal disease in animals. We hypothesized that erythritol could be used to prevent and improve periodontal disease also in canines and investigated the effects of erythritol on canine periodontal disease-related pathogenic bacteria using both in vitro and in vivo methods. The effect of erythritol on the proliferation of Porphyromonas gulae, which is reportedly associated with canine periodontal disease, was investigated in vitro. In addition, a 4-week intervention trial using an external gel preparation containing 5% erythritol was performed in canines with mild periodontal disease; changes in the microbiota around periodontal lesions were investigated using next-generation sequencing and bioinformatics analysis. The growth of P. gulae was significantly suppressed by erythritol in vitro. In the intervention study, the Shannon index, an indicator of the species distribution α-diversity, and the occupancy of several canine periodontal disease - related bacteria ( P. gulae, P. cangingivalis) were significantly decreased in periodontal lesions. Based on the results of in vitro and in vivo studies, we conclude that, as in humans, erythritol has bacteriostatic effects against periodontal disease - related bacteria in canines.

Fibronectin plays a major role in hypoxia-induced lenvatinib resistance in hepatocellular carcinoma PLC/PRF/5 cells

Resistance to lenvatinib mesylate (LEN), a systemic chemotherapy that can be administered orally, has been a major issue for treatment of hepatocellular carcinoma (HCC). Although HCC is the tumor that most exhibits intratumoral hypoxia, which has been shown to be involved in the development of treatment resistance, there are no reports of LEN resistance in HCC treatment under hypoxia. The purpose of our study was to elucidate the mechanism of treatment resistance to LEN under hypoxia using HCC cell lines. We confirmed LEN resistance under hypoxic conditions in HCC cell lines. There was a significant increase in the IC₅₀ value of PLC/PRF/5 cells from 13.0±0.8 μM in normoxia to 21.3±1.1 μM in hypoxia, but in HepG2 cells, the increase was not significant. To elucidate the LEN resistance mechanism of PLC/PRF/5 cells under hypoxia, we performed microarray analysis and extracted genes that are thought to be related to this mechanism. Furthermore, in-silico analysis confirmed significant changes in the extracellular matrix, and among them, FN1 encoding fibronectin was determined as the hub of the gene cluster. The expression of fibronectin in PLC/PRF/5 cells examined with immunofluorescence staining was significantly elevated in and outside of cells under hypoxia, and tended to decrease when cells were exposed to LEN under normoxia. Furthermore, the fibronectin concentration in the culture solution of PLC/PRF/5 cells examined by ELISA was 2.3 times higher under hypoxia than under normoxia under LEN(-) conditions, and 1.6 times higher under hypoxia than under normoxia under LEN(+) conditions. It is assumed that in PLC/PRF/5 cells, fibronectin is probably suppressed as an indirect effect of LEN under normoxia, but transcription factors such as HIF-1α are induced under hypoxia, thus enhancing the production of fibronectin and attenuating the effect of LEN, resulting in drug resistance. This behavior of fibronectin with LEN exposure under hypoxia is probably specific to PLC/PRF/5 cells. Further studies should verify the combined effective inhibition of fibronectin and the MAPK pathway as a promising therapeutic strategy to enhance the value of LEN in HCC treatment.

Search for B^{+}→K^{+}νν[over ¯] Decays Using an Inclusive Tagging Method at Belle II

A search for the flavor-changing neutral-current decay B^{+}→K^{+}νν[over ¯] is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The data sample corresponds to an integrated luminosity of 63  fb^{-1} collected at the ϒ(4S) resonance and a sample of 9  fb^{-1} collected at an energy 60 MeV below the resonance. Because the measurable decay signature involves only a single charged kaon, a novel measurement approach is used that exploits not only the properties of the B^{+}→K^{+}νν[over ¯] decay, but also the inclusive properties of the other B meson in the ϒ(4S)→BB[over ¯] event, to suppress the background from other B meson decays and light-quark pair production. This inclusive tagging approach offers a higher signal efficiency compared to previous searches. No significant signal is observed. An upper limit on the branching fraction of B^{+}→K^{+}νν[over ¯] of 4.1×10^{-5} is set at the 90% confidence level.

Dialogue as therapy: the role of the expert in the ICRP Dialogues

Science communication is commonly framed as a battle with ignorance and the field of radiological protection is not exempt from this tendency. By correcting deficits in the public's understanding of science, the expert is often imagined to be able to convince the public of its objective safety ('anzen'), thereby inspiring a sense of calm ('anshin'). In the wake of the 2011 Fukushima Daiichi disaster, however, the International Commission on Radiological Protection has sought to break with this tradition by organising a series of participatory seminars in which experts engage those affected by the disaster as equals. Drawing on ethnographic fieldwork, this article suggests that the Dialogue seminars can be best understood using the metaphor of therapy; using it to describe the premise, form, and objectives of the Dialogues with a view to identifying good practice for future radiological protection scenarios.

Evaluation of the stability of Yamakagashi (Rhabdophis tigrinus) Equine Antivenom after 20 years storage

In 2000, an equine Yamakagashi (Rhabdophis tigrinus) antivenom (Lot 0001) was testmanufactured as an unapproved drug for treatment of Yamakagashi bites. It was stocked on the premise of super-legal use from the viewpoint of emergency health crisis management. The antivenom showed a strong neutralizing ability against the hemorrhagic and coagulation activity of the Yamakagashi venom in its potency test. One vial of the antivenom can effectively neutralize at least about 4 mg of Yamakagashi venom. Its efficacy has also been confirmed in patients with severe cases of R. tigrinus bite that has been used in emergency. In 2020, this antivenom (Lot 0001) has reached 20 years after its production. To evaluate the integrity and potency of the antivenom, quality control, safety and potency tests had been conducted almost every year since 2012. Physical and chemical tests (property test, moisture content test, insoluble foreign matter test, osmotic pressure ratio test, pH test, protein content test, endotoxin test, sterility test) of the antivenom, showed no significant changes throughout the years, when compared to the results immediately after its production in 2000. All the parameters measured were also within the standard values. In animal safety tests (test for absence of toxicity and pyrogen), there was no change in the test results during the storage period and no abnormalities were observed. The potency test (anti-coagulant activity) after 20 years of the product, showed the same potency as those recorded immediately after production. Therefore, in all of the stability monitoring tests conducted so far, the product did not show any significant change compared to the results immediately after production. This confirms the stability of the product during the stockpiling period to the present, that is, 20 years after production.

POS0868 THE FORMULA TO PREDICT TACROLIMUS CONCENTRATION ACCORDING TO GENOTYPING OF CYP3A5 IS USEFUL FOR EFFECTIVE TREATMENT IN INTERSTITIAL LUNG DISEASE WITH DERMATOMYOSITIS

Background:

Tacrolimus (TAC), an immunosuppressant, can be used in second-line maintenance therapy for interstitial lung disease (ILD) in patients with dermatomyositis (DM) [1]. Although some studies reported the clinical efficacy of initial high-trough levels of TAC in combination with GC and IVCY in induction therapy for severe DM-ILD [2], there have been no useful clinical tools for deciding suitable initial dose of TAC. Genotype of polymorphisms in cytochrome P450 (CYP) 3A5 enzyme was reported to play an important role in pharmacokinetics of TAC [3], and we made a formula for deciding initial dose of TAC according to CYP3A5 genotypes in our previous study.

Objectives:

In our previous study (retrospective study), we set the target trough according to the severity for nine DM-ILD patients, six of whom were CYP3A5 *3/*3 and investigated the dose of TAC that could attain the trough using their CYP3A5 genootyping. Using these results, we developed a formula for deciding initial daily dose of TAC (target trough*weight / [(151.1, if CYP3A5 *3/*3) or (86.5, if CYP3A5 *1 allele)]). In this study, we prospectively examined the usefulness and accuracy of this formula.

Methods:

We introduced TAC for new six DM-ILD patients who visited our hospital between November 2019 and May 2020 (prospective study). The starting dose of TAC was decided by using the formula. We assessed the association between predicted and observed trough concentration of TAC at first measurement date (from day 2 to day4), using linear regression analysis. We also assessed the days for attaining the target trough concentration between the patients using the formula (prospective group) and six patients with CYP3A5 *3/*3 (retrospective group).

Results:

CYP3A5 genotype of all six DM-ILD patients were *3/*3 and underwent the TAC treatment by using the formula. The predicted and observed trough concentration of first measurement date were significantly correlated in the patients (r 2= 0.897, p=0.0041) (Fig.1). Compared with our retrospective study, target trough was more quickly attained in patients of the prospective study (Fig.2).

Conclusion:

The formula which we made for attainment target trough concentration based on CYP3A5 genotype was useful for deciding the starting dose of TAC. We also showed that we could attain the target trough concentration at early stage of initial treatment by using the formula.

References:

[1]Oddis CV and Aggarwal R. Nat Rev Rheumatol 2018;14(5):279-89.

[2]Suzuka T et al. Int J Rheum dis 2019;22: 303-13.

[3]Y. Muraki et al. Exp Ther Med 2018;15:532-38.

Figure 1.

Correlation of predicted and observed tacrolimus trough concentration at first measurement in the prospective study

Figure 2.

Days to attain the target trough concentration of tacrolimus in the prospective group and the retrospective group

Disclosure of Interests:

None declared

Genetic determinants of risk in autoimmune pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a devastating lung disease caused by abnormal surfactant homeostasis, with a prevalence of 6-7 cases per million population worldwide. While mutations causing hereditary PAP have been reported, the genetic basis contributing to autoimmune PAP (aPAP) has not been thoroughly investigated. Here, we conducted a genome-wide association study of aPAP in 198 patients and 395 control participants of Japanese ancestry. The common genetic variant, rs138024423 at 6p21, in the major-histocompatibility-complex (MHC) region was significantly associated with disease risk (Odds ratio [OR] = 5.2; P = 2.4 × 10-12). HLA fine-mapping revealed that the common HLA class II allele, HLA-DRB1*08:03, strongly drove this signal (OR = 4.8; P = 4.8 × 10-12), followed by an additional independent risk allele at HLA-DPβ1 amino acid position 8 (OR = 0.28; P = 3.4 × 10-7). HLA-DRB1*08:03 was also associated with an increased level of anti-GM-CSF antibody, a key driver of the disease (β = 0.32; P = 0.035). Our study demonstrated a heritable component of aPAP, suggesting an underlying genetic predisposition toward an abnormal antibody production.

Effect of zymosan on feed passage in the digestive tract in chicks

1. The purpose of the present study was to examine whether zymosan, which is a component of fungi, affects feed passage through the digestive tract in chicks (Gallus gallus).2. Intraperitoneal (IP) injection of 2.5 mg zymosan significantly reduced the crop-emptying rate and this effect was similar to that of 100 µg lipopolysaccharide (LPS). Zymosan affected phenol red transit from the proventriculus.3. Zymosan significantly affected the gene expression of interleukin-1β (IL-1β), IL-6, IL-8 and histidine decarboxylase in various regions of the digestive tract.4. The present study suggested that zymosan retarded feed passage through the digestive tract in chick and interleukins and histamine may be participating in this process.

Alpelisib plus fulvestrant for PIK3CA-mutated, hormone receptor-positive, human epidermal growth factor receptor-2-negative advanced breast cancer: final overall survival results from SOLAR-1

BACKGROUND

Activation of the phosphatidylinositol-3-kinase (PI3K) pathway via PIK3CA mutations occurs in 28%-46% of hormone receptor-positive (HR+), human epidermal growth factor receptor-2-negative (HER2-) advanced breast cancers (ABCs) and is associated with poor prognosis. The SOLAR-1 trial showed that the addition of alpelisib to fulvestrant treatment provided statistically significant and clinically meaningful progression-free survival (PFS) benefit in PIK3CA-mutated, HR+, HER2- ABC.

PATIENTS AND METHODS

Men and postmenopausal women with HR+, HER2- ABC whose disease progressed on or after aromatase inhibitor (AI) were randomized 1 : 1 to receive alpelisib (300 mg/day) plus fulvestrant (500 mg every 28 days and once on day 15) or placebo plus fulvestrant. Overall survival (OS) in the PIK3CA-mutant cohort was evaluated by Kaplan-Meier methodology and a one-sided stratified log-rank test was carried out with an O'Brien-Fleming efficacy boundary of P ≤ 0.0161.

RESULTS

In the PIK3CA-mutated cohort (n = 341), median OS [95% confidence interval (CI)] was 39.3 months (34.1-44.9) for alpelisib-fulvestrant and 31.4 months (26.8-41.3) for placebo-fulvestrant [hazard ratio (HR) = 0.86 (95% CI, 0.64-1.15; P = 0.15)]. OS results did not cross the prespecified efficacy boundary. Median OS (95% CI) in patients with lung and/or liver metastases was 37.2 months (28.7-43.6) and 22.8 months (19.0-26.8) in the alpelisib-fulvestrant and placebo-fulvestrant arms, respectively [HR = 0.68 (0.46-1.00)]. Median times to chemotherapy (95% CI) for the alpelisib-fulvestrant and placebo-fulvestrant arms were 23.3 months (15.2-28.4) and 14.8 months (10.5-22.6), respectively [HR = 0.72 (0.54-0.95)]. No new safety signals were observed with longer follow-up.

CONCLUSIONS

Although the analysis did not cross the prespecified boundary for statistical significance, there was a 7.9-month numeric improvement in median OS when alpelisib was added to fulvestrant treatment of patients with PIK3CA-mutated, HR+, HER2- ABC. Overall, these results further support the statistically significant prolongation of PFS observed with alpelisib plus fulvestrant in this population, which has a poor prognosis due to a PIK3CA mutation. CLINICALTRIALS.

GOV ID

NCT02437318.