Using a Claims-Based Frailty Index to Investigate Frailty, Survival, and Healthcare Expenditures among Older Adults Hospitalized for COVID-19 at an Academic Medical Center

BACKGROUND

Frailty is associated with mortality in older adults hospitalized with COVID-19, yet few studies have quantified healthcare utilization and spending following COVID-19 hospitalization.

OBJECTIVE

To evaluate whether survival and follow-up healthcare utilization and expenditures varied as a function of claims-based frailty status for older adults hospitalized with COVID-19.

DESIGN

Retrospective cohort study.

PARTICIPANTS

136 patients aged 65 and older enrolled in an Accountable Care Organization (ACO) risk contract at an academic medical center and hospitalized for COVID-19 between March 11, 2020 - June 3, 2020.

MEASUREMENTS

We linked a COVID-19 Registry with administrative claims data to quantify a frailty index and its relationship to mortality, healthcare utilization, and expenditures over 6 months following hospital discharge. Kaplan Meier curves and Cox Proportional Hazards models were used to evaluate survival by frailty. Kruskal-Wallis tests were used to compare utilization. A generalized linear model with a gamma distribution was used to evaluate differences in monthly Medicare expenditures.

RESULTS

Much of the cohort was classified as moderate to severely frail (65.4%), 24.3% mildly frail, and 10.3% robust or pre-frail. Overall, 27.2% (n=37) of the cohort died (n=26 during hospitalization, n=11 after discharge) and survival did not significantly differ by frailty. Among survivors, inpatient hospitalizations during the 6-month follow-up period varied significantly by frailty (p=0.02). Mean cost over follow-up was $856.37 for the mild and $4914.16 for the moderate to severe frailty group, and monthly expenditures increased with higher frailty classification (p <.001).

CONCLUSIONS

In this cohort, claims-based frailty was not significantly associated with survival but was associated with follow-up hospitalizations and Medicare expenditures.

[Suitability of estimated urine protein using different estimated 24 h urine creatinine equations in children with glomerular diseases]

Objective: To assess the reliability of estimated urine protein to predict 24 h urine protein excretion in children with glomerular diseases. Methods: Four hundred and forty-three children with glomerular diseases, who were admitted to pediatric department of Peking University First Hospital from January 2001 to December 2021, were enrolled in the cross-sectional study. The 24 h estimated urine creatinine which calculated by 6 previously described equations, 24 h measured urine creatinine, measured urine protein-to-creatinine ratio(UPCR), 24 h urine protein (24 hUP) and urinary sediment analysis with microscopy were collected, estimated urine protein was computed as the product of measured UPCR and estimated or measured 24 h urine creatinine. Spearman correlation analysis, Bland-Altman analysis and linear regression analysis were used to compare the correlation, agreement and accuracy between estimated urine protein and 24 hUP, and the effect of urinary protein level and erythrocyte numbers on their relationship was analyzed. Results: Of 443 children with glomerular diseases (aged (11±4) years, 221 male, 222 female), there were 216 participants with nephrotic syndrome, 78 participants with IgA nephropathy, 47 participants with Alport syndrome, 42 participants with lupus nephritis, 58 participants with purpura nephropathy, and 2 participants with isolated proteinuria. Spearman correlation analysis showed a strong correlation between estimated urine protein and 24 hUP (r=0.90, P<0.05), and the correlation improved after multiplying the measured UPCR by 24 h measured urine creatinine (r=0.94, P<0.05). Improved correlation was also observed using the estimated urine creatinine which calculated by Hellerstein formula, Ghazali-Barratt formula, Ellam formula, Walser formula, Cockcroft-Gault formula, Ix formula (r=0.93, 0.94, 0.90, 0.90, 0.94, 0.93, all P<0.05).Bland-altman analysis showed that the difference between measured UPCR and 24 hUP was (-0.30±2.22) g, consistency limit was -4.65-4.04, and the consistency improved after 24 h measured urine creatinine correction (difference was (0.27±1.31) g, consistency limit -2.30-2.84). The consistency of estimated urine protein was further improved after correction by different formulas, and the Cockcroft-Gault formula showed the best consistency between estimated urine protein and 24 hUP (difference was (0.11±1.18)g, consistency limit was -2.20-2.42). Linear regression analysis showed that measured UPCR had poor accuracy in predicting 24 hUP (R²=0.55, α=0.48, β=0.60, P<0.05), and the accuracy improved after 24 h measured urine creatinine correction, the accuracy of estimated urine protein for predicting 24 hUP was further improved by using different formulas, and Cockcroft-Gault formula was the best (R²=0.81, α=0.18, β=0.96, P<0.05). With the increase of urinary protein level and the decrease of urinary erythrocyte numbers, the correlation, agreement and accuracy between estimated urine protein and measured UPCR and 24 hUP were improved(all P<0.05). Except Ellam and Ix formulas, estimated urine protein using the rest four formulas outperformed measured UPCR(all P<0.05). Conclusion: The 24 h urine creatinine excretion rate (obtained by the Cockcroft-Gault equation)-weighted urine protein-to-creatinine ratio more reliably predicts 24 hUP than measured UPCR alone in children with glomerular diseases.

[Clinical observation of superior rectus transposition with/without augmented suture and vertical rectus transposition for the treatment of strabismus caused by complete abducens nerve palsy]

Objective: To evaluate the efficacy and safety of superior rectus transposition (SRT) with/without augmented suture and vertical rectus transposition (VRT) for the treatment of strabismus caused by complete abducens nerve palsy. Methods: This was a retrospective cohort study. Forty-two patients (42 eyes) with complete abducens nerve palsy underwent strabismic surgeries from January 2015 to November 2020 in Tianjin Eye Hospital. According to the different procedures, the patients were divided into three groups: SRT group (16 cases, SRT with medial rectus recession), superior rectus transposition with augmented suture (SRTA) group (13 cases, SRT with Buckley suture and medial rectus recession) and VRT group (13 cases). The preoperative and postoperative (1, 6 and 12 months) data including deviations, ocular motility, binocular vision and surgical complications among three groups were analyzed and compared. χ² test was used for comparison of count data among three groups. The measurement data were compared among three groups by the repeated measures ANOVA. LSD-t test was used for within-group comparison and between-group comparison. Results: There was no difference in sex ratio, age and course of disease among the groups (all P>0.05). The horizontal deviations of the three groups at 1, 6 and 12 months after surgeries was lower than that before surgeries, and the difference was statistically significant (all P<0.001). The horizontal deviations of the SRT group, SRTA group and VRT group at 12 months after surgeries were (+0.8±5.8), (+0.8±4.5), (+1.2±2.5) prism diopters (PD), respectively, lower than that of the preoperative (+82.8±17.2), (+77.7±26.1), (+71.5±18.6) PD. However, there was no significant difference among different postoperative follow-up timepoints (all P>0.05). There was no difference in horizontal deviations before surgeries and at 1, 6 and 12 months after surgeries among three groups (P>0.05). There were significant differences in the scales of abduction motility among preoperative, postoperative 1, 6 and 12 months measurements for three group (all P<0.001). The scales of abduction before surgeries in the SRT group, SRTA group, and VRT group were (-4.4±0.5), (-4.4±0.5), (-4.5±0.5) scale and at 12 months after surgeries were (-2.3±0.7), (-2.2±0.5), (-2.1±0.6) scale respectively. But there was no change among different postoperative follow-up timepoints (all P>0.05). Preoperative and postoperative 1-, 6-and 12-month abduction motility was similar among three groups (P>0.05). There were significant differences in the scales of adduction limitation among preoperative, postoperative 1-, 6-and 12-months measurements for three group (all P<0.05). But there was no change among different postoperative follow-up timepoints (all P>0.05). There were significant differences between the SRT group [(-0.9±0.6), (-0.8±0.6) scale] and the SRTA groups [(-1.5±0.5), (-1.4±0.5) scale] (t=-2.62, -2.52) and between the SRTA group and the VRT group [(-0.8±0.8), (-0.6±0.7) scale] (t=2.62, 3.01) at 6 and 12 months after surgeries (all P<0.05). The outcomes of binocular vision at postoperative 12 months were similar among three groups (P>0.05). No patient had torsional diplopia and anterior segment ischemia. Only 2 patients from the SRTA group had hypotropia of 4 to 5 PD in the primary position associated with supraduction limitation. Conclusions: SRT with/without augmented suture and VRT are effective and safe procedures for the treatment of strabismus caused by complete abducens nerve palsy. They could correct deviations, improve abduction motility and restore binocular vision, with stable outcomes and a small risk of vertical and torsional diplopia.

[C1q or IgA deposition in glomeruli of children with primary membranous nephropathy]

Objective: To assess the correlation of glomerular C1q or IgA deposition with clinical and pathological features of primary membranous nephropathy (PMN) in children. Methods: The clinical and pathological manifestations including (phospholipase A2 receptor, PLA2R) and IgG subclasses staining in renal biopsies, serum anti-PLA2R antibody and therapeutic response of 33 children diagnosed with PMN in Peking University First Hospital from December 2012 to December 2020 were retrospectively summarized and analyzed. According to results of PLA2R test and findings renal pathological, the patients were divided into PLA2R-related group and non-PLA2R-related group, typical MN group and atypical MN group, C1q deposit group and non-C1q deposit group, as well as IgA deposit group and non-IgA deposit group respectively. T-test, Mann-Whitney U test and Fisher's exact probability test were used for comparison between the groups. Results: Among the 33 children with PMN, there were 20 males and 13 females, of that the age of onset was 11 (8, 13) years, and 32 patients had nephrotic level proteinuria. Renal biopsies were performed at 4.6 (2.1, 11.6) months after onset, and 28 patients (85%) received glucocorticoid or immunosuppressive therapy prior to renal biopsy. There were 20 cases (61%) with PLA2R-related MN and 13 cases (39%) with non-PLA2R-related MN. Compared with the non-PLA2R-related group, the PLA2R-related group had an older age of onset (12 (10, 13) vs. 7 (3, 12) years, Z=-2.52, P=0.011), a lower preceding infection rate (45% (9/20) vs. 11/13, P=0.032) and lower spontaneous remission rate (0 vs. 4/13, P=0.017). Renal PLA2R positivity was significantly associated with predominant or co-deposition of IgG4 (13/17 vs. 5/15, P=0.031) and low albumin levels at renal biopsy ((25±6) vs. (29±7) g/L, t=2.14, P=0.041). There were 12 patients with typical PMN and 21 patients with atypical PMN, and no significant difference in clinical and pathological manifestations was found between these 2 groups (all P>0.05). There were 10 cases (32.3%) with glomerular C1q deposition, and their disease course before renal biopsy was significantly shorter than those without C1q deposition (1.8 (0.8, 5.9) vs. 6.0 (2.5, 22.3) months, Z=-2.27, P=0.023). Twelve cases (36.4%) had glomerular IgA deposition, and their course of disease,clinical and pathological manifestations were not significantly different from those without IgA deposition (all P>0.05). Conclusion: Glomerular C1q or IgA deposition may not affect the clinical manifestations, glomerular PLA2R and IgG subclasses staining pattern, or the response to treatment of PMN in children.

[Application of indocyanine green iris angiography in the evaluation of anterior segment blood supply in different strabismus patients]

Objective: To evaluate the perfusion features of the anterior segment in patients with different types of strabismus. Methods: A cross-sectional study. Sixteen strabismus patients (16 eyes) who received the examination of iris indocyanine green angiography (ICGA) in Tianjin Eye Hospital from November 2016 to December 2021 were enrolled and divided into two groups according to whether they had a history of extraocular muscle injury/rectus muscle surgery. All patients underwent routine ophthalmic examinations. Angiographic images were obtained by the anterior segment camera, and indicators such as arm to iris circulation time, whole iris filling time, regression onset time, and complete regression time were recorded. The independent sample t test or Mann-Whitney U test was used to compare iris perfusion aspects of the two groups, and the Pearson/Spearman correlation tests was used to analyze the correlation of arm to iris circulation time and whole iris filling time with age and course of strabismus. Results: Among the 16 patients, there were 10 males and 6 females. The mean age was (49.2±13.2) years, and the course of strabismus ranged from 2 to 31 months. There were 7 patients in the group of without extraocualr muscle injury and 9 patients in the extraocular muscle injury/surgery group. There was no significant difference in age and course of strabismus between the two groups (both P>0.05). The arm to iris circulation time [M (Q₁, Q₃)] of the group without extraocular muscle injury and the group with extraocular muscle injury/surgery were 18 (18, 21) and 22 (20, 24) s, respectively. The average whole iris filling time was (13.86±1.95) and (12.22±3.60) s, respectively. There was no statistical significance between the two groups (both P>0.05). Correlation analysis showed that arm to iris circulation time was not correlated with age and course of strabismus (r=-0.033, -0.079; both P>0.05). And the whole iris filling time was not correlated with age and course of disease (r=0.057, -0.119; both P>0.05). The matrix scatter plots showed that in the group of extraocular muscle injury/surgery, there were three patients who were older than the average (49.2 years) and above the median of arm to iris circulation time (20 s) (two cases with the vertical muscle involved), meanwhile, there were three patients (all with the vertical muscle involved) whose course of strabismus was longer than 6 months and above the median of arm to iris circulation time, which were more than those in the group of without extraocular muscle injury (1 case, respectively). Conclusions: ICGA in patients with strabismus show that a history of injury to the extraocular muscle or surgical treatment beyond 2 months had no effect on iris perfusion. Age and course have no correlation with iris reperfusion. The vertical muscle involvement has more effects on the blood supply to the anterior segment.

P-561 Long-read amplicon guided haplotype imputation enabling comprehensive preimplantation genetic testing in families with de novo pathogenic variants

Study question

Can we use comprehensive genome-wide haplotyping PGT for couples carrying de novo mutations, given the absence of phasing references to establish the disease-associated haplotype?

Summary answer

Targeted amplicon long-read sequencing represents a valuable approach for PGT workup that leverages comprehensive PGT application in families with de novo mutations.

What is known already

Preimplantation genetic testing (PGT) aims to select embryos devoid of inherited pathogenic variants. Current comprehensive genome-wide haplotyping PGT methods cannot be applied for couples where one of the partners carries a de novo mutation, as absence of affected close relatives restricts variant phasing to establish the disease-associated haplotype. For such families targeted approaches are currently used instead, thus missing genome-wide embryo analysis.

Study design, size, duration

To overcome the forementioned limitation, we developed a long-read amplicon guided haplotype imputation method. From January 2017 till June 2021 thirty-two couples were enrolled into the PGT program at the Centre for Human Genetics, UZ Leuven, in the context of a de novo variant causing a known monogenic disorder in one of the two partners.

Participants/materials, setting, methods

Genomic DNA from the partner carrying the variant (proband) and his/her parents was used for trio analysis via long-range PCR and long-read amplicon sequencing using the PacBio RSII and/or Oxford Nanopore platforms. Targeted haplotype phasing was then performed to impute the disease-associated allele.

Main results and the role of chance

The parental origin of the mutant allele was identified in 20 patients, resulting in the current 62.5% success rate. Most de novo mutations occurred on the paternal allele. In the remaining families, the region of interest either had no SNPs or had insufficient number of informative SNPs linked to mutation. From the successfully analyzed couples, eight have proceeded to PGT cycle and so far, three disease-free children have been born.

Limitations, reasons for caution

A costly family-specific work-up is required, allowing nevertheless the implementation of a generic genome-wide method at the embryo analysis stage. The sequencing cost itself is anticipated to decrease in time. To avoid non-informative results, the analysis of multiple amlpicons is recommended.

Wider implications of the findings

Current practices for the handling of couples with de novo variants are mostly targeted, require the combination of direct and indirect approaches and often require the multiple biopsies. Targeted amplicon long-read sequencing represents a valuable approach for PGT workup that leverages comprehensive PGT application in families with de novo mutations.

Trial registration number

not applicable

Relationship of resting heart rate and blood pressure with all-cause and cardiovascular disease mortality

OBJECTIVES

This study aimed to investigate associations of resting heart rate (RHR) and blood pressure (BP) with all-cause and cardiovascular disease (CVD) mortality.

STUDY DESIGN

A retrospective cohort study.

METHODS

A total of 67,028 Chinese participants aged ≥60 years were included in the analysis. RHR, systolic blood pressure (SBP), and diastolic blood pressure (DBP) were evaluated according to quartiles ([41-69, 70-74, 75-79, 80-127 beats/min], [80-119, 120-129, 130-139, 140-238 mm Hg], and [40-70, 71-79, 80-84, 85-133 mm Hg]). Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause and CVD mortality with RHR, SBP, and DBP. Restricted cubic splines were used to evaluate the dose-response association.

RESULTS

During the 361,975 person-year follow-up, 9326 deaths were recorded, of which 5039 deaths were due to CVD. The risk of all-cause mortality was increased by 25% with the quartiles four vs quartile one of RHR (HR [95% CI]:1.25 [1.17-1.33]), and CVD mortality was increased by 32% (HR [95% CI]: 1.32 [1.22-1.44]). Similar results were observed when comparing the quartiles four vs quartile one of SBP with the risk of all-cause and CVD mortality (HRs [95% CIs]: 1.14 [1.07, 1.22] and 1.23 [1.12. 1.34]) and DBP with the risk of all-cause and CVD mortality (HRs [95% CIs]: 1.17 [1.11. 1.24] and 1.36 [1.26. 1.47]). We found linear associations of RHR, SBP, and DBP with all-cause and CVD mortality (P_{non-linearity} >0.05), except for the approximately J-shaped association between DBP and all-cause mortality (P_{non-linearity} = 0.008). There was a significant interaction of RHR and SBP with all-cause and CVD mortality (P_interaction <0.05).

CONCLUSIONS

RHR and BP increased the risk of all-cause and CVD mortality, especially fast RHR combined with high SBP.

OP0113 FUNCTIONAL GENOMICS IN PRIMARY T CELLS AND MONOCYTES IDENTIFIES MECHANISMS BY WHICH GENETIC SUSCEPTIBILITY LOCI INFLUENCE SYSTEMIC SCLEROSIS RISK

Background

Systemic sclerosis (SSc) is a complex autoimmune disease with a strong genetic component. However, the underlying mechanism by which genetics increase disease risk is still unknown. The most recent GWAS studies have identified 27 independent signals associated to SSc [1]. However, the majority of these signals affect regulatory elements that can regulate genes often located hundreds of kilobases away.

The challenge in the post-GWAS era is to use functional genomics to translate genetic findings into patients’ benefit, particularly in disease-relevant cell types.

Objectives

In this study we use chromatin conformation and gene expression analysis in patient derived primary cells and healthy individuals to assess potential mechanisms by which GWAS variants increase disease risk. We identify the potentially affected genes in a cell type specific manner and potential drug targets already in use or with potential for re-purposing.

Methods

Promoter capture Hi-C (pCHi-C) and RNA sequencing experiments were performed in a total of 15 CD4+ T cells and CD14+ monocytes samples each isolated from peripheral blood from SSc patients and healthy controls. We linked SSc-associated variants with their target genes and performed differential expression and differential interaction analyses between both cell types. Potential drug targets were identified using a protein-protein interaction model and queried against the OpenTargets database.

Results

We linked SSc-associated loci to 39 new potential target genes, confirming 7 previously assigned genes. We highlight novel causal genes, such as CXCR5 as the most probable candidate gene for the DDX6 locus (Figure 1). We confirm some previously linked SSc genes such as IRF8, STAT4, or CD247 which interestingly showed cell type specific interactions. We also identified 15 potential drug targets already in use in other similar immune-mediated diseases that could be repurposed for SSc treatment. Furthermore, we observed that interactions are directly related with the expression of important genes implicated in cell type specific pathways.

Figure 1.

Promoter Capture Hi-C interactions linking the DDX6 GWAS loci with the promoter of CXCR5 in CD4+ T cells and CD14+ monocytes. CD4+ T cells show significantly stronger interactions as well as CXCR5 gene expression.

Conclusion

Our study reveals potential causal genes for SSc-associated loci, some of them acting in a cell type specific manner, suggesting novel drug targets and biological mechanisms that may mediate SSc pathogenesis.

References

[1]López-Isac E, Acosta-Herrera M, Kerick M, et al (2019) GWAS for systemic sclerosis identifies multiple risk loci and highlights fibrotic and vasculopathy pathways. Nat Commun 10:. https://doi.org/10.1038/s41467-019-12760-y

Acknowledgements

This work was supported by the Spanish Ministry of Science and Innovation (grants RTI2018101332-B-100 and SAF2015-66761-P), the Cooperative Research Thematic Network (RETICS) programme (RD16/0012/0013) (RIER) from Instituto de Salud Carlos III (ISCIII, Spanish Ministry of Economy, Industry and Competitiveness), the Wellcome Trust (award references 207491/Z/17/Z and 215207/Z/19/Z), Versus Arthritis (award reference 21754), and the NIHR Manchester Biomedical Research Centre. DGS was supported by the Spanish Ministry of Economy and Competitiveness through the FPI programme (SAF2015-66761-P).

Disclosure of Interests

None declared

POS0035 GENE REGULATION IN T-CELLS FROM PsA PATIENTS DIFFERS BETWEEN PERIPHERAL BLOOD AND THE INFLAMED JOINTS: IMPLICATIONS FOR THE INTERPRETATION OF GWAS SIGNALS

Background

Genome-wide association studies (GWAS) have identified variants that are associated with complex diseases such as Psoriatic Arthritis (PsA). The majority of these variants do not affect the coding sequence of proteins but rather regulatory elements which are highly cell type and state specific, and can affect distally located genes via chromatin interaction mechanisms.

We and others have previously analysed GWAS loci for multiple conditions (including PsA and Rheumatoid Arthrtitis) in cell lines using functional genomics techniques, providing putative mechanisms to many loci with previously unknown function [1].

However, multiple studies have identified large differences in gene regulatory mechanisms between cell lines and primary cells, which could significantly alter the proposed mechanisms. Differences between between samples from healthy volunteers and patients, in particular from the affected tissue, have although not been exhaustively investigated.

Objectives

To assess the impact of using primary cells derived from PsA patients compared to healthy volunteers in functional genomics studies.

Methods

CD4+ and CD8+ T cells were isolated from peripherial blood from 10 healthy controls and 48 PsA patients and from 6 PsA synovial fluid samples.

We performed RNA-seq and ATAC-seq on these two cell types to analyse the global patterns of gene expression and chromatin activity.

Results

We find subtle differences between PsA patients and healthy controls in cells isolated from blood. RNA-seq analysis identified only a handful of differentially expressed genes whilst ATAC-seq analysis identified only 28 differential loci.

On the other hand, T cells isolated from synovial fluid showed significant differences compared to T cells isolated from patient’s blood. Interestingly, we find that CD4+ T cells show substantially more differentially expressed genes compared to CD8+ T cells (1168 vs 346 Log2FoldChange > 1, FDR < 0.01). Genes overexpressed in synovial CD4+ T cells are more strongly enriched for immune pathways such as cytokine signaling and T cell proliferation compared to synovial CD8+ T cells

We also find that synovial CD4+ T cells highly overexpress MHC class II genes (Figure 1).

Figure 1.

Normalized counts of the alpha chains of MHC class 2 genes in CD4+ and CD8+ T cells purified from blood from healthy subjects and patients and synovial fluid.

Conclusion

This preliminary analysis suggests that T cells isolated from peripherial blood do not seem to differ significantly between PsA patients and healthy controls. In contrast, cells isolated from synovial fluid are highly specialized and activated. Moreover, these cells do not resemble canonically activated T cells which means that this state can not be easily emulated in vitro.

This study indicates the importance of not only studying GWAS loci in relevant primary cells from patients, but also that attention needs to be given to cells isolated from the affected site.

References

[1]Shi C, Ray-Jones H, Ding J, et al (2021) Chromatin Looping Links Target Genes with Genetic Risk Loci for Dermatological Traits. J Invest Dermatol 141:1975–1984. https://doi.org/10.1016/J.JID.2021.01.015

Acknowledgements

This work was funded by the Wellcome Trust (award references 207491/Z/17/Z and 215207/Z/19/Z), the Versus Arthritis (award reference 21754), the NIHR Manchester Biomedical Research Centre, and the Medical Research Council (award reference MR/N00017X/1).

Disclosure of Interests

None declared

OP0222 IDENTIFICATION OF CAUSAL GENES AND MECHANISMS BY WHICH GENETIC VARIATION MEDIATES JUVENILE IDIOPATHIC ARTHRITIS SUSCEPTIBILITY USING FUNCTIONAL GENOMICS AND CRISPR-CAS9

Background

We recently performed the largest juvenile idiopathic arthritis (JIA) genome-wide association study (GWAS) to date 1. Disease-associated loci contain multiple single nucleotide polymorphism (SNPs), and the majority map to non-coding enhancers, making it challenging to define causal variants and genes.

Functional genomics datasets in disease-relevant tissues have shown to be essential for the functional interpretation of GWAS loci. In particular, capture Hi-C (CHi-C) has been successful in detecting chromosomal interactions linking GWAS loci to their target genes. However, such datasets are lacking in JIA.

Objectives

The aim of this study is to bridge this gap and advance the knowledge of the biological mechanisms that underpin susceptibility to JIA, by integrating GWAS with public epigenomics datasets and in-house generated CHi-C from JIA patients. We focus on CD4+ T-cells, which have been shown to be one of the most relevant cell types in JIA. In addition, we use CRISPR-Cas9 to validate the regulatory effect of prioritised variants on their predicted target genes.

Methods

Credible SNP sets for the top JIA risk loci (P < 5x10-6) were annotated using EpiMap data 2. Low input whole genome promoter CHi-C (PCHi-C) was performed on CD4+ T-cells isolated from blood from 3 JIA oligoarthritis patients, and data was analysed using CHiCAGO 3. GWAS and PCHi-C data were combined to prioritise causal genes using the Capture Hi-C Omnibus Gene Score (COGS) pipeline 4. We subsequently employed CRISPR activation (CRISPRa) and CRISPR interference (CRISPRi) in Jurkats to assess whether prioritized JIA variants were capable of regulating the expression of the interacting genes.

Results

614 credible SNPs (out of 735) were found to overlap active enhancers in CD4+ T-cells, and were prioritized for further analysis.

We identified numerous significant chromatin interactions in 19 out of 44 non-MHC JIA associated loci, linking JIA SNPs mapping to T-cell enhancers to a total of 61 target genes and revealing potential novel disease pathways. Moreover, COGS prioritised a total of 7 genes (RGS14, ERAP2, HIPK1, CCR4, CCRL2, CCR2, CCR3).

A JIA associated locus on chromosome 3 contains 39 SNPs. It maps to an intergenic region and the causal gene/s are unclear. Our PCHi-C data revealed that this JIA locus presents chromatin interactions with the promoters of several genes, such as CCRL2, CCR2, CCR3 and CCR5, three of which were prioritised by COGS. Two variants were selected for further analysis: rs79815064, which had the highest posterior probability, and rs8005404,the only variant within a CD4+ T-cell enhancer linked to surrounding gene activity.

When both SNPs were targeted with CRISPRa and CRISPRi, we observed an increased and decreased expression, respectively, of CCRL2, CCR2, CCR3 and CCR5, confirming their role in disease. These genes belong to the chemokine receptor family and are important regulators of the inflammatory response.

Conclusion

Our work shows how functional genomics can help identify biological mechanisms by which GWAS variants increase risk of JIA, which in turn will benefit patients through personalised medicine and the identification of therapeutic targets.

References

[1]López-Isac, E. et al. Combined genetic analysis of juvenile idiopathic arthritis clinical subtypes identifies novel risk loci, target genes and key regulatory mechanisms. Ann. Rheum. Dis.80, 321–328 (2021).

[2]Boix, C. A., James, B. T., Park, Y. P., Meuleman, W. & Kellis, M. Regulatory genomic circuitry of human disease loci by integrative epigenomics. Nat. 2021 5907845590, 300–307 (2021).

[3]Cairns, J. et al. CHiCAGO: Robust detection of DNA looping interactions in Capture Hi-C data. Genome Biol.17, 1–17 (2016).

[4]Javierre, B. M. et al. Lineage-Specific Genome Architecture Links Enhancers and Non-coding Disease Variants to Target Gene Promoters. Cell167, 1369 (2016).

Disclosure of Interests

Antonio Frantzesko: None declared, Valeriya Malysheva: None declared, Chenfu Shi: None declared, James Ding: None declared, John Bowes: None declared, Wendy Thomson: None declared, Stephen Eyre: None declared, Mikhail Spivakov Shareholder of: co-founder and shareholder of Enhanc3D Genomics Ltd, Gisela Orozco: None declared

[Clinical characteristics of biliary obstruction patients with Clonorchis sinensis infections]

OBJECTIVE

To analyze the clinical characteristics of biliary obstruction patients with Clonorchis sinensis infections, so as to provide insights into the clinical diagnosis and therapy of this comorbidity.

METHODS

A total of 45 biliary obstruction patients with C. sinensis infections that were admitted to the Second Affiliated Hospital of Harbin Medical University from October 2012 to September 2019 were enrolled, and 45 patients with biliary obstruction alone at the hospital during the same study period were recruited as controls. Univariate analysis was performed to analyze the epidemiological characteristics, clinical manifestations, laboratory examination results and imaging manifestations related to C. sinensis infection, and the statistically significant univariate was used as an independent variable for multivariate logistic regression analysis.

RESULTS

Compared with biliary obstruction alone, males (91.11% vs. 46.67%; χ² = 20.737, P < 0.01) and rural areas (62.22% vs. 22.22%; χ² = 14.757, P < 0.01) showed a significantly higher proportion in biliary obstruction patients with C. sinensis infections. The major clinical symptoms involved in had jaundice (45 cases, 100%) and abdominal pain (40 cases, 88.89%) in C. sinensis-infected patients. Logistic regression analysis showed that males [odds ratio (OR) = 10.717, 95% confidential interval (CI): (2.571, 44.662)] and drinking alcohol [OR = 4.474, 95% CI: (1.019, 19.642)] were risk factors for biliary obstruction patients with C. sinensis infections, while living in city [OR = 0.128, 95% CI: (0.038, 0.435)] was a protective factor. Additionally, in biliary obstruction patients with C. sinensis infections, lower total bilirubin (Z = -2.566, P <0.05) and direct bilirubin (Z = -3.454, P <0.05), higher indirect bilirubin (Z = -3.821, P < 0.05), thickening of the bile duct wall and dilatation of the intrahepatic bile duct were detected.

CONCLUSIONS

A comprehensive diagnosis requires to be made based on clinical symptoms, laboratory and imaging examinations, in order to improve the diagnosis of biliary obstruction patients with C. sinensis infections.

Acceleration of Brain Susceptibility-Weighted Imaging with Compressed Sensitivity Encoding: A Prospective Multicenter Study

BACKGROUND AND PURPOSE

While three-dimensional susceptibility-weighted imaging has been widely suggested for intracranial vessel imaging, hemorrhage detection, and other neuro-diseases, its relatively long scan time has necessitated the clinical verification of recent progresses of fast imaging techniques. Our aim was to evaluate the effectiveness of brain SWI accelerated by compressed sensitivity encoding to identify the optimal acceleration factors for clinical practice.

MATERIALS AND METHODS

Ninety-nine subjects, prospectively enrolled from 5 centers, underwent 8 brain SWI sequences: 5 different folds of compressed sensitivity encoding acceleration (CS2, CS4, CS6, CS8, and CS10), 2 different folds of sensitivity encoding acceleration (SF2 and SF4), and 1 without acceleration. Images were assessed quantitatively on both the SNR of the red nucleus and its contrast ratio to the CSF and, subjectively, with scoring on overall image quality; visibility of the substantia nigra-red nucleus, basilar artery, and internal cerebral vein; and diagnostic confidence of the cerebral microbleeds and other intracranial diseases.

RESULTS

Compressed sensitivity encoding showed a promising ability to reduce the acquisition time (from 202 to 41 seconds) of SWI while increasing the acceleration factor from 2 to 10, though at the cost of decreasing the SNR, contrast ratio, and the scores of visual assessments. The visibility of the substantia nigra-red nucleus and internal cerebral vein became unacceptable in CS6 to CS10. The basilar artery was well-distinguished, and diseases including cerebral microbleeds, cavernous angiomas, intracranial gliomas, venous malformations, and subacute hemorrhage were well-diagnosed in all compressed sensitivity encoding sequences.

CONCLUSIONS

Compressed sensitivity encoding factor 4 is recommended in routine practice. Compressed sensitivity encoding factor 10 is potentially a fast surrogate for distinguishing the basilar artery and detecting susceptibility-related abnormalities (eg, cerebral microbleeds, cavernous angiomas, gliomas, and venous malformation) at the sacrifice of visualization of the substantia nigra-red nucleus and internal cerebral vein.

Abnormal keratin expression pattern in prurigo nodularis epidermis

Background

Prurigo nodularis (PN) is a highly pruritic, chronic dermatosis and difficult to treat. PN lesions are characterized by existence of many hyperkeratotic, erosive papules and nodules. However, the pathogenesis of PN still remains unelucidated.

Aim

To clarify the keratin role in the epidermis hyperproliferation, the keratin expression pattern in the PN lesional skin.

Methods

In this study, we enrolled 24 patients with PN and 9 healthy control volunteers. K1/K10, K5/K14, K6/K16/K17 expression pattern were investigated by using immunohistochemical staining.

Results

The lesional skin consists of the thickened spinous layers, in which active cell division was found. K5/K14 were upregulated in PN lesional epidermis, the staining signal localized in the basal layer and lower suprabasal layers. Hyperproliferation‐associated K6 was found in all layers of epidermal lesional skin, especially in the spinous layers. In contrast, K16 was only detected in the basal and lower suprabasal layers, K17 was observed in the basal and spinous layers. Terminal differential keratins K1/K10 were upregulated, detected in the pan‐epidermis, but spared in the basal and low suprabasal layers.

Conclusion

The keratinocytes enter an alternative differentiation pathway, which are responsible for the activated keratinocyte phenotype, abnormal keratins expression potentially contributes to the keratinocytes proliferation, subsequently lead to increased lesional skin epidermis thickness, hyperkeratiosis and alteration of skin barrier properties.

Relationship between Egg Consumption and Metabolic Syndrome. A Meta-Analysis of Observational Studies

OBJECTIVES

Aims: To explore the association between egg consumption and metabolic syndrome (MetS) in the adult population.

METHODS

The PubMed, Web of Science and Embase electronic databases were searched up to December 2021 for observational studies on the association between egg consumption and MetS in the adult population. The pooled relative risk (RR) of MetS for the highest versus lowest category of egg consumption, and the standard mean difference (SMD) of egg consumption for MetS versus control subjects were calculated. Egg consumption was assessed by a food-frequency questionnaire (FFQ) and the 24-hour recall method. The criteria for MetS were National Cholesterol Education Program-Adult Treatment Panel III (NCEP ATP III), International Diabetes Federation (IDF), Joint Interim Statement (JIS) and American Heart Association (AHA).

RESULTS

A total of 19 articles with 20 observational studies (331667 participants) were included in this meta-analysis. The overall multivariable adjusted RR (18 studies included) demonstrated that higher egg consumption was associated with a lower probability of having MetS (RR=0.92, 95%CI: 0.88 to 0.96; P<0.001). Subgroup analysis confirmed these findings in cross-sectional studies (RR=0.91, 95% CI: 0.88 to 0.95; P<0.001), studies that used the NCEP ATP III criteria (RR=0.94, 95% CI: 0.89 to 0.99; P=0.02), Asia (RR=0.92, 95% CI: 0.86 to 0.99; P=0.02), studies with samples sizes >5000 (RR=0.92, 95% CI: 0.86 to 0.96; P<0.001), studies that adjusted body mass index (BMI) (RR=0.90, 95% CI: 0.86 to 0.95; P<0.001) and energy intake (RR=0.89, 95% CI: 0.83 to 0.94; P<0.001) and high-quality studies (RR=0.91, 95% CI: 0.88 to 0.95; P<0.001). Moreover, the overall combined SMD (5 studies included) showed that the level of egg consumption in subjects with MetS was also lower than that in control subjects. (SMD=-0.22, 95% CI: -0.25 to -0.20; P<0.001). Sensitivity analysis demonstrated that this finding only existed in studies with samples sizes >5000 (SMD=-0.21, 95% CI: -0.29 to -0.12; P<0.001) and high-quality studies (SMD=-0.23, 95% CI: -0.26 to -0.20; P<0.001).

CONCLUSION

Our results suggest that higher egg consumption is associated with a lower probability of having MetS in the adult population. However, due to the limited evidence, more global well-designed prospective cohort studies are still needed.

[Oxymatrine improves renal fibrosis and inflammation in diabetic rats by modulating CHK1/2 phosphorylation]

OBJECTIVE

To explore the role of cell cycle checkpoint kinase 1/2 (CHK1/2) in mediating the inhibitory effect of oxymatrine (OMT) against renal inflammation and fibrosis in diabetic rats.

METHODS

SD rats were randomly divided into normal control group, diabetes model group (DM) and OMT treatment group (n=6). HE and Masson staining were used to observe histopathological changes of the renal tissue, and the expressions of CHK1, CHK2, p-CHK1 and p-CHK2 were localized by immunohistochemical staining. The contents of interleukin-6 (IL-6) and IL-1β in the renal tissue were detected using ELISA, and the expression levels of CHK1, CHK2, p-CHK1, p-CHK2, type Ⅲ collagen (Col-Ⅲ), type Ⅳ collagen (Col-Ⅳ), and fibronectin (FN) were determined using Western blotting. The changes in the expressions of CHK1, CHK2, p-CHK1, p-CHK2, Col-Ⅲ, Col-Ⅳ and FN proteins were also examined with Western blotting in NRK-52E cells in response to high glucose exposure, OMT treatment and siRNA-mediated CHK1/2 knockdown.

RESULTS

In diabetic rats, OMT treatment significantly decreased the levels of blood glucose, serum creatinine and 24 h urinary protein (P < 0.05) and obviously improved inflammatory cell infiltration and fibrosis phenotype in the renal tissue (P < 0.05). CHK1 and CHK2 were mainly expressed in the cytoplasm and nuclei of renal tubule cells, and their phosphorylation levels were significantly higher in DM group than in the control group and OMT group. OMT treatment significantly decreased the protein expression levels of p-CHK1, p-CHK2, Col-Ⅲ, Col-Ⅳ and FN in the renal tissue of diabetic rats and in NRK-52E cells exposed to high glucose (P < 0.05). In NRK-52E cells, CHK1/2 knockdown resulted in significant reduction of the protein expressions of p-CHK1/2, Col-Ⅲ, Col-Ⅳ and FN (P < 0.05).

CONCLUSION

The inhibitory effects of OMT against renal inflammation and fibrosis in diabetic rats are mediated probably by lowered phosphorylation levels of CHK1 and CHK2, which result in reduced release of the downstream inflammatory mediators and decreased secretion and deposition of extracellular matrix.

[Identification of potential regulatory genes for embryonic stem cell self-renewal and pluripotency by random forest]

OBJECTIVE

To identify novel genes associated with self-renewal and pluripotency of mouse embryonic stem cells(mESCs)by integrating multiomics data based on machine learning methods.

METHODS

We integrated multiomics information of mESCs involving transcriptome, histone modifications, chromatin accessibility, transcription factor binding and architectural protein binding, and compared the signal differences between known stem cell self-renewal and pluripotency genes and other genes.By integrating these multiomics data, we established prediction models based on several machine learning classifiers including random forests and performed 5-fold cross validations.The model was trained using the training dataset containing two thirds of the input samples, and the remaining one third of the input samples were used as the test dataset to assess the performance of the model in independent tests.Finally, the results predicted by the model were validated through gene function annotation and cell function experiments including cell viability assay, colony formation assay and cell cycle analysis.

RESULTS

Compared with the random genes, the genes known to be associated with self-renewal and pluripotency of mESCs in the multiomics data showed significantly different features.Random forest outperformed the other machine learning algorithms tested on these multiomics data, with an area under the curve (AUC) of 0.883±0.018 for cross validation and an AUC of 0.880±0.028 for independent test.Based on this model, we identified 893 potential regulatory genes associated wwith self-renewal and pluripotency of mESCs, which were similar to the known genes in functional annotation.Known-down of the predicted novel regulator gene Cct6a resulted in significant decreases in the cell viability of mESCs (P < 0.0001) and the number of cell clones (P < 0.01), significantly increased the number of cells in G1 phase (P < 0.01) and decreasedthe number of S phase cells (P < 0.05).Knockdown of Cct6a also led to failure of positive alkaline phosphatase staining of the mESCs.

CONCLUSION

Machine learning model based on multiomics data can be used to predict potential self-renewal and pluripotency regulators with high performance.By using this model, we predicted potential self-renewal and pluripotency regulatory genes including Cct6a and applied experimental validation.This model provides new insights into the regulatory mechanism of mESCs and contribute to stem cell research.

[A case of pulmonary barotrauma complicated with cerebral arterial air embolism in a diver]

Pulmonary barotrauma is a kind of disease caused by the injury of lung tissue or blood vessel when the gas pressure of lung is too high or too lower than the external pressure of the body, which causes the air to enter the blood vessel and adjacent tissue. It could be happened in the escape of the divers with the light diving equipment or the sailors from submarine. Generally, the decompression chamber was used to treating the disease, and the minimum air pressure of 0.5 MPa recompression therapeutic schedule was used to selecting. In November 2019, a patient with pulmonary barotrauma combined with cerebral arterial gas embolism caused by improper underwater escape with light diving equipment was admitted to the General Hospital of Eastern War Zone. He was treated with 0.12 MPa oxygen inhalation recompression scheme in the oxygen chamber pressurized with air. 7 days later, the patient recovered and discharged.