Evaluating the causal effect of circulating proteome on the risk of osteoarthritis-related traits.

OBJECTIVES: This study aims to identify circulating proteins that are causally associated with osteoarthritis (OA)-related traits through Mendelian randomisation (MR)-based analytical framework. METHODS: Large-scale two-sample MR was employed to estimate the effects of thousands of plasma proteins on 12 OA-related traits. Additional analyses including Bayesian colocalisation, Steiger filtering analysis, assessment of protein-altering variants and mapping expression quantitative trait loci to protein quantitative trait loci were performed to investigate the reliability of the MR findings; protein-protein interaction, pathway enrichment analysis and evaluation of drug targets were conducted to deepen the understanding and identify potential therapeutic targets of OA. RESULTS: Dozens of circulating proteins were identified to have putatively causal effects on OA-related traits, and a majority of these proteins were either drug targets or considered druggable. CONCLUSIONS: Through MR analysis, we have identified numerous plasma proteins associated with OA-related traits, shedding light on protein-mediated mechanisms and offering promising therapeutic targets for OA.

Longitudinal association of infrapatellar fat pad signal intensity alteration with biochemical biomarkers in knee osteoarthritis.

OBJECTIVE: To explore the longitudinal association of quantitative infrapatellar fat pad (IPFP) signal intensity alteration with OA-related biomarkers. METHODS: Eighteen OA-related biochemical biomarkers of 600 knee OA participants in the Foundation for the National Institutes of Health OA Biomarkers Consortium (FNIH) study were extracted. The quantitative IPFP signal intensity measures were acquired based on magnetic resonance imaging, including mean value [Mean (IPFP)] and standard deviation [sDev (IPFP)] of the whole IPFP signal intensity, median value [Median (H)] and upper quartile value [UQ (H)] of high signal intensity, the ratio of volume of high signal intensity to volume of whole IPFP signal intensity [Percentage (H)] and Clustering factor (H). The linear mixed-effect model was applied to determine the longitudinal associations between IPFP signal intensity alteration and biochemical biomarkers over 2 years. RESULTS: All IPFP measures except for Clustering factor (H) were positively associated with urine collagenase-cleaved type II collagen neoepitope (uC2C), urine C-terminal cross-linked telopeptide of type II collagen (uCTX-II), urine C-terminal cross-linked telopeptide of type I collagen-α (uCTX-Iα) and urine N-terminal cross-linked telopeptide of type I collagen (uNTX-I). Mean (IPFP), Median (H) and Percentage (H) were positively associated with the nitrated form of an epitope located in the triple helix of type II collagen (Coll2-1 NO2). Mean (IPFP), Median (H) and UQ (H) were positively associated with sCTX-I and uCTX-Iß. Positive associations between sDev (IPFP), Percentage (H) and serum hyaluronic acid (sHA) were found. CONCLUSION: Our results suggest a role of IPFP signal intensity alteration in joint tissue remodelling on a molecular level.

Association of serum levels of inflammatory markers and adipokines with joint symptoms and structures in participants with knee osteoarthritis.

OBJECTIVE: To investigate the longitudinal associations of serum inflammatory markers and adipokines with joint symptoms and structures in participants with knee OA. METHODS: Two hundred participants (46.5% female, mean age 63.1 years, mean BMI 29.5 kg/m2) from Tasmania, part of the VIDEO (Vitamin D Effect on OA) study, were randomly selected in the current study. Serum levels of 19 biomarkers, scores of WOMAC and MRI-assessed knee structures were evaluated at baseline and month 24. The patterns of biomarkers were derived from principal component analysis and their association with knee symptoms and structures were examined using adjusted generalized estimating equations. RESULTS: Five components explained 78% of the total variance. IL-1ß, -2, -4, -6, -8, -17 A, -17 F, -21, -22 and -23 loaded the highest on the first component, which was associated with increased bone marrow lesions (BMLs) and WOMAC dysfunction score. IL-10, -12 and GM-CSF loaded on the second component, which was associated with increased cartilage volume, and decreased effusion synovitis and WOMAC scores. Leptin, adipsin and CRP loaded on the third component, which was positively associated with WOMAC scores. Resistin loaded on the fourth component, which was associated with increased BMLs and cartilage defects. Apelin-36 and adiponectin loaded on the fifth component, which was associated with increased BMLs. CONCLUSION: Various inflammatory and metabolic components were associated differently with joint symptoms and structural changes in knee OA, suggesting a complex inflammatory and metabolic interrelationship in the pathogenesis of knee OA.

Associations of blood pressure and arterial stiffness with knee cartilage volume in patients with knee osteoarthritis.

OBJECTIVE: To describe the associations of blood pressure and arterial stiffness with knee cartilage volume in patients with knee OA. METHODS: A secondary analysis was performed on the data from participants in a randomized controlled trial that identified the effects of vitamin D supplementation on knee structures and symptoms among patients with symptomatic knee OA. Brachial and central blood pressure, arterial stiffness indicators and knee cartilage volume were measured at baseline and the 2 year follow-up. Associations were assessed using generalized estimating equations. RESULTS: Among 231 participants (average age 63.2 years), 48.9% were females. Higher supine systolic and diastolic pressures were significantly associated with lower tibial cartilage volume (systolic: lateral ß -6.23, medial ß -5.14, total ß -11.35 mm3/mmHg; diastolic: lateral ß -10.25, medial ß -11.29, total ß -21.50 mm3/mmHg). Higher supine systolic pressure was associated with lower femoral cartilage volume (lateral ß -17.35, total ß -28.31 mm3/mmHg). Central systolic pressure and arterial stiffness indicators (including pulse wave velocity, central pulse pressure and peripheral pulse pressure) were largely not associated with knee cartilage volume; however, higher augmentation index was associated with lower tibial and femoral cartilage volume (tibial: medial ß -8.24, total ß -19.13 mm3/%; femoral: lateral ß -23.70, medial ß -26.42, total ß -50.12 mm3/%). CONCLUSIONS: Blood pressure and arterial stiffness are associated with knee cartilage volume at several sites in knee OA patients. This supports that blood pressure and arterial stiffness may involve in the progression of knee OA.

Plasma Long Non-Coding RNA Expression Profiles in Patients with Rheumatoid Arthritis.

BACKGROUND: Recently, long non-coding RNAs (lncRNAs) have attracted substantial attention owing to their unforeseen critical roles in a wide range of biological processes. The aim of our study was to provide an overview of lncRNA expression profiles in plasma of RA patients. METHODS: The Agilent LncRNA + mRNA Human Gene Expression Microarray V4.0 was employed to determine differentially expressed (DE) lncRNAs and mRNAs in plasma of four female newly diagnosed and DMARD-naïve RA patients and four female age-matched healthy controls. The KOBAS (KEGG Orthology Based Annotation System) software was applied to determine the gene ontology (GO) terms and pathway in which the DE mRNAs were enriched. Furthermore, a lncRNA-mRNA co-expression network was constructed according to the correlation between DE lncRNAs and mRNAs. RESULTS: Compared with healthy controls, a total of 289 DE lncRNAs (169 up-regulated and 120 down-regulated) and 468 DE mRNAs (280 up-regulated and 188 down-regulated) were found in the plasma of patients with RA. Bioinformatics analysis indicated that the DE mRNAs might be involved in the pathogenesis of RA mainly through platelets. In addition, a co-expression network composed of 229 network nodes and 340 connections between 116 lncRNAs and 113 mRNAs was constructed. CONCLUSIONS: We characterized the plasma lncRNA expression profiles in RA patients for the first time. Our results could shed new light on the pathogenesis of RA and help identify lncRNAs as novel diagnostic biomarkers and therapeutic targets for RA.

The clinical value of hematological markers in rheumatoid arthritis patients treated with tocilizumab.

BACKGROUND: Emerging evidence indicates that some hematological markers have critical value in evaluating treatment response. This study was performed to determine the clinical value of hemoglobin (Hb), platelet (Plt), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) in rheumatoid arthritis (RA) patients treated with tocilizumab (TCZ). METHODS: Fifty-two RA patients receiving TCZ were recruited and followed for 6 months. The values of abovementioned hematological markers were collected. Clinical disease activity index (CDAI) and disease activity score based on 28 joints (DAS28)-ESR were calculated. Correlation analysis was conducted by calculating Pearson's correlation coefficient. The change in disease activity between groups according to the baseline level of hematological markers was compared by t test. RESULTS: Significant correlation between change in NLR (△NLR), change in PLR (△PLR), and change in CDAI (△CDAI) was found (△NLR: r = 0.30, P = 0.03; △PLR: r = 0.31, P = 0.03). The change in Plt (△Plt) was correlated with change in DAS28-ESR (△DAS28-ESR) (r = 0.36, P = 8.24 × 10-3 ). Greater improvement in CDAI was seen in patients categorized into Plt high group (t = 2.06, P = 0.04), NLR high group (t = 2.15, P = 0.04), and PLR high group (t = 2.41, P = 0.02) compared with the contrast group. CONCLUSION: Our study demonstrated that △Plt, △NLR, and △PLR could be used to monitor the clinical response to TCZ. RA patients with high baseline levels of Plt, NLR, and PLR achieved more improvement, indicating these hematological markers might be utilized to guide TCZ treatment.

Associations of TRAF1/C5 rs10818488 and rs3761847 polymorphisms with genetic susceptibility to rheumatoid arthritis: a case-control study and updated meta-analysis.

The results on associations of tumor necrosis factor (TNF)-receptor associated factor 1/complement component 5 (TRAF1/C5) rs10818488 and rs3761847 polymorphisms with rheumatoid arthritis (RA) are controversial, thus this study was performed to examine whether the aforementioned polymorphisms were associated with RA in a Chinese population. Furthermore, an updated meta-analysis was conducted. The polymorphisms were genotyped in 328 Chinese RA patients and 449 healthy controls. Studies examining the association of TRAF1/C5 rs10818488 and/or rs3761847 polymorphism with RA were exhaustively searched. No significant difference in either genotype or allele distribution between RA patients and controls was found. The updated meta-analysis was conducted based on 19 articles including the present study. A significant association of RA with TRAF1/C5 rs10818488 polymorphism G allele in Europeans (OR = 0.843, 95% CI = 0.730-0.975, p = 0.021) and in Asians (OR = 1.070, 95% CI = 1.009-1.136, p = 0.024) was found. Additionally, a significant association of RA with TRAF1/C5 rs10818488 polymorphism G allele under the recessive model in Asians (OR = 1.129, 95% CI = 1.023-1.246, p = 0.016) and in Africans (OR = 0.657, 95% CI = 0.507-0.851, p = 0.001) was found. Only a borderline significant association of RA with TRAF1/C5 rs3761847 polymorphism A allele was found in Europeans. Non-significant associations of RA with TRAF1/C5 rs10818488 and rs3761847 polymorphisms were found in our study. The updated meta-analysis results demonstrate that TRAF1/C5 rs10818488 polymorphism is associated with RA in Europeans, Asians and Africans, and TRAF1/C5 rs3761847 polymorphism is associated with RA in Europeans with borderline significant evidence.

LBH mRNA Expression and Polymorphisms in Patients with Rheumatoid Arthritis.

Background: This study was performed to determine the mRNA expression levels of limb-bud and heart (LBH) in peripheral blood mononuclear cells (PBMCs) from patients with rheumatoid arthritis (RA), and to assess the associations of LBH rs7579944 and rs906868 polymorphisms with RA in a Chinese population. Methods: Real-time transcription-polymerase chain reaction analysis was used to determine the LBH mRNA expression in PBMCs from 53 patients with RA and 58 healthy controls, and LBH rs7579944 and rs906868 polymorphisms were genotyped in 328 RA patients and 449 healthy controls. Results: The LBH mRNA expression levels were significantly decreased in RA patients compared with healthy controls (p = 0.02). However, non-significant correlation between LBH mRNA expression in PBMCs and ESR (r = 0.14, p = 0.36), CRP (r = 0.17, p = 0.27) or DAS28-ESR (r = 0.23, p = 0.12) was found. There was no significant difference in neither genotype (p = 0.90) nor allele (p = 0.97) distribution of the LBH rs7579944 polymorphism between RA patients and healthy controls. The relationships between the major allele T of LBH rs7579944 polymorphism and the risk of RA under dominant and recessive model were examined, whereas non-significant evidence was found. Similarly, a non-significant signal was detected for the association of LBH rs906868 polymorphism with RA. Conclusions: Decreased expression of LBH mRNA in PBMCs might contribute to the pathogenesis of RA.

A study on associations of single-nucleotide polymorphisms within H19 and HOX transcript antisense RNA (HOTAIR) with genetic susceptibility to rheumatoid arthritis in a Chinese population.

OBJECTIVE: The purpose of our study was to examine whether the H19 rs2839698, rs217727, and HOX transcript antisense RNA (HOTAIR) rs12826786 polymorphisms were associated with genetic susceptibility to rheumatoid arthritis (RA) in a Chinese population. METHODS: A total of 777 participants were enrolled in this study, including 328 RA patients and 449 healthy controls. The H19 rs2839698, rs217727, and HOTAIR rs12826786 polymorphisms were detected by the ligase detection reaction-polymerase chain reaction (LDR-PCR) technology. RESULTS: No significant difference in genotype distribution between RA patients and healthy controls was found (P = 0.38 for rs2839698; P = 0.79 for rs217727; P = 0.39 for rs12826786). The difference in allele frequencies between RA patients and controls was also non-significant (rs2839698 T versus C, P = 0.23, odds ratio (OR) = 1.15, 95% confidence interval (CI) = 0.92-1.43; rs217727 C versus T, P = 0.55, OR = 1.07, 95% CI = 0.87-1.32; and rs12826786 T versus C, P = 0.32, OR = 1.14, 95% CI = 0.88-1.47). We have also evaluated the relationships of above-mentioned polymorphisms with risk of RA under dominant model and recessive model, but non-significant evidence was found. No significant evidence was detected for the relationships of H19 rs2839698, rs217727, and HOTAIR rs12826786 polymorphisms with risk of different serotypes of RA. CONCLUSIONS: Our results indicated that H19 rs2839698, rs217727, and HOTAIR rs12826786 polymorphisms might not be involved in the genetic background of RA in Chinese.

Association between CARD8 rs2043211 polymorphism and inflammatory bowel disease: a meta-analysis.

OBJECTIVE: The aim of this study was to determine whether caspase recruitment domain-containing protein 8 (CARD8) rs2043211 polymorphism was associated with susceptibility to inflammatory bowel disease (IBD). METHODS: Relevant studies were searched using PubMed and Embase up to February 2014. A meta-analysis was conducted on the association between rs2043211 polymorphism and IBD using: (1) allele contrast, (2) the dominant model, (3) the recessive model, and (4) homozygote contrast. The pooled estimated of risk was obtained by random-effects model or fixed-effects model. Publication bias was assessed by Egger's test. RESULTS: Eight relevant articles with a total of 10 534 IBD patients [6785 Crohn's disease (CD), 3713 ulcerative colitis (UC) and 36 indeterminate colitis (IC)] and 6755 healthy controls were included in the meta-analysis, which consisted of 12 studies, 12 for CD, 10 for UC, 2 for IC. There was no significant association between rs2043211 polymorphism and IBD, CD, and IC in overall population. However, stratified meta-analysis by ethnicity showed significant association between rs2043211 polymorphism and CD in the European population under the dominant model [odds ratio (OR) = 1.210, 95% confidence interval (CI) = 1.013-1.445, p = 0.036] and homozygote contrast (OR = 1.212, 95% CI = 1.005-1.461, p = 0.044). CONCLUSIONS: Our meta-analysis results indicated significant association between rs2043211 polymorphism and the susceptibility to CD under the dominant model and homozygote contrast in the European population.

Lack of association between the polymorphisms of hypoxia-inducible factor 1A (HIF1A) gene and SLE susceptibility in a Chinese population.

Hypoxia-inducible factor 1 (HIF-1) introduced the immune imbalance between Th17 and Treg cells, which may play an important role in the pathogenesis of systemic lupus erythematosus (SLE). The aim of the present study was to determine whether the HIF1A gene influences the susceptibility to SLE. A study on this relationship has not been conducted to date. A total of 3,793 subjects (1,497 SLE patients and 2,296 controls) were included in this study. The genotyping of five single-nucleotide polymorphisms (SNPs) (rs11549465, rs12434438, rs1957757, rs1951795, rs7143164) was determined by Sequenom MassARRAY technology. The statistical analysis was conducted using chi-square test. Odds ratio (OR) with 95% confidence interval (CI) was calculated using unconditional logistic regression with adjustment of age and sex. The allele frequencies were not associated with the disease. No significant differences in genotype frequencies existed between the patients with SLE and the controls in all five SNPs. It is worth mentioning that the allele T at rs11549465, located at the exon sequence, revealed a trend but no significant difference towards the more frequent allele T in SLE than in controls (C versus T: OR=1.206, 95 % CI=0.972-1.495, p =0.088). The genotype effects of recessive, dominant, and codominant models were observed; however, no significant evidence for association was detected. Our findings suggest that the gene polymorphisms of HIF1A might not contribute to SLE susceptibility in the Chinese population. However, further studies are needed on an independent cohort from different genetic backgrounds to confirm HIF1A as an SLE genetic factor.

Prevalence of systemic lupus erythematosus and risk factors in rural areas of Anhui Province.

Systemic lupus erythematosus (SLE) is a severe complex rheumatic disease, but good estimate of its prevalence and risk factors is lacking in China. The aim of the study was to explore the prevalence of SLE and risk factors in rural areas of Anhui Province of China. Eleven counties were randomly selected in Anhui Province, and then, 15% of the villages in selected counties were randomly sampled as study sites. Patients with SLE were identified through two phases. Based on the cases identified, a population-based case-control study was designed to examine risk factors associated with SLE. A total of 1,253,832 individuals and identified 471 SLE cases were surveyed. Crude and age-standardized prevalence were estimated at 37.56 and 36.03 per 100,000 persons, respectively. Gender difference in the prevalence of SLE was significant (P = 4.62 × 10(-76)), and the age-standardized prevalence was 6.17 for males and 67.78 for females per 100,000 persons. The distribution of SLE prevalence was significant by age group (P = 1.78 × 10(-53)), and the peak prevalence was observed at 40-50 years. Multiple environmental factors were associated with SLE, including birth conditions, sweet food, cooking oil, taste, fruit consumption, sunlight exposure, quality of sleep, physical activities, drinking water, residence, negative life events, hepatitis B vaccine, age of menarche, and age at birth of first child (P < 0.05). Our large population-based epidemiological survey estimated the prevalence of SLE at 37.56 per 100,000 persons. Multiple environmental factors were associated with the development of SLE.

Causal associations of plasma omega-3 polyunsaturated fatty acids with sarcopenia-related traits: a two-sample Mendelian randomization study.

OBJECTIVE: To evaluate the causal effect of plasma omega-3 polyunsaturated fatty acids (PUFAs) on sarcopenia-related traits (lean mass, grip strength and walking pace) utilizing two-sample Mendelian randomization (MR) approach. METHODS: Based on genome-wide association study (GWAS) summary statistics, we performed two-sample MR applying the inverse variance weighted (IVW) as the primary method, supplemented with four additional sensitivity analyses. Furthermore, multivariable MR (MVMR) was applied to assess these associations independent of alcohol drinking, type 2 diabetes (T2D), triglycerides (TG), estimated glomerular filtration rate (eGFR) and C-reactive protein (CRP). RESULTS: In univariable MR, the IVW analysis suggested no significant causal effect of genetically determined plasma omega-3 PUFAs on fat-free mass (right leg: ß = 0.01, 95% CI = -0.02 to 0.05, P = 0.375; left leg: ß = 0.01, 95% CI = -0.02 to 0.04, P = 0.446; right arm: ß = 0.01, 95% CI = -0.02 to 0.05, P = 0.376; left arm: ß = 0.01, 95% CI = -0.02 to 0.04, P = 0.384; trunk:ß = 0.02, 95% CI = -0.02 to 0.06, P = 0.283; whole: ß = 0.01, 95% CI = -0.03 to 0.04, P = 0.631), grip strength (right hand: ß = -0.01, 95% CI = -0.03 to 0.01, P = 0.387; left hand: ß = -0.01, 95% CI = -0.02 to 0.01, P = 0.553) and walking pace (ß = 0.00, 95% CI = -0.01 to 0.02, P = 0.575), and sensitive analysis generated similar non-significant results. Furthermore, the MVMR revealed no independent causal association. CONCLUSIONS: Genetically determined plasma omega-3 PUFAs have no causal effect on sarcopenia-related traits.

Association of P2X7R gene polymorphisms with systemic lupus erythematosus in a Chinese population.

The P2X7 receptor is a ligand-gated cationic channel receptor that is actived by ATP and normally expressed by a variety of immune system cells, including macrophages and lymphocytes. Because it leads to release of IL-1ß and cell death by apoptosis or necrosis, it is a potential therapeutic target for a variety of autoimmune inflammatory diseases, such as systemic lupus erythematosus (SLE). The P2X7R gene is highly polymorphic, and many single-nucleotide polymorphisms (SNPs) have been detected. A case-control study was performed to investigate the associations of SNPs in the P2X7R gene (rs1718119, rs2230911 and rs3751143) with susceptibility to SLE in 535 Chinese SLE patients and 532 controls. Results showed that rs1718119 was associated with SLE; in particular carriers of the A allele and AA/AG/(AG+AA) genotypes were at lower risk of the disease [A versus G, P < 0.001, odds ratio (OR) = 0.543, 95% CI: 0.424-0.697; AG versus GG, P = 0.018, OR = 0.659, 95% CI: 0.466-0.931; AA versus GG, P = 0.011, OR = 0.176, 95% CI: 0.046-0.668; AG+AA versus GG, P = 0.004, OR = 0.607, 95% CI: 0.433-0.850], but no significant differences in rs2230911 and rs3751143 were observed between SLE patients and controls. Stratification of cases for the presence of nephritis showed that rs2230911 G allele and CG/(CG+GG) genotypes were at a lower risk of SLE with nephritis (LN) (G versus C, P = 0.011, OR = 0.640, 95% CI: 0.454-0.903; CG versus CC, P = 0.035, OR = 0.645, 95% CI: 0.429-0.970; GG versus CC, P = 0.101, OR = 0.349, 95% CI: 0.099-1.228; CG+GG versus CC, P = 0.015 OR = 0.612, 95% CI: 0.411-0.910), but rs1718119 and rs3751143 were not associated with LN. Analysis of the haplotypes revealed one haplotype (ACA) that appeared to be a significantly 'protective' haplotype (P = 0.009, OR = 0.708, 95% CI: 0.546-0.918) with SLE. The findings suggest that the P2X7R gene might contribute to SLE susceptibility in the Chinese population.

Association of interleukin-1 receptor-associated kinase (IRAK1) gene polymorphisms (rs3027898, rs1059702) with systemic lupus erythematosus in a Chinese Han population.

OBJECTIVE: The purpose of this study was to examine the association of interleukin-1 receptor-associated kinase (IRAK1) polymorphisms (rs3027898, rs1059702) with systemic lupus erythematosus (SLE) in a Chinese Han population. METHODS: A total of 667 SLE patients and 667 healthy controls were collected in this study. The genotyping of polymorphisms (rs3027898, rs1059702) was determined by TaqMan allele discrimination assay on the 7300 real-time polymerase chain reaction system. The statistical analysis was conducted by chi square test or Fisher's exact test. RESULTS: The frequency of C allele for rs3027898 in patients was significantly higher than in controls (C versus A: OR = 1.438, 95 % CI = 1.180-1.753, p < 0.001), and a similar association was shown in rs1059702 (A versus G: OR = 1.383, 95 % CI = 1.143-1.674, p = 0.001). Interestingly, the C allele of rs3027898 was associated with a decreased risk for patients with oral ulcers. However, no significant difference was detected in IRAK1 rs1059702 polymorphism and the clinical manifestations. CONCLUSIONS: Our data demonstrate that the polymorphisms rs3027898 and rs1059702 of IRAK1 gene are associated with SLE in the Chinese Han population.

Lack of association between IL-23R gene polymorphisms and systemic lupus erythematosus in a Chinese population.

OBJECTIVE: The aim to this study was to investigate the association between the single-nucleotide polymorphisms (SNPs) of interleukin (IL)-23 receptor gene and systemic lupus erythematosus (SLE) in a Chinese population. METHODS: A case-control study was performed to investigate the associations of SNPs in IL-23R gene (rs10889677 and rs1884444) with susceptibility to SLE in 521 Chinese SLE patients and 527 normal controls. The chi-square test and unconditional Logistic regression were used to analysis by SPSS 10.1 software. RESULTS: No significant differences were detected for the distribution of allele and genotype frequencies of these two SNPs between patients and controls as well as SLE patients with nephritis (LN) and those without nephritis. CONCLUSION: The findings suggest that the polymorphisms of IL-23R gene might not contribute to the susceptibility of SLE in the Chinese population.

CTLA-4 -1722T/C polymorphism and systemic lupus erythematosus susceptibility: a meta-analysis involving ten separate studies.

Cytotoxic T lymphocyte associated antigen-4 (CTLA-4) -1722T/C polymorphism has been identified as a susceptibile gene for systemic lupus erythematosus (SLE), but studies are inconsistent. To better assess the association between CTLA-4 -1722T/C polymorphism and SLE, a meta-analysis was performed, including 10 studies, total of 1 387 patients and 1 617 controls. Overall, the CTLA-4 -1722T/C polymorphism was significantly associated with SLE susceptibility (T VS C: OR = 1.17, 95% CI = 0.86-1.60, P = 0.304; T/T VS C/C: OR = 1.92, 95% CI = 1.09-3.39, P = 0.024; T/C VS C/C: OR = 1.50, 95% CI = 0.91-2.49, P = 0.114; T/T VS T/C: OR = 1.29, 95% CI = 0.95-1.75, P = 0.107). When stratified by ethnicity, the CTLA-4 -1722T/C polymorphism was associated with SLE only in Asians (T VS C: OR = 1.47, 95% CI = 1.10-1.96, P = 0.010; T/T VS C/C: OR = 2.09, 95% CI = 1.13-3.85, P = 0.018; T/C VS C/C: OR = 1.53, 95% CI = 0.87-2.69, P = 0.141; T/T VS T/C: OR = 1.42, 95% CI = 0.97-2.09, P = 0.070). In summary, the CTLA-4 -1722T/C polymorphism confers to SLE risk, especially in Asians.

Arthritis and incident pulmonary diseases in middle-aged and elderly Chinese: a longitudinal population-based study.

BACKGROUND: The coexistence of arthritis and pulmonary abnormalities has long been observed, but the causal inter-relationships among them are still uncertain especially in elderly adults. METHODS: We extracted data from The China Health and Retirement Longitudinal Study (CHARLS). A total of 7534 participants without chronic lung diseases or/and asthma at the baseline and have complete follow-up information were included. Multivariate Cox proportional hazards models were used to estimate the adjusted hazard ratios (HRs) for developing chronic lung diseases or asthma. We also utilized generalized linear models to examine the association between arthritis and baseline peak expiratory flow (PEF). RESULTS: During 50,615 and 51,975 person-years of follow-up, 629 and 188 participants incident chronic lung diseases and asthma, respectively. Compared to those without arthritis, participants with arthritis had a higher risk of chronic lung diseases (HR = 1.54, 95%CI = 1.31-1.81, P = 1.23 × 10-7) and asthma (HR = 1.70, 95%CI = 1.27-2.28, P = 3.78 × 10-4). Arthritis subjects demonstrated significantly lower PEF than those without arthritis [ß = - 11.85 (95%CI = - 17.56, - 6.14), P = 4.81 × 10-5]. The results were stable after excluding these participates who incident chronic lung diseases or asthma in the first 1 year of follow-up. CONCLUSION: Arthritis increased the risk of pulmonary diseases among middle-aged and elderly Chinese. Early detection and treatment of pulmonary abnormalities among arthritis patients could help decrease the mortality and reduce the global burden of arthritis. Key Points • The coexistence of arthritis and pulmonary abnormalities has long been observed, but whether arthritis status can trigger pulmonary disorders is still uncertain. • Arthritis status are associated with increased risk of pulmonary diseases (chronic lung diseases/asthma) among middle-aged and elderly Chinese. • Early detection and treatment of pulmonary abnormalities among arthritis patients could help decrease the mortality and reduce the global burden of arthritis.

Diet-derived circulating antioxidants and risk of knee osteoarthritis, hip osteoarthritis and rheumatoid arthritis: a two-sample Mendelian randomization study.

Objective: To examine the causal associations of diet-derived circulating antioxidants with knee osteoarthritis (OA), hip OA, and rheumatoid arthritis (RA) within the two-sample Mendelian randomization (MR) framework. Method: Independent single-nucleotide polymorphisms (SNPs) significantly associated with circulating levels of diet-derived antioxidants (retinol, ß-carotene, lycopene, vitamin C and vitamin E) were extracted as genetic instruments. Summary statistics of genetic instruments associated with knee OA, hip OA, and RA were obtained from corresponding genome-wide association studies (GWASs). The inverse-variance weighted (IVW) was applied as the primary analysis method, with four sensitivity analysis approaches employed to evaluate the robustness of the primary results. Results: Genetically determined per unit increment of absolute circulating levels of retinol was significantly associated with a reduced risk of hip OA [odds ratio (OR) = 0.45, 95% confidence interval (CI) 0.26-0.78, p = 4.43 × 10-3], while genetically determined per unit increase in absolute circulating levels of ß-carotene was suggestively associated with increased risk of RA (OR = 1.32, 95% CI 1.07-1.62, p = 9.10 × 10-3). No other causal association was found. Significant evidence for heterogeneity and pleiotropic outlier was only identified when absolute circulating vitamin C was evaluated as the exposure, whereas all sensitive analysis provided consistently non-significant results. Conclusion: Our results demonstrated that genetically determined lifelong higher exposure to absolute circulating levels of retinol is associated with a decreased risk of hip OA. Further MR study with more genetic instruments for absolute circulating levels of antioxidants are needed to confirm our results.

Quantitative infrapatellar fat pad signal intensity alteration as an imaging biomarker of knee osteoarthritis progression.

OBJECTIVE: To determine the association of quantitative infrapatellar fat pad (IPFP) signal intensity alteration with knee osteoarthritis (OA) progression. METHOD: This study was performed based on the Foundation for the National Institutes of Health OA Biomarkers Consortium study, a nested case-control study consisting of 600 participants. The IPFP signal intensity alterations were quantitatively measured at baseline, 12 months and 24 months. The associations of baseline and time-integrated values over 12 and 24 months of IPFP signal intensity measures with knee OA progression over 48 months were evaluated with adjustment for baseline confounders. RESULTS: The baseline level of clustering effect of high signal intensity (Clustering factor (H)) was predictive of clinically relevant progression (both radiographic and pain progression) (OR 1.22). The time-integrated values of all IPFP signal intensity measures, except for mean value of IPFP signal intensity (Mean (IPFP)) over 24 months (ORs ranging from 1.23 to 1.39) as well was all except for Mean (IPFP) and mean value of IPFP high signal intensity (Mean (H)) over 12 months (ORs ranging from 1.20 to 1.31), were positively associated with clinically relevant progression. When the associations of quantitative IPFP signal intensity measures with radiographic and pain progression were examined separately, more IPFP signal intensity measures with stronger effect sizes were associated with radiographic progression compared with pain progression. CONCLUSION: The associations of short-term alteration in quantitative IPFP signal intensity measures with long-term knee OA progression suggest that these measures might serve as efficacy of intervention biomarkers of knee OA.