The purposes of this study were to compare the perceived and actual 10-year risk for cardiovascular disease (CVD) and to evaluate the influence of cardiovascular risk factors on perceived CVD risk in patients with rheumatoid arthritis (RA) in Korea. Additionally, the attainment of CVD prevention guideline goals by 3 levels of CVD risk (low, moderate, and high) was presented.
For this cross-sectional study, data were collected from 208 patients with RA. Actual CVD risk was estimated with the Systematic Coronary Risk Evaluation (SCORE), and goal attainment was assessed based on the European League Against Rheumatism guidelines. Actual CVD risk and perceived risk were compared with cross-tabulation. Chi-square tests were used to evaluate differences in cardiovascular risk factors by perceived risk. Levels of goal attainment were presented in percentages.
Among patients with RA, 13.9% were identified as being at high risk for CVD, whereas 39.9% were at moderate risk, and 46.2% were at low risk. The majority of those at high risk (96.6%) underestimated their risk for CVD. The use of antihypertensive or lipid-lowering medications and having a parental history of CVD significantly increased the likelihood that subjects with RA would perceive themselves as being at high risk for CVD. Diabetes, smoking, physical inactivity, and obesity did not affect perceived risk. A substantial proportion of the subjects with RA did not meet the prevention guideline goals.
Patients with RA who are at increased risk of developing CVD must be managed as soon as possible to attain the guideline goals and, accordingly, lower their risk of future CVD.
cardiovascular disease; guideline adherence; rheumatoid arthritis; risk factor; risk perception
Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder whose etiology is incompletely understood, but likely involves environmental triggers in genetically susceptible individuals. We sought to identify the genetic loci associated with SLE in a Korean population by performing an unbiased genome-wide association scan.
A total of 1,174 Korean SLE cases and 4,248 population controls were genotyped with strict quality control measures and analyzed for association. For select variants, replication was tested in an independent set of 1,412 SLE cases and 1,163 population controls of Korean and Chinese ancestries.
Eleven regions outside the HLA exceeded genome-wide significance (P<5×10−8). A novel SNP-SLE association was identified between FCHSD2 and P2RY2 peaking at rs11235667 (P = 1.0×10−8, odds ratio (OR) = 0.59) on a 33kb haplotype upstream to ATG16L2. Replication for rs11235667 resulted in Pmeta-rep=0.001 and Pmeta-overall=6.67×10−11 (OR=0.63). Within the HLA region, association peaked in the Class II region at rs116727542 with multiple independent effects. Classical HLA allele imputation identified HLA-DRB1*1501 and HLA-DQB1*0602, both highly correlated, as most strongly associated with SLE. We replicated ten previously established SLE risk loci: STAT1-STAT4, TNFSF4, TNFAIP3, IKZF1, HIP1, IRF5, BLK, WDFY4, ETS1 and IRAK1-MECP2. Of these loci, we identified previously unreported independent second effects in TNFAIP3 and TNFSF4 as well as differences in the association for a putative causal variant in the WDFY4 region.
Further studies are needed to identify true SLE risk effects in other suggestive loci and to identify the causal variant(s) in the regions of ATG16L2, FCHSD2, and P2RY2.
S100A8/A9 has been suggested as a marker of disease activity in patients with adult-onset Still’s disease (AOSD). We evaluated the clinical significance of S100A8/A9 as a biomarker and its pathogenic role in AOSD. Blood samples were collected prospectively from 20 AOSD patients and 20 healthy controls (HCs). Furthermore, skin and lymph node biopsy specimens of AOSD patients were investigated for S100A8/A9 expression levels via immunohistochemistry. Peripheral blood mononuclear cells (PBMCs) of active AOSD patients and HCs were investigated for S100A8/A9 cell signals. S100A8/A9, interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) levels in active AOSD patients were higher than those of HCs. S100A8/A9 levels correlated positively with IL-1β, TNF-α and C-reactive protein. The inflammatory cells expressing S100A8/A9 were graded from one to three in skin and lymph node biopsies of AOSD patients. The grading for S100A8/A9 was more intense in the skin lesions with karyorrhexis, mucin deposition, and neutrophil infiltration. Like lipopolysaccharide (LPS), S100A8/A9 induced phosphorylation of p38 and c-Jun amino-terminal kinase (JNK) in PBMCs, suggesting that S100A8/A9 activates Toll-like receptor 4 signaling pathways. These findings suggest that S100A8/A9 may be involved in the inflammatory response with induction of proinflammatory cytokines and may serve as a clinicopathological marker for disease activity in AOSD.
adult-onset Still’s disease; S100A8/A9; interleukin-1β; biomarker; disease activity
Systemic lupus erythematosus (SLE) has a strong but incompletely understood genetic architecture. We conducted an association study with replication in 4,492 SLE cases and 12,675 controls from six East-Asian cohorts, to identify novel and better localize known SLE susceptibility loci. We identified 10 novel loci as well as 20 known loci with genome-wide significance. Among the novel loci, the most significant was GTF2IRD1-GTF2I at 7q11.23 (rs73366469, Pmeta=3.75×10−117, OR=2.38), followed by DEF6, IL12B, TCF7, TERT, CD226, PCNXL3, RASGRP1, SYNGR1 and SIGLEC6. We localized the most likely functional variants for each locus by analyzing epigenetic marks and gene regulation data. Ten putative variants are known to alter cis- or trans-gene expression. Enrichment analysis highlights the importance of these loci in B- and T-cell biology. Together with previously known loci, the explained heritability of SLE increases to 24%. Novel loci share functional and ontological characteristics with previously reported loci, and are possible drug targets for SLE therapeutics.
Psychological stress has been shown to trigger systemic lupus erythematosus (SLE). However, objective evidence of symptom aggravation due to mental stress is difficult to identify. We aimed to investigate the relationship between SLE disease activity and mental stress, and the usefulness of saliva as an assessment index for stress in patients with SLE.
We prospectively assessed the salivary stress hormone and disease-related biomarkers, and questionnaire data regarding stress and depression in 100 patients with SLE and 49 sex- and age-matched normal controls (NCs).
Patients with SLE had higher mean salivary α-amylase levels (5.7 ± 4.6 U/mL vs 2.7 ± 2.5 U/mL, P < 0.001), anti-chromatin antibody levels (25.3 ± 22.9 U/mL vs 15.9 ± 10.9 U/mL, P < 0.001), and Beck Depression Index (BDI) scores (11.1 ± 9.2 vs 5.3 ± 5.1, P < 0.001) than NCs. However, salivary cortisol levels and Perceived Stress Scale (PSS) scores did not differ between the groups. The BDI scores correlated with the SLE disease activity index (SLEDAI) scores (r = 0.253, P = 0.011) and erythrocyte sedimentation rates (r = 0.234, P = 0.019). SLE patients with the highest-quartile PSS scores had significantly increased SLEDAI scores compared to those with the lowest-quartile PSS scores after 4 to 5 months’ follow-up. Moreover, SLE patients with elevated SLEDAI scores had higher baseline PSS scores.
Patients with SLE showed uncoupling of the sympathetic nervous system and hypothalamic–pituitary–adrenal axis; higher salivary α-amylase and no different cortisol levels compared with NCs. Also, patients with SLE were more depressed, which correlated with disease activity. Furthermore, perceived stress was not correlated with disease activity; however, disease activity worsened several months later with elevated perceived stress levels.
Considerable sharing of disease alleles among populations is well-characterized in autoimmune disorders (e.g., rheumatoid arthritis), but there are some exceptional loci showing heterogenic association among populations. Here we investigated genetic variants with distinct effects on the development of rheumatoid arthritis in Asian and European populations. Ancestry-related association heterogeneity was examined using Cochran’s homogeneity tests for the disease association data from large Asian (n = 14,465; 9,299 discovery subjects and 5,166 validation subjects; 4 collections) and European (n = 45,790; 11 collections) rheumatoid arthritis case-control cohorts with Immunochip and genome-wide SNP array data. We identified significant heterogeneity between the two ancestries for the common variants in the GTF2I locus (PHeterogeneity = 9.6 × 10−9 at rs73366469) and showed that this heterogeneity was due to an Asian-specific association effect (ORMeta = 1.37 and PMeta = 4.2 × 10−13 in Asians; ORMeta = 1.00 and PMeta = 1.00 in Europeans). Trans-ancestral comparison and bioinfomatics analysis revealed a plausibly causal or disease-variant-tagging SNP (rs117026326; in linkage disequilibrium with rs73366469), whose minor allele is common in Asians but rare in Europeans. In conclusion, we identified largest-ever effect on Asian rheumatoid arthritis across human non-HLA regions at GTF2I by heterogeneity mapping followed by replication studies, and pinpointed a possible causal variant.
The aim of this study was to determine whether decreased serum sodium concentration could be associated with the disease activity in SLE. We retrospectively analyzed the data of the two independent cohorts of children and adults with SLE in two centers. Hyponatremia was associated with serum chloride (p = 0.004), albumin (p = 0.002) and SLE disease activity index (SLEDAI) (p = 0.026) in children with SLE. Serum sodium levels were correlated negatively with ESR (p =0.001) and positively with serum albumin levels (p < 0.0001) and C3 (p = 0.008) in children with SLE and those levels were correlated negatively with serum interleukin-6 levels (p = 0.003) in adults with SLE. Independent risk factors for the development of hyponatremia were the decreased serum C3 levels (OR 1.069, p = 0.031), the decreased serum chloride levels (OR 2.054, p = 0.006) and increased erythrocyte sedimentation rate (ESR) (OR 1.066, p = 0.03) in children with SLE and increased C-reactive protein (CRP) (OR 1.480, p = 0.023) in combined cohorts with SLE by multiple logistic regression analyses. Our study firstly showed that hyponatremia could reflect a disease activity and severe inflammation of SLE.
Hemophagocytic syndrome (HPS) is a potentially life-threatening complication of systemic inflammatory disorders. Adult-onset Still disease (AOSD) is one of the systemic autoimmune diseases associated with reactive hemophagocytic syndrome (RHS). This study aimed to evaluate the characteristic findings, predictive factors, and prognosis of RHS in patients with AOSD.
We retrospectively evaluated 109 patients diagnosed with AOSD and reviewed their clinical data and laboratory findings, including the biopsy results of 21 AOSD patients with RHS. Moreover, data from 17 hemophagocytic lymphohistiocytosis (HLH) patients evaluated during the same period were compared with those from the RHS patients.
Twenty-one patients (19.3%) developed RHS during the course of AOSD, and only 7 patients (6.4%) were confirmed by bone marrow, liver, or lymph node biopsy. AOSD patients with RHS showed significantly higher frequencies of splenomegaly, hepatomegaly, and lymphadenopathy than did those without RHS. Moreover, patients with RHS showed significantly higher relapse rates than those without RHS (61.9% vs 18.2%, P < 0.001). Possible triggering factors inducing hemophagocytosis were detected in 16 of 21 RHS patients (76.2%): disease flare in 12 patients (75%), infection in 3 patients (18.8%), and drug use in 1 patient (6.3%). AOSD patients with RHS showed higher frequencies of leukopenia, anemia, thrombocytopenia, hypoalbuminemia, hypofibrinogenemia, hypertriglyceridemia, hyperferritinemia, and elevated lactate dehydrogenase levels than did those without RHS. Multivariate logistic regression with forward selection procedure showed that low platelet count (<121,000/mm3), anemia, and hepatomegaly were independent predictors of RHS. Patients with definite RHS and those with probable RHS showed comparable results. Although RHS is a life-threatening complication of AOSD, long-term prognosis was observed to be similar in patients with and those without RHS. Compared to RHS patients, HLH patients had poor prognosis, such as higher death rates (52.9% vs 9.5%, P = 0.005).
RHS can be considered when an AOSD patient shows at least 2 of the following 3 findings: low platelet count, anemia, and hepatomegaly. Diagnostic confirmation by biopsy may not be essential if typical clinical findings of RHS are present. Moreover, prognosis of RHS was better than that of HLH diagnosed by the presence of trilineage cytopenia at admission.
Systemic lupus erythematosus (SLE) predominantly affects women in their reproductive years and has a significant impact on childbearing. We investigated the influence of personal decision on family size among Korean women with SLE and factors that affect the decisions. A case-control study comparing childbearing history and decisions of 112 SLE patients and 135 controls was performed. Women with SLE participating in the Network for Lupus Clinical Research in South Korea and matching controls between ages of 18-45, who are/were married or living with a partner were included. Data regarding socio-demographics, reproductive history, and childbearing decisions were collected through a survey using a standardized questionnaire and medical record review. More women with SLE reported at least one pregnancy (85.7% vs. 71.9%, P = 0.009) or at least one live birth (85.7% vs. 71.9%, P = 0.003) compared with controls. Mean number of pregnancies was significantly higher (2.4 ± 1.6 vs. 1.4 ± 1.3, P < 0.001), and mean number of live births was significantly lower in women with SLE (1.2 ± 0.8 vs. 1.6 ± 0.8, P < 0.001). Significantly more women with SLE made the decision not to have children compared with controls (54.5% vs. 40.7%, P = 0.031), and health-related concerns were the major cause of the decision. Other socio-demographic factors did not influence the decision to limit childbearing in SLE women. The disease-related concerns had significant impact on family size and childbearing decisions among Korean women with SLE.
Systemic Lupus Erythematosus; Family Size; Childbearing Decisions; Korean
Patients who develop an active tuberculosis infection during tumor necrosis factor (TNF) inhibitor treatment typically discontinue TNF inhibitor and receive standard anti-tuberculosis treatment. However, there is currently insufficient information on patient outcomes following resumption of TNF inhibitor treatment during ongoing anti- tuberculosis treatment. Our study was designed to investigate the safety of resuming TNF inhibitors in ankylosing spondylitis (AS) patients who developed tuberculosis as a complication of the use of TNF inhibitors.
Through the nationwide registry of the Korean Society of Spondyloarthritis Research, 3929 AS patients who were prescribed TNF inhibitors were recruited between June 2003 and June 2014 at fourteen referral hospitals. Clinical information was analyzed about the patients who experienced tuberculosis after exposure to TNF inhibitors. The clinical features of resumers and non-resumers of TNF inhibitors were compared and the outcomes of tuberculosis were surveyed individually.
Fifty-six AS patients were treated for tuberculosis associated with TNF inhibitors. Among them, 23 patients resumed TNF inhibitors, and these patients were found to be exposed to TNF inhibitors for a longer period of time and experienced more frequent disease flare-up after discontinuation of TNF inhibitors compared with those who did not resume. Fifteen patients resumed TNF inhibitors during anti-tuberculosis treatment (early resumers) and 8 after completion of anti-tuberculosis treatment (late resumers). Median time to resuming TNF inhibitor from tuberculosis was 3.3 and 9.0 months in the early and late resumers, respectively. Tuberculosis was treated successfully in all resumers and did not relapse in any of them during follow-up (median 33.8 [IQR; 20.8–66.7] months).
Instances of tuberculosis were treated successfully in our AS patients, even when given concomitantly with TNF inhibitors. We suggest that early resumption of TNF inhibitors in AS patients could be safe under effective coverage of tuberculosis.
The genetic association of HLA-DRB1 with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) is well documented, but association with other HLA-DR beta genes (HLA-DRB3, HLA-DRB4 and HLA-DRB5) has not been thoroughly studied, despite their similar functions and chromosomal positions. We examined variants in all functional HLA-DR beta genes in RA and SLE patients and controls, down to the amino-acid level, to better understand disease association with the HLA-DR locus. To this end, we improved an existing HLA reference panel to impute variants in all protein-coding HLA-DR beta genes. Using the reference panel, HLA variants were inferred from high-density SNP data of 9,271 RA-control subjects and 5,342 SLE-control subjects. Disease association tests were performed by logistic regression and log-likelihood ratio tests. After imputation using the newly constructed HLA reference panel and statistical analysis, we observed that HLA-DRB1 variants better accounted for the association between MHC and susceptibility to RA and SLE than did the other three HLA-DRB variants. Moreover, there were no secondary effects in HLA-DRB3, HLA-DRB4, or HLA-DRB5 in RA or SLE. Of all the HLA-DR beta chain paralogs, those encoded by HLA-DRB1 solely or dominantly influence susceptibility to RA and SLE.
The aim of the study was to examine the clinical characteristics and prognosis according to severity of thrombocytopenia and response to treatment for thrombocytopenia in patients with systemic lupus erythematosus (SLE).
We retrospectively evaluated 230 SLE patients with thrombocytopenia, and reviewed their clinical data and laboratory findings. Thrombocytopenia was defined as platelet counts under 100,000/mm3, and patients were divided into 3 thrombocytopenia groups according to severity: mild (platelet counts >50,000/mm3), moderate (>20,000/mm3, ≤50,000/mm3), and severe (≤20,000/mm3). Clinical characteristics, treatments, and prognoses were compared among the groups. Furthermore, complete remission of thrombocytopenia was defined as platelet counts >100,000/mm3 after treatment.
There was no significant difference in clinical or laboratory findings among the groups according to severity of thrombocytopenia. However, hemorrhagic complications were more frequent in severe thrombocytopenia (P < 0.001) and mortality was also higher (P = 0.001). Complete remission was achieved in 85.2% of patients. The clinical characteristics and modality of treatment did not differ between the patients with and without complete remission. Mortality in patients with complete remission (1.5%) was significantly lower than in those without complete remission (29.4%, P < 0.001). Survival was significantly higher in patients with complete remission from thrombocytopenia (odds ratio = 0.049, 95% confidence interval: 0.013–0.191, P < 0.001).
The severity of thrombocytopenia in SLE patients can be a useful independent prognostic factor to predict survival. Moreover, complete remission of thrombocytopenia after treatment is an important prognostic factor. The severity of thrombocytopenia and response to treatment should be closely monitored to predict prognosis in SLE patients.
The presence of the HLA-B*27 allele is a major risk factor for the development of ankylosing spondylitis (AS), which causes chronic inflammation of the spine and other sites. We investigated residual effects outside HLA-B within the major histocompatibility complex (MHC) region in the Korean population.
Using the Korean HLA reference panel, we inferred the classic HLA alleles and amino-acid residues of the six HLA genes (HLA-A, -B, -C,-DPB1, -DQB1, and -DRB1) and MHC single-nucleotide polymorphisms in 3820 Korean subjects, including 654 Korean cases of AS and 3166 controls, who were genotyped by using Immunochip. Logistic regression and log-likelihood ratio tests were used in AS association tests for imputed markers.
The most significant associations were identified at amino-acid positions in the epitope-binding site of HLA-B (P = 1.71 × 10−481 at position 70, P = 7.20 × 10−479 at position 97, and P = 2.54 × 10−484 at positions 114), highlighting the risk effect of the HLA-B*27 allele and the protective effects of other classic alleles. A secondary effect was located at the leucine at amino-acid position 116 in the epitope-binding site of HLA-C (P = 1.69 × 10−14), completely tagging the HLA-C*15:02 allele. This residue had a large effect in HLA-B*27-negative patients (odds ratio = 6.6, 95 % confidence interval = 3.8 to 11.4).
The four amino-acid positions of HLA-B and -C account for most of the associations between AS and MHC in the Korean population. This finding updates the list of AS susceptibility loci and provides new insight into AS pathogenesis mediated by MHC class I molecules.
Electronic supplementary material
The online version of this article (doi:10.1186/s13075-015-0855-3) contains supplementary material, which is available to authorized users.
C-X-C motif chemokine 10 (CXCL10) is produced in response to interferon-γ, and tumor necrosis factor-α (TNF-α) triggers the accumulation of activated lymphocytes. CXCL13 is constitutively expressed in secondary lymphoid tissues, and the expression is upregulated by TNF-α, via T cell stimulation. It appears that CXCL10 and CXCL13 could play a potential role in the pathogenesis of adult-onset Still’s disease (AOSD), therefore, we investigated the associations between CXCL10 and CXCL13 levels and clinical manifestations in patients with active AOSD.
Blood samples were collected from 39 active AOSD patients, 32 rheumatoid arthritis (RA) patients and 40 healthy controls (HC). Of the AOSD patients, follow-up samples were collected from 15 9.6 ± 9.2 months later. Serum levels of CXCL10 and CXCL13 were determined using enzyme-linked immunosorbent assay. CXCL10, CXCL13, and C-X-C chemokine receptor type 3 (CXCR3) expression levels in biopsy specimens obtained from 26 AOSD patients with skin rashes were investigated via immunohistochemistry.
The CXCL10 levels in AOSD patients (1,031.3 ± 2,019.6 pg/mL) were higher than in RA (146.3 ± 91.4 pg/mL, p = 0.008) and HC (104.4 ± 47.9 pg/mL, p = 0.006). Also, the CXCL13 levels of AOSD patients (158.8 ± 151.2 pg/mL) were higher than those of RA (54.4 ± 61.1 pg/mL, p < 0.001) and HC (23.5 ± 18.1 pg/mL, p < 0.001). Serum CXCL10 levels correlated with ferritin and systemic scores. Serum CXCL13 levels correlated with those of hemoglobin, C-reactive protein, ferritin, and albumin, and systemic scores. In follow-up AOSD patients, the levels of CXCL10 and CXCL13 fell significantly (153.7 ± 130.1 pg/mL, p = 0.002, and 89.1 ± 117.4 pg/mL, p = 0.001, respectively). On immunohistochemistry, the percentages of inflammatory cells expressing CXCL10 ranged from 1 to 85 %, CXCL13 from 1 to 72 %, and CXCR3 from 2 to 65 %. The percentage of CXCL10-positive inflammatory cells was higher in skin biopsy samples exhibiting mucin deposition than in those that did not (p = 0.01). CXCL13 levels were correlated with those of CD4 and CD68.
Serum CXCL10 and CXCL13 levels may serve as clinical markers for assessment of disease activity in AOSD. CXCL10/CXCR3 and CXCL13 may contribute to the inflammatory response, especially skin manifestations thereof, in AOSD.
Electronic supplementary material
The online version of this article (doi:10.1186/s13075-015-0773-4) contains supplementary material, which is available to authorized users.
Polymyalgia rheumatica is an inflammatory disease affecting elderly and involving the shoulder and pelvic girdles. No epidemiological study of polymyalgia rheumatica was conducted in Korea. We retrospectively evaluated patients with polymyalgia rheumatica followed up at the rheumatology clinics of 10 tertiary hospitals. In total 51 patients, 36 patients (70.6%) were female. Age at disease onset was 67.4 yr. Twenty-three patients (45.1%) developed polymyalgia rheumatica in winter. Shoulder girdle ache was observed in 45 patients (90%) and elevated erythrocyte sedimentation rate (> 40 mm/h) in 49 patients (96.1%). Initial steroid dose was 23.3 mg/d prednisolone equivalent. Time to normal erythrocyte sedimentation rate was 4.1 months. Only 8 patients (15.7%) achieved remission. Among 41 patients followed up, 28 patients (68.3%) had flare at least once. Number of flares was 1.5 ± 1.6. The frequency of flare was significantly lower in patients with remission (P = 0.02). In Korea, polymyalgia rheumatica commonly develops during winter. Initial response to steroid is fairly good, but the prognosis is not benign because remission is rare with frequent relapse requiring long-term steroid treatment.
Polymyalgia Rheumatica; Symptoms; Treatment; Steroids; Remission; Prognosis
Little is known about hair mineral status in fibromyalgia patients. This study evaluated the characteristics of hair minerals in female patients with fibromyalgia compared with a healthy reference group. Forty-four female patients diagnosed with fibromyalgia according to the American College of Rheumatology criteria were enrolled as the case group. Ageand body mass index-matched data were obtained from 122 control subjects enrolled during visit for a regular health check-up. Hair minerals were analyzed and compared between the two groups. The mean age was 43.7 yr. General characteristics were not different between the two groups. Fibromyalgia patients showed a significantly lower level of calcium (775 µg/g vs 1,093 µg/g), magnesium (52 µg/g vs 72 µg/g), iron (5.9 µg/g vs 7.1 µg/g), copper (28.3 µg/g vs 40.2 µg/g) and manganese (140 ng/g vs 190 ng/g). Calcium, magnesium, iron, and manganese were loaded in the same factor using factor analysis; the mean of this factor was significantly lower in fibromyalgia group in multivariate analysis with adjustment for potential confounders. In conclusion, the concentrations of calcium, magnesium, iron, and manganese in the hair of female patients with fibromyalgia are lower than of controls, even after adjustment of potential confounders.
Fibromyalgia; Fibromyalgia Syndrome; Trace Minerals; Calcium; Magnesium
A highly polygenic etiology and high degree of allele-sharing between ancestries have been well-elucidated in genetic studies of rheumatoid arthritis. Recently, the high-density genotyping array Immunochip for immune disease loci identified 14 new rheumatoid arthritis risk loci among individuals of European ancestry. Here, we aimed to identify new rheumatoid arthritis risk loci using Korean-specific Immunochip data.
We analyzed Korean rheumatoid arthritis case-control samples using the Immunochip and GWAS array to search for new risk alleles of rheumatoid arthritis with anti-citrullinated peptide antibodies. To increase power, we performed a meta-analysis of Korean data with previously published European Immunochip and GWAS data, for a total sample size of 9,299 Korean and 45,790 European case-control samples.
We identified 8 new rheumatoid arthritis susceptibility loci (TNFSF4, LBH, EOMES, ETS1–FLI1, COG6, RAD51B, UBASH3A and SYNGR1) that passed a genome-wide significance threshold (p<5×10−8), with evidence for three independent risk alleles at 1q25/TNFSF4. The risk alleles from the 7 new loci except for the TNFSF4 locus (monomorphic in Koreans), together with risk alleles from previously established RA risk loci, exhibited a high correlation of effect sizes between ancestries. Further, we refined the number of SNPs that represent potentially causal variants through a trans-ethnic comparison of densely genotyped SNPs.
This study demonstrates the advantage of dense-mapping and trans-ancestral analysis for identification of potentially causal SNPs. In addition, our findings support the importance of T cells in the pathogenesis and the fact of frequent overlap of risk loci among diverse autoimmune diseases.
Rheumatoid arthritis; Gene polymorphism; Anti-CCP
Adult-onset Still disease (AOSD) is characterized by fever, skin rash, and lymphadenopathy with leukocytosis and anemia as common laboratory findings. We investigated the characteristic pathologic findings of skin, lymph node, liver, and bone marrow to assist in proper diagnosis of AOSD.
Forty AOSD patients were included in the study. The skin (26 patients), lymph node (8 patients), liver (8 patients), or bone marrow biopsies (22 patients) between 1998 and 2013 were retrospectively analyzed. AOSD patients were diagnosed according to the Yamaguchi criteria after excluding common infections, hematological and autoimmune diseases. Immunohistochemistry, immunofluorescence, and Epstein–Barr virus–encoded RNA (EBER) in situ hybridization were performed.
Most skin biopsies revealed mild lymphocytic or histiocytic infiltration in the upper dermis. Nuclear debris was frequently found in the dermis in 14 cases (53.8%). More than half of the cases (n = 14, 53.8%) showed interstitial mucin deposition. Some cases showed interface dermatitis with keratinocyte necrosis or basal vacuolization (n = 10; 38.5%). The lymph node biopsies showed a paracortical or diffuse hyperplasia pattern with immunoblastic and vascular proliferation. The liver biopsies showed sparse portal and sinusoidal inflammatory cell infiltration. All cases showed various degrees of Kupffer cell hyperplasia. The cellularity of bone marrow varied from 20% to 80%. Myeloid cell hyperplasia was found in 14 out of the 22 cases (63.6%). On immunohistochemistry, the number of CD8-positive lymphocytes was greater than that of CD4-positive lymphocytes in the skin, liver, and bone marrow, but the number of CD4-positive lymphocytes was greater than that of CD8-positive lymphocytes in the lymph nodes.
The relatively specific findings with respect to the cutaneous manifestation of AOSD were mild inflammatory cell infiltration in the upper dermis, basal vacuolization, keratinocyte necrosis, presence of karyorrhexis, and mucin in the dermis. In all cases, pathologic findings in the lymph nodes included paracortical hyperplasia with vascular and immunoblastic proliferation. Skin and lymph node pathology in addition to clinical findings can aid in the diagnosis of AOSD.
Systemic lupus erythematosus (SLE) is a typical autoimmune disease that's characterized by various autoantibodies to nuclear and cytoplasmic antigens. The presence of antinuclear antibodies (ANA) in serum is generally considered a decisive diagnostic sign of SLE. However, a small subset of SLE patients who had the typical clinical features of SLE was reported to show persistently negative ANA tests. Our report describes a 16-yr-old female who presented with the clinical manifestations of SLE such as malar rash, photosensitivity, arthritis, lymphopenia, pericarditis and proteinuria. The serum autoantibodies were all negative and renal biopsy showed that the histopathological changes of immune complex mediated the focal segmental necrotizing glomerulonephritis with crescent formation. She was treated with monthly pulse cyclophosphamide along with corticosteroids. During the 2-yr follow-up period, the proteinuria was markedly decreased and all of the ANA and anti-double stranded DNA antibody tests were negative. This case suggests that ANA may not be required in the pathogenesis of lupus nephritis.
Antinuclear antibody; Lupus nephritis; Systemic lupus erythematosus
The purpose of this study was to clarify the correlation between microRNA-21 (miR-21) expression and inflammation in a herpes simplex virus (HSV)-induced Behçet’s Disease (BD) mouse model. miR-21 was compared between BD patients and healthy controls in peripheral blood mononuclear cells (PBMC). For miR-21 inhibition, miR-21 antagomir was applied to BD mice. The change of symptoms was monitored. The levels of cytokines and related molecules were determined by ELISA and real time qPCR. Treatment with colchicine or pentoxifylline down-regulated the level of miR-21 with improved symptoms in mice. miR-21 inhibition was accompanied by down-regulated serum levels of IL-17 and IL-6. The expression levels of PDCD4, RhoB, PD-1, IL-12p35, and toll-like receptor-4 were also regulated by miR-21 inhibition. miR-21 was correlated with HSV-induced BD-like inflammation in mice and BD patients. The expression of miR-21 was regulated by antagomir in mice.
microRNA-21; herpes simplex virus-induced inflammation; mouse model; Behçet’s Disease; miR-21 antagomir
Recent reports have associated NCF2, encoding a core component of the multi-protein NADPH oxidase (NADPHO), with systemic lupus erythematosus (SLE) susceptibility in individuals of European ancestry. To identify ethnicity-specific and -robust variants within NCF2, we assessed 145 SNPs in and around the NCF2 gene in 5325 cases and 21 866 controls of European-American (EA), African-American (AA), Hispanic (HS) and Korean (KR) ancestry. Subsequent imputation, conditional, haplotype and bioinformatic analyses identified seven potentially functional SLE-predisposing variants. Association with non-synonymous rs17849502, previously reported in EA, was detected in EA, HS and AA (PEA = 1.01 × 10−54, PHS = 3.68 × 10−10, PAA = 0.03); synonymous rs17849501 was similarly significant. These SNPs were monomorphic in KR. Novel associations were detected with coding variants at rs35937854 in AA (PAA = 1.49 × 10−9), and rs13306575 in HS and KR (PHS = 7.04 × 10−7, PKR = 3.30 × 10−3). In KR, a 3-SNP haplotype was significantly associated (P = 4.20 × 10−7), implying that SLE predisposing variants were tagged. Significant SNP–SNP interaction (P = 0.02) was detected between rs13306575 and rs17849502 in HS, and a dramatically increased risk (OR = 6.55) with a risk allele at each locus. Molecular modeling predicts that these non-synonymous mutations could disrupt NADPHO complex assembly. The risk allele of rs17849501, located in a conserved transcriptional regulatory region, increased reporter gene activity, suggesting in vivo enhancer function. Our results not only establish allelic heterogeneity within NCF2 associated with SLE, but also emphasize the utility of multi-ethnic cohorts to identify predisposing variants explaining additional phenotypic variance (‘missing heritability’) of complex diseases like SLE.
The object of this study was to evaluate the seasonality of gout in Korea. We retrospectively examined data from 330 patients seen at nine rheumatology clinics, treated with urate lowering therapy (ULT) more than one year after stopping prophylactic medication. Demographic data, clinical and laboratory features, and seasonality of gout onset and flares were collected. Season was classified in three-month intervals. The mean age was 52.2 yr and mean disease duration was 26.8 months. The male to female count was 318:12. The onset of acute gouty attacks was obtained in 256 patients. Gout developed most commonly in summer season (36.7%) (P<0.001) and in June (15.6%, P=0.002). During ULT, there were 147 (male 97.3%) gout flares. Although there was no statistically significant difference, gout flares were more common in summer (30.6%). Aggravating factors were identified in 57 flares: alcohol (72.0%) was most common. In the patients who attained target serum uric acid (<6 mg/dL) at the end of prophylaxis, gout flares were high in fall (35.8%) and September (17.0%). In Korea, the summer is most common season of gout onset and there is a tendency for gout flares to increase during ULT in summer/fall season.
Gout Onset; Flares; Seasonality; Summer; Korea
Serum rheumatoid factor (RF) is important in the diagnosis and prognosis of rheumatoid arthritis (RA). The purpose of this study is to compare the clinical characteristics and treatment patterns of RA according to the presence of RF in Korean patients. A retrospective analysis was performed on the records of 109 patients who were followed for at least 2 years, among 230 RA patients who visited at the rheumatology clinic in Ajou University Hospital and who fulfilled the 1987 revised American College of Rheumatology criteria for RA. Sixty-four patients were RF positive (58.7%) and 91 patients were female (83.5%). There was no significant difference in demographic characteristics, joint involvements, or percentage of morning stiffness between seropositive and seronegative groups. Anti-nuclear antibody was detected more frequently in the seropositive group (p<0.05). At initial diagnosis, the seropositive group had higher white blood cell and platelet counts than the seronegative group (p<0.01). However, the difference was disappeared at the last follow-up. Inflammatory markers such as ESR and CRP were also higher at diagnosis in the seropositive group (p<0.01). These inflammatory markers were still greater than the seronegative group at the last follow-up (p<0.01). There was no significant difference in the use of disease modifying antirheumatic drug (DMARD) and steroid dosage between groups. However, DMARD combination therapy was more commonly used in the seropositive group (p<0.05), especially triple DMARD combination. These results suggest that disease activity is more severe in the seropositive than the seronegative group, and more aggressive treatments are needed in the seropositive group.
Rheumatoid arthritis; rheumatoid factor; inflammation; antirheumatic drug; combination therapy
Dermatomyositis in pregnancy is rare. Pregnancy may be a precipitating factor at the onset or may develop during the course of dermatomyositis, which would exacerbate disease activity. In this study, we report a 22-year-old female patient who developed generalized skin rash and progressive muscle weakness in the twelfth week of pregnancy. She was diagnosed with dermatomyositis and underwent therapeutic abortion, due to the high fetal mortality rate of the disease when developed in the first trimester. Her symptoms improved with treatment of intravenous immunoglobulin and a high dose of corticosteroids.
Liver X receptors are established sensors of lipid and cholesterol homeostasis. Recent studies have reported that these receptors are involved in the regulation of inflammation and immune responses. We attempted to identify single nucleotide polymorphisms (SNPs) of the NR1H3 gene associated with the susceptibility to systemic lupus erythematosus (SLE).
SNPs were genotyped using SNaPSHOT assay in 300 Korean patients with SLE and 217 normal controls (NC), and in replication samples (160 SLE patients and 143 NC). Also, the functional effects of NR1H3 gene promoter polymorphisms were analyzed using a luciferase assay, real-time polymerase chain reaction, B cell proliferation assay and an electrophoretic mobility shift assay.
We identified five polymorphisms: -1851 T > C (rs3758673), -1830 T > C (rs3758674), -1003 G > A (new), -840 C > A (rs61896015) and -115 G > A (rs12221497). There was a significant and reproducible difference in the -1830 T > C, -1003 G > A and -115 G > A polymorphisms between the SLE and the NC. Luciferase activity of the structure containing -1830 C was less enhanced compared to the structure containing -1830 T in basal, GW3965 and T0901317 treated Hep3B cells (P = 0.009, P = 0.034 and P <0.001, respectively). Proliferation of the -1830 TC type was increased compared to the -1830 TT type in basal, GW3965 and T0901317 treated B cells from SLE patients (P = 0.011, P = 0.040 and P = 0.017, respectively). Transcription factor GATA-3 preferentially bound the -1830 T allele in the promoter.
NR1H3 genetic polymorphisms may be associated with disease susceptibility and clinical manifestations of SLE. Specifically, -1830 T > C polymorphism within NR1H3 promoter region may be involved in regulation of NR1H3 expression.