Mi-Kyoung Lim

Genome-Wide Copy Number Variation Analysis Identifies Deletion Variants Associated With Ankylosing Spondylitis

To identify ankylosing spondylitis (AS)–associated copy number variations (CNVs) in Korean subjects and their synergistic roles in the development of AS.

Association of FOXJ1 polymorphisms with systemic lupus erythematosus and rheumatoid arthritis in Korean population

The forkhead-box J1 (FOXJ1) transcription factor could suppress a spontaneous activation of T cells and B cells through an induction of IκBβ that results in repression of NF-κB activity. In Foxj1 deficiency mice, systemic autoimmune inflammation is quite common symptom. Therefore, deregulated Foxj1 is supposed to be associated with autoimmune diseases and/or other inflammatory diseases. Previously, we identified that polymorphisms of human FOXJ1 gene (g.-460C>T, g.1805G>T and g.3375G>C) are associated with allergic rhinitis in a Korean population. In present study, we compared the genotype and allele frequencies of these SNPs between healthy controls and systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA) patients. We also investigated the relationships between each genotype and the expression levels of anti-nuclear antibodies in SLE patients, and rheumatoid factor and anti-cyclic citrullinated peptide in RA patients. The frequencies of haplotypes constructed by these FOXJ1 SNPs were compared between controls and SLE (or RA) patients. The results of genotype and allele analysis showed that the prevalence of polymorphism g.3375G>C was associated with the susceptibility of SLE (P = 0.0072 and 0.0042, respectively). But no significant association was found with RA. In the haplotype analysis, however, the main CGG showed a weak association between controls and RA patients (P = 0.048).

Associations of Vitamin D Binding Protein Gene Polymorphisms with the Development of Peripheral Arthritis and Uveitis in Ankylosing Spondylitis

Objective. Genetic factors account for more than 90% of overall susceptibility to ankylosing spondylitis (AS), and recent studies have focused on non-major histocompatibility complex genes. Vitamin D binding protein (DBP) is a highly polymorphic protein that transports vitamin D and its metabolites. In addition to its sterol binding capacity, DBP has many other roles in the inflammatory and immune systems, and has been reported to be associated with autoimmune diseases. We investigated the association between DBP polymorphisms and susceptibility to AS. Methods. This case-control study was conducted in 223 patients with AS and 239 ethnically matched controls who were genotyped for 8 single-nucleotide polymorphisms (SNP) in the DBP and its promoter. Genomic DNA was isolated from peripheral blood leukocytes using the standard phenolchloroform method, and the GoldenGate assay was used for genotyping. Results. No significant association was found between the susceptibility to AS and DBP polymorphisms. In a subgroup analysis of patients with AS, G alleles at rs222016 and rs222020 (OR 0.63, 95% CI 0.42–0.95, p = 0.03; OR 0.63, 95% CI 0.42–0.95, p = 0.03, respectively) and A allele at rs3733359 (OR 0.59, 95% CI 0.39–0.90, p = 0.01) showed the decreased risk of peripheral arthritis. G allele at rs4752 showed increased risk of uveitis (OR 2.04, 95% CI 1.12–3.72, p = 0.02). On the haplotype analyses, haplotype 2 (AGGA) protected against the development of peripheral arthritis (p = 0.01) and haplotype 3 (GAAG) was associated with an increased likelihood of uveitis (p = 0.02). Conclusion. DBP gene polymorphisms are associated with the development of peripheral arthritis and uveitis in Korean patients with AS. Given the influence of different DBP variants on the immune system, larger-scale studies are warranted to elucidate the role of DBP in the pathogenesis of AS.

Anti-Cyclic Citrullinated Peptide Antibodies Distinguish Hepatitis B Virus (HBV)-associated Arthropathy from Concomitant Rheumatoid Arthritis in Patients with Chronic HBV Infection

Objective. To determine whether anti-cyclic citrullinated peptide (anti-CCP) antibodies, which are a highly specific test for rheumatoid arthritis (RA), could differentiate between hepatitis B virus (HBV)-associated arthropathy and concomitant RA in Korean patients with chronic HBV infection. Methods. We investigated 240 patients with HBV infection. Anti-CCP antibodies were measured by ELISA and rheumatoid factor (RF) by the latex fixation test. Patient records were reviewed, and a standard form was used to record all demographic, clinical, and laboratory characteristics. Patients were divided into 4 groups according to joint symptoms: asymptomatic, arthralgia, oligoarthritis, and RA. We categorized liver disease into 3 groups: carrier, chronic hepatitis, and cirrhosis. Results. Anti-CCP antibodies and RF were detected in 11 and 28 of 240 patients, respectively. Anti-CCP antibodies were detected in 9 of 10 RA (90%) and 2 of 230 non-RA patients (0.86%). The positive rate for RF was 90% in RA and 8.3% in non-RA. Eight of 10 RA patients were positive for both RF and anti-CCP antibodies. RF was detected in 11 patients without joint symptoms, 4 with arthralgia, and 4 with oligoarthritis, whereas anti-CCP antibodies were found in 1 patient without joint symptoms and 1 with oligoarthritis. Specificity of anti-CCP antibody for RA was 99.1%, whereas RF showed 91.7% specificity (p < 0.0002). We compared the titers and positive detection rates of anti-CCP antibodies and RF among liver disease subgroups. There was no significant between–subgroup difference. Conclusion. Measurement of anti-CCP antibodies is better than RF detection to discriminate HBV-associated arthropathy from concomitant RA in patients with chronic HBV infection.

Role of Citrullinated Fibrinogen Peptides in the Activation of CD4 T Cells from Patients with Rheumatoid Arthritis

This study was conducted to determine whether CD4 T cell responses to citrullinated fibrinogen occur in patients with rheumatoid arthritis (RA), especially in HLA-DR4-positive subjects. Whole peripheral blood mononuclear cells (PBMCs) of RA patients and control subjects were stimulated with citrullinated fibrinogen peptides, and T-cell production of proliferation and proinflammatory cytokines, such as interferon-γ(IFN-γ) and interleukin-17A (IL-17A), were measured. In addition, CD4 T cells from RA patients were stimulated with the citrullinated fibrinogen peptide, Fib-α R84Cit, identified as a DRB1*0401-restricted T cell epitope in HLA-DR4 transgenic mice, and the degree of T cell activation was examined similarly. No proliferative responses to the citrullinated fibrinogen peptides were observed in whole PBMCs or CD4 T cells from RA patients. Furthermore, no increased production of IFN-γ or IL-17A was found in whole PBMCs or CD4 T cells stimulated with the citrullinated fibrinogen peptides, although these cells responded to recall antigen, a mixture of tetanus toxoid, purified protein derivative (PPD) from Mycobacterium tuberculosis, and Candida albicans. The results of this study indicate that anti-citrulline immunity in RA patients may be mediated by fibrinogen because there is no evidence of CD4 T cell-mediated immune responses to citrullinated fibrinogen peptides.

Anti-cyclic citrulline peptide antibody in non-tuberculous mycobacteria sera: a negative association

Dear Editor, We read with great interest the article by Guedes-Barbosa [1] titled “Anticitrulline peptide antibodies (anti-CCP) in leprosy sera: a negative association.” They emphasized high specificity of anti-CCP for the diagnosis of rheumatoid arthritis (RA); however, anti-CCP has been less well studied in many other diseases [2]. Recent studies showed 0–32% anti-CCP positive in patients with active pulmonary tuberculosis [3–5]. Guedes-Barbosa [1] reported two patients positive, among 64 patients, with leprosy [1]. Various musculoskeletal manifestations by non-tuberculous mycobacteria (NTM), such as tenosynovitis, arthritis, spondylitis, and so on, are difficult to distinguish between infections associated arthropathy and concomitant RA. To date, anti-CCP in NTM has not been studied. The aim of the present study was to determine the prevalence anti-CCP in patients with NTM. The study population consisted of 35 patients with NTM pulmonary diseases satisfying the clinical, radiographic, and microbiological diagnostic criteria published by the American Thoracic Society [6]. Blood samples were collected before starting treatment. All the subjects were recruited from Eulji University Hospital and Asan Medical Center. Ethics approval for study was obtained. Acid-fast bacilli staining was done using Ziehl–Neelson staining and culture using egg-based Ogawa medium. The cultured colonies were identified as Mycobacterium tuberculosis or NTM using the AccuProbe test (GenProbe Inc., San Diego, USA) or duplex PCR kit (M&D, Wonju, Korea). The species of NTM was identified using a polymerase chain reaction–restriction fragment length polymorphism method, based on the rpoB gene [7]. AntiCCP was determined by enzyme-linked immunosorbent assay using DIASTAT anti-CCP kit (MBL Co., Nagoya, Japan) and read by automated EIA analyzer, CODA (BioRAD Co., Japan). According to the manufacturer’s instructions, anti-CCP was considered positive when the absorbance was higher than the cutoff value (5 U/ml). RF was measured by the latex fixation test using Hitachi 7170 S (Hitachi Co., Tokyo, Japan). The cutoff value for positivity was 18 IU/ml. All patients had pulmonary manifestations, but no joint symptoms. Serological HIV tests were performed in all subjects and all with negative results. We could find no patients with anti-CCP positive, whereas, five patients (14%) were positive for RF (Table 1). The average titers of anti-CCP and RF were 1.06±0.54 and 14±5.22 IU/ml, respectively. Among five patients with RF+ (one female and four males), two patients were infected by MycobacM.-K. Lim :D.-H. Sheen : S.-C. Shim (*) Division of Rheumatology, Department of Internal Medicine, School of Medicine and Medical Sciences Research Institute, Eulji University, Dunsandong 1306, 302-799 Daejeon, South Korea e-mail: ssc@eulji.ac.kr

Restoration of Overexpressed Variable Heavy Chain 2 Transcripts with Tumor Necrosis Factor Inhibitors in Ankylosing Spondylitis

To the Editor: Ankylosing spondylitis (AS) is a chronic inflammatory disorder characterized by progressive and destructive arthritis of the spine and pelvis1. B cells are involved in the pathogenesis of autoimmune diseases through antibody production, cytokine release, and antibody presentation to auto-reactive T cells. In AS, the role of B cells in the pathogenesis is still incompletely understood2. It has been hypothesized that the production of high affinity monoreactive autoantibodies in autoimmune disease could arise from intrinsic abnormalities in the generation of immunoglobulin genes3. Immunoglobulin gene usage can be regarded as an important factor of pathogenesis of autoimmune diseases. Investigation of variable heavy chain (VH) gene usage is important for determining whether usage of particular gene families is distorted. Several studies have investigated the VH gene usage in various autoimmune diseases, including systemic lupus erythematosus4, myasthenia gravis5, rheumatoid arthritis (RA)6, Sjogren syndrome7, and AS8 … Address correspondence to Dr. S-C. Shim, Division of Rheumatology, Department of Medicine, Daejeon Rheumatoid and Degenerative Arthritis Center, Chungnam National University Hospital, 6 munwha-ro Jung-gu, Daejeon, South Korea. E-mail: shimsc{at}cnuh.co.kr

Long-term Treatment with Anti-platelet Agents for Collagen-induced Arthritis Improves Radiological Findings

Objectives The objectives of this study were to evaluate the long-term effect of anti-platelet treatment on the radiological progression of collagen-induced arthritis in rats. Methods Female Lewis rats with collagen-induced arthritis were divided into three experimental groups: saline, aspirin monotherapy (n = 12), and aspirin–clopidogrel dual therapy (n = 12). Drugs were administered daily and continued up to 70 days after the induction of arthritis. The clinical arthritis index (weight, morphology score, and paw thickness) and radiological scores were evaluated. Results The clinical arthritis index peaked on day 20, while the radiological scores peaked on day 35. No intergroup difference was observed in the clinical arthritis index throughout the experiment. The aspirin–clopidogrel dual therapy group had a significantly higher mean radiological score than the other groups (p = 0.045) on day 35. Further treatments resulted in significantly improved radiological findings in the aspirin monotherapy and aspirin–clopidogrel dual therapy groups on day 70 but no significant improvement in the saline group. Conclusion Anti-platelet agent treatment improved radiological findings on day 70. These observations emphasize the importance of a future long-term study of the effects of anti-platelet agent treatment on arthritis.