Ji-Hyeon Ju

IL-10 suppresses Th17 cells and promotes regulatory T cells in the CD4+ T cell population of rheumatoid arthritis patients.

Interleukin-17-producing CD4(+) T cells (Th17 cells) are the dominant pathogenic cellular component in autoimmune inflammatory diseases, including autoimmune arthritis. IL-10 promotes the generation of Foxp3(+) regulatory T cells via the IL-10 receptor signal. The objective of this study was to examine whether IL-10, which acts as an anti-inflammatory cytokine, has a suppressive effect on the activation of human Th17 cells. Expression of IL-17 and IL-10 was examined immunohistochemically in tissue obtained from rheumatoid arthritis patients. Human peripheral blood CD4(+) T cells were isolated and cultured under various stimulatory conditions. Th17 cells and regulatory T (Treg) cells were detected by flow cytometry. The gene expression of related cytokines and transcription factors were assessed by ELISA and RT-PCR. IL-17 was overexpressed in rheumatoid arthritis patients. IL-10 treatment significantly decreased the numbers of IL-17-producing and RORc-expressing cells among human CD4(+) T cells that had been activated in vitro by Th17-differentiating conditions in autoimmune arthritis patients. IL-10 induced Foxp3(+) regulatory T cells in the human CD4(+) T cell population. Our results demonstrate that IL-17 is overexpressed in autoimmune disease patients and that IL-10 suppresses IL-17 expression. IL-10 may be useful in the treatment of autoimmune diseases.

Thrombotic thrombocytopenic purpura in systemic lupus erythematosus: risk factors and clinical outcome: a single centre study.

The study was undertaken to investigate clinical characteristics of thrombotic thrombocytopenic purpura (TTP) in patients with SLE and to determine risk factors and clinical outcome of TTP in patients with SLE. Among the 1203 patients with SLE admitted to catholic medical centre of the catholic university of Korea from January 1990 to December 2006, 26 patients with SLE were found to admit with TTP. TTP was defined if microangiopathic haemolytic anaemia, thrombocytopenia and negative Coombs’ test were present and when at least one of the following signs was noted: renal impairment, neurologic deficit or fever. Eighty-seven patients with SLE who admitted with other manifestations, matched for age and sex, were included as disease controls. Data were retrospectively analysed based on medical records. There were no significant demographic characteristics between SLE patients with TTP and those with other manifestations. Multivariate analysis showed that independent risk factors for the development of TTP included high SLE disease activity index score (SLEDAI > 10, P = 0.006) and coexisting nephritis (P = 0.004). Among the 26 SLE patients with TTP, 12 died during admission period (in-hospital mortality rate: 46.1%). SLE patients with infection or neurologic manifestations had higher mortality rates. Multivariate analysis showed that infection is the only independent risk factor for mortality in SLE patients with TTP (P = 0.035). Patients with SLE who are in the active stage or who have renal involvement have the increased risk for TTP. Development of TTP in patients with SLE can be fatal. Therefore, intensive therapy will be needed especially in the presence of infection.

Grape seed proanthocyanidin extract (GSPE) attenuates collagen-induced arthritis

To examine whether grape seed proanthocyanidin extract (GSPE) which is known to act as an antioxidant has therapeutic effect on collagen-induced arthritis (CIA) in mice, an animal model of rheumatoid arthritis. Mice were treated with an intraperitoneal injection of GSPE (10, 50, or 100 mg/kg) or saline. Clinical, histological, and biochemical parameters were assessed. The effects of GSPE on osteoclastogenesis were determined by tartrate-resistant acid phosphatase (TRAP) staining of the inflamed joints and bone-marrow cells cultured with the receptor activator of nuclear factor B ligand (RANKL) and macrophage colony-stimulating factor (M-CSF). Intracellular levels of hydrogen peroxide were determined using carboxy-dichlorodihydrofluorescein diacetate. GSPE treatment significantly attenuated the severity of CIA in a dose-dependent manner and reduced the histology scores for synovial inflammation, cartilage erosion, bone erosion, and the number of TRAP+ osteoclasts. GSPE treatment significantly reduced the numbers of tumor necrosis factor alpha (TNF-alpha)- or interleukin 17 (IL-17)-producing cells in the synovial tissue and the spontaneous production of TNF-alpha and IL-17 by splenocytes compared with those in the control mice. The serum levels of type-II-collagen-specific IgG2a and plasma levels of 8-isoprostane in the GSPE-treated mice were significantly lower than those in the control mice. GSPE dose-dependently suppressed osteoclastogenesis in vitro. GSPE significantly reduced hydrogen peroxide production by anti-CD3-monoclonal-antibody-stimulated CD4+ splenocytes. These results indicate that intraperitoneal injection of GSPE attenuated CIA in mice. GSPE may be useful in the treatment of rheumatoid arthritis.

Lupus enteritis: clinical characteristics, risk factor for relapse and association with anti-endothelial cell antibody

The study was undertaken to evaluate clinical and laboratory characteristics of patients with lupus enteritis and to investigate its association with anti-endothelial cell antibodies (AECAs). Systemic lupus erythematosus (SLE) patients who were admitted to Kangnam St. Marys Hospital with complaints of acute abdominal pain from January 1990 to July 2006 were reviewed retrospectively. The clinical features, laboratory data and prognosis of these patients were analyzed. Among the 706 SLE patients admitted during the study period, 87 were found to admit for acute abdominal pain. Among them, 41 patients were identified with lupus enteritis. The SLE disease activity index score at admission and the mean prednisolone dose administered during the last three months prior to admission were significantly higher in patients with lupus enteritis than those with other causes (P < 0.001, P = 0.036). Serum anti-endothelial cell antibody (AECA-IgG) titer was also significantly higher in patients with lupus enteritis than those with other manifestations or healthy controls (P = 0.040, P < 0.001). Four out of 13 recurrent patients had pre-existing anti-phospholipid syndrome (APS), whereas only one out of 28 non-recurrent patients had pre-existing APS (P = 0.028). Most of the patients with lupus enteritis showed good response to high-dose intravenous steroids and there was no death directly associated with lupus enteritis. Lupus (2007) 16, 803—809.

Diffuse alveolar hemorrhage in systemic lupus erythematosus: risk factors and clinical outcome: results from affiliated hospitals of Catholic University of Korea:

This study was undertaken to investigate clinical characteristics of diffuse alveolar hemorrhage (DAH) in patients with systemic lupus erythematosus (SLE) and to determine risk factors and clinical outcomes of DAH in SLE patients. Among the 1521 patients with SLE admitted between January 1993 and June 2009 to affiliated hospitals of Catholic University of Korea, 21 SLE were admitted for DAH. The inclusion criteria for DAH was defined as new infiltrates on chest radiographs, an acute hemoglobin drop of at least 1.5u2009g/dl in the absence of an obvious source of bleeding, and one or more of the following signs: hemoptysis, hypoxemia, bronchoscopic or biopsy evidence of DAH. Included as disease controls were 83 SLE patients, matched for age and sex, who were admitted for other manifestations. Data based on medical records were analyzed retrospectively. There were no significantly differing demographic characteristics between SLE patients with DAH and those with other manifestations. Multivariate analysis demonstrated coexisting neuropsychiatric lupus (pu2009=u20090.002) and high SLE disease activity index scores (SLEDAIu2009>u200910) as independent risk factors in the development of DAH (pu2009=u20090.029). Among the 21 SLE patients with DAH, 13 died during the admission period (in-hospital mortality rate: 61.9%). Mortality was associated with infection and requirements of mechanical ventilation. Collectively, SLE patients who have neuropsychiatric manifestations or are in the active stage of the disease have an increased risk for developing DAH. Due to the high mortality of SLE patients with DAH, early recognition of risk factors and appropriate intervention is essential.

Incidence of cancer among patients with systemic sclerosis in Korea: results from a single centre

Objective: The aim of this study was to determine whether the incidence of cancer has increased among patients with systemic sclerosis (SSc) in Korea. Methods: The study subjects consisted of 112 patients who had been consecutively evaluated for at least 6 months between 1990 and 2007. We retrospectively reviewed their medical records, investigated the incidence rate of cancer and compared it with that of the Korea National Cancer Centre database. Results: Nine out of 112 patients developed cancer (four males and five females). The average age at diagnosis of cancer was 56.4 years and the mean disease duration was 8.9 years. The standardized incidence ratio (SIR) for SSc patients was 4.2 [95% confidence interval (CI) 2.3–6.1], 3.7 for women (95% CI 1.2–6.2) and 6.4 for men (95% CI 1.6–11.2). Lung cancer was the most common cancer (n = 4), followed by oesophagus (n = 1), stomach (n = 1), liver (n = 1), pancreas (n = 1), and squamous cell carcinoma of unknown origin (n = 1). All patients who developed lung cancer were female and non‐small cell carcinoma in origin. The SIR of lung cancer in female patients was 23.0 (95% CI 6.0–40.0). Two out of four lung cancer patients had concomitant interstitial lung disease (ILD); all were non‐smokers. Treatment agents, autoantibodies, smoking, and lung involvement were not significantly different between SSc patients with or without cancer. Conclusion: The SIR of cancer was significantly higher in SSc patients, and especially in those who were male, than in the general population. Lung cancer was the most common cancer. Active surveillance for the detection of cancer should be performed in all SSc patients.

IL-17 induces the production of IL-16 in rheumatoid arthritis

The purpose of this study was to investigate the expression of IL-16 in the rheumatoid synovium and the role of inflammatory cytokines and Toll-like receptor (TLR) ligands in IL-16 production by fibroblastlike synoviocytes (FLS) of rheumatoid arthritis (RA) patients. Immunohistochemical staining was performed with a monoclonal antibody to IL-16 in synovial tissues from patients with RA and likewise in patients with osteoarthritis (OA). FLS were isolated from RA synovial tissues and stimulated with IL-15, IL-1β, IFN-γ, and IL-17. The IL-16 mRNA level was assessed by semiquantitative RT-PCR and real time (RT) PCR and a comparison was made between IL-16 mRNA levels produced by RA-FLS and OA-FLS. Production of IL-16 was identified by a western blot assay, and IL-16 production after stimulation by specific ligands of TLR2 and TLR4 was assessed by RT-PCR. While immunohistochemical staining demonstrated strong expression of IL-16 mRNA in synovial tissues from patients with RA, similar findings were not present in the OA group. Moreover, mRNA expression of IL-16 by RA-FLS increased after treatment with IL-17 but not with IL-15, IL-1β, and IFN-γ. Specifically, IL-17 increased IL-16 mRNA level by RA-FLS and peripheral blood mononuclear cells in a dose-dependent manner. However, IL-17 did not stimulate IL-16 production in OA-FLS. Peptidoglycan, a selective TLR2 ligand, also increased production of IL-16 by RA-FLS dosedependently, whereas LPS, a selective TLR4 ligand, had no such stimulatory effect. The results from our data demonstrate that IL-17 and TLR2 ligands stimulate the production of IL-16 by RA-FLS.

Hydroxychloroquine and pregnancy on lupus flares in Korean patients with systemic lupus erythematosus

We investigated the clinical and laboratory characteristics of pregnancies with systemic lupus erythematosus (SLE) and identified lupus flare predictors during pregnancy. Additionally, we examined lupus activity and pregnancy outcomes in SLE patients who continued, discontinued or underwent no hydroxychloroquine (HCQ) treatment during pregnancy. We retrospectively analyzed 179 pregnancies in 128 SLE patients at Seoul St. Mary’s Hospital, Korea, between 1998 and 2012 and then assessed the clinical profiles and maternal and fetal outcomes. Overall, 90.5% of pregnancies resulted in a successful delivery and were divided into two groups: those who experienced lupus flares (80 pregnancies, 44.7%) and those who did not (99 pregnancies, 55.3%). Increased preeclampsia, preterm births, low birth weight, intrauterine growth restriction (IUGR), and low 1-minute Apgar scores occurred in pregnancies with lupus flares compared to pregnancies in quiescent disease. Lupus flares were predicted by HCQ discontinuation, a history of lupus nephritis, high pre-pregnancy serum uric acid and low C4 levels. Our study indicates that achieving pre-pregnancy remission and continuing HCQ treatment during pregnancy are important for preventing lupus flares.

IL-23 induces receptor activator of NF-κB ligand expression in fibroblast-like synoviocytes via STAT3 and NF-κB signal pathways

Interleukin (IL)-23 stimulates T lymphocytes to produce inflammatory molecules, which can cause inflammatory arthritis. This study was undertaken to explore the role of IL-23 in stimulating the expression of the receptor activator of the nuclear factor kappa B (NF-kappaB) ligand (RANKL) and osteoclastogenic activity in human fibroblast-like synoviocytes (FLS). These cells were separated from the synovium of patients with rheumatoid arthritis (RA-FLS) and osteoarthritis (OA-FLS) and stimulated with IL-23. RANKL expression was measured by real-time polymerase chain reaction (PCR) amplification and immunostaining. Osteoclast precursor cells were cocultured with IL-23-stimulated RA-FLS and OA-FLS and subsequently stained for tartrate-resistant acid phosphatase (TRAP) activity. IL-23 upregulated RANKL expression in RA-FLS. The expression of RANKL mRNA and protein was blocked completely by inhibitors of NF-kappaB (parthenolide) or of the JAK II-STAT3 pathway (AG490), showing that the RANKL expression pathway is mediated by NF-kappaB and STAT3. TRAP-positive osteoclastogenesis was enhanced in IL-23-stimulated FLS. RA-FLS were more responsive to IL-23 in terms of their RANKL expression than OA-FLS or normal FLS. Thus, IL-23 appears to induce joint inflammation and bone destruction by stimulating RANKL expression in RA-FLS. These interactions between IL-23 and FLS indicate possible new therapeutic approaches for treating bone destruction in patients with inflammatory diseases.

Expression of CCR2A, an isoform of MCP-1 receptor, is increased by MCP-1, CD40 ligand and TGF-β in fibroblast like synoviocytes of patients with RA

Cytokine and chemokine receptors play a key role in inflammation caused by rheumatoid arthritis (RA). Two isoforms of human CC chemokine receptor R2 (CCR2), the receptor of monocyte chemoattractant protein 1 (MCP-1), have been identified but their relative expression in fibroblast-like synoviocytes (FLS) and their contribution to inflammatory responses mediated by MCP-1 or inflammatory cytokines in patients with RA remain uncertain. We examined the pattern of expression of two CCR2 isoforms upon stimulation by proinflammatory cytokines and CD40 ligation. FLS were prepared from the synovial tissues of RA patients and cultured in the presence of MCP-1, soluble CD40 ligand (sCD40L), TGF-β, IL-1β, IL-18, IL-15, and LPS. CCR2A and CCR2B expression was examined by immunohistochemistry, RT-PCR and western blot analysis. IL-15, TNF-α and MCP-1 production was determined by ELISA. Immunohistochemistry showed that CCR2A is highly expressed in RA synovium compared with OA synovium. Transcripts of both CCR2A and CCR2B were detected in FLS. Exogenous MCP-1, CD40L, TGF-β, and IL-15 significantly increased the expression of CCR2A but not CCR2B. Exposure of FLS to sCD40L caused strong upregulation of CCR2A but not of CCR2B protein expression. MCP-1 increased the proliferation of FLS and the production of IL-15, TNF-α, and IL-18. Because CCR2A is the main target of regulation by cytokines and CD40 ligation, the relatively higher expression of CCR2A on the cell surface suggests that this isoform of MCP-1 receptor functions as the principal mediator of inflammatory signals in RA FLS.