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1.
Ann Acad Med Singap ; 52(2): 80-87, 2023 02.
Article in English | MEDLINE | ID: mdl-36880819

ABSTRACT

INTRODUCTION: There is a paucity of information on the cytokine, complement, endothelial activation, and coagulation profiles of multisystem inflammatory syndrome in adults (MIS-A), a rare but serious complication following recovery from SARS-CoV-2 infection. We aim to examine the immune biomarker and coagulation profiles in association with the clinical presentation and course of MIS-A. METHOD: The clinical features of MIS-A patients admitted to our tertiary hospital were documented. Their levels of interleukin (IL)-1ß, IL-6, IL-10, IL-17, IL-18, interferon-α (IFN-α), IFN-γ, interferon gamma-induced protein 10 (IP-10), tumour necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, complement activation product (complement 5a [C5a]), and endothelial biomarker intercellular adhesion molecule-1 (ICAM-1) levels were assayed. The haemostatic profile was assessed with standard coagulation testing and thromboelastography. RESULTS: Three male patients were diagnosed with MIS-A at our centre from January to June 2022 with a median age of 55 years. All had tested positive for SARS-CoV-2 12-62 days prior to MIS-A presentation, with gastrointestinal and cardiovascular systems as the most commonly involved. Levels of IL-6, IL-10, IL-18, IP-10 and MCP-1 were raised whereas IL-1ß, IFN-α, IFN-γ, IL-17 and TNF-α remained normal. Markedly elevated levels of C-reactive protein (CRP), ferritin and ICAM-1 were present in all. C5a was elevated in 2 patients. A hypercoagulable state was demonstrated by raised levels of D-dimer, factor VIII, von Willebrand factor antigen, and ristocetin cofactor with corresponding raised parameters in thromboelastography in the 2 patients who had their coagulation profile assessed. CONCLUSION: MIS-A patients demonstrate activation of pro-inflammatory cytokines, endotheliopathy, complement hyperactivation and hypercoagulability.


Subject(s)
COVID-19 , Connective Tissue Diseases , Hemostatics , Humans , Adult , Male , Middle Aged , COVID-19/complications , Interleukin-10 , Interleukin-18 , Intercellular Adhesion Molecule-1 , Interleukin-17 , Chemokine CXCL10 , Interleukin-6 , SARS-CoV-2
2.
J Infect Dis ; 227(8): 1002-1006, 2023 04 18.
Article in English | MEDLINE | ID: mdl-36200239

ABSTRACT

Serological testing of Singaporeans who received childhood smallpox vaccination found anti-vaccinia IgG binding and neutralizing activity indicating long-term humoral immunity. There was correlation between IgG and neutralizing titers indicating IgG could be used as a surrogate marker for humoral immunity. In 2019, Singapore experienced a case of imported monkeypox. As with smallpox, disease can be prevented through vaccination, which was mandatory for Singaporean infants until 1981. However, the degree of residual immunity in older vaccinated Singaporeans remains unknown. Sera from individuals born 1946-1984 were therefore tested and those born prior to 1981 were found to have higher anti-vaccinia IgG and neutralizing activity titers. This suggests that protective humoral immunity remains, which could reduce disease severity in an orthopoxvirus outbreak. Correlation between IgG and neutralizing titers was observed indicating that serology could be used as a surrogate marker for immunity.


Subject(s)
Smallpox Vaccine , Smallpox , Vaccinia , Variola virus , Infant , Humans , Child , Aged , Immunity, Humoral , Smallpox/prevention & control , Vaccinia virus , Vaccination , Immunoglobulin G , Antibodies, Viral
3.
Lupus ; 31(14): 1759-1769, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36218127

ABSTRACT

OBJECTIVES: The Montreal Cognitive Assessment (MoCA) is an increasingly used screening tool for cognitive impairment. The aim of this study was to examine how MoCA performed in identifying cognitive impairment (CI) domains in SLE patients compared with formal standardized neuropsychological testing (NPT). Factors related to SLE disease, immunologic and psychological state associated with CI were also explored. METHODS: This cross-sectional study recruited 50 SLE patients without overt neuropsychiatric manifestations from April 2017 to May 2018. The patients were evaluated with MoCA, formal NPT and the Depression, Anxiety, and Stress Scales (DASS) 42-item self-report questionnaire. Values of sensitivity and specificity were computed for different cut-offs of MoCA within each cognitive domain of NPT and descriptive analysis was used to identify the factors affecting cognitive function. RESULTS: The median score for MoCA was 27.5 (range 22-30). Using a MoCA cutoff of <26, 18 (36%) were identified to have CI using NPT compared to 8 (16%) using MoCA. The most frequently affected cognitive domain was executive functioning with 15 affected patients. Sensitivities and specificities of the MoCA range from 50% to 100% and 5.7% to 16.7%, respectively, across cognitive domains. A lower MoCA cutoff of <25 improve sensitivity of identifying impairment in executive functioning from 60% to 80%. In univariate analysis, DASS scores, disease activity, presence of antiphospholipid antibodies, presence of concurrent autoimmune disease, current, and cumulative corticosteroid therapy did not predict cognitive performance. CONCLUSION: MoCA may be a useful screening tool to identify the most frequently affected cognitive domain which is executive functioning using a lower cutoff of <25 in SLE patients without overt neuropsychiatric manifestations.


Subject(s)
Cognitive Dysfunction , Lupus Erythematosus, Systemic , Humans , Cross-Sectional Studies , Lupus Erythematosus, Systemic/complications , Lupus Erythematosus, Systemic/diagnosis , Lupus Erythematosus, Systemic/psychology , Mental Status and Dementia Tests , Cognitive Dysfunction/etiology , Cognitive Dysfunction/complications , Executive Function , Neuropsychological Tests
4.
Vaccines (Basel) ; 10(10)2022 Oct 21.
Article in English | MEDLINE | ID: mdl-36298637

ABSTRACT

Since the introduction of coronavirus disease 2019 (COVID-19) messenger ribonucleic acid (mRNA) vaccines, there have been multiple reports of post-vaccination myocarditis (mainly affecting young healthy males). We report on four patients with active autoimmune rheumatic diseases (ARDs) and probable or confirmed myocarditis following COVID-19 mRNA vaccination managed at a tertiary hospital in Singapore; we reviewed the literature on post-COVID-19 mRNA vaccination-related myocarditis and ARD flares. Three patients had existing ARD flares (two had systemic lupus erythematosus (SLE), one had eosinophilic granulomatosis polyangiitis (EGPA)), and one had new-onset EGPA. All patients recovered well after receiving immunosuppressants comprising high-dose glucocorticoids, cyclophosphamide, and rituximab. Thus far, only one case of active SLE with myocarditis has been reported post-COVID-19 mRNA vaccination in the literature. In contrast to isolated post-COVID-19 mRNA vaccination myocarditis, our older-aged patients had myocarditis associated with ARD flares post-COVID-19 vaccination (that occurred after one dose of an mRNA vaccine), associated with other features of ARD flares, and required increased immunosuppression to achieve myocarditis resolution. This case series serves to highlight the differences in clinical and therapeutic aspects in ARD patients, heighten the vigilance of rheumatologists for this development, and encourage the adoption of risk reduction strategies in this vulnerable population.

7.
Vaccines (Basel) ; 9(9)2021 Aug 31.
Article in English | MEDLINE | ID: mdl-34579211

ABSTRACT

Anaphylactic reactions were observed after Singapore's national coronavirus disease 2019 (COVID-19) vaccination programme started in December 2020. We report the clinical and laboratory features of three patients in our institution who developed anaphylactic reactions after receiving the Pifzer BNT162b2 vaccine. IgM and IgG antibodies, but not IgE antibodies to the Pfizer BNT162b2 vaccine, were detected in all subjects. Similarly, mild to high elevated levels of anti-polyethylene glycol (PEG) IgG (1035-19709 U/mL, vs. vaccine-naive < 265 U/mL, vaccine-tolerant < 785 U/mL) and IgM (1682-5310 U/mL, vs. vaccine-naive < 1011 U/mL, vaccine-tolerant < 1007 U/mL) were detected in two out of three patients via commercial ELISA. High levels of serum anaphylatoxin C3a (79.0 ± 6.3 µg/mL, mean ± SD, vs. normal < 10 µg/mL) were observed in all three patients during the acute phase of the reaction, while tryptase levels, a marker of mast cell activation, were not elevated. Finally, one patient with the highest levels of anti-PEG IgG, IgM, and anti-Pfizer BNT162b2 IgG and IgM exhibited an enhanced Th2 cytokine serum profile during an acute reaction, with high levels of IL-4 (45.7 pg/mL, vs. vaccine-naive/tolerant < 2.30 pg/mL), IL-33 (86.4 pg/mL, vs. vaccine-naive/tolerant < 5.51 pg/mL) and IL-10 (22.9 pg/mL, vs. vaccine-naive/tolerant < 12.49 pg/mL) diminishing over time following corticosteroid treatment. Taken together, we propose these cases of anaphylaxis described are driven by a complement activation-related pseudoallergy (CAPRA), rather than classical IgE-mediated mechanisms.

8.
Cells ; 9(1)2019 Dec 27.
Article in English | MEDLINE | ID: mdl-31892200

ABSTRACT

Cytokine dysregulation is characteristic of systemic lupus erythematosus (SLE), a systemic autoimmune disease of considerable heterogeneity. Insights gained about the cytokine dysregulation in SLE have the potential for identifying patient subsets before the onset of clinical disease and during established disease. Clustering patients by cytokine and disease activity subsets is more informative than isolated cytokine studies, as both pro inflammatory and immunoregulatory cytokines contribute to the cytokine dysregulated state in SLE. Endogenous anti-cytokine autoantibodies (ACAAs) may be involved in the regulation of cytokine biology by reducing excessive production or by prolonging their half-life in the circulation through the formation of cytokine-antibody immune complexes. Although endogenous ACAAs may have deleterious effects such as contributing to immunodeficiency states, their role in the pathophysiology of autoimmune conditions such as SLE has yet to be clearly elucidated. The aim of the present article is to provide a focused review of the current knowledge of ACAAs in SLE.


Subject(s)
Autoantibodies/immunology , Autoimmunity , Cytokines/immunology , Disease Susceptibility/immunology , Lupus Erythematosus, Systemic/etiology , Animals , Biomarkers , Cytokines/antagonists & inhibitors , Cytokines/metabolism , Humans , Immunomodulation , Inflammation Mediators/metabolism , Lupus Erythematosus, Systemic/metabolism , Lupus Erythematosus, Systemic/pathology
9.
Arthritis Rheumatol ; 68(5): 1197-1209, 2016 05.
Article in English | MEDLINE | ID: mdl-26663301

ABSTRACT

OBJECTIVE: Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder whose etiology is incompletely understood, but likely involves environmental triggers in genetically susceptible individuals. Using an unbiased genome-wide association (GWA) scan and replication analysis, we sought to identify the genetic loci associated with SLE in a Korean population. METHODS: A total of 1,174 SLE cases and 4,246 population controls from Korea were genotyped and analyzed with a GWA scan to identify single-nucleotide polymorphisms (SNPs) significantly associated with SLE, after strict quality control measures were applied. For select variants, replication of SLE risk loci was tested in an independent data set of 1,416 SLE cases and 1,145 population controls from Korea and China. RESULTS: Eleven regions outside the HLA exceeded the genome-wide significance level (P = 5 × 10(-8) ). A novel SNP-SLE association was identified between FCHSD2 and P2RY2, peaking at rs11235667 (P = 1.03 × 10(-8) , odds ratio [OR] 0.59) on a 33-kb haplotype upstream of ATG16L2. In the independent replication data set, the SNP rs11235667 continued to show a significant association with SLE (replication meta-analysis P = 0.001, overall meta-analysis P = 6.67 × 10(-11) ; OR 0.63). Within the HLA region, the SNP-SLE association peaked in the class II region at rs116727542, with multiple independent effects observed in this region. Classic HLA allele imputation analysis identified HLA-DRB1*1501 and HLA-DQB1*0602, each highly correlated with one another, as most strongly associated with SLE. Ten previously established SLE risk loci were replicated: STAT1-STAT4, TNFSF4, TNFAIP3, IKZF1, HIP1, IRF5, BLK, WDFY4, ETS1, and IRAK1-MECP2. Of these loci, previously unreported, independent second risk effects of SNPs in TNFAIP3 and TNFSF4, as well as differences in the association with a putative causal variant in the WDFY4 region, were identified. CONCLUSION: Further studies are needed to identify true SLE risk effects in other loci suggestive of a significant association, and to identify the causal variants in the regions of ATG16L2, FCHSD2, and P2RY2.


Subject(s)
Asian People/genetics , Autophagy-Related Proteins/genetics , Carrier Proteins/genetics , Lupus Erythematosus, Systemic/genetics , Membrane Proteins/genetics , Receptors, Purinergic P2Y2/genetics , Case-Control Studies , Genetic Predisposition to Disease , Genotype , HLA-DQ beta-Chains/genetics , HLA-DRB1 Chains/genetics , Humans , OX40 Ligand/genetics , Polymorphism, Single Nucleotide , Republic of Korea , Tumor Necrosis Factor alpha-Induced Protein 3/genetics
10.
Rheumatol Int ; 33(7): 1693-703, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23271425

ABSTRACT

We analyzed the epidemiological changes of rheumatoid arthritis (RA) over three decades using patients from a single center in Singapore. All patients who fulfill the 1987 American College of Rheumatology criteria for RA were invited to enroll in a prospective disease registry. We analyzed the patient demographics, disease manifestation, management and patient-reported outcomes, including quality of life (QoL), in the three categories according to the year of disease onset: before 1989 (group I), 1990-1999 (group II) and after 2000 (group III). There were 1,153 patients with 231, 532 and 390 in groups I, II and III, respectively. The mean disease durations were 25, 12 and 4.8 years, respectively. The majority was female (84.1 %) and Chinese (76.6 %) with no socio-demographic differences across the three periods. The age of onset rises and the prevalence of rheumatoid factor falls with the proximity of disease onset. Patients with most recent disease onset had the earliest access to the rheumatologist. They also had the highest tender and swollen joint counts, lowest deformed joint count and highest remission rate. Patients in group I report better mental and emotional QoL though many developed marked disability. We have documented changes of the manifestations of RA that are dependent and independent of improved treatment. Significant differences in accessibility to the rheumatologist, RA activity, functional capacity, quality of life and comorbidities were seen in subsequent cohorts due to treatment evolution and more efficient healthcare delivery.


Subject(s)
Antirheumatic Agents/therapeutic use , Arthritis, Rheumatoid/drug therapy , Arthritis, Rheumatoid/ethnology , Delivery of Health Care/trends , Rheumatology/trends , Aged , Analysis of Variance , Arthritis, Rheumatoid/diagnosis , Arthritis, Rheumatoid/physiopathology , Arthritis, Rheumatoid/psychology , Chi-Square Distribution , Disability Evaluation , Emotions , Female , Humans , Male , Mental Health , Middle Aged , Predictive Value of Tests , Prospective Studies , Quality of Life , Registries , Remission Induction , Singapore/epidemiology , Surveys and Questionnaires , Time Factors , Treatment Outcome
11.
J Clin Rheumatol ; 18(2): 89-91, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22334267

ABSTRACT

We describe a 35-year-old Chinese woman with Behçet disease complicated by recurrent gastrointestinal flares. During admission for acute lower abdominal pain, a computed tomographic scan of the abdomen showed thrombosis of the left ovarian vein. She was treated with increased immunosuppressant and oral anticoagulant. Although she was not compliant to oral anticoagulant with her international normalized ratio frequently subtherapeutic, her symptoms abated and the thrombosis resolved. There has been only 1 reported case of a patient with Behçet disease presenting with postpartum ovarian vein thrombosis and pulmonary embolism and no reported case of Behçet disease with ovarian vein thrombosis occurring outside pregnancy and the puerperium. Ovarian vein thrombosis is a rare cause of abdominal pain that should be considered in patients with Behçet disease.


Subject(s)
Abdominal Pain , Behcet Syndrome , Ovary/blood supply , Venous Thrombosis , Abdominal Pain/complications , Abdominal Pain/physiopathology , Adult , Anticoagulants/administration & dosage , Behcet Syndrome/complications , Behcet Syndrome/physiopathology , Drug Monitoring/methods , Female , Humans , Immunosuppressive Agents/administration & dosage , International Normalized Ratio , Tomography, X-Ray Computed , Treatment Outcome , Veins/physiopathology , Venous Thrombosis/diagnosis , Venous Thrombosis/drug therapy , Venous Thrombosis/etiology , Venous Thrombosis/physiopathology
12.
Int J Rheum Dis ; 15(1): 13-6, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22324942

ABSTRACT

AIM: We sought to evaluate the relationship of urine levels of soluble cellular adhesion molecules sVCAM-1 (vascular) and sICAM-1 (intercellular) in systemic lupus erythematosus (SLE) patients with or without lupus nephritis, and to explore their correlation with renal disease activity. METHODS: Paired serum and urine samples of 121 Asian SLE patients, and urine samples of 19 normal healthy controls were collected. Demographic data, disease activity and damage scores, and selected laboratory parameters, including levels of anti-double stranded DNA antibody, complements C3, C4, and creatinine were captured. Renal disease activity was scored with renal SLE Activity Measure revised (rSLAM-R). Serum and urine sVCAM-1 and sICAM-1 levels were assayed by enzyme-linked immunosorbent assay. RESULTS: Urinary sVCAM-1 and sICAM-1 were elevated in SLE patients compared to controls. Significantly higher levels of urine sVCAM-1 found in patients with active lupus nephritis correlated with rSLAM-R. In addtion, significantly more patients with active lupus nephritis had detectable levels of urine sICAM-1, but no correlation with renal activity was observed. CONCLUSION: Urinary sVCAM-1 may serve as a potential biomarker for early diagnosis of lupus nephritis as levels correlated with even mild abnormalities of urine sediment. In addition, both urine sVCAM-1 and sICAM-1 levels may be useful in identifying patients at risk of lupus nephritis.


Subject(s)
Intercellular Adhesion Molecule-1/urine , Lupus Nephritis/diagnosis , Vascular Cell Adhesion Molecule-1/urine , Adult , Biomarkers/blood , Biomarkers/urine , Case-Control Studies , Early Diagnosis , Enzyme-Linked Immunosorbent Assay , Female , Humans , Intercellular Adhesion Molecule-1/blood , Logistic Models , Lupus Nephritis/blood , Lupus Nephritis/immunology , Lupus Nephritis/urine , Male , Middle Aged , Multivariate Analysis , Predictive Value of Tests , Severity of Illness Index , Singapore , Up-Regulation , Vascular Cell Adhesion Molecule-1/blood
13.
Ann Rheum Dis ; 71(1): 129-35, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21953348

ABSTRACT

BACKGROUND: Alcohol intake is inversely related to rheumatoid arthritis (RA) disease incidence and severity. Resveratrol, a safe, well-described plant-derived compound, possesses anti-inflammation and immune-regulatory properties and is present in red wine. As such, it could mediate anti-inflammatory properties of the latter and offer novel therapeutic utility in is own right. OBJECTIVE: To evaluate the therapeutic effect of resveratrol on collagen-induced arthritis (CIA) and its putative immune modulation in mice. METHODS: CIA was induced in DBA1 mice by immunisation with collagen II. Different doses of resveratrol were administered before or after the development of CIA. The levels of antibody and cytokines in serum or in draining lymph node (DLN) lymphocyte culture supernatants were measured by ELISA and Th17 cell development in DLN was monitored by flow cytometry. RESULTS: Either prophylactic or therapeutic administration of resveratrol attenuated clinical parameters and bone erosion in CIA mice. The arthritis-protective effects were associated with markedly reduced serum levels of pro-inflammatory cytokines and collagen-specific, but not total, IgG, and with reduced numbers of Th17 cells and the production of IL-17 in DLN. CONCLUSION: Resveratrol modulates inflammatory arthritis in rodents by selectively suppressing key cellular and humoral responses necessary for disease development. This may partly explain the protective effects of red wine but importantly may offer a novel, effective and safe pathway whereby novel agents could be developed to treat RA.


Subject(s)
Arthritis, Experimental/drug therapy , B-Lymphocytes/drug effects , Immunosuppressive Agents/therapeutic use , Stilbenes/therapeutic use , Th17 Cells/drug effects , Animals , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Arthritis, Experimental/immunology , Arthritis, Experimental/prevention & control , Autoantibodies/biosynthesis , B-Lymphocytes/immunology , Cells, Cultured , Cytokines/biosynthesis , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical/methods , Immunosuppressive Agents/administration & dosage , Immunosuppressive Agents/pharmacology , Inflammation Mediators/metabolism , Male , Mice , Mice, Inbred DBA , Resveratrol , Stilbenes/administration & dosage , Stilbenes/pharmacology , Th17 Cells/immunology
14.
J Spinal Disord Tech ; 24(3): 202-7, 2011 May.
Article in English | MEDLINE | ID: mdl-20634732

ABSTRACT

OBJECTIVES: This study aimed to identify potential blood-derived biomarkers distinguishing patients with ankylosing spondylitis from those with mechanical low back pain. METHODS: Serum and synovial fluid samples from our cohorts were assayed by using enzyme-linked immunosorbent assay for the following inflammatory biomarkers: interleukin (IL)-1α, IL-6, IL-8, IL-17, IL-23, monocyte chemotactic protein (MCP)-1, macrophage inflammatory proteins (MIP)-1α, MIP-1ß, tumor necrosis factor-α (TNF-α), interferon-α (IFN-α), IFN-ß, metalloproteinase (MMP-3), and bone morphogenetic protein 7 (BMP-7). RESULTS: After screening, a panel of serum and synovial fluid samples with a series of potential biomarkers, cytokines including IL-6, IL-8, MMP-3, and MCP-1 were selected for additional testing because they exhibited higher concentrations than paired serum samples in the synovial fluid. Sera obtained from 50 patients with ankylosing spondylitis and 27 patients with mechanical low back pain were measured for these biomarkers. CONCLUSIONS: The MCP-1 serum was identified as a biomarker candidate, distinguishing ankylosing spondylitis from mechanical low back pain with a sensitivity of 96% and a specificity of 83.3%.


Subject(s)
Chemokine CCL2/blood , Low Back Pain/blood , Low Back Pain/diagnosis , Spondylitis, Ankylosing/blood , Spondylitis, Ankylosing/diagnosis , Adolescent , Adult , Aged , Biomarkers/blood , Cohort Studies , Diagnosis, Differential , Female , Humans , Low Back Pain/etiology , Male , Middle Aged , Sensitivity and Specificity , Spondylitis, Ankylosing/complications , Young Adult
15.
Proc Natl Acad Sci U S A ; 107(36): 15838-43, 2010 Sep 07.
Article in English | MEDLINE | ID: mdl-20733074

ABSTRACT

Systemic lupus erythematosus (SLE) is a multisystem, autoimmune disease that predominantly affects women. Previous findings that duplicated Toll-like receptor 7 (Tlr7) promotes lupus-like disease in male BXSB mice prompted us to evaluate TLR7 in human SLE. By using a candidate gene approach, we identified and replicated association of a TLR7 3'UTR SNP, rs3853839 (G/C), with SLE in 9,274 Eastern Asians (P(combined) = 6.5 x 10(-10)), with a stronger effect in male than female subjects [odds ratio, male vs. female = 2.33 (95% CI = 1.64-3.30) vs. 1.24 (95% CI = 1.14-1.34); P = 4.1 x 10(-4)]. G-allele carriers had increased TLR7 transcripts and more pronounced IFN signature than C-allele carriers; heterozygotes had 2.7-fold higher transcripts of G-allele than C-allele. These data established a functional polymorphism in type I IFN pathway gene TLR7 predisposing to SLE, especially in Chinese and Japanese male subjects.


Subject(s)
Genetic Diseases, X-Linked/genetics , Lupus Erythematosus, Systemic/genetics , Sex Factors , Toll-Like Receptor 7/genetics , Alleles , Asian People , Genetic Predisposition to Disease , Humans , Male , Polymorphism, Single Nucleotide , RNA, Messenger/genetics
16.
J Immunol ; 181(11): 8010-7, 2008 Dec 01.
Article in English | MEDLINE | ID: mdl-19017993

ABSTRACT

Sphingosine kinase (SphK) is a key enzyme in the sphingolipid metabolic pathway responsible for phosphorylating sphingosine into sphingosine-1-phosphate (S1P). SphK/S1P play a critical role in angiogenesis, inflammation, and various pathologic conditions. Recently, S1P(1) receptor was found to be expressed in rheumatoid arthritis (RA) synovium, and S1P signaling via S1P(1) enhances synoviocyte proliferation, COX-2 expression, and prostaglandin E(2) production. Here, we examined the role of SphK/S1P in RA using a potent SphK inhibitor, N,N-dimethylsphingosine (DMS), and a molecular approach against one of its isoenzymes, SphK1. We observed that levels of S1P in the synovial fluid of RA patients were significantly higher than those of osteoarthritis patients. Additionally, DMS significantly reduced the levels of TNF-alpha, IL-6, IL-1beta, MCP-1, and MMP-9 in cell-contact assays using both Jurkat-U937 cells and RA PBMCs. In a murine collagen-induced arthritis model, i.p. administration of DMS significantly inhibited disease severity and reduced articular inflammation and joint destruction. Treatment of DMS also down-regulated serum levels IL-6, TNF-alpha, IFN-gamma, S1P, and IgG1 and IgG2a anti-collagen Ab. Furthermore, DMS-treated mice also displayed suppressed proinflammatory cytokine production in response to type II collagen in vitro. Moreover, similar reduction in incidence and disease activity was observed in mice treated with SphK1 knock-down via small interfering RNA approach. Together, these results demonstrate SphK modulation may provide a novel approach in treating chronic autoimmune conditions such as RA by inhibiting the release of pro-inflammatory cytokines.


Subject(s)
Arthritis, Rheumatoid/immunology , Leukocytes, Mononuclear/immunology , Lysophospholipids/immunology , Phosphotransferases (Alcohol Group Acceptor)/immunology , Signal Transduction/immunology , Sphingosine/analogs & derivatives , Synovial Fluid/immunology , Animals , Arthritis, Rheumatoid/enzymology , Arthritis, Rheumatoid/pathology , Cell Proliferation/drug effects , Collagen Type II/immunology , Collagen Type II/pharmacology , Cyclooxygenase 2/biosynthesis , Cyclooxygenase 2/metabolism , Cytokines/blood , Cytokines/immunology , Disease Models, Animal , Enzyme Inhibitors/pharmacology , Gene Expression Regulation/immunology , Humans , Inflammation/enzymology , Inflammation/immunology , Inflammation/pathology , Inflammation Mediators/blood , Inflammation Mediators/immunology , Jurkat Cells , Leukocytes, Mononuclear/enzymology , Leukocytes, Mononuclear/pathology , Lysophospholipids/metabolism , Matrix Metalloproteinase 9/biosynthesis , Matrix Metalloproteinase 9/immunology , Mice , Mice, Inbred DBA , Neovascularization, Physiologic/immunology , Phosphotransferases (Alcohol Group Acceptor)/antagonists & inhibitors , Phosphotransferases (Alcohol Group Acceptor)/metabolism , RNA, Small Interfering/immunology , Receptors, Lysosphingolipid/biosynthesis , Receptors, Lysosphingolipid/immunology , Signal Transduction/drug effects , Sphingosine/immunology , Sphingosine/metabolism , Sphingosine/pharmacology , Synovial Fluid/enzymology , U937 Cells
18.
Arthritis Rheum ; 57(6): 980-5, 2007 Aug 15.
Article in English | MEDLINE | ID: mdl-17665463

ABSTRACT

OBJECTIVE: We have previously validated the English version of the Systemic Lupus Erythematosus Quality of Life Questionnaire (SLEQOL) in our patients with lupus. Many of our Chinese patients are not fluent in English and therefore a Chinese version (SLEQOL-C) has been adapted for their use. METHODS: Two independent translators translated the SLEQOL into Chinese. A consensus version was derived from both sets of translations. Back translation of this version was performed by another 2 independent translators who had neither been involved in the forward translation nor encountered the SLEQOL. The final version, SLEQOL-C, was finalized after rectifying the discrepancies revealed by the back translation. Linguistic validity was tested in open interviews with bilingual patients with lupus. The SLEQOL-C and SLEQOL were administered to patients to determine whether they displayed differential item functioning (DIF). RESULTS: In general, most of the items in English could be expressed in Chinese precisely, although a few instructions had to be altered slightly to make them more idiomatic. The forward and back translations of the SLEQOL were accomplished without major difficulties. A total of 638 patients were interviewed (62.8% with the SLEQOL and 37.2% with the SLEQOL-C). Using DIF analysis, there was no detectable test bias due to language use after controlling for repeated observations, age, sex, and ethnicity. CONCLUSION: The SLEQOL-C has semantic, idiomatic, and conceptual equivalence to the SLEQOL. The rigorous process of cross-cultural translation provides some measure of quality in the content validity.


Subject(s)
Cross-Cultural Comparison , Language , Lupus Erythematosus, Systemic/physiopathology , Quality of Life , Surveys and Questionnaires , Adult , China , Female , Humans , Lupus Erythematosus, Systemic/complications , Lupus Erythematosus, Systemic/psychology , Male , Middle Aged , Reproducibility of Results
19.
Ann Acad Med Singap ; 36(2): 135-41, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17364081

ABSTRACT

Recent therapeutic advances, in particular the use of anti-tumour necrosis factor (anti-TNF) agents, have revived interest in the seronegative spondyloarthropathies (SpA), a group of arthritides characterised by axial skeletal involvement and the absence of rheumatoid factor. The purpose of this article is to review the studies that have been done in the Asia Pacific region, as a broad understanding of the scope and severity of this group of diseases would enable rheumatologists and physicians in this part of the world to better manage their patients. The majority of genetic studies have focused on the associations of HLA-B27 with ankylosing spondylitis (AS) and SpA, while a few studies examined the associations of the CARD, IL-1, LMP2, TAP and TGF with AS. There are a handful of studies on the immunological responses to bacteria and cytokine levels in AS. The onset and clinical features of SpA have been reported from most countries in the region, but no data on patient outcomes, using current measurement tools such as the Bath Ankylosing Spondylitis Disease Activity index (BASDAI), is available. Validation of these instruments of measurement as well as classification criteria in different ethnic populations is necessary where no prior data exist. Future studies will likely be focused on better clinical characterisation of patient cohorts, particularly with regard to the use of currently used measurement tools for disease activity and spinal function and mobility, and the identification of the need for biologic therapy in each country.


Subject(s)
Spinal Diseases , Arthritis/epidemiology , Arthritis/genetics , Arthritis/immunology , Arthritis/therapy , Asian People , Genetic Predisposition to Disease , HLA-B27 Antigen/genetics , Humans , Sensitivity and Specificity , Spinal Diseases/epidemiology , Spinal Diseases/genetics , Spinal Diseases/immunology , Spinal Diseases/therapy , Spondylitis, Ankylosing/genetics , Spondylitis, Ankylosing/immunology , Transforming Growth Factor beta1/immunology
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