Ning-Sheng Lai

Anti–citrullinated protein antibodies bind surface-expressed citrullinated Grp78 on monocyte/macrophages and stimulate tumor necrosis factor α production

OBJECTIVE Anti-citrullinated protein antibodies (ACPAs), which are the most specific autoantibody marker in patients with rheumatoid arthritis (RA), correlate with disease activity; however, the role of ACPAs in RA pathogenesis has not been elucidated. We hypothesized that ACPAs may directly stimulate mononuclear cells to produce inflammatory cytokines. Thus, we identified cognate antigens of ACPAs on monocyte/macrophages and examined their immunopathologic roles in the pathogenesis of RA. METHODS ACPAs were purified from pooled ACPA-positive RA sera by cyclic citrullinated peptide-conjugated affinity column. After coculture of U937 cells with ACPAs, the tumor necrosis factor alpha (TNFalpha) production and NF-kappaB DNA binding activity of the cells were measured by enzyme-linked immunosorbent assay. The cognate antigens of ACPAs on the U937 cell surface were probed by ACPAs, and the reactive bands were examined via proteomic analysis. RESULTS ACPAs specifically enhanced TNFalpha production and increased the DNA-binding activity of NF-kappaB in U937 cells. Proteomic analysis revealed that Grp78 protein (72 kd) was one of the cognate antigens of ACPAs. The truncated form of cell surface-expressed Grp78 (55 kd) on U937 cells contained citrulline capable of binding with ACPAs. After citrullination, glutathione S-transferase-tagged recombinant Grp78 (97.52 kd) became a 72-kd fragment and bound with ACPAs. ACPAs also bound to human monocytes and lymphocytes to promote TNFalpha production. CONCLUSION We clearly demonstrated that ACPAs enhance NF-kappaB activity and TNFalpha production in monocyte/macrophages via binding to surface-expressed citrullinated Grp78.

The Combined Effect of Individual and Neighborhood Socioeconomic Status on Cancer Survival Rates

Background This population-based study investigated the relationship between individual and neighborhood socioeconomic status (SES) and mortality rates for major cancers in Taiwan. Methods A population-based follow-up study was conducted with 20,488 cancer patients diagnosed in 2002. Each patient was traced to death or for 5 years. The individual income-related insurance payment amount was used as a proxy measure of individual SES for patients. Neighborhood SES was defined by income, and neighborhoods were grouped as living in advantaged or disadvantaged areas. The Cox proportional hazards model was used to compare the death-free survival rates between the different SES groups after adjusting for possible confounding and risk factors. Results After adjusting for patient characteristics (age, gender, Charlson Comorbidity Index Score, urbanization, and area of residence), tumor extent, treatment modalities (operation and adjuvant therapy), and hospital characteristics (ownership and teaching level), colorectal cancer, and head and neck cancer patients under 65 years old with low individual SES in disadvantaged neighborhoods conferred a 1.5 to 2-fold higher risk of mortality, compared with patients with high individual SES in advantaged neighborhoods. A cross-level interaction effect was found in lung cancer and breast cancer. Lung cancer and breast cancer patients less than 65 years old with low SES in advantaged neighborhoods carried the highest risk of mortality. Prostate cancer patients aged 65 and above with low SES in disadvantaged neighborhoods incurred the highest risk of mortality. There was no association between SES and mortality for cervical cancer and pancreatic cancer. Conclusions Our findings indicate that cancer patients with low individual SES have the highest risk of mortality even under a universal health-care system. Public health strategies and welfare policies must continue to focus on this vulnerable group.

Aberrant expression of microRNAs in T cells from patients with ankylosing spondylitis contributes to the immunopathogenesis

Ankylosing spondylitis (AS) is a chronic inflammatory disorder characterized by dysregulated T cells. We hypothesized that the aberrant expression of microRNAs (miRNAs) in AS T cells involved in the pathogenesis of AS. The expression profile of 270 miRNAs in T cells from five AS patients and five healthy controls were analysed by real‐time polymerase chain reaction (PCR). Thirteen miRNAs were found potentially differential expression. After validation, we confirmed that miR‐16, miR‐221 and let‐7i were over‐expressed in AS T cells and the expression of miR‐221 and let‐7i were correlated positively with the Bath Ankylosing Spondylitis Radiology Index (BASRI) of lumbar spine in AS patients. The protein molecules regulated by miR‐16, miR‐221 and let‐7i were measured by Western blotting. We found that the protein levels of Toll‐like receptor‐4 (TLR‐4), a target of let‐7i, in T cells from AS patients were decreased. In addition, the mRNA expression of interferon (IFN)‐γ was elevated in AS T cells. Lipopolysaccharide (LPS), a TLR‐4 agonist, inhibited IFN‐γ secretion by anti‐CD3+anti‐CD28 antibodies‐stimulated normal T cells but not AS T cells. In the transfection studies, we found the increased expression of let‐7i enhanced IFN‐γ production by anti‐CD3+anti‐CD28+ lipopolysaccharide (LPS)‐stimulated normal T cells. In contrast, the decreased expression of let‐7i suppressed IFN‐γ production by anti‐CD3+anti‐CD28+ LPS‐stimulated AS T cells. In conclusion, we found that miR‐16, miR‐221 and let‐7i were over‐expressed in AS T cells, but only miR‐221 and let‐7i were associated with BASRI of lumbar spine. In the functional studies, the increased let‐7i expression facilitated the T helper type 1 (IFN‐γ) immune response in T cells.

Higher LPS-stimulated TNF-α mRNA levels in peripheral blood mononuclear cells from Chinese ankylosing spondylitis patients with −308G/A polymorphism in promoter region of tumor necrosis factor: association with distinct A33/B58/Cw10 haplotypes

To investigate the effects of TNF-α −308, −238 promoter polymorphisms on TNF-α transcription in B27 positive Chinese patients with ankylosing spondylitis (AS). The possible relationship between polymorphisms, MHC antigens, and quantitative TNF-α mRNA expression were evaluated. Single nucleotide polymorphisms (SNPS) of TNF-α −308 and −238 were performed by PCR-amplification refractory mutation system method (PCR-ARMS) in sixty-seven B27-positive AS patients and 60 HLA-B27 positive healthy controls in Chinese. Quantitative measurement of TNF-α mRNA in peripheral blood mononuclear cells was performed with real time RT-PCR. The polymorphisms were correlated to quantitative TNF-α mRNA, and MHC antigens (determined by SSP method) in AS patients. The prevalence rate of both −308G/A and −238G/A TNF-α promoter polymorphisms in patients were not significantly different from those in normal subjects. However, a significant high LPS-stimulated TNF-α mRNA expression was found in peripheral blood mononuclear cells from patients with promoter −308G/A polymorphism (TNF2) as compared to those in −308G/G genotype (TNF1). Furthermore, −308G/A polymorphism in patients was found to be tightly associated with distinct haplotypes of A33/B58/Cw10 [12 out of 14 –308G/A patients (85.7%) versus none in 53 –308G/G patients], independent of B27 antigen. HLA-A33-B58-Cw10 haplotypes associated TNF-α promoter −308G/A polymorphism might play an important role in disease pathogenesis of AS in Chinese population, partially related to a driving force of a higher TNF-α production. It confirms once again the importance and complexity of MHC related molecules in disease pathogenesis of AS.

Renal vein thrombosis in Chinese patients with systemic lupus erythematosus

OBJECTIVES To evaluate the risk factors associated with renal vein thrombosis (RVT) in Chinese patients with systemic lupus erythematosus (SLE). METHODS Data on clinical symptoms, renal biopsy, antiphospholipid antibody syndrome profile, and serological examinations of lupus features were examined retrospectively in six patients with RVT confirmed by angiography from a total of 625 patients with SLE over a 14 year period (1982–1996). RESULTS The lupus patients with RVT did not have acute symptoms of severe flank pain, haematuria, and oligouria. In contrast, most patients were suspected to have RVT because of peripheral oedema and worsening proteinuria. Roentgenological examinations (including renal sonography, renal computer tomography, or renal Doppler, or all three) were positive only in some patients. Positive antiphospholipid antibody profiles were found in four of six lupus patients. By renal biopsy, only two samples were confirmed as World Health Organisation (WHO) class V lupus membranous glomerulonephritis. The others were class IV in three patients, and class III in the remaining one. No RVT was found in lupus patients without nephrotic syndrome. Peripheral thrombophlebitis was, however, noted in only one patient. CONCLUSION Nephrotic syndrome could be a distinct risk factor in the development of RVT in Chinese SLE patients, in contrast with that reported in white populations in whom the peripheral thrombotic events were recognised as a determining factor.

Predicting insulin resistance using the triglyceride-to-high-density lipoprotein cholesterol ratio in Taiwanese adults

BackgroundThe triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C) has been advocated as a simple clinical indicator of insulin resistance. Thresholds of TG/HDL-C appeared to depend on ethnicity. However, no studies have specifically compared the accuracy of TG/HDL-C with and without other clinical and demographic factors in predicting insulin resistance in Taiwanese adults. The aim of the present investigation was to use TG/HDL-C and other clinical available factors to predict insulin resistance in Taiwanese adults.MethodsA total of 812 subjects were recruited from at the time of their general health examination at the Buddhist Dalin Tzu Chi General Hospital, Taiwan. Demographic information and clinical characteristics were obtained. Insulin resistance was defined by the homeostasis model assessment for insulin resistance (HOMA-IR). Simple and multiple logistic regression analyses were used to obtain probabilities of insulin resistance (HOMA-IR > 2) using TG/HDL-C with (Model 2) and without (Model 1) other clinical variables. A receiver operating characteristic (ROC) analysis was conducted to evaluate the ability of the two models to correctly discriminate between subjects of low and elevated HOMA-IR.ResultsFemale sex, greater waist circumferences, and higher ALT levels were significantly associated with the risk of elevated HOMA-IR in addition to TG/HDL-C in the multiple logistic regression (Model 2). The area under the ROC curve (AUC) of Model 2 was 0.71 [95% CI = 0.67-0.75] and was significantly higher (P = 0.007) than the AUC 0.66 [95% CI = 0.62-0.71] of Model 1.ConclusionsThe diagnostic accuracy of insulin resistance, defined by HOMA-IR, using TG/HDL-C can be significantly enhanced by including three additional clinically available factors - sex, waist circumferences, and ALT levels.

Risk of Rheumatoid Arthritis in Patients with Type 2 Diabetes: A Nationwide Population-Based Case-Control Study

Objective Type 2 diabetes is associated with chronic, low-grade inflammation and could potentially trigger the progression of other, more prominent inflammatory diseases such as rheumatoid arthritis (RA). Therefore, we aimed to investigate the risk of incident RA in Taiwanese patients with type 2 diabetes using a population-based health claims database. Methods This nationwide, population-based, case-control study used administrative data to identify 1,416 patients with RA (age ≥20 years) as cases and 7,080 controls that were frequency-matched for sex, 10-year age group, and year of catastrophic illness certificate application date (index year). All subjects were retrospectively traced back, up to 13 years prior to the index year, for their first diagnosis of type 2 diabetes. Logistic regression analysis was conducted to quantify the association between incident RA and type 2 diabetes. Results The odds of developing RA were significantly higher in female (odds ratio [OR] 1.46, 95% confidence interval [95% CI] 1.24–1.72) but not in male (OR 1.00, 95% CI 0.72–1.37) patients who had previously diagnosed with type 2 diabetes. Subgroup analysis indicated that the odds of developing RA were more prominent in younger females (20 to 44 years of age) with type 2 diabetes. In addition, the odds of developing RA in female patients with type 2 diabetes were higher in those with a shorter time interval between the diagnosis of type 2 diabetes and RA. Conclusions This large nationwide, population-based, case-control study showed an elevated risk of RA in female Taiwanese patients with type 2 diabetes. Our findings were consistent with the hypothesis that chronic low-grade inflammation in type 2 diabetes may elicit the development of RA in genetically susceptible individuals.

Increased expression of long noncoding RNAs LOC100652951 and LOC100506036 in T cells from patients with rheumatoid arthritis facilitates the inflammatory responses.

The aim of this study was to evaluate whether the presence of aberrantly expressed lncRNAs could promote T cell inflammatory responses in patients with RA. The expression levels of 10 potential aberrantly expressed lncRNAs were evaluated in T cells from 39 patients with RA and 17 controls using real-time reverse transcription polymerase chain reaction. The aberrantly expressed lncRNAs were measured in Jurkat cells co-cultured with or without ionomycin and phorbol 12-myristate 13-acetate. Transfection studies using small interfering RNA (siRNA) were conducted for biological functions, and microarray analysis was performed to search for target genes of specific lncRNAs. We confirmed that the expression levels of LOC100652951 and LOC100506036 were higher in RA T cells compared with controls. RA patients treated with biologic agents had lower expression levels of LOC100652951, and female RA patients had lower LOC100506036 expression levels after multivariate analysis. After activation, the expression levels of LOC100506036, but not LOC100652951, increased in Jurkat cells. Transfection of siRNA targeting LOC100506036 inhibited interferon gamma production and the expression of nuclear factor of activated T cells in activated Jurkat cells. After the microarray analysis with validation, inhibition of LOC100506036 expression by siRNA leaded to the decreased expression of sphingomyelin phosphodiesterase 1 (SMPD1). In conclusion, the expression levels of LOC100652951 and LOC100506036 were increased in RA T cells. Treatment with biologic agents could lower the expression of LOC100652951 in RA T cells. LOC100506036 could regulate the expression of SMPD1 and NFAT1 and could contribute to the inflammatory responses in RA.

Increased frequency and costs of ambulatory medical care utilization prior to the diagnosis of rheumatoid arthritis: a national population-based study.

To investigate the frequency and costs associated with ambulatory medical care utilization over an 8‐year period in patients prior to the diagnosis of rheumatoid arthritis (RA).

Increased risk of primary Sjogren's syndrome in female patients with thyroid disorders: a longitudinal population-based study in Taiwan.

Background A number of reports have indicated an association between thyroid diseases and primary Sjögrens syndrome (pSS). However, fewer studies have investigated whether the presence of thyroid diseases is associated with increased risk of developing pSS. Thus, the aim of our study was to use a nationwide health claims database to explore the prevalence and risk of pSS in female patients with thyroid diseases. Methods From the Registry of Catastrophic Illness database in the National Health Insurance Research Database in Taiwan, we identified 389 female patients with a diagnosis of pSS from 2005 to 2010. We also obtained 1945 control subjects frequency-matched on sex, 10-year age interval, and year of index date from the Longitudinal Health Insurance Database (LHID2000). Both groups were retrospectively traced back to a period of eight years to obtain diagnosis of thyroid diseases prior to index date. Results A significantly higher risk of pSS was associated with the presence of thyroid diseases (adjusted odds ratio (AOR) = 2.1, 95% confidence interval (CI) = 1.6–2.9). Among the sub-categories of thyroid diseases, patients with thyroiditis (AOR = 3.6, 95% CI = 1.7–7.5), thyrotoxicosis (AOR = 2.5, 95% CI = 1.6–3.8), and unspecified hypothyroidism (AOR = 2.4, 95% CI = 1.2–4.6), and simple and unspecified goiter (AOR = 2.0, 95% CI = 1.3–3.3) were significantly associated with increased risk of pSS. The associations were generally stronger in the mid-forties to mid-sixties age group, except in patients with unspecified hypothyroidism. Conclusions The risk of pSS was significantly increased in female patients with thyroid diseases, particularly those in their mid-forties to mid-sixties. An increased awareness of the possibility of pSS in perimenopausal females with thyroid diseases is important to preserve their quality of life and to avoid comorbidity.