Predictive value of anti-CarP and anti-PAD3 antibodies alone or in combination with RF and ACPA for the severity of rheumatoid arthritis.

OBJECTIVES: The objective of this study was to analyse the predictive value of anti-carbamylated protein (anti-CarP) and anti-peptidyl-arginine deiminase type-3 (anti-PAD3) antibodies, alone or in combination with RF and ACPA, to identify patients at high risk of developing severe RA outcomes. METHODS: Patients within the Swiss Clinical Quality Management registry with a biobank sample were tested for RF, ACPA, anti-CarP, and anti-PAD3 antibodies. We examined the association of each autoantibody with DAS28, HAQ and radiographic damage (Ratingen) at baseline and longitudinally. RESULTS: Analyses included 851 established RA patients and 516 disease controls [axial spondyloarthritis (axSpA = 320) and PsA (196)]. Anti-CarP and anti-PAD3 antibodies were, respectively, present in 22.4% and 10.7% of the whole RA population, and in 13.2% and 3.8% of the RF and ACPA double seronegative patients. At baseline, RA patients with anti-PAD3 had higher DAS28 (4.2 vs 3.7; P= 0.005) and significantly more radiographic damage (14.9 vs 8.8; P= 0.02) than anti-PAD3-negative patients. In the ACPA-negative subgroup, baseline Ratingen scores were significantly higher in anti-PAD3-positive patients (P= 0.01). The combination of anti-PAD3, RF IgM, and ACPA was associated with significantly higher baseline radiographic scores than the double seropositive group (P= 0.04). The presence of any two of the previous autoantibodies was associated with significantly greater radiographic progression over 10 years than if all were absent (P= 0.02). There were no differences in RA outcome measures with regards to anti-CarP. CONCLUSIONS: Anti-PAD3 antibodies are associated with higher disease activity and joint damage scores in RA patients.

Presence of IL-17 in synovial fluid identifies a potential inflammatory osteoarthritic phenotype.

PURPOSE: Osteoarthritis (OA) is a common and heterogeneous arthritic disorder. Patients suffer pain and their joints are characterized by articular cartilage loss and osteophyte formation. Risk factors for OA include age and obesity with inflammation identified as a key mediator of disease pathogenesis. Interleukin-17A (IL-17) is a pro-inflammatory cytokine that has been implicated in inflammatory diseases such as rheumatoid arthritis. IL-17 can upregulate expression of inflammatory cytokines and adipocytokines. The aim of this study was to evaluate IL-17 levels in the synovial fluid of patients with end-stage knee and hip OA in relation to inflammation- and pain-related cytokines and adipocytokines in synovial fluid and serum, and clinical and radiographic disease parameters. METHODS: This is a cross-sectional study of 152 patients undergoing total hip and knee arthroplasty for OA. IL-17, IL-6, leptin, adiponectin, visfatin, resistin, C-C Motif Chemokine Ligand 2 (CCL2), C-C Motif Chemokine Ligand 7 (CCL7) and nerve growth factor (NGF) protein levels were measured in synovial fluid and serum using enzyme-linked immunosorbent assay (ELISA). Baseline characteristics included age, sex, body mass index, co-morbidities, pain and function, and radiographic analyses (OA features, K&L grade, minimal joint space width). RESULTS: 14 patients (9.2%) had detectable IL-17 in synovial fluid. These patients had significantly higher median concentrations of IL-6, leptin, resistin, CCL7 and NGF. Osteophytes, sclerosis and minimum joint space width were significantly reduced in patients with detectable IL-17 in synovial fluid. No differences were found in pain, function and comorbidities. IL-17 concentrations in synovial fluid and serum were moderately correlated (r = 0.482). CONCLUSION: The presence of IL-17 in the synovial fluid therefore identifies a substantial subset of primary end-stage OA patients with distinct biological and clinical features. Stratification of patients on the basis of IL-17 may identify those responsive to therapeutic targeting.

The prevalence of anticitrullinated protein antibodies increases with age in healthy individuals at risk for rheumatoid arthritis.

Transition from genetic risk to the development of systemic autoimmunity associated with rheumatoid arthritis (RA) is considered a key step for the development of RA and often referred to as the immune onset of the disease. The aim of this study is to identify predictors for the presence of anticitrullinated protein antibodies (ACPA) as a marker of systemic autoimmunity associated with RA in a high-risk population, an ongoing cohort of first-degree relatives of patients with RA. We assessed the presence of ACPA in individuals without clinical evidence of RA. We examined characteristics associated with ACPA positivity using general estimation equations to account for multiple observations per individual. A total of 1159 serum samples from 1025 subjects were analyzed, 69 samples (6%) were ACPA-positive, and 227 (20%) positive for rheumatoid factor. Participants had a median age of 45 years (interquartile range (IQR): 33-55) at baseline and 76% were women. Overall, ACPA positivity increased with age (p < 0.001). Among women, ACPA positivity was particularly associated with the age group 45 to 55 years (p = 0.003), but not among men (p = 0.7). In multivariable adjusted analyses, age older than 45, female sex and tobacco smoking were independently associated with ACPA positivity. In our cohort, the presence of ACPA was associated with older age and peaked in women around age 45 to 55 years, the perimenopausal period, suggesting that the development of ACPA may be favored by the decline in ovarian function.

Elevated serum levels of free interleukin-18 in adult-onset Still's disease.

OBJECTIVE: IL-18 is a pro-inflammatory cytokine of the IL-1 family that is naturally inhibited by IL-18 binding protein (IL-18BP). High levels of IL-18 have been described in the serum of adult-onset Still's disease (AOSD) patients, but only total IL-18 levels (including inactive IL-18 bound to IL-18BP) have been measured. With a specific immunoassay, we aimed to measure free IL-18 serum levels in AOSD patients and other rheumatic diseases. METHODS: An ELISA was developed to measure free IL-18. Its sensitivity and specificity were tested by spiking recombinant IL-18 or IL-18BP in serum and PBS supplemented with 5% BSA. The binding affinity of IL-18 to IL-18BP was calculated by titration experiments using the ELISA and by Biacore analysis. Sera of 37 AOSD patients and 138 controls (40 healthy controls, 30 RA, 29 SLE, 21 AS and 18 PsA) were assayed for free IL-18, IL-18BP, total IL-18 and other cytokines. Correlations were performed between free IL-18 and markers of disease activity in AOSD patients. RESULTS: Free IL-18 serum levels were significantly higher in AOSD patients (median 8.89 pg/ml) than in healthy and disease controls (1.37 pg/ml; P < 0.01). Free IL-18 serum levels correlated with AOSD activity. The affinity of IL-18 to IL-18BP was found to be much higher than previously described, with a dissociation constant ranging from 30 to 50 pM. CONCLUSION: Free IL-18 levels are specifically elevated in AOSD compared with other inflammatory diseases, suggesting that IL-18 represents a potential target for the treatment of AOSD.

Adipokines correlate with pain in lower limb osteoarthritis: different associations in hip and knee.

PURPOSE: Our aim was to investigate whether serum and synovial-fluid (SF) concentrations of interleukin-6 (IL-6), leptin, adiponectin, resistin or visfatin are associated with joint pain in hip and knee in end-stage osteoarthritis (OA). METHODS: A cross-sectional study assessing patients with hip and knee OA undergoing total joint arthroplasty between January and December 2010 was conducted at a large university hospital. Serum and SF cytokine and adipokine concentrations were determined in samples obtained on the day of surgery. The main outcome was pain severity measured pre-operatively using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and visual analogue scale (VAS) pain scores. RESULTS: A total of 206 patients were involved (112 with hip and 94 with knee OA). Median age was 72 years [interquartile range (IQR) 66-79], 59% were women. All adipokine levels were significantly higher in the SF of hip joints than in that of knee joints, except for leptin, which tended to be higher in the knee. In both hip and knee OA, median serum concentrations of leptin, adiponectin, resistin and visfatin exceeded those in SF, whereas for IL-6, median concentrations were much higher in SF than in serum. In hip OA, worse pain was significantly associated with high SF concentrations of IL-6, visfatin and leptin; in knee OA, it was associated with high SF leptin and low SF adiponectin concentrations and a low adiponectin-leptin ratio. CONCLUSION: Our findings support a connection between intra-articular concentrations of several adipokines and severity of preoperative OA pain. However, the specific adipokines differed by joints: in hip OA, pain was associated with IL-6 and visfatin and in knee OA with adiponectin; leptin played a role in both hip and knee OA.

In Black Africans with rheumatoid arthritis, ACPA recognize citrullinated fibrinogen and the derived peptides α36-50Cit38,42 and ß60-74Cit60,72,74, like in Caucasians.

Well documented in Caucasians and Asians, the diagnostic value of anti-CCP2 antibodies has been confirmed in Black African populations. However, autoantibodies to other citrullinated peptides/proteins and their fine specificities have not yet been studied. Here, we show that in Cameroonian patients, anti-citrullinated fibrinogen autoantibodies (AhFibA) are sensitive (73%) diagnostic markers for RA. We also determine that autoantibodies directed to α36-50Cit38,42 or ß60-74Cit60,72,74 peptides which bear the immunodominant epitopes of citrullinated fibrin, are present in similar proportions in Black Africans and Caucasians with 25/56 (45%) and 41/56 (73%) positive RA-sera in Cameroonians, respectively. They also account for almost all the AhFibA reactivities since 38/41 (93%) AhFibA-positive sera contain anti-α36-50Cit38,42 and/or anti-ß60-74Cit60,72,74 autoantibodies. Finally, HLA-DRB1 SE alleles were associated with higher titres of AhFibA and anti-ß60-74Cit60,72,74 autoantibodies. In the genetic and environmental backgrounds of Black Africans, AhFibA are a hallmark of RA like in Caucasians, moreover they recognize the same fibrin epitopes.

Myeloid-related proteins 8 and 14 contribute to monosodium urate monohydrate crystal-induced inflammation in gout.

OBJECTIVE: Monosodium urate monohydrate (MSU) crystal-induced interleukin-1ß (IL-1ß) secretion is a critical factor in the pathogenesis of gout. However, without costimulation by a proIL-1ß-inducing factor, MSU crystals alone are insufficient to induce IL-1ß secretion. The responsible costimulatory factors that act as a priming endogenous signal in vivo are not yet known. We undertook this study to analyze the costimulatory properties of myeloid-related protein 8 (MRP-8) and MRP-14 (endogenous Toll-like receptor 4 [TLR-4] agonists) in MSU crystal-induced IL-1ß secretion and their relevance in gout. METHODS: MRP-8/MRP-14 was measured in paired serum and synovial fluid samples by enzyme-linked immunosorbent assay (ELISA) and localized in synovial tissue from gout patients by immunohistochemistry. Serum levels were correlated with disease activity, and MSU crystal-induced release of MRPs from human phagocytes was measured. Costimulatory effects of MRP-8 and MRP-14 on MSU crystal-induced IL-1ß secretion from phagocytes were analyzed in vitro by ELISA, Western blotting, and polymerase chain reaction. The impact of MRP was tested in vivo in a murine MSU crystal-induced peritonitis model. RESULTS: MRP-8/MRP-14 levels were elevated in the synovium, tophi, and serum of patients with gout and correlated with disease activity. MRP-8/MRP-14 was released by MSU crystal-activated phagocytes and increased MSU crystal-induced IL-1ß secretion in a TLR-4-dependent manner. Targeted deletion of MRP-14 in mice led to a moderately reduced response of MSU crystal-induced inflammation in vivo. CONCLUSION: MRP-8 and MRP-14, which are highly expressed in gout, are enhancers of MSU crystal-induced IL-1ß secretion in vitro and in vivo. These endogenous TLR-4 ligands released by activated phagocytes contribute to the maintenance of inflammation in gout.

Do synovial leptin levels correlate with pain in end stage arthritis?

PURPOSE: We evaluated whether synovial fluid (SF) leptin concentrations correlate with pain severity in patients with hip or knee endstage osteoarthritis (OA) and whether they mediate the association between increased joint pain and (1) female gender and (2) obesity. METHODS: We conducted a cross-sectional study including patients with primary hip and knee OA undergoing joint replacement between January and December 2010. SF leptin concentrations obtained on the day of surgery were assessed. Main outcome was pain severity measured pre-operatively using WOMAC and VAS pain scales. RESULTS: A total of 219 patients were included, 123 hip and 96 knee arthroplasties. Mean age was 72 years, 59% were women. Mean SF leptin levels were 22.9 (±25.6) ng/ml in women and 5.4 (±5.9) ng/ml in men. Levels >19.6 ng/ml (highest quartile) were significantly associated with increased pain on both WOMAC (mean difference -9.6, 95% CI -15.1 to -4.0) and VAS scale (mean difference 0.8, 95% CI 0.2-1.3). Associations remained unchanged after adjusting for age, co-morbidities, contra-lateral arthritic joint, OA site, and disability. The associations observed between increased pain and female gender or obesity were substantially reduced after adjusting for SF leptin. CONCLUSION: Joint pain is associated with SF leptin concentrations. Increased pre-operative pain observed in women and obese may be related to high intra-articular leptin levels.

Investigation of Caucasian rheumatoid arthritis susceptibility loci in African patients with the same disease.

INTRODUCTION: The largest genetic risk to develop rheumatoid arthritis (RA) arises from a group of alleles of the HLA DRB1 locus ('shared epitope', SE). Over 30 non-HLA single nucleotide polymorphisms (SNPs) predisposing to disease have been identified in Caucasians, but they have never been investigated in West/Central Africa. We previously reported a lower prevalence of the SE in RA patients in Cameroon compared to European patients and aimed in the present study to investigate the contribution of Caucasian non-HLA RA SNPs to disease susceptibility in Black Africans. METHODS: RA cases and controls from Cameroon were genotyped for Caucasian RA susceptibility SNPs using Sequenom MassArray technology. Genotype data were also available for 5024 UK cases and 4281 UK controls and for 119 Yoruba individuals in Ibadan, Nigeria (YRI, HapMap). A Caucasian aggregate genetic-risk score (GRS) was calculated as the sum of the weighted risk-allele counts. RESULTS: After genotyping quality control procedures were performed, data on 28 Caucasian non-HLA susceptibility SNPs were available in 43 Cameroonian RA cases and 44 controls. The minor allele frequencies (MAF) were tightly correlated between Cameroonian controls and YRI individuals (correlation coefficient 93.8%, p = 1.7E-13), and they were pooled together. There was no correlation between MAF of UK and African controls; 13 markers differed by more than 20%. The MAF for markers at PTPN22, IL2RA, FCGR2A and IL2/IL21 was below 2% in Africans. The GRS showed a strong association with RA in the UK. However, the GRS did not predict RA in Africans (OR = 0.71, 95% CI 0.29 - 1.74, p = 0.456). Random sampling from the UK cohort showed that this difference in association is unlikely to be explained by small sample size or chance, but is statistically significant with p<0.001. CONCLUSIONS: The MAFs of non-HLA Caucasian RA susceptibility SNPs are different between Caucasians and Africans, and several polymorphisms are barely detectable in West/Central Africa. The genetic risk of developing RA conferred by a set of 28 Caucasian susceptibility SNPs is significantly different between the UK and Africa with p<0.001. Taken together, these observations strengthen the hypothesis that the genetic architecture of RA susceptibility is different in different ethnic backgrounds.

Evaluation of cardiovascular risk in patients with rheumatoid arthritis: do cardiovascular biomarkers offer added predictive ability over established clinical risk scores?

OBJECTIVE: To determine whether adding C-reactive protein, anti-cyclic citrullinated peptide antibodies, rheumatoid factor, N-terminal pro-brain natriuretic peptide (NT-proBNP), oxidized low-density lipoprotein (ox-LDL), or anti-apolipoprotein A-I (anti-Apo A-I) IgG to the Framingham 10-year cardiovascular (CV) risk score (FRS) could improve its CV prognostic accuracy in rheumatoid arthritis (RA). METHODS: We performed an ancillary study derived from a prospective single-center cohort consisting of 118 RA patients without CV disease at baseline. The FRS and the various biomarkers were assessed at enrollment and their prognostic accuracy was determined using receiver operating characteristic (ROC) curve analysis. The incremental predictive ability of biomarkers was assessed using the integrated discrimination improvement (IDI) statistics. RESULTS: During a median followup period of 9 years, the incidence of CV events was 16%. Both the FRS and 3 of the biomarkers (NT-proBNP, ox-LDL, and anti-Apo A-I) were significant predictors of subsequent CV events (area under the ROC curve [AUC] between 0.68 and 0.73). Anti-Apo A-I was the only biomarker to significantly improve the prognostic ability of the FRS, with AUCs increasing from 0.72 to 0.81 and the IDI improving by 175% (P < 0.001). CONCLUSION: Among the biomarkers tested, only anti-Apo A-I significantly improved the FRS predictive ability.

Distinct serum and synovial fluid interleukin (IL)-33 levels in rheumatoid arthritis, psoriatic arthritis and osteoarthritis.

OBJECTIVES: Recent evidence suggests a role for interleukin (IL)-33 and its receptor ST2 in arthritis. In this study, we quantified IL-33 and soluble (s)ST2 levels in serum and synovial fluid (SF), and assessed synovial IL-33 expression levels and pattern in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), or osteoarthritis (OA). METHODS: Serum and SF IL-33 and sST2 levels were assessed by ELISA. IL-33 mRNA was quantified by RT-qPCR. Synovial IL-33 protein expression pattern was examined by immunohistochemistry. RESULTS: Serum and SF IL-33 levels tended to be higher in RA than in OA patients. In contrast to RA, IL-33 was not detectable in PsA serum and SF. Serum sST2 levels were higher in RA than in OA. There was a wide variation of synovial tissue IL-33 mRNA expression within each disease group and IL-33 mRNA levels were not significantly different between the groups. A similar IL-33 protein expression pattern was observed in RA, PsA and OA synovium, with strong nuclear expression of IL-33 in endothelial cells and, in a subset of RA, PsA and OA patients, in cells morphologically consistent with synovial fibroblasts. DISCUSSION/CONCLUSIONS: This study confirms increased circulating IL-33 levels in RA. In addition, we report that IL-33 is undetectable in the serum or SF of PsA patients. Local expression of IL-33 in the synovium was observed at similar variable levels in RA, PsA and OA, suggesting that inflamed joints do not represent the primary source of elevated serum and SF levels of IL-33 in RA.

Chlamydia trachomatis heat shock proteins 60 and 10 induce apoptosis in endocervical epithelial cells.

AIM AND OBJECTIVE: The potential role of chlamydial heat shock proteins (cHSP) 60 and cHSP10 in apoptosis of primary cervical epithelial cells was investigated. METHODS: Primary cervical epithelial cells were stimulated with cHSP60 and cHSP10 for 4 h. Quantitative measurements of apoptosis were made using cytofluorometry, and apoptosis-related genes were analyzed by microarray, real-time PCR and western blotting. Further, levels of proinflammatory cytokines (IL-18 and IL-1ß) were determined by semi-quantitative RT-PCR. RESULTS: After a 4-h incubation in the presence of recombinant cHSP60 or cHSP10, the number of cells exhibiting annexin V binding activity increased 6- and 5-fold, respectively (P < 0.05). A DNA microarray study showed significant (P < 0.05) upregulation of interleukin (IL)-1 ß-convertase, and caspase-3, -8 and -9 genes in cHSP60- and cHSP10-stimulated than in control cells as confirmed by real-time RT-PCR and western blotting. Transcript levels of IL-1ß and IL-18 in cells treated with cHSP60 and cHSP10 were found to be significantly (P < 0.05) higher in stimulated than in control cells. CONCLUSION: cHSP60- and cHSP10-induced caspase expression, proinflammatory cytokine production and apoptosis of primary cervical epithelial cells might play a role in the pathogenesis of infertility in women with persistent chlamydial infection.

Spontaneous secretion of interleukin-17 and -22 by human cervical cells in Chlamydia trachomatis infection.

To investigate whether IL-17A (IL-17) and IL-22 are produced in response to Chlamydia trachomatis infection, the cervical washes of 27 women with C. trachomatis infection and 17 C. trachomatis negative controls were collected. The levels of cytokines were determined in the cervical wash and in the supernatant of cervical and systemic cell cultures upon C. trachomatis antigen stimulation. C. trachomatis infection appeared to activate local IL-17 and IL-22 production more efficiently than IFN-γ production. In the cervical wash of infected women, median concentrations of IL-17 and -22 were 5- and 3-fold higher, respectively, than in negative controls. The spontaneous intracellular expression of these cytokines was analysed by flow cytometry in blood and cervical cells and 26% of cervical mononuclear cells from infected women were shown to produce IL-22 and 12% to coproduce IL-17 and IL-22. In addition, it was demonstrated that 20-25% of IL-22 producing and IL-17-IL-22 coproducing cervical CD4+ T cells expressed the mucosal homing receptor CCR6. These results suggest that CCR6 is involved in the migration of these cells to the cervix and that IL-17 and IL-22 might play a role in the immune response at the site of C. trachomatis infection.

Serum lipoproteins attenuate macrophage activation and Toll-Like Receptor stimulation by bacterial lipoproteins.

BACKGROUND: Chlamydia trachomatis was previously shown to express a lipoprotein, the macrophage infectivity potentiator (Mip), exposed at the bacterial surface, and able to stimulate human primary monocytes/macrophages through Toll Like Receptor (TLR)2/TLR1/TLR6, and CD14. In PMA-differentiated THP-1 cells the proinflammatory activity of Mip was significantly higher in the absence than in the presence of serum. The present study aims to investigate the ability of different serum factors to attenuate Mip proinflammatory activity in PMA-differentiated THP-1 cells and in primary human differentiated macrophages. The study was also extend to another lipoprotein, the Borrelia burgdorferi outer surface protein (Osp)A. The proinflammatory activity was studied through Tumor Necrosis Factor alpha (TNF-α) and Interleukin (IL)-8 release. Finally, TLR1/2 human embryonic kidney-293 (HEK-293) transfected cells were used to test the ability of the serum factors to inhibit Mip and OspA proinflammatory activity. RESULTS: In the absence of any serum and in the presence of 10% delipidated FBS, production of Mip-induced TNF-α and IL-8 in PMA-differentiated THP-1 cells were similar whereas they were significantly decreased in the presence of 10% FBS suggesting an inhibiting role of lipids present in FBS. In the presence of 10% human serum, the concentrations of TNF-α and IL-8 were 2 to 5 times lower than in the presence of 10% FBS suggesting the presence of more potent inhibitor(s) in human serum than in FBS. Similar results were obtained in primary human differentiated macrophages. Different lipid components of human serum were then tested (total lipoproteins, HDL, LDL, VLDL, triglyceride emulsion, apolipoprotein (apo)A-I, B, E2, and E3). The most efficient inhibitors were LDL, VLDL, and apoB that reduced the mean concentration of TNF-α release in Mip-induced macrophages to 24, 20, and 2%, respectively (p < 0.0001). These lipid components were also able to prevent TLR1/2 induced activation by Mip, in HEK-293 transfected cells. Similar results were obtained with OspA. CONCLUSIONS: These results demonstrated the ability of serum lipids to attenuate proinflammatory activity of bacterial lipoproteins and suggested that serum lipoproteins interact with acyl chains of the lipid part of bacterial lipoproteins to render it biologically inactive.

Anti-apolipoprotein A-1 IgG predicts major cardiovascular events in patients with rheumatoid arthritis.

OBJECTIVE: To determine whether anti-apolipoprotein A-1 (anti-Apo A-1) IgG are associated with major cardiovascular events in patients with rheumatoid arthritis (RA). METHODS: We determined anti-Apo A-1 IgG levels and the concentrations of cytokines, oxidized low-density lipoprotein (LDL), and matrix metalloproteinase 1 (MMP-1) MMP-2, MMP-3, and MMP-9 in sera from 133 patients with RA who did not have cardiovascular disease at baseline, all of whom were longitudinally followed up over a median period of 9 years. A major cardiovascular event was defined as a fatal or nonfatal stroke or acute coronary syndrome. The proinflammatory effects of anti-Apo A-1 IgG were assessed on human macrophages in vitro. RESULTS: During followup, the overall incidence of major cardiovascular events was 15% (20 of 133 patients). At baseline, anti-Apo A-1 IgG positivity was 17% and was associated with a higher incidence of major cardiovascular events (adjusted hazard ratio 4.2, 95% confidence interval 1.5-12.1). Patients who experienced a subsequent major cardiovascular event had higher circulating levels of anti-Apo A-1 IgG at baseline compared with those who did not have a major cardiovascular event. Receiver operating curve analysis showed that anti-Apo A-1 IgG was the strongest of all tested biomarkers for the prediction of a subsequent major cardiovascular event, with an area under the curve value of 0.73 (P = 0.0008). At the predefined and previously validated cutoff levels, the specificity and sensitivity of anti-Apo A-1 IgG to predict major cardiovascular events were 50% and 90%, respectively. Anti-Apo A-1 IgG positivity was associated with higher median circulating levels of interleukin-8 (IL-8), oxidized LDL, and MMP-9 and higher proMMP-9 activity as assessed by zymography. On human macrophages, anti-Apo A-1 IgG induced a significant dose-dependent increase in IL-8 and MMP-9 levels and proMMP-9 activity. CONCLUSION: Anti-Apo A-1 IgG is an independent predictor of major cardiovascular events in RA, possibly by affecting vulnerability to atherosclerotic plaque.

Influence of anti-infliximab antibodies and residual infliximab concentrations on the occurrence of acquired drug resistance to infliximab in rheumatoid arthritis patients.

BACKGROUND: Infliximab (IFX) can be immunogenic for humans and lead to the formation of antibodies against IFX (anti-IFX Ab), which could induce acquired IFX resistance. OBJECTIVE: To test whether the presence of anti-IFX Ab and residual circulating IFX levels are associated with acquired IFX resistance in RA. METHODS: A multivariate logistic regression was used to analyze the relationship between anti-IFX Ab, residual IFX concentrations, and acquired IFX resistance in a nested cohort within the Swiss RA registry (SCQM-RA). RESULTS: Sixty-four RA patients on longstanding IFX therapy were included; 24 with an acquired therapeutic resistance to IFX and 40 with continuous good response to IFX. The two groups had similar disease characteristics, but patients with acquired IFX resistance required significantly higher dosage of IFX (5.4 mg/kg versus 4.3 mg/kg, p=0.02) and shorter infusion intervals (7.1 versus 8.7 weeks, p=0.01) than long-term good responders. The presence of residual IFX tended to be associated with a decreased risk of acquired therapeutic resistance (OR 0.4 [95% CI: 0.1-1.5]), while the presence of anti-IFX Ab tended to be associated with an increased risk of acquired therapeutic resistance (OR: 1.8 [95% CI: 0.4 - 9.0]). The presence of either high anti-IFX Ab levels or low residual IFX concentrations was strongly associated with acquired therapeutic resistance to IFX (OR 5.9, 95% CI 1.3 - 26.6). However, just 42% of patients with acquired IFX resistance had either low IFX or high anti-IFX Ab levels. CONCLUSION: These results suggest that the assessment of anti-IFX Ab and residual IFX levels is of limited value for individual patients in routine clinical care.

Diagnostic value of anti-cyclic citrullinated peptides and association with HLA-DRB1 shared epitope alleles in African rheumatoid arthritis patients.

INTRODUCTION: The purpose of this study was to examine the diagnostic performance of autoantibodies against citrullinated peptides/proteins (ACPA) and to determine the prevalence of HLA-DRB1 shared epitope alleles (SE) in African patients with rheumatoid arthritis (RA). METHODS: Serum levels of anti-cyclic citrullinated peptides antibodies (anti-CCP2, anti-CCP3), IgM and IgA rheumatoid factors (RF) were measured by enzyme-linked immunosorbent assay in the serum of 56 consecutive RA patients regularly followed in the Rheumatology Unit of the School of Medicine, University of Yaoundé, Yaoundé, Cameroon. Genotyping of HLA-DRB1 alleles was performed by polymerase chain reaction and hybridization with sequence-specific oligonucleotide probes on microbeads arrays. Fifty-one patients with other inflammatory rheumatic diseases and 50 healthy individuals were included as controls. RESULTS: An anti-CCP2 assay showed the best diagnosis sensitivity (82%) and specificity (98%) with high positive predictive (PPV) (96%) and negative predictive values (NPV) (91%). Thirty percent of RA patients were carrying at least one copy of the HLA-DRB1 shared epitope (SE) compared to 10% and 14% of patients with other inflammatory rheumatic diseases and healthy individuals, respectively. The presence of the SE was associated with the production of ACPA. CONCLUSIONS: Anti-CCP2 antibodies are useful markers of RA in African patients. In this cohort, the prevalence of the SE is higher in RA patients than in controls but lower than that reported in patient cohorts of European ancestry. The discrepancy between the high prevalence of ACPA-positive patients and the relatively low number of SE-positive cases suggest that, in addition to SE, other genetic factors control the development of ACPA in African RA patients.

Cervical epithelial cells from Chlamydia trachomatis-infected sites coexpress higher levels of chlamydial heat shock proteins 60 and 10 in infertile women than in fertile women.

BACKGROUND/AIMS: The objective of the present study was to examine the possible relationship between the chlamydial heat shock proteins (cHSP) 60 and 10 expression and the damaging sequelae of a Chlamydia trachomatis infection, such as infertility. METHODS: Seven fertile and 7 infertile female patients infected with C. trachomatis attending the gynecology outpatient department of Safdarjung hospital (New Delhi, India) were enrolled. The relative transcript levels and intracellular expression of cHSP60 and cHSP10 in cervical cells were assessed using real-time RT-PCR and flow cytometry, respectively. RESULTS: Quantitative real-time RT-PCR analysis showed that transcript levels of both cHSP60 (p = 0.007) and cHSP10 (p = 0.0006) were higher in infertile women than in fertile women. Flow cytometric analysis showed significantly higher intracellular levels of cHSP60 (p = 0.0006) and cHSP10 (p = 0.0041) in fertile women infected with Chlamydia than in infertile women. However, the percentage of double-positive cells (both cHSP60- and cHSP10-expressing cells) were higher (p = 0.0006) in infertile women than in fertile women. CONCLUSION: Our results suggest that cHSP60 and cHSP10 have a different pattern of expression in infertile women compared to fertile women reflecting a probable difference in the metabolic state of Chlamydia with the presence of an abnormal cryptic form of C. trachomatis in infertile women.

In infertile women, cells from Chlamydia trachomatis infected sites release higher levels of interferon-gamma, interleukin-10 and tumor necrosis factor-alpha upon heat-shock-protein stimulation than fertile women.

BACKGROUND: The magnitude of reproductive morbidity associated with sexually transmitted Chlamydia trachomatis infection is enormous. Association of antibodies to chlamydial heat shock proteins (cHSP) 60 and 10 with various disease sequelae such as infertility or ectopic pregnancy has been reported. Cell-mediated immunity is essential in resolution and in protection to Chlamydia as well as is involved in the immunopathogenesis of chlamydial diseases. To date only peripheral cell mediated immune responses have been evaluated for cHSP60. These studies suggest cHSPs as important factors involved in immunopathological condition associated with infection. Hence study of specific cytokine responses of mononuclear cells from the infectious site to cHSP60 and cHSP10 may elucidate their actual role in the cause of immunopathogenesis and the disease outcome. METHODS: Female patients (n = 368) attending the gynecology out patient department of Safdarjung hospital, New Delhi were enrolled for the study and were clinically characterized into two groups; chlamydia positive fertile women (n = 63) and chlamydia positive infertile women (n = 70). Uninfected healthy women with no infertility problem were enrolled as controls (n = 39). cHSP60 and cHSP10 specific cytokine responses (Interferon (IFN)-gamma, Interleukin (IL)-10, Tumor Necrosis Factor (TNF)-alpha, IL-13 and IL-4) were assessed by ELISA in stimulated cervical mononuclear cell supernatants. RESULTS: cHSP60 and cHSP10 stimulation results in significant increase in IFN-gamma (P = 0.006 and P = 0.04 respectively) and IL-10 levels (P = 0.04) in infertile group as compared to fertile group. A significant cHSP60 specific increase in TNF-alpha levels (P = 0.0008) was observed in infertile group as compared to fertile group. cHSP60 and cHSP10 specific IFN-gamma and IL-10 levels were significantly correlated (P < 0.0001, r = 0.54 and P = 0.004, r = 0.33 respectively) in infertile group. CONCLUSION: Our results suggest that exposure to chlamydial heat shock proteins (cHSP60 and cHSP10) could significantly affect mucosal immune function by increasing the release of IFN-gamma, IL-10 and TNF-alpha by cervical mononuclear cells.

The proinflammatory cytokine response to Chlamydia trachomatis elementary bodies in human macrophages is partly mediated by a lipoprotein, the macrophage infectivity potentiator, through TLR2/TLR1/TLR6 and CD14.

Chlamydiae components and signaling pathway(s) responsible for the production of proinflammatory cytokines by human monocytes/macrophages are not clearly identified. To this aim, Chlamydia trachomatis-inactivated elementary bodies (EB) as well as the following seven individual Ags were tested for their ability to induce the production of proinflammatory cytokines by human monocytes/macrophages and THP-1 cells: purified LPS, recombinant heat shock protein (rhsp)70, rhsp60, rhsp10, recombinant polypeptide encoded by open reading frame 3 of the plasmid (rpgp3), recombinant macrophage infectivity potentiator (rMip), and recombinant outer membrane protein 2 (rOmp2). Aside from EB, rMip displayed the highest ability to induce release of IL-1beta, TNF-alpha, IL-6, and IL-8. rMip proinflammatory activity could not be attributed to Escherichia coli LPS contamination as determined by the Limulus Amoebocyte lysate assay, insensitivity to polymyxin B (50 microg/ml), and different serum requirement. We have recently demonstrated that Mip is a "classical" bacterial lipoprotein, exposed at the surface of EB. The proinflammatory activity of EB was significantly attenuated in the presence of polyclonal Ab to rMip. Native Mip was able to induce TNF-alpha and IL-8 secretion, whereas a nonlipidated C20A rMip variant was not. Proinflammatory activity of rMip was unaffected by heat or proteinase K treatments but was greatly reduced by treatment with lipases, supporting a role of lipid modification in this process. Stimulating pathways appeared to involve TLR2/TLR1/TLR6 with the help of CD14 but not TLR4. These data support a role of Mip lipoprotein in pathogenesis of C. trachomatis-induced inflammatory responses.