Simplified Disease Activity Index remission at month 6 is an independent predictor of functional and structural remissions at month 12 during abatacept treatment in patients with rheumatoid arthritis: A multi-center, prospective cohort study in Japan.

OBJECTIVE: To evaluate association of clinical remission at month 6 with functional and structural remissions at month 12 during abatacept treatment in patients with rheumatoid arthritis (RA). METHODS: This 12-month prospective, multicenter cohort study enrolled 168 patients with RA who started abatacept. Outcomes were assessed using composite measures, quality of life indices, and the van der Heijde-modified total Sharp score (mTSS). The logistic regression analysis was applied to identify factors associated with outcomes and their odds ratios (OR) with 95% confidence interval (95% CI). RESULTS: At month 6 and 12, 21.4% and 26.2% of the patients achieved Simplified Disease Activity Index (SDAI) remission (SDAI <3.3), and 40.6% and 41.7% achieved Health Assessment Questionnaire-Disability Index (HAQ-DI <0.5) remission. Among 129 patients whose mTSS progression was evaluated at month 12, 83 (64.3%) achieved structural remission (ΔmTSS ≤0.5 for 12 months). SDAI remission at month 6 was identified as a significant predictor of both functional (OR, 3.732; 95% CI, 1.328-10.489) and structural remissions (OR, 4.301; 95% CI, 1.298-14.243) at month 12 after adjusting for covariates. CONCLUSIONS: Aiming for SDAI remission at month 6 is an appropriate strategy to obtain good functional and structural outcomes at month 12.

Risk for malignancy in rheumatoid arthritis patients treated with biological disease-modifying antirheumatic drugs compared to the general population: A nationwide cohort study in Japan.

OBJECTIVES: To investigate and compare the risk for malignancy in rheumatoid arthritis (RA) patients treated with biologics in Japan to the general population. METHODS: Data for 14,440 patients from 335 institutions who were given infliximab, etanercept, adalimumab, golimumab, tocilizumab, or abatacept were retrieved from the SafEty of biologics in Clinical Use in Japanese patients with RhEumatoid arthritis (SECURE) database. RESULTS: We identified 333 incidents of malignancies in 320 patients during 49,320 patient-years (PY). The age- and sex-standardized incidence rate (ASR) (95% confidence interval [CI]) for overall malignancy of the SECURE cohort was 313.9/10(5) PY (271.4-361.3), and the standardized incidence rate ratio (SIR) (95% CI) was 0.745 (0.667-0.826). The ASR was decreased compared to the estimated incidence rate of malignancies in the Japanese general population (462.4/10(5) PY). The SIRs for site-specific nonhematopoietic malignancies of the SECURE cohort were not significantly elevated compared to the Japanese general population. A significant increase of SIR for malignant lymphoma (6.183, 95% CI, 4.809-7.643) was found in the SECURE cohort, similar to or slightly higher than the SIR previously reported from Japanese cohorts for RA patients. CONCLUSIONS: Continued vigilance with larger numbers of patients, longer observation periods, and inclusion of different biologics are recommended.

Head-to-head comparison of the safety of tocilizumab and tumor necrosis factor inhibitors in rheumatoid arthritis patients (RA) in clinical practice: results from the registry of Japanese RA patients on biologics for long-term safety (REAL) registry.

INTRODUCTION: The objective of this study was to directly compare the safety of tocilizumab (TCZ) and TNF inhibitors (TNFIs) in rheumatoid arthritis (RA) patients in clinical practice. METHODS: This prospective cohort study included RA patients starting TCZ [TCZ group, n=302, 224.68 patient-years (PY)] or TNFIs [TNFI group, n=304, 231.01 PY] from 2008 to 2011 in the registry of Japanese RA patients on biologics for long-term safety registry. We assessed types and incidence rates (IRs) of serious adverse events (SAEs) and serious infections (SIs) during the first year of treatment. Risks of the biologics for SAEs or SIs were calculated using the Cox regression hazard analysis. RESULTS: Patients in the TCZ group had longer disease duration (P<0.001), higher disease activity (P=0.019) and more frequently used concomitant corticosteroids (P<0.001) than those in the TNFI group. The crude IR (/100 PY) of SIs [TCZ 10.68 vs. TNFI 3.03; IR ratio (95% confidence interval [CI]), 3.53 (1.52 to 8.18)], but not SAEs [21.36 vs. 14.72; 1.45 (0.94 to 2.25)], was significantly higher in the TCZ group compared with the TNFI group. However, after adjusting for covariates using the Cox regression hazard analysis, treatment with TCZ was not associated with higher risk for SAEs [hazard ratio (HR) 1.28, 95% CI 0.75 to 2.19] or SIs (HR 2.23, 95% CI 0.93 to 5.37). CONCLUSIONS: The adjusted risks for SAEs and SIs were not significantly different between TCZ and TNFIs, indicating an influence of clinical characteristics of the patients on the safety profile of the biologics in clinical practice.

Assessment of risks of pulmonary infection during 12 months following immunosuppressive treatment for active connective tissue diseases: a large-scale prospective cohort study.

OBJECTIVE: Pulmonary infections (PI) are leading causes of death in patients with connective tissue diseases (CTD). The PREVENT study (Pulmonary infections in patients REceiving immunosuppressiVE treatmeNT for CTD) assessed risk of PI in patients with active CTD in the contemporary era of advanced immunosuppressive therapy. METHODS: In patients who started corticosteroids (n = 763), conventional immunosuppressants or biologics for active CTD were enrolled. Clinical and laboratory data, usage of drugs, and occurrence of PI were collected for 12 months. Baseline risk factors were investigated using Cox regression analysis. A nested case-control (NCC) study was performed with 1:2 matched case-control pairs to assess the risk for each drug category. RESULTS: During the observation period, 32 patients died (4.2%) and 66 patients were lost to followup (8.6%). Patients with PI (n = 61, 8%) had a significantly worse accumulated survival rate than patients without (p < 0.01). Cox hazard regression analysis using baseline data showed that these factors were significantly associated with PI: age ≥ 65 years (HR 3.87, 95% CI 2.22-6.74), ≥ 20 pack-years of smoking (2.63, 1.37-5.04), higher serum creatinine level (1.21, 1.05-1.41 per 1.0 mg/dl increase), and maximum prednisolone (PSL) dose during the first 2 weeks of treatment (2.81, 1.35-5.86 per 1.0 mg/kg/day increase). Logistic regression analysis by an NCC study revealed that maximum PSL dose within 14 days before PI (OR 4.82, 95% CI 1.36-17.01 per 1.0 mg/dl increase; 2.57, 1.28-5.16 if ≥ 0.5 mg/kg/day) was significantly associated with the events, while other immunosuppressants were not. CONCLUSION: Physicians should be aware of the higher risks for corticosteroids of PI than other immunosuppressants and assess these risk factors before immunosuppressive treatment, to prevent PI.

Pulmonary infections following immunosuppressive treatments during hospitalization worsen the short-term vital prognosis for patients with connective tissue disease-associated interstitial pneumonia.

OBJECTIVE: Connective tissue disease-associated interstitial pneumonia (CTD-IP) significantly affects the mortality of patients with CTD. The purpose of the present study is to identify causes and risk factors for death during hospitalization for immunosuppressive treatment of CTD-IP. METHODS: A multicenter, retrospective study was conducted that collected data from patients with CTD who had been hospitalized for commencing or intensifying immunosuppressive treatment of CTD-IP using a standardized case report form. Risk factors were identified using the Cox proportional hazard regression model. RESULTS: A total of 322 CTD-IP patients were enrolled with rheumatoid arthritis (n = 84), systemic lupus erythematosus (n = 13), polymyositis (n = 33), dermatomyositis (n = 69), systemic sclerosis (n = 55), mixed connective tissue disease (n = 21), microscopic polyangiitis (n = 19), and overlap syndrome (n = 28). Of the 42 patients who died during hospitalization, 22 died from CTD-IP, 15 from CTD-IP and pulmonary infection, 2 from pulmonary infection, and 3 from other causes. Age ≥ 65 years and development of pulmonary infections after commencing or intensifying immunosuppressive treatments were identified as risk factors for death during hospitalization after adjusting for covariates. CONCLUSION: Careful consideration of the benefit-risk balance of immunosuppressive treatment for CTD-IP is indispensable for improving the short-term vital prognosis of these patients.

Successful treatment of eosinophilic granulomatosis with polyangiitis (EGPA; formerly Churg-Strauss syndrome) with rituximab in a case refractory to glucocorticoids, cyclophosphamide, and IVIG.

A 44-year old woman with eosinophilic granulomatosis with polyangiitis (EGPA) developed sequential paralysis of different cranial nerves despite treatments including methylpredonisolone pulse therapy, intravenous immunoglobulins (IVIG), and cyclophosphamide. Infusions of rituximab ameliorated her neurological symptoms and serological inflammatory findings. Rituximab, a specific B cell-targeting therapy, might offer an alternative for refractory EGPA with possible advantages of cost and ease of use compared to IVIG, which also targets (at least in part) B lymphocytes and immunoglobulin production.

Clinical characteristics and risk factors for Pneumocystis jirovecii pneumonia in patients with rheumatoid arthritis receiving adalimumab: a retrospective review and case-control study of 17 patients.

OBJECTIVES: To investigate the clinical characteristics and risk factors of Pneumocystis jirovecii pneumonia (PCP) in rheumatoid arthritis (RA) patients treated with adalimumab. METHODS: We conducted a multicenter, retrospective, case-control study to compare RA patients treated with adalimumab with and without PCP. Data from 17 RA patients who were diagnosed with PCP and from 89 RA patients who did not develop PCP during adalimumab treatment were collected. RESULTS: For the PCP patients, the median age was 68 years old, with a median RA disease duration of eight years. The median length of time from the first adalimumab injection to the development of PCP was 12 weeks. At the onset of PCP, the median dosages of prednisolone and methotrexate were 5.0 mg/day and 8.0 mg/week, respectively. The patients with PCP were significantly older (p < 0.05) and had more structural changes (p < 0.05) than the patients without PCP. Computed tomography of the chest revealed ground-glass opacity without interlobular septal boundaries in the majority of the patients with PCP. Three PCP patients died. CONCLUSIONS: PCP may occur early in the course of adalimumab therapy in patients with RA. Careful monitoring, early diagnosis, and proper management are mandatory to secure a good prognosis for these patients.

Drug retention rates and relevant risk factors for drug discontinuation due to adverse events in rheumatoid arthritis patients receiving anticytokine therapy with different target molecules.

OBJECTIVE: To compare reasons for discontinuation and drug retention rates per reason among anticytokine therapies, infliximab, etanercept and tocilizumab, and the risk of discontinuation of biological agents due to adverse events (AE) in patients with rheumatoid arthritis (RA). METHOD: This prospective cohort study included Japanese RA patients who started infliximab (n=412, 636.0 patient-years (PY)), etanercept (n=442, 765.3 PY), or tocilizumab (n=168, 206.5 PY) as the first biological therapy after their enrolment in the Registry of Japanese Rheumatoid Arthritis Patients for Long-term Safety (REAL) database. Drug retention rates were calculated using the Kaplan-Meier method. To compare risks of drug discontinuation due to AE for patients treated with these biological agents, the Cox proportional hazard model was applied. RESULTS: The authors found significant differences among the three therapeutic groups in demography, clinical status, comorbidities and usage of concomitant drugs. Development of AE was the most frequent reason for discontinuation of biological agents in the etanercept and tocilizumab groups, and the second most frequent reason in the infliximab group. Discontinuation due to good control was observed most frequently in the infliximab group. Compared with etanercept, the use of infliximab (HR 1.69; 95% CI 1.14 to 2.51) and tocilizumab (HR 1.98; 95% CI 1.04 to 3.76) was significantly associated with a higher risk of discontinuation of biological agents due to AE. CONCLUSIONS: Reasons for discontinuation are significantly different among biological agents. The use of infliximab and tocilizumab was significantly associated with treatment discontinuation due to AE compared with etanercept.

Time-dependent increased risk for serious infection from continuous use of tumor necrosis factor antagonists over three years in patients with rheumatoid arthritis.

OBJECTIVE: To investigate associations between continuous treatments with tumor necrosis factor (TNF) antagonists and risk for developing serious infections (SIs) over 3 years in Japanese patients with rheumatoid arthritis (RA) enrolled in the Registry of Japanese RA Patients for Long-Term Safety (REAL) database. METHODS: We analyzed 727 RA patients who had started either infliximab or etanercept (the anti-TNF group; 1,480.1 patient-years [PY]) and 571 RA patients who had started conventional nonbiologic disease-modifying antirheumatic drugs (the unexposed group; 1,104.1 PY) at the time of enrollment in the REAL. We assessed the occurrence of SIs within a 3-year observation period, including the period after switching to other TNF antagonists, and all SIs, unlimited to the first one in each patient as reported in other studies, to evaluate the real safety of TNF antagonists in daily practice. RESULTS: The incidence rate of SIs per 100 PY was 5.54 (95% confidence interval [95% CI] 4.44-6.84) in the anti-TNF group and 2.72 (95% CI 1.87-3.83) in the unexposed group. Poisson regression analysis revealed that the relative risk (RR) of continuous use of TNF antagonists for SIs after adjusting for baseline and time-dependent covariates was significantly elevated both overall (1.97, 95% CI 1.25-3.19) and for the first year (2.40, 95% CI 1.20-5.03), but not for the second and third years combined (1.38, 95% CI 0.80-2.43). The adjusted RR for SIs of etanercept compared to infliximab was not significantly elevated. CONCLUSION: Continuous anti-TNF therapy was significantly associated with increased risks for developing SIs during, but not after, the first year.

Pneumocystis jirovecii pneumonia associated with etanercept treatment in patients with rheumatoid arthritis: a retrospective review of 15 cases and analysis of risk factors.

OBJECTIVES: The association of anti-tumor necrosis factor therapy with opportunistic infections in rheumatoid arthritis (RA) patients has been reported. The goal of this study was to clarify the clinical characteristics and the risk factors of RA patients who developed Pneumocystis jirovecii pneumonia (PCP) during etanercept therapy. METHODS: We conducted a multicenter, case-control study in which 15 RA patients who developed PCP were compared with 74 RA patients who did not develop PCP during etanercept therapy. RESULTS: PCP developed within 26 weeks following the first injection of etanercept in 86.7% of the patients. All PCP patients presented with a rapid and severe clinical course and the overall mortality was 6.7%. Independent risk factors were identified using multivariate analysis and included age ≥65 years [hazard ratio (HR) 3.35, p = 0.037], coexisting lung disease (HR 4.48, p = 0.009), and concomitant methotrexate treatment (HR 4.68, p = 0.005). In patients having a larger number of risk factors, the cumulative probability of developing PCP was significantly higher (p < 0.001 for patients with two or more risk factors vs. those with no risk factor, and p = 0.001 for patients with one risk factor vs. those with no risk factor). CONCLUSION: Physicians must consider the possibility of PCP developing during etanercept therapy in RA patients, particularly if one or more risk factors are present.

Pneumocystis jirovecii pneumonia associated with etanercept treatment in patients with rheumatoid arthritis: a retrospective review of 15 cases and analysis of risk factors.

Objectives The association of anti-tumor necrosis factor therapy with opportunistic infections in rheumatoid arthritis (RA) patients has been reported. The goal of this study was to clarify the clinical characteristics and the risk factors of RA patients who developed Pneumocystis jirovecii pneumonia (PCP) during etanercept therapy. Methods We conducted a multicenter, case-control study in which 15 RA patients who developed PCP were compared with 74 RA patients who did not develop PCP during etanercept therapy. Results PCP developed within 26 weeks following the first injection of etanercept in 86.7% of the patients. All PCP patients presented with a rapid and severe clinical course and the overall mortality was 6.7%. Independent risk factors were identified using multivariate analysis and included age ≥ 65 years [hazard ratio (HR) 3.35, p = 0.037], coexisting lung disease (HR 4.48, p = 0.009), and concomitant methotrexate treatment (HR 4.68, p = 0.005). In patients having a larger number of risk factors, the cumulative probability of developing PCP was significantly higher (p < 0.001 for patients with two or more risk factors vs. those with no risk factor, and p = 0.001 for patients with one risk factor vs. those with no risk factor). Conclusion Physicians must consider the possibility of PCP developing during etanercept therapy in RA patients, particularly if one or more risk factors are present.

Incidence and risk factors for serious infection in patients with rheumatoid arthritis treated with tumor necrosis factor inhibitors: a report from the Registry of Japanese Rheumatoid Arthritis Patients for Longterm Safety.

OBJECTIVE: To compare tumor necrosis factor-α (TNF-α) inhibitors to nonbiological disease-modifying antirheumatic drugs (DMARD) for the risk of serious infection in Japanese patients with rheumatoid arthritis (RA). METHODS: Serious infections occurring within the first year of the observation period were examined using the records for patients recruited to the Registry of Japanese Rheumatoid Arthritis Patients for Longterm Safety (REAL), a hospital-based prospective cohort of patients with RA. The analysis included 1144 patients, 646 of whom were treated with either infliximab or etanercept [exposed group: 592.4 patient-years (PY)]. The remaining 498 patients received nonbiological DMARD with no biologics (unexposed group: 454.7 PY). RESULTS: In the unexposed group, the incidence rate for all serious adverse events (SAE) was 9.02/100 PY and for serious infections, 2.64/100 PY. In the exposed group, SAE occurred in 16.04/100 PY and serious infections in 6.42/100 PY. The crude incidence rate ratio comparing serious infections in the exposed group with the unexposed group was 2.43 (95% CI 1.27-4.65), a significant increase. A multivariate analysis revealed that the use of TNF inhibitors is a significant independent risk factor for serious infection (relative risk 2.37, 95% CI 1.11-5.05, p = 0.026). CONCLUSION: Our study has provided the first epidemiological data on Japanese patients with RA for the safety of TNF inhibitors compared to nonbiological DMARD for up to 1 year of treatment. Anti-TNF therapy was associated with a significantly increased risk for serious infections, compared to treatment with nonbiological DMARD.

Tacrolimus-induced pulmonary injury in rheumatoid arthritis patients.

BACKGROUND: Tacrolimus (TAC) was approved in Japan in 2005 for rheumatoid arthritis (RA) patients having inadequate response to other disease-modifying anti-rheumatic drugs. As of May 2007, spontaneous reports identified twenty-seven cases of exacerbation or new development of interstitial pneumonia among RA patients given TAC in Japan. OBJECTIVE: To describe the clinical and radiological characteristics of TAC-induced pulmonary injury (TIPI). PATIENTS AND METHODS: Eleven RA patients diagnosed with de novo pulmonary injury or exacerbation of IP during treatment with TAC were identified. Clinical, radiological, and laboratory data of ten of these cases were retrospectively analyzed. RESULTS: Baseline data for the ten patients were a mean age of 69.7 years; gender, 70% female; mean RA disease duration, 9.1 years; and pulmonary comorbidities, 90%. Six cases were classified as presumptive TAC-induced pulmonary injury (TIPI) and four as probable TIPI. Among the six presumptive cases, TIPI developed at an average of 84 days after initiation of treatment (n = 5) or four days after reinstitution of TAC (n = 1). Five cases were an exacerbation of pre-existing interstitial pneumonia and one was a de novo pulmonary injury. Radiological patterns of thoracic computed tomography (CT) scans of patients in the presumptive TIPI cases were hypersensitivity pneumonia like-pattern (n = 3), ground-glass opacity (n = 2), and organizing pneumonia-pattern (n = 1). All patients with presumptive TIPI were treated with high dosage glucocorticosteroids and one received concomitant immunosuppressants. Two of the six presumptive TIPI patients died. CONCLUSION: Rheumatologists should be aware of this rare but potentially life-threatening adverse event in RA patients receiving TAC.

Diagnostic reliability of cerebral spinal fluid tests for acute confusional state (delirium) in patients with systemic lupus erythematosus: interleukin 6 (IL-6), IL-8, interferon-alpha, IgG index, and Q-albumin.

OBJECTIVE: Acute confusional state (ACS) is an uncommon but severe central nervous system (CNS) syndrome in systemic lupus erythematosus (SLE) defined by clinical manifestations. To develop useful and reliable diagnostic tools for ACS, we evaluated the association of cerebral spinal fluid (CSF) tests with ACS and their predictive values for the diagnosis of ACS in SLE. METHODS: We performed a prospective study using a cohort of 59 patients with SLE and compared those with and without ACS. Associations between ACS and each CSF test [interleukin 6 (IL-6), IL-8, interferon-alpha, IgG index, and Q-albumin] were statistically evaluated. Each patient underwent all CSF evaluations. RESULTS: ACS was diagnosed in 10 patients (ACS group), SLE-related CNS syndromes except ACS in 13, and no CNS syndromes in 36 (non-CNS group). CSF IL-6 levels in the ACS group were significantly higher than those in the non-CNS group (p < 0.05). A positive IgG index (p = 0.028) was significantly associated with ACS. No other test showed a significant association with ACS. The positive and negative predictive values for the diagnosis of ACS in SLE were 80% and 85% for elevated CSF IL-6 levels (> or = 31.8 pg/ml), and 75% and 83% for the IgG index, respectively. CONCLUSION: No single CSF test had sufficient predictive value to diagnose ACS in SLE, although CSF IL-6 levels and the IgG index showed statistical associations with ACS. Use of CSF tests combined with careful history and clinical examinations is recommended for proper diagnosis of ACS in SLE.

Momordica charantia constituents and antidiabetic screening of the isolated major compounds.

Bioguided fractionation of the methanol extract of Momordica charantia dried gourds led to the isolation of three new cucurbitane triterpenoids (1-3), together with eight known compounds (4-11). The aglycone of momordicoside I was isolated from the ether soluble fraction in a high amount. The structures of the metabolites were established on the basis of one and two dimensional NMR spectroscopic evidence, X-ray analysis, and comparison with the reported data in the literature. A number of phytochemicals have been isolated from Momordica charantia but the constituents responsible for the hypoglycaemic/antihyperglycaemic activities have not been determined. Therefore, in order to evaluate the contribution of the cucurbitane triterpenoids of the ether fraction of M. charantia methanol extract to in vivo anti-diabetic effects, the major compounds, 5beta,19-epoxy-3beta,25-dihydroxycucurbita-6,23(E)-diene (4), and 3beta,7beta,25-trihydroxycucurbita-5,23(E)-dien-19-al (5) have been tested and have shown blood hypoglycaemic effects in the diabetes-induced male ddY mice strain at 400 mg/kg. The two aglycones of charantin did not show any hypoglycaemic effects. Our finding is the first demonstration that major pure cucurbutanoid compounds of M. charantia have in vivo hypoglycaemic effects.

Expression and function of inducible co-stimulator in patients with systemic lupus erythematosus: possible involvement in excessive interferon-gamma and anti-double-stranded DNA antibody production.

Inducible co-stimulator (ICOS) is the third member of the CD28/cytotoxic T-lymphocyte associated antigen-4 family and is involved in the proliferation and activation of T cells. A detailed functional analysis of ICOS on peripheral blood T cells from patients with systemic lupus erythematosus (SLE) has not yet been reported. In the present study we developed a fully human anti-human ICOS mAb (JTA009) with high avidity and investigated the immunopathological roles of ICOS in SLE. JTA009 exhibited higher avidity for ICOS than a previously reported mAb, namely SA12. Using JTA009, ICOS was detected in a substantial proportion of unstimulated peripheral blood T cells from both normal control individuals and patients with SLE. In CD4+CD45RO+ T cells from peripheral blood, the percentage of ICOS+ cells and mean fluorescence intensity with JTA009 were significantly higher in active SLE than in inactive SLE or in normal control individuals. JTA009 co-stimulated peripheral blood T cells in the presence of suboptimal concentrations of anti-CD3 mAb. Median values of [3H]thymidine incorporation were higher in SLE T cells with ICOS co-stimulation than in normal T cells, and the difference between inactive SLE patients and normal control individuals achieved statistical significance. ICOS co-stimulation significantly increased the production of IFN-gamma, IL-4 and IL-10 in both SLE and normal T cells. IFN-gamma in the culture supernatants of both active and inactive SLE T cells with ICOS co-stimulation was significantly higher than in normal control T cells. Finally, SLE T cells with ICOS co-stimulation selectively and significantly enhanced the production of IgG anti-double-stranded DNA antibodies by autologous B cells. These findings suggest that ICOS is involved in abnormal T cell activation in SLE, and that blockade of the interaction between ICOS and its receptor may have therapeutic value in the treatment of this intractable disease.

Amplification of the synovial inflammatory response through activation of mitogen-activated protein kinases and nuclear factor kappaB using ligation of CD40 on CD14+ synovial cells from patients with rheumatoid arthritis.

OBJECTIVE: To determine the signal transduction pathways in CD14+ synovial cells from patients with rheumatoid arthritis (RA) after CD40 ligation, and to examine their role in amplifying synovial inflammation in affected joints. METHODS: Expression of messenger RNA was analyzed using quantitative reverse transcription-polymerase chain reaction. Cytokines and chemokines were measured using enzyme-linked immunosorbent assay. Activation of kinases was detected using Western blotting. Nuclear translocation of NF-kappaB was examined using immunohistochemistry. CD14+ synovial cells were enriched using magnetic cell sorting. Fibroblast-like synoviocytes (FLS) were obtained by passaging primary synovial cell culture. RESULTS: Stimulation of CD14+ synovial cells from RA patients by recombinant soluble CD154 (rsCD154) significantly induced expression of tumor necrosis factor alpha (TNFalpha), interleukin-1alpha (IL-1alpha), and IL-1beta. CD14+ RA synovial cells stimulated with rsCD154 plus interferon-gamma (IFNgamma) induced significantly higher production of IL-6, IL-8, and monocyte chemoattractant protein 1 by FLS compared with unstimulated CD14+ synovial cells, through TNFalpha-, IL-1alpha-, and IL-1beta-mediated pathways. Stimulation with rsCD154 plus IFNgamma induced the activation of ERK-1/2, p38 MAPK, and NF-kappaB. Specific inhibitors of MAPK/ERK-1/2 kinases and p38 MAPK significantly reduced the production of TNFalpha and IL-1beta by rsCD154 plus IFNgamma-stimulated CD14+ synovial cells, and also inhibited production of these cytokines by freshly isolated synovial cells from RA patients. CONCLUSION: These data indicate that the CD40-CD154 interaction activates the ERK, p38, and NF-kappaB pathways in CD14+ synovial cells from RA patients to produce TNFalpha, IL-1alpha, and IL-1beta, which in turn amplifies inflammatory responses by stimulating FLS. Inhibition of the CD40-CD154 interaction or its signal transduction pathways would be a strong and efficient strategy for the management of synovial inflammation in RA.