Impact of Dengue Vaccination on Serological Diagnosis: Insights From Phase III Dengue Vaccine Efficacy Trials.

Background: We previously reported that vaccination with the tetravalent dengue vaccine (CYD-TDV; Dengvaxia) may bias the diagnosis of dengue based on immunoglobulin M (IgM) and immunoglobulin G (IgG) assessments. Methods: We undertook a post hoc pooled analysis of febrile episodes that occurred during the active surveillance phase (the 25 months after the first study injection) of 2 pivotal phase III, placebo-controlled CYD-TDV efficacy studies that involved ≥31000 children aged 2-16 years across 10 countries in Asia and Latin America. Virologically confirmed dengue (VCD) episode was defined with a positive test for dengue nonstructural protein 1 antigen or dengue polymerase chain reaction. Probable dengue episode was serologically defined as (1) IgM-positive acute- or convalescent-phase sample, or (2) IgG-positive acute-phase sample and ≥4-fold IgG increase between acute- and convalescent-phase samples. Results: There were 1284 VCD episodes (575 and 709 in the CYD-TDV and placebo groups, respectively) and 17673 other febrile episodes (11668 and 6005, respectively). Compared with VCD, the sensitivity and specificity of probable dengue definition were 93.1% and 77.2%, respectively. Overall positive and negative predictive values were 22.9% and 99.5%, respectively, reflecting the much lower probability of correctly confirming probable dengue in a population including a vaccinated cohort. Vaccination-induced bias toward false-positive diagnosis was more pronounced among individuals seronegative at baseline. Conclusions: Caution will be required when interpreting IgM and IgG data obtained during routine surveillance in those vaccinated with CYD-TDV. There is an urgent need for new practical, dengue-specific diagnostic algorithms now that CYD-TDV is approved in a number of dengue-endemic countries. Clinical Trials Registration: NCT01373281 and NCT01374516.

Comorbidities increase in-hospital mortality in dengue patients in Brazil.

Dengue remains an unmet public health burden. We determined risk factors for dengue in-hospital mortality in Brazil. Of 326,380 hospitalised dengue cases in 9-45-year-old individuals, there were 971 deaths. Risk of dying was 11-times higher in the presence of underlying common comorbidities (renal, infectious, pulmonary disease and diabetes), similar to the risk of dying from severe dengue and much higher with the combination. Ensuring access to integrated dengue preventative measures in individuals aged ≥ 9 years including those with comorbidities may help achieve the WHO objective of 50% reduction in mortality and 25% reduction in morbidity due to dengue by 2020.

Efficacy of immunotherapy with TG4040, peg-interferon, and ribavirin in a Phase 2 study of patients with chronic HCV infection.

BACKGROUND & AIMS: TG4040 is a modified vaccinia Ankara (MVA) virus that expresses the hepatitis C virus (HCV) proteins NS3, NS4, and NS5B. We performed a phase II open-label study to determine the efficacy, safety, and immunotherapeutic properties of TG4040 in combination with pegylated interferon α-2a and ribavirin (PEG-IFNα/RBV) in patients with chronic HCV infection. METHODS: Treatment-naive patients with HCV genotype 1 infection were assigned randomly to 1 of the following groups: PEG-IFNα/RBV for 48 weeks (group A, n = 31), PEG-IFNα/RBV for 4 weeks followed by PEG-IFNα/RBV for 44 weeks with 6 injections of TG4040 (group B, n = 63), or TG4040 for 12 weeks (7 injections) followed by PEG-IFNα/RBV for 48 weeks with 6 injections of TG4040 (group C, n = 59). The primary end point was complete early virologic response (cEVR), defined as HCV-RNA level less than 10 IU/mL after 12 weeks of PEG-IFNα/RBV treatment. RESULTS: In group C, 64.2% of evaluable patients achieved cEVR, compared with 30.0% in group A and 45.9% in group B (P = .0003 for group C vs A). A higher percentage of patients achieved a sustained virologic response 24 weeks after therapy ended in group C (58.2%) than in groups A (48.4%) or B (50.8%). HCV- and MVA-specific T-cell responses were observed predominantly in group C. As expected, most patients given injections of TG4040 developed anti-MVA antibodies. The combination of TG4040 and PEG-IFNα/RBV was reasonably well tolerated. However, PEG-IFNα-associated thrombocytopenia developed in 3 patients who carried the class II HLA allele DRB01*04. CONCLUSIONS: A higher percentage of patients with chronic HCV infection who received immunotherapy with TG4040 followed by TG4040 and PEG-IFNα/RBV achieved a cEVR compared with patients who received only PEG-IFNα/RBV therapy. These findings show that immunotherapies that activate T cells are effective in patients with chronic HCV infection. ClinicalTrials.gov number, NCT01055821.

A poxvirus vaccine is safe, induces T-cell responses, and decreases viral load in patients with chronic hepatitis C.

BACKGROUND & AIMS: Therapy for chronic hepatitis C (CHC) has limited efficacy, adverse effects, and high costs. Cohort and vaccine-based preclinical studies have indicated the importance of T-cell-based immunity in controlling viral infection. TG4040 is a recombinant poxvirus vaccine that expresses the hepatitis C virus (HCV) proteins NS3, NS4, and NS5B. We performed a phase I clinical trial to assess the safety, immunogenicity, and early antiviral efficacy of TG4040 in patients with CHC. METHODS: In an open-label, dose-escalating study, patients with mild CHC (genotype 1) were assigned to 3 groups of 3 patients each; they received subcutaneous injections of 106, 107, or 108 plaque-forming units of TG4040 on study days 1, 8, and 15. Six additional patients were given the highest dose of vaccine (108 plaque-forming units). Patients were followed for 6 months after the last injection. T-cell-based and antibody responses and levels of HCV RNA were measured. RESULTS: All 3 doses of TG4040 were well tolerated, without serious adverse events. Vaccine-induced HCV-specific cellular immune responses were observed in 5 of the 15 patients (33%). A transient decrease in circulating levels of HCV RNA, from -0.52 log10 to -1.24 log10, was observed in 8 patients; in 5 patients, the lowest level of HCV RNA was observed on day 37, after the first injection. The most pronounced decrease in viral load occurred in 2 patients, who also had marked vaccine-induced T-cell responses. CONCLUSIONS: In patients with CHC, the viral-vector-based vaccine TG4040 had a good safety profile, induced HCV-specific cellular immune responses, and reduced viral load. This vaccine should be investigated in further clinical studies, in combination with standard of care.

IL-17A- versus IL-17F-induced intracellular signal transduction pathways and modulation by IL-17RA and IL-17RC RNA interference in rheumatoid synoviocytes.

OBJECTIVE: The aim of this study was to compare the effects of interleukin (IL)-17A and IL-17F on gene expression and signalling in human rheumatoid arthritis (RA) synoviocytes. METHODS: IL-17A- and IL-17F-induced mRNA expression was analysed using Affymetrix microarrays. IL-6 and IL-8 secretion was evaluated by ELISA. Inhibition of two receptors (IL-17RA and IL-17RC) was achieved by small interfering RNA (saran). The effects on mitogen-activated protein kinase (MAPK), activator protein 1 (AP-1) and nuclear factor κB (NF-κB) expression and activation were evaluated by western blotting, qRT-PCR and DNA binding assay. RESULTS: IL-17A and IL-17F induced a molecular pattern characterised by 27 inflammation-related genes for IL-17F and 165 for IL-17A. Virtually all IL-17A and IL-17F inducible genes were dependent on NF-κB activation, whereas a small number were modulated by p38. IL-17A induced activation of all three MAPKs (ERK, p38 and JNK) and downstream transcription factors AP-1 and p65 NF-κB. IL-17F was less potent but induced activation of p50 NF-κB. IL-17A was more potent at inducing IL-6 secretion than IL-17F, which was inactive alone. IL-17A and, to a lesser extent, IL-17F induced TRAF6 but not MyD88. Inhibition of either IL-17RA or IL-17RC expression via siRNA led to near complete abrogation of IL-6 expression mediated by IL-17A and the combination of IL-17F and tumour necrosis factor α. CONCLUSION: Like IL-17A, IL-17F regulates proinflammatory gene expression by a very similar but not identical signalling pathway involving IL-17RA and IL-17RC.

Immunogenicity and Safety of a Tetravalent Dengue Vaccine Administered Concomitantly or Sequentially With Tdap Vaccine: Randomized Phase IIIb Trial in Healthy Participants 9-60 Years of Age in the Philippines.

BACKGROUND: Incorporating dengue vaccination into existing childhood vaccination programs could increase vaccine coverage. This study assessed the safety and immunogenicity of concomitant versus sequential administration of the combined tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine and the tetravalent dengue vaccine (CYD-TDV). METHODS: This phase IIIb, randomized, open-label, multicenter study was conducted in the Philippines in individuals 9-≤60 years of age (NCT02992418). Participants were to receive 3 CYD-TDV doses 6 months apart, the first dose administered either concomitantly or sequentially (28 days post-Tdap). Antibody levels were measured at baseline and 28 days post-first doses of Tdap vaccine and CYD-TDV, using enzyme-linked immunosorbent assay (pertussis, tetanus), micrometabolic inhibition test-toxin neutralization assay (diphtheria) and plaque reduction neutralization test (dengue). Immunogenicity was assessed for all participants, and statistical analysis reported for baseline dengue seropositive participants. Safety was assessed throughout. RESULTS: Among 688 randomized participants, 629 (91.4%) were baseline dengue seropositive (concomitant group, n = 314 and sequential group, n = 315). After the first dose, non-inferiority of immune responses between concomitant and sequential vaccination was achieved; between-group geometric mean antibody concentration ratios were close to 1 for anti-PT, anti-FHA, anti-PRN and anti-FIM, between-group differences in percent achieving seroprotection (titers ≥0.1 IU/mL) were 0.26% (diphtheria) and 0.66% (tetanus), and between-group geometric mean antibody titer ratios were close to 1 for dengue serotypes 1-4. Safety profiles in both study groups were comparable. CONCLUSIONS: CYD-TDV and Tdap vaccine administered concomitantly or sequentially in baseline dengue seropositive participants elicited comparable immunogenicity and safety profiles.

Immunogenicity and safety of a tetravalent dengue vaccine and a bivalent HPV vaccine given concomitantly or sequentially in girls aged 9 to 14 years in Mexico.

Dengue is endemic in several regions, and the global incidence is increasing. The recombinant, live, attenuated, tetravalent dengue vaccine (CYD-TDV) is recommended for dengue seropositive individuals ≥ 9 years. Human papillomavirus (HPV) vaccination is recommended for girls aged 9-14 years to prevent HPV infection-related cancers. This study assessed the immunogenicity and safety of a bivalent HPV (types 16 and 18) vaccine and CYD-TDV when co-administered concomitantly or sequentially. This was a Phase IIIb, randomized, open-label, multicenter study in girls aged 9-14 years in Mexico (NCT02979535). Participants were randomized 1:1 to receive three doses of CYD-TDV 6 months apart and two doses of bivalent HPV vaccine either concomitantly with, or 1 month before (sequentially), the first 2 CYD-TDV doses. Antibody levels were measured at baseline and 28-days after each vaccine dose for all participants, using an enzyme-linked immunosorbent assay for HPV-16 and HPV-18 antibodies, and a plaque reduction neutralization test for the four dengue serotypes; results are reported only for participants who were seropositive at baseline. Safety was assessed for all randomized participants throughout the study. Of the randomized participants, 305/478 (63.8%) were seropositive for dengue at baseline: 154 in the concomitant group and 151 in the sequential group. After the last HPV vaccine dose, the antibody titers for HPV were comparable in seropositive participants between treatment groups, with between group titer ratios of 0.966 for HPV-16 and 0.999 for HPV-18. After dose 3 of CYD-TDV, antibody titers were comparable for the concomitant and sequential groups across all serotypes, with between-group ratios close to 1 (serotype 1: 0.977; serotype 2: 0.911; serotype 3: 0.921; serotype 4: 0.931). CYD-TDV and a bivalent HPV vaccine administered concomitantly or sequentially in dengue seropositive girls aged 9-14 years elicited comparable immune responses with similar safety profiles.

Immunogenicity and Safety of a Tetravalent Dengue Vaccine Administered Concomitantly or Sequentially With Quadrivalent Human Papillomavirus Vaccine in Boys and Girls 9-13 Years of Age in Malaysia: A Phase IIIb, Randomized, Open-label Study.

BACKGROUND: Incorporating dengue vaccination within existing vaccination programs could help improve dengue vaccine coverage. We assessed the immunogenicity and safety of a quadrivalent human papillomavirus (HPV) vaccine administered concomitantly or sequentially with a tetravalent dengue vaccine (CYD-TDV) in healthy children 9-13 years of age in Malaysia. METHODS: In this phase IIIb, open-label, multicenter study (NCT02993757), participants were randomized 1:1 to receive 3 CYD-TDV doses 6 months apart and 2 doses of quadrivalent HPV vaccine concomitantly with, or 1 month before (sequentially), the first 2 CYD-TDV doses. Only baseline dengue-seropositive participants received the 3 doses. Antibody levels were measured at baseline and 28 days after each injection using an enzyme-linked immunosorbent assay for HPV-6, -9, -16 and -18, and the 50% plaque reduction neutralization test for the 4 dengue serotypes; immunogenicity results are presented for baseline dengue-seropositive participants. Safety was assessed throughout the study for all participants. RESULTS: At baseline, 197 of 528 (37.3%) randomized participants were dengue-seropositive [n = 109 (concomitant group) and n = 88 (sequential group)]. After the last HPV vaccine dose, antibody titers for HPV among baseline dengue-seropositive participants were similar between treatment groups, with between-group titer ratios close to 1 for HPV-6 and 0.8 for HPV-11, -16, and -18. After CYD-TDV dose 3, dengue antibody titers were similar between treatment groups for all serotypes [between-group ratios ranged from 0.783 (serotype 2) to 1.07 (serotype 4)]. No safety concerns were identified. CONCLUSIONS: The immunogenicity and safety profiles of CYD-TDV and quadrivalent HPV vaccines were unaffected when administered concomitantly or sequentially in dengue-seropositive children.

Mortality among Hospitalized Dengue Patients with Comorbidities in Mexico, Brazil, and Colombia.

Dengue patients with comorbidities may be at higher risk of death. In this cross-sectional study, healthcare databases from Mexico (2008-2014), Brazil (2008-2015), and Colombia (2009-2017) were used to identify hospitalized dengue cases and their comorbidities. Case fatality rates (CFRs), relative risk, and odds ratios (OR) for in-hospital mortality were determined. Overall, 678,836 hospitalized dengue cases were identified: 68,194 from Mexico, 532,821 from Brazil, and 77,821 from Colombia. Of these, 35%, 5%, and 18% were severe dengue, respectively. Severe dengue and age ≥ 46 years were associated with increased risk of in-hospital mortality. Comorbidities were identified in 8%, 1%, and 4% of cases in Mexico, Brazil, and Colombia, respectively. Comorbidities increased hospitalized dengue CFRs 3- to 17-fold; CFRs were higher with comorbidities regardless of dengue severity or age. The odds of in-hospital mortality were significantly higher in those with pulmonary disorders (11.6 [95% CI 7.4-18.2], 12.7 [95% CI 9.3-17.5], and 8.0 [95% CI 4.9-13.1] in Mexico, Brazil, and Colombia, respectively), ischemic heart disease (23.0 [95% CI 6.6-79.6], 5.9 [95% CI 1.4-24.6], and 7.0 [95% CI 1.9-25.5]), and renal disease/failure (8.3 [95% CI 4.8-14.2], 8.0 [95% CI 4.5-14.4], and 9.3 [95% CI 3.1-28.0]) across the three countries; the odds of in-hospital mortality from dengue with comorbidities was at least equivalent or higher than severe dengue alone (4.5 [95% CI 3.4-6.1], 9.6 [95% CI 8.6-10.6], and 9.0 [95% CI 6.8-12.0). In conclusion, the risk of death because of dengue increases with comorbidities independently of age and/or disease severity.

Role of IL-17 in the Th1 systemic defects in rheumatoid arthritis through selective IL-12Rbeta2 inhibition.

BACKGROUND: Patients with rheumatoid arthritis (RA) have a systemic Th1 defect associated with inflammation. OBJECTIVE: To examine the hypothesis that interleukin 17 (IL-17) contributes to this defect. METHODS: IL-17 effects on Th1 markers were examined on T-bet and interferon gamma (IFNgamma) expression in peripheral blood mononuclear cells (PBMCs) from patients with RA or healthy controls (HC). Receptor specificities were determined by analysis of the Th1-specific IL-12 receptor beta2 (IL-12Rbeta2), Th17-specific IL-23R and the common IL-12Rbeta1 chain expression. Effects of IL-17 or IFNgamma on IL-6, IL-1, IL-8, matrix metalloproteinase-8 (MMP-8) were measured by real-time RT-PCR in RA synovial cells. RESULTS: RA PBMCs were less responsive to IL-12-induced IFNgamma than HC PBMCs. IL-12 hyporesponsiveness was increased by IL-17 treatment associated with a selective reduction in IL-12Rbeta2, but not IL-23R, IL-12Rbeta1 or T-bet, which was reversed with IL-17R inhibition. IL-17 inhibited IL-12Rbeta2 expression in developing Th1 cells. In RA synovial cells, IL-17 induced IL-6, IL-1, IL-8 and MMP-8, whereas IFNgamma had minimal or inhibitory effects. CONCLUSION: In RA, IL-12 hyporesponsiveness is associated with IL-17R-mediated downregulation of IL-12Rbeta2 expression. IL-17 may reinforce Th17 lineage commitment and proinflammatory and destructive effects through Th1 inhibition and positive feedback effects in RA synovial cells. Anti-inflammatory effects of IL-17/IL-17R antagonism may include the restoration of protective Th1 responses.

IL-17 inhibits human Th1 differentiation through IL-12R beta 2 downregulation.

Th17 cells are critical in adaptive immunity and autoimmune disease. The polarized development of Th17, Th1 and Th2 cells is dependent on counterregulatory effects on each other. Whereas IFN-gamma inhibits Th17 development, the effect of IL-17 in human Th1 development is not known. We report a novel negative regulatory role of IL-17 on IL-12R beta 2 expression associated with reduced IL-12 responsiveness. IL-17 decreased IL-12-induced IFN-gamma expression in PBMC and developing Th1 cells, associated with a selective reduction in IL-12R beta 2, and not IL-23R, IL-12R beta 1 or T-bet. Counterregulatory effects of human Th17 on Th1 lineage cytokines may contribute to lineage divergence. In autoimmune disease, IL-17 may reinforce its own developmental programme by reducing IL-12 responsiveness, thus limiting inhibitory effects of IFN-gamma on Th17 development.

Bone- and cartilage-protective effects of a monoclonal antibody against colony-stimulating factor 1 receptor in experimental arthritis.

OBJECTIVE: Colony-stimulating factor 1 receptor (CSF-1R) essentially modulates monocyte proliferation, migration, and activation, which are considered important for the pathogenesis of rheumatoid arthritis (RA). We undertook this study to determine CSF-1R expression in human RA as well as the efficacy of a specific anti-CSF-1R monoclonal antibody (AFS98) in 2 different animal models of RA. METHODS: CSF-1R expression was examined in blood, synovium, and bone samples from RA patients, osteoarthritis (OA) patients, and healthy subjects. The efficacy of AFS98 was examined by clinical assessment, histology, and bone histomorphometry in collagen-induced arthritis (CIA) and serum-transfer arthritis. RESULTS: CSF-1R expression was increased in the synovium of RA patients compared to OA patients and healthy controls in fibroblast-like synoviocytes, follicular dendritic cells, macrophages, and osteoclasts. Circulating RA monocytes and neutrophils but not lymphocytes were CSF-1R+. In mice, blockade of CSF-1R abrogated cartilage damage, bone erosion, and systemic bone loss, and this was associated with the depletion of osteoclasts in both models. While blockade of CSF-1R did not affect inflammation in passive serum-transfer arthritis, it significantly reduced inflammation in CIA, and this was associated with the absence of synovial macrophages and reduced splenic CD11b+Gr-1- monocytes. CONCLUSION: CSF-1R was broadly expressed in human RA. Blockade of CSF-1R protected against bone and cartilage destruction in both mouse models and also showed significant antiinflammatory effects in the CIA model. These data provide evidence for CSF-1R as a therapeutic target in RA.

Comorbidities increase in-hospital mortality in dengue patients in Brazil

Dengue remains an unmet public health burden. We determined risk factors for dengue in-hospital mortality in Brazil. Of 326,380 hospitalised dengue cases in 9-45-year-old individuals, there were 971 deaths. Risk of dying was 11-times higher in the presence of underlying common comorbidities (renal, infectious, pulmonary disease and diabetes), similar to the risk of dying from severe dengue and much higher with the combination. Ensuring access to integrated dengue preventative measures in individuals aged ≥ 9 years including those with comorbidities may help achieve the WHO objective of 50% reduction in mortality and 25% reduction in morbidity due to dengue by 2020.

A unique anti-CD115 monoclonal antibody which inhibits osteolysis and skews human monocyte differentiation from M2-polarized macrophages toward dendritic cells.

Cancer progression has been associated with the presence of tumor-associated M2-macrophages (M2-TAMs) able to inhibit anti-tumor immune responses. It is also often associated with metastasis-induced bone destruction mediated by osteoclasts. Both cell types are controlled by the CD115 (CSF-1R)/colony-stimulating factor-1 (CSF-1, M-CSF) pathway, making CD115 a promising target for cancer therapy. Anti-human CD115 monoclonal antibodies (mAbs) that inhibit the receptor function have been generated in a number of laboratories. These mAbs compete with CSF-1 binding to CD115, dramatically affecting monocyte survival and preventing osteoclast and macrophage differentiation, but they also block CD115/CSF-1 internalization and degradation, which could lead to potent rebound CSF-1 effects in patients after mAb treatment has ended. We thus generated and selected a non-ligand competitive anti-CD115 mAb that exerts only partial inhibitory effects on CD115 signaling without blocking the internalization or the degradation of the CD115/CSF-1 complex. This mAb, H27K15, affects monocyte survival only minimally, but downregulates osteoclast differentiation and activity. Importantly, it inhibits monocyte differentiation to CD163(+)CD64(+) M2-polarized suppressor macrophages, skewing their differentiation toward CD14(-)CD1a(+) dendritic cells (DCs). In line with this observation, H27K15 also drastically inhibits monocyte chemotactic protein-1 secretion and reduces interleukin-6 production; these two molecules are known to be involved in M2-macrophage recruitment. Thus, the non-depleting mAb H27K15 is a promising anti-tumor candidate, able to inhibit osteoclast differentiation, likely decreasing metastasis-induced osteolysis, and able to prevent M2 polarization of TAMs while inducing DCs, hence contributing to the creation of more efficient anti-tumor immune responses.

Role of interleukin 17 in arthritis chronicity through survival of synoviocytes via regulation of synoviolin expression.

BACKGROUND: The use of TNF inhibitors has been a major progress in the treatment of chronic inflammation. However, not all patients respond. In addition, response will be often lost when treatment is stopped. These clinical aspects indicate that other cytokines might be involved and we focus here on the role of IL-17. In addition, the chronic nature of joint inflammation may contribute to reduced response and enhanced chronicity. Therefore we studied the capacity of IL-17 to regulate synoviolin, an E3 ubiquitin ligase implicated in synovial hyperplasia in human rheumatoid arthritis (RA) FLS and in chronic reactivated streptococcal cell wall (SCW)-induced arthritis. METHODOLOGY/PRINCIPAL FINDINGS: Chronic reactivated SCW-induced arthritis was examined in IL-17R deficient and wild-type mice. Synoviolin expression was analysed by real-time RT-PCR, Western Blot or immunostaining in RA FLS and tissue, and p53 assessed by Western Blot. Apoptosis was detected by annexin V/propidium iodide staining, SS DNA apoptosis ELISA kit or TUNEL staining and proliferation by PCNA staining. IL-17 receptor A (IL-17RA), IL-17 receptor C (IL-17-RC) or synoviolin inhibition were achieved by small interfering RNA (siRNA) or neutralizing antibodies. IL-17 induced sustained synoviolin expression in RA FLS. Sodium nitroprusside (SNP)-induced RA FLS apoptosis was associated with reduced synoviolin expression and was rescued by IL-17 treatment with a corresponding increase in synoviolin expression. IL-17RC or IL-17RA RNA interference increased SNP-induced apoptosis, and decreased IL-17-induced synoviolin. IL-17 rescued RA FLS from apoptosis induced by synoviolin knockdown. IL-17 and TNF had additive effects on synoviolin expression and protection against apoptosis induced by synoviolin knowndown. In IL-17R deficient mice, a decrease in arthritis severity was characterized by increased synovial apoptosis, reduced proliferation and a marked reduction in synoviolin expression. A distinct absence of synoviolin expressing germinal centres in IL-17R deficient mice contrasted with synoviolin positive B cells and Th17 cells in synovial germinal centre-like structures. CONCLUSION/SIGNIFICANCE: IL-17 induction of synoviolin may contribute at least in part to RA chronicity by prolonging the survival of RA FLS and immune cells in germinal centre reactions. These results extend the role of IL-17 to synovial hyperplasia.

Reactive hemophagocytic syndrome in adult-onset Still disease: clinical features and long-term outcome: a case-control study of 8 patients.

Reactive hemophagocytic syndrome (RHS) is a rare, life-threatening, and little-known complication of rheumatic diseases. This disorder is characterized by fever, pancytopenia, liver failure, coagulopathy, and neurologic symptoms. RHS may develop in patents who have lymphoma, organ transplantation, serious infection, and rheumatic diseases, most notably systemic lupus erythematosus and adult-onset Still disease (AOSD). Observations of specific cases of RHS in AOSD remain rare, and the significance of this syndrome during the course of AOSD remains unknown. We retrospectively studied 16 episodes of AOSD-associated RHS in 8 patients. To determine whether RHS is associated with a particular phenotype of AOSD, we conducted a case-control study from the cohort of AOSD patients seen during the same period. The estimated frequency of RHS in AOSD patients from our cohort was 15.3% (8/52). The median age at RHS diagnosis was 44.5 years. We collected clinical and laboratory data. RHS was the first manifestation of AOSD in 7 cases. The main symptoms were fever (n = 8), salmon rash (n = 6), arthralgia (n = 7), lymphadenopathy (n = 6), and shock (n = 4). Serum ferritin concentration was consistently elevated (>1000 microg/L in 8 cases), and the level of glycosylated ferritin was low in all cases (<5% in 7 cases, 15% in 1 case). Six patients presented with coagulopathy; hypertriglyceridemia was found in 6 cases. Admission to the intensive care unit was required in 4 cases. Treatment included corticosteroids (n = 8) and intravenous immunoglobulin (n = 6), cyclophosphamide in 2 cases, infliximab in the same 2 cases, and cyclosporine in 1 case. With a follow-up ranging from 2 to 15 years, the patients were in remission with prednisone plus methotrexate (n = 4), prednisone plus infliximab (n = 2), and low-dose prednisone alone (n = 2). We compared the 8 patients included in this study with 44 control patients with AOSD without RHS. Low haptoglobin levels, very high ferritin levels (>10,000 microg/L), and a normal or low neutrophil count seem to be predictive factors of the occurrence of RHS in AOSD.

IL-17RA and IL-17RC receptors are essential for IL-17A-induced ELR+ CXC chemokine expression in synoviocytes and are overexpressed in rheumatoid blood.

IL-17A is a cytokine secreted by the newly described Th17 cells implicated in rheumatoid arthritis (RA). Less is known about its receptors in synoviocytes. IL-17RA and IL-17RC were found to be overexpressed in RA peripheral whole blood and their expression was detected locally in RA synovium. In vitro, IL-17A synergized with TNF-alpha to induce IL-6, IL-8, CCL-20, and matrix metalloproteinase-3. Using microarrays, a specific up-regulation of Glu-Leu-Arg+ CXC chemokines was observed in IL-17A-treated synoviocytes. Using both posttranslational inhibitions by silencing interfering RNA and extracellular blockade by specific inhibitors, we showed that both IL-17RA and IL-17RC are implicated in IL-17A-induced IL-6 secretion, whereas in the presence of TNF-alpha, the inhibition of both receptors was needed to down-regulate IL-17A-induced IL-6 and CCL-20 secretion. Thus, IL-17A-induced IL-6, IL-8, and CCL20 secretion was dependent on both IL-17RA and IL-17RC, which are overexpressed in RA patients. IL-17A-induced pathogenic effects may be modulated by IL-17RA and/or IL-17RC antagonism.

The role of T cells in rheumatoid arthritis: new subsets and new targets.

PURPOSE OF REVIEW: To update the knowledge on the contribution of T cells in rheumatoid arthritis, a selection of publications between the end of 2005 and 2006 were reviewed. RECENT FINDINGS: Th17 cells driven by TGF-beta, IL-1, IL-6 and IL-23 challenge previous concepts of 'Th1'-induced rheumatoid arthritis. Other advancements in IL-17 studies include novel concepts on the IL-17 receptor and additional information on the mechanism of IL-17-induced effects. Regulatory T cells fail to control disease due to defective function secondary to the synovial inflammatory milieu. The predominance of pathogenic effector T cells in the presence of impaired T-cell regulatory mechanisms may therefore contribute to rheumatoid arthritis chronicity. Cellular therapies attempt to restore the balance that includes production of immunoregulatory cytokines such as IL-4 or IL-10. Better T-cell-targeted therapies controlling costimulation are in place with purported increased efficacy and durability, including anti-tumour necrosis factor nonresponders. Additional direct and indirect T-cell approaches include antagonism of T-cell-derived cytokines, T-cell activation or B-cell ablation. SUMMARY: A renewed interest in T cells comes from the discovery of Th17 in rheumatoid arthritis and from novel findings on the role of T cells in rheumatoid arthritis induction, chronicity and relapse.

IL-17A versus IL-17F induced intracellular signal transduction pathways and modulation by IL-17RA and IL-17RC RNA interference in AGS gastric adenocarcinoma cells.

Inflammatory processes are implicated in gastric cancer development. In contrast, the role of inflammation and proinflammatory cytokines in established cancer remains to be clarified. We investigated the contribution of IL-17A versus IL-17F-mediated intracellular signalling pathways in human gastric adenocarcinoma AGS cells. IL-8 secretion was evaluated by ELISA, mitogen-activated protein kinase (MAPK)(4) by Western blotting, and activator protein 1(AP-1) and nuclear factor kappa B (NFkappaB) by TransAM transcription factor assay or qRT-PCR. IL-17RA and IL-17RC inhibition were achieved by small interfering RNA (siRNA). IL-17A significantly induced activation of all three MAPK (ERK, p38 and JNK) and downstream transcription factors AP-1 and p65 NFkappaB. IL-17F was less potent but induced a significant activation of p65 NFkappaB. Consistently, IL-17A was more potent to induce IL-8 secretion than IL-17F. Inhibition of either IL-17RA or IL-17RC expression via siRNA led to near complete abrogation of IL-17A-mediated c-Jun and p65 activation. These data suggest that in gastric cancer, absence of either IL-17RA or IL-17RC can inhibit IL-17 responsiveness. Conversely, downstream of IL-17R binding, IL-17A and IL-17F induce key signal transduction pathways implicated in inflammation and carcinogenesis. IL-17A, and possibly IL-17F, may contribute to amplification and persistence of inflammatory processes implicated in inflammation-associated cancer.

Overexpression of synoviolin in peripheral blood and synoviocytes from rheumatoid arthritis patients and continued elevation in nonresponders to infliximab treatment.

OBJECTIVE: Synoviolin is a novel E3 ubiquitin ligase that has been implicated in the pathogenesis of rheumatoid arthritis (RA). The purpose of this study was to examine the expression and regulation of synoviolin by tumor necrosis factor alpha (TNFalpha), both in vivo and in vitro. METHODS: A total of 54 RA patients and 23 healthy control subjects were analyzed before, 4 hours after the first infusion, and at week 22 of infliximab treatment. Clinical response was assessed by the American College of Rheumatology criteria for 20% improvement and the Disease Activity Score in 28 joints (DAS28) at 6 months. Synoviolin messenger RNA expression was measured by real-time reverse transcription-polymerase chain reaction in peripheral blood (PB) and fibroblast-like synoviocytes (FLS) and with and without TNFalpha or interleukin-1beta (IL-1beta) stimulation. RESULTS: Synoviolin expression was increased in whole PB obtained from RA patients as compared with that from healthy controls and was significantly reduced early and late after infliximab treatment in responders, but in not nonresponders. Reduction in synoviolin expression was associated with reduced levels of markers of disease activity, including C-reactive protein levels. Nonresponders to infliximab therapy had significantly higher synoviolin expression at baseline as compared with responders, and this elevation persisted despite infliximab therapy. PB CD14+ monocytes expressed increased synoviolin levels compared with CD3+ lymphocytes, and TNFalpha or IL-1beta induced a further increase in expression in CD3+ cells. TNFalpha or IL-1beta induced sustained synoviolin expression in RA FLS. CONCLUSION: Elevated PB levels of synoviolin were identified in circulating PB mononuclear cells and were associated with nonresponse to infliximab treatment. Sustained up-regulation of synoviolin by IL-lbeta and TNFalpha may contribute to prolonged survival of immune cells and dysregulated FLS proliferation, leading to RA chronicity.