Yukiko Komano

Pneumocystis jiroveci pneumonia in patients with rheumatoid arthritis treated with infliximab: A retrospective review and case–control study of 21 patients

OBJECTIVE To establish proper management of Pneumocystis jiroveci pneumonia (PCP) in rheumatoid arthritis (RA) patients treated with infliximab. PCP has been observed in 0.4% of patients with RA treated with infliximab in Japan. METHODS Data from patients with RA (n = 21) who were diagnosed with PCP during infliximab treatment and from 102 patients with RA who did not develop PCP during infliximab therapy were collected from 14 rheumatology referral centers in Japan. A retrospective review of these patients and a case-control study to compare patients with and without PCP were performed. RESULTS The median length of time from the first infliximab infusion to the development of PCP was 8.5 weeks. At the onset of PCP, the median dosages of prednisolone and methotrexate were 7.5 mg/day and 8 mg/week, respectively. Pneumocystis jiroveci was microscopically identified in only 2 patients, although the polymerase chain reaction test for the organism was positive in 20 patients. The patients with PCP had significantly lower serum albumin levels (P < 0.001) and lower serum IgG levels (P < 0.001) than the patients without PCP. Computed tomography of the chest in all patients with PCP revealed ground-glass opacity either with sharp demarcation by interlobular septa or without interlobular septal boundaries. Sixteen of the 21 patients with PCP developed acute respiratory failure, but all survived. CONCLUSION PCP is a serious complication that may occur early in the course of infliximab therapy in patients with RA. For the proper clinical management of this infectious disease, physicians need to be aware of the possibility of PCP developing during infliximab therapy.

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.

Identification of a human peripheral blood monocyte subset that differentiates into osteoclasts

Increased bone resorption mediated by osteoclasts causes various diseases such as osteoporosis and bone erosion in rheumatoid arthritis (RA). Osteoclasts are derived from the monocyte/macrophage lineage, but the precise origin remains unclear. In the present study, we show that the purified CD16- human peripheral blood monocyte subset, but not the CD16+ monocyte subset, differentiates into osteoclast by stimulation with receptor activator of NF-κB ligand (RANKL) in combination with macrophage colony-stimulating factor (M-CSF). Integrin-β3 mRNA and the integrin-αvβ3 heterodimer were only expressed on CD16- monocytes, when they were stimulated with RANKL + M-CSF. Downregulation of β3-subunit expression by small interfering RNA targeting β3 abrogated osteoclastogenesis from the CD16- monocyte subset. In contrast, the CD16+ monocyte subset expressed larger amounts of tumor necrosis factor alpha and IL-6 than the CD16- subset, which was further enhanced by RANKL stimulation. Examination of RA synovial tissue showed accumulation of both CD16+ and CD16- macrophages. Our results suggest that peripheral blood monocytes consist of two functionally heterogeneous subsets with distinct responses to RANKL. Osteoclasts seem to originate from CD16- monocytes, and integrin β3 is necessary for osteoclastogenesis. Blockade of accumulation and activation of CD16- monocytes could therefore be a beneficial approach as an anti-bone resorptive therapy, especially for RA.

Chemokine receptor expression and functional effects of chemokines on B cells: implication in the pathogenesis of rheumatoid arthritis.

IntroductionAccumulation of B cells in the rheumatoid arthritis (RA) synovium has been reported, and it has been thought that these cells might contribute to the pathogenesis of RA by antigen presentation, autoantibody production, and/or inflammatory cytokine production. Chemokines could enhance the accumulation of B cells in the synovium. The aims of this study were to determine chemokine receptor expression by B cells both in the peripheral blood of normal donors and subjects with RA, and at the inflammatory site in RA, and the effects of chemokines on B cell activation.MethodsCell surface molecule expression was analyzed by flow cytometry. Cellular migration was assessed using chemotaxis chambers. Cellular proliferation was examined by 3H-thymidine incorporation. Tumor necrosis factor (TNF) production was assayed by enzyme-linked immunosorbent assay.ResultsSignificant numbers of peripheral blood B cells of healthy donors and subjects with RA expressed CC chemokine receptor (CCR)5 and CXCR3, and most B cells expressed CCR6, CCR7, CXCR4 and CXCR5. CCR5 expression was more frequent on CD27+ than CD27- peripheral blood B cells of healthy donors and RA. Synovial B cells more frequently expressed CCR5, but less often expressed CCR6, CCR7 and CXCR5 compared to peripheral blood in RA. Further functional analyses were performed on peripheral blood B cells from healthy donors. Migration of peripheral blood B cells, especially CD27+ B cells, was enhanced by CC chemokine ligand (CCL)20, CCL19, CCL21 and CXCL12. All four chemokines alone induced B cell proliferation; with CCL21 being the most effective. CCL21 also enhanced the proliferation of anti-immunoglobulin (Ig)M-stimulated B cells and blockade of CCR7 inhibited this effect. CCL20, CCL21 and CXCL12 enhanced TNF production by anti-IgM mAb-stimulated B cells. Finally, stimulation with CXCL12, but not CCL20, CCL19 and CCL21, enhanced inducible costimulator-ligand (ICOSL) expression by peripheral blood B cells of healthy donors and RA, but did not increase B cell-activating factor receptor or transmembrane activator and CAML-interactor.ConclusionsThe data suggest that CCR5, CCR6, CCR7, CXCR3, CXCR4 and CXCR5 may be important for the B cell migration into the synovium of RA patients, and also their local proliferation, cytokine production and ICOSL expression in the synovium.

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

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.

Arthritic Joint-Targeting Small Interfering RNA-Encapsulated Liposome: Implication for Treatment Strategy for Rheumatoid Arthritis

RNA interference, mediated by small interfering RNA (siRNA), is effective in silencing genes with a high degree of specificity. To explore the therapeutic potential of systemically administered siRNA for rheumatoid arthritis (RA), we tested the complex of siRNA and the recently developed wrapsome (siRNA/WS) containing siRNA-encapsulated liposome in mice with collagen-induced arthritis (CIA). Mice with CIA received an intravenous injection of Cy5-labeled siRNA/WS. Fluorescence stereoscopic microscopy and flow cytometry were used to assess the siRNA/WS tissue distribution. The efficacy of siRNA-targeting tumor necrosis factor (TNF)-α/WS in CIA was evaluated by arthritis score. TNF-α mRNA levels in the joints were measured by real-time reverse transcriptase-polymerase chain reaction. The intensity of Cy5 fluorescence was higher in arthritic joints than in nonarthritic sites in Cy5-siRNA/WS-treated mice and remained higher up to 48 h after injection, compared with that in naked Cy5-siRNA-treated mice. Cy5 fluorescence intensity was higher in synovial cells than in splenocytes, bone marrow cells, and peripheral blood leukocytes. The majority of Cy5-positive synovial cells were CD11b+ with only a few CD3+ cells. Treatment with TNF-α siRNA/WS resulted in significant decreases in severity of arthritis and TNF-α mRNA level in the joints compared with control siRNA/WS. In conclusion, the use of our WS allowed efficient and targeted delivery of siRNAs to arthritic joints. The siRNA/WS was mainly incorporated into CD11b+ cells, including macrophages and neutrophils, in the inflamed synovium, suggesting its potential therapeutic effects in RA by silencing the expression of inflammatory molecules produced by these cells.

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

Abstract 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 313.9/105 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 (462.4/105 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.

NF-κB inhibitor dehydroxymethylepoxyquinomicin suppresses osteoclastogenesis and expression of NFATc1 in mouse arthritis without affecting expression of RANKL, osteoprotegerin or macrophage colony-stimulating factor

Inhibition of NF-κB is known to be effective in reducing both inflammation and bone destruction in animal models of arthritis. Our previous study demonstrated that a small cell-permeable NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), suppresses expression of proinflammatory cytokines and ameliorates mouse arthritis. It remained unclear, however, whether DHMEQ directly affects osteoclast precursor cells to suppress their differentiation to mature osteoclasts in vivo. The effect of DHMEQ on human osteoclastogenesis also remained elusive. In the present study, we therefore examined the effect of DHMEQ on osteoclastogenesis using a mouse collagen-induced arthritis model, and using culture systems of fibroblast-like synovial cells obtained from patients with rheumatoid arthritis, and of osteoclast precursor cells from peripheral blood of healthy volunteers. DHMEQ significantly suppressed formation of osteoclasts in arthritic joints, and also suppressed expression of NFATc1 along the inner surfaces of bone lacunae and the eroded bone surface, while serum levels of soluble receptor activator of NF-κB ligand (RANKL), osteoprotegerin and macrophage colony-stimulating factor were not affected by the treatment. DHMEQ also did not suppress spontaneous expression of RANKL nor of macrophage colony-stimulating factor in culture of fibroblast-like synovial cells obtained from patients with rheumatoid arthritis. These results suggest that DHMEQ suppresses osteoclastogenesis in vivo, through downregulation of NFATc1 expression, without significantly affecting expression of upstream molecules of the RANKL/receptor activator of NF-κB/osteoprotegerin cascade, at least in our experimental condition. Furthermore, in the presence of RANKL and macrophage colony-stimulating factor, differentiation and activation of human osteoclasts were also suppressed by DHMEQ, suggesting the possibility of future application of NF-κB inhibitors to rheumatoid arthritis therapy.

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.

Joint-Targeting Drug Delivery System for Rheumatoid Arthritis: siRNA Encapsulated Liposome

Rheumatoid Arthritis (RA) is characterized by persistent inflammation in multiple joints. Uncontrolled active RA causes disability, decreases quality of life, and increases comorbidity. Over the past two decades, the importance of aggressive treatment as early as possible has been emphasized to improve outcomes, and, most importantly, inhibit the destruction of joints. RNA interference, mediated by small interfering RNA (siRNA), is a powerful method used to silence genes with a high degree of specificity. Developing a means to deliver siRNA via a systemic injection to multiple affected joints is of importance for applying this technology to the treatment of RA. A recent study showed that a wrapsome (WS), which was designed with a core composed of a cationic lipid bilayer and siRNA complex enveloped in a neutral lipid bilayer with polyethylene glycol on the surface, could be a potential vehicle for siRNA delivery for the treatment of arthritis. The complex of siRNA and WS (siRNA/WS) selectively accumulated in the inflamed synovium. Furthermore, treatment with siRNA-targeting tumor necrosis factor-α/WS ameliorated arthritis in a murine model. In this manuscript, we review potential of siRNA as a therapeutic tool for rheumatoid arthritis.