Clinical subsets associated with different anti-aminoacyl transfer RNA synthetase antibodies and their association with coexisting anti-Ro52.

OBJECTIVE: To characterize clinical features of polymyositis/dermatomyositis (PM/DM) patients with different anti-aminoacyl transfer RNA synthetase (ARS) antibodies and their association with anti-Ro52. METHODS: Autoantibodies in sera from 97 Japanese patients (36 PM, 56 DM, and 5 clinically amyopathic DM), who satisfied Bohan and Peter or modified Sontheimer's criteria, were characterized by immunoprecipitation and enzyme-linked immunosorbent assay. Clinical information was from medical records. Features associated with different anti-ARS and anti-Ro52 antibodies were analyzed. RESULTS: The prevalence of anti-ARS was similar to other studies (Jo-1, 22%; EJ, 4%; OJ, 1%; PL-12, 1%), except for a high prevalence of anti-PL-7 (12%), which allowed us to characterize patients carrying this specificity. Serum creatine kinase >3000 IU/l was less common in anti-PL-7-positive patients (57%) than anti-Jo-1-positive patients (18%) (p = 0.0328) and was not found in anti-EJ-positive individuals. Interstitial lung disease was common in anti-ARS-positive patients (97%) (p < 0.0001 vs. 48% in anti-ARS-negative). Anti-Ro52 antibodies were frequently detected with anti-ARS (59%) (57% in anti-Jo-1, 67% in anti-PL-7) (vs. 21% in anti-ARS-negative, p < 0.0002). Anti-Ro52 was associated with overlap syndrome (26%) (vs. 7% in anti-Ro52-negative, p = 0.0119). CONCLUSIONS: Patients with different anti-ARS in combination with anti-Ro52 appear to be associated with distinctive clinical subsets.

Efficacy of switching from originator etanercept to biosimilar YLB113 in real-world patients with rheumatoid arthritis: A retrospective 12 months follow-up study.

Purpose: To investigate the disease activity in real-world patients with rheumatoid arthritis (RA) who switched from originator etanercept (ETN) to biosimilar YLB113. Methods: Forty one RA patients who switched from ETN to YLB113 were divided into 2 groups based on the Disease Activity Score based on the 28-joint count (DAS28) 12 months after switching (R group: DAS28 < 2.6, N group: DAS28 ≥ 2.6), and the baseline characteristics were statistically examined. A receiver operating characteristics (ROC) analysis was performed to estimate the cut-off value of DAS28 at baseline to achieve remission 12 months after switching. Results: There was no significant difference in the DAS28 at baseline and 12 months after switching (p = .83). Sixteen out of the 20 patients in remission at baseline achieved remission after switching. A univariate analysis revealed the rheumatoid factor (p = .04) and DAS28 (p < .001) at baseline were significantly lower in the R group than in the N group. Furthermore, logistic regression analysis revealed DAS28 was an independent factor (p = .004) for achieving remission 12 months after switching. An ROC curve analysis showed the optimal cut-off value for DAS28 at baseline to achieve remission at 12 months after switching was 2.5. Conclusions: RA patients who achieved remission using originator ETN, were able to maintain remission even if they switched to YLB113.

Hypoxia-induced endogenous prostaglandin E2 negatively regulates hypoxia-enhanced aberrant overgrowth of rheumatoid synovial tissue.

OBJECTIVE: During isometric exercise, the synovial joint tissue is prone to hypoxia, which is further enhanced in the presence of synovial inflammation. Hypoxia is also known to induce inflammatory cascades, suggesting that periodic hypoxia perpetuates synovitis in rheumatoid arthritis. We previously established an ex vivo cellular model of rheumatoid arthritis using the synovial tissue-derived inflammatory cells, which reproduced aberrant synovial overgrowth and pannus-like tissue development in vitro. Using this model, we investigated the regulatory mechanism of synovial cells against hypoxia in rheumatoid arthritis. METHODS: Inflammatory cells that infiltrated synovial tissue from patients with rheumatoid arthritis were collected without enzyme digestion, and designated as synovial tissue-derived inflammatory cells. Under normoxia or periodic hypoxia twice a week, their single-cell suspension was cultured in medium alone to observe an aberrant overgrowth of inflammatory tissue in vitro. Cytokines produced in the culture supernatants were measured by enzyme-linked immunosorbent assay kits. RESULTS: Primary culture of the synovial tissue-derived inflammatory cells under periodic hypoxia resulted in the attenuation of the spontaneous growth of inflammatory tissue in vitro compared to the culture under normoxia. Endogenous prostaglandin E2 (PGE2) production was enhanced under periodic hypoxia. When endogenous PGE2 was blocked by indomethacin, the aberrant tissue overgrowth was more enhanced under hypoxia than normoxia. Indomethacin also enhanced the production of tumor necrosis factor-α (TNF-α), macrophage colony-stimulating factor (M-CSF), and matrix metalloproteinase-9 (MMP-9) under periodic hypoxia compared to normoxia. The EP4-specific antagonist reproduced the effect of indomethacin. Exogenous PGE1 and EP4-specific agonist effectively inhibited the aberrant overgrowth and the production of the inflammatory mediators under periodic hypoxia as well as normoxia. CONCLUSIONS: The enhancing effect of periodic hypoxia on the aberrant overgrowth of rheumatoid synovial tissue was effectively down-regulated by the simultaneously induced endogenous PGE2.

Endogenous prostaglandin E2 inhibits aberrant overgrowth of rheumatoid synovial tissue and the development of osteoclast activity through EP4 receptor.

OBJECTIVE: We recently developed an ex vivo cellular model of pannus, the aberrant overgrowth of human synovial tissue. This study was undertaken to use that model to investigate the role of prostaglandin E2 (PGE2) and its receptor subtypes in the development of pannus growth and osteoclast activity in rheumatoid arthritis (RA). METHODS: Inflammatory cells that infiltrated pannus from patients with RA were collected without enzyme digestion and designated synovial tissue-derived inflammatory cells. Their single-cell suspensions were cultured in medium alone to observe an aberrant overgrowth of inflammatory tissue in vitro. Levels of cytokines produced in culture supernatants were measured using enzyme-linked immunosorbent assay kits. Osteoclast activity was assessed by the development of resorption pits in calcium phosphate-coated slides. RESULTS: Primary culture of the synovial tissue-derived inflammatory cells resulted in spontaneous reconstruction of inflammatory tissue in vitro within 4 weeks, during which tumor necrosis factor α, PGE2, macrophage colony-stimulating factor, and matrix metalloproteinase 9 were produced in the supernatant. This aberrant overgrowth was inhibited by antirheumatic drugs including methotrexate and infliximab. On calcium phosphate-coated slides, synovial tissue-derived inflammatory cells showed numerous resorption pits. In the presence of inhibitors of endogenous prostanoid production such as indomethacin and NS398, exogenous PGE1 and EP4-specific agonists significantly inhibited all these activities of synovial tissue-derived inflammatory cells in a dose-dependent manner. Addition of indomethacin, NS398, or EP4-specific antagonist resulted in the enhancement of these cells' activities. EP2-specific agonist had a partial effect, while EP1- and EP3-specific agonists had no significant effects. CONCLUSION: These results suggest that endogenous PGE2 produced in rheumatoid synovium negatively regulates aberrant synovial overgrowth and the development of osteoclast activity via EP4.

Anti-drug antibodies and rheumatoid factor level in patients with rheumatoid arthritis using the infliximab biosimilar CT-P13.

BACKGROUND: This study evaluated the existence of anti-drug antibodies (ADAs) before and 52 weeks after switching from intravenous infliximab (IFX) to intravenous CT-P13 in patients with rheumatoid arthritis (RA). METHODS: We performed a prospective observational study. Twenty-eight patients (7 males and 21 females) received intravenous CT-P13 after intravenous IFX, and the clinical data were collected from medical records. Rheumatoid factor (RF) and anti-CCP antibody were examined at baseline. At baseline and 52 weeks after the start of CT-P13 treatment, the Disease Activity Score based on the 28-joint count and the levels of C-reactive protein, matrix metalloproteinase-3, and ADA, as well as the erythrocyte sedimentation rate were evaluated. ADAs were measured using an enzyme-linked immunosorbent assay kit. RESULTS: Seven (25%) and 6 (21.4%) cases were positive for ADAs at baseline and 52 weeks after, respectively. One case became newly positive for ADAs at week 52. Two of the ADA-positive cases became ADA-negative 52 weeks after. The ADA-positive group showed significantly higher RF values at baseline than the ADA-negative group (p = 0.03). No difference was observed between the ADA-positive group and the ADA-negative group regarding other clinical parameters. CONCLUSIONS: The positive rate of ADAs did not increase after switching from intravenous IFX to intravenous CT-P13. Among the patients with ADAs, a high level of RF was observed at baseline.

Retrospective investigation of side effects and prognoses of moderate-dose trimethoprim-sulfamethoxazole treatment for pneumocystis pneumonia that developed in patients with autoimmune diseases.

Trimethoprim-sulfamethoxazole (TMP/SMX) treatment for pneumocystis pneumonia (PCP) in patients with autoimmune diseases who developed PCP was conducted in a retrospective study of the following: dosage, frequency of side effects and persistence rate of TMP/SMX and prognosis of patients. Seven patients (two males and five females, mean age: 72 years) were hospitalized between April 1, 2013 and August 31, 2015, and their underlying diseases were rheumatoid arthritis (six patients) and microscopic polyangiitis (one patient). Moderate-dose TMP/SMX (TMP equivalent to TMP/SMX, average: 9.6 mg/kg/day, range: 5.1-12.5 mg/kg/day) was used for PCP treatment. As a result, patients experienced the following side effects: hyponatremia in five patients (71.4%), exanthema in four patients (57.1%), and thrombocytopenia in two patients (28.6%). Elevated creatinine level, increased blood pressure, malaise, and hyperkalemia were experienced by each patient. Six patients (85.7%) discontinued TMP/SMX treatment due to side effects, but once they had recovered, desensitization to TMP/SMX was used to treat them. Eventually, four patients were successfully treated with TMP/SMX (final persistence rate, 57.1%). Their prognoses were good, and no patients died for at least 60 days after admission. Moderate-dose TMP/SMX treatment for PCP in patients with autoimmune diseases who developed PCP may have therapeutic effects equal to high-dose TMP/SMX treatment, and therefore collecting more case studies is expected.

Dual role of interleukin-17 in pannus growth and osteoclastogenesis in rheumatoid arthritis.

INTRODUCTION: In a murine model, interleukin (IL)-17 plays a critical role in the pathogenesis of arthritis. There are controversies, however, regarding whether IL-17 is a proinflammatory mediator in rheumatoid arthritis (RA). We previously established an ex vivo cellular model using synovial tissue (ST)-derived inflammatory cells, which reproduced pannus-like tissue growth and osteoclastic activity in vitro. Using this model, we investigated the effects of IL-17 on pannus growth and osteoclastogenesis in RA. METHODS: Inflammatory cells that infiltrated synovial tissue from patients with RA were collected without enzyme digestion and designated as ST-derived inflammatory cells. ST-derived inflammatory cells were cultured in the presence or absence of IL-17 or indomethacin, and the morphologic changes were observed for 4 weeks. Cytokines produced in the culture supernatants were measured by using enzyme-linked immunosorbent assay kits. Osteoclastic activity was assessed by the development of resorption pits in calcium phosphate-coated slides. RESULTS: Exogenous addition of IL-17 dramatically enhanced the spontaneous production of IL-6 and prostaglandin E2 (PGE2) by the ST-derived inflammatory cells, while it had no effect on the production of tumor necrosis factor (TNF)-α and macrophage colony-stimulating factor (M-CSF). Furthermore, IL-17 did not affect the spontaneous development of pannus-like tissue growth and osteoclastic activity by the ST-derived inflammatory cells. On the other hand, IL-17 enhanced pannus-like tissue growth, the production of TNF-α and M-CSF and the development of osteoclastic activity in the presence of indomethacin, an inhibitor of endogenous prostanoid production, while exogenous addition of PGE1 suppressed their activities. CONCLUSIONS: The present study suggests that IL-17 induces negative feedback regulation through the induction of PGE2, while it stimulates proinflammatory pathways such as inflammatory cytokine production, pannus growth and osteoclastogenesis in RA.