Tetsuya Furukawa

Reliability and clinical utility of Enzyme-linked immunosorbent assay for detection of anti-aminoacyl-tRNA synthetase antibody.

Anti-aminoacyl-tRNA synthetase (ARS) antibody is one of the myositis-specific autoantibodies to make a diagnosis of polymyositis (PM) and dermatomyositis (DM). Recently a new enzyme-linked immunosorbent assay (ELISA) kit of concurrently detected anti-ARS antibodies (anti-Jo-1, anti-PL-7, anti-PL-12, anti-EJ and anti-KS) have become to measure in the clinical setting. To evaluate the reliability of this ELISA kit, we measured anti-ARS antibodies in 75 PM and DM patients using by this ELISA assay and compared them with the results by RNA immunoprecipitation assay. Between the measurements of anti-PL-7, anti-PL-12, anti-EJ and anti-KS autoantibodies by ELISA assay and RNA-IP assay, the concordance rate of reproducibility is 95.1% and the positive agreement rate is 90.9% and negative agreement rate is 96.0% and kappa statistic is 0.841. Between the measurements of existing anti-Jo-1 antibody ELISA kit and anti-ARS antibody ELISA kit, the concordance rate of reproducibility is 96.9%, the positive agreement rate is 100%, negative agreement rate is 96.1% and kappa statistic is 0.909. The lung involvement in patients with PM and DM patients are positive of anti-ARS antibodies and anti-melanoma differentiation associated gene5 (MDA5) antibody at a rate around 70%. Then most life-threatening ILD with anti-MDA5 positive clinically amyopathic dermatomyositis patients could be highly guessed when anti-ARS antibodies are negative.

Relationship between YKL-40 and pulmonary arterial hypertension in systemic sclerosis

Abstract Objectives: Systemic sclerosis (SSc) is an intractable connective tissue disease that causes skin and organ fibrosis. Interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) affect its prognosis. YKL-40 protein impacts inflammation and tissue remodeling. Therefore, we evaluated the utility of YKL-40 blood levels in identifying patients with SSc complicated by PAH, as confirmed by immunohistochemistry (IHC) examination. Methods: We retrospectively analyzed 78 patients with SSc and performed IHC on 7 normal and 7 SSc skin samples in the Japanese population. Age-adjusted YKL-40 serum levels were analyzed. Results: YKL-40 age percentile was significantly elevated in SSc patients. There was no difference between patients with SSc with and without ILD and PAH. YKL-40 age percentile was greater in patients with PAH complication. YKL-40 immunostaining was negative in normal skin and prominent in the subcutaneous vascular wall of all SSc samples. Receiver operating characteristic (ROC) curve analysis indicated that YKL-40 age percentile correctly differentiated between patients with and without PAH with a sensitivity of 80% and a specificity of 94.1%. Conclusion: A higher YKL-40 level with PAH may be reflective of angiogenesis due to capillary injury in SSc. YKL-40 may offer a useful and easily applicable diagnostic biomarker of SSc complicated with PAH.

IL-2–Anti–IL-2 Monoclonal Antibody Immune Complexes Inhibit Collagen-Induced Arthritis by Augmenting Regulatory T Cell Functions

IL-2 induces regulatory T cells (Tregs) and reduces disease severity, such as in graft-versus-host disease and systemic lupus erythematosus. To investigate the regulatory network of IL-2 in rheumatoid arthritis, we examined the effects of IL-2–anti–IL-2 mAb immune complexes (IL-2ICs) in a rheumatoid arthritis model of collagen-induced arthritis (CIA). CIA was induced in male DBA/1 mice by two immunizations with type II collagen at 3-wk intervals. IL-2ICs were prepared by mixing 5 μg of an anti–IL-2 mAb (clone JES6-1D) with 1 μg of mouse IL-2 and were injected i.p. every day for 3 d. Mouse paws were scored for arthritis using a macroscopic scoring system. Th1, Th2, Th17, and Tregs were analyzed by flow cytometry. Joint histopathology was examined by H&E and immunohistochemical staining. Treg functions were examined by studying in vitro suppression using flow cytometry. IL-2IC administration effectively elicited a 1.6-fold expansion of CD4+Foxp3+ Tregs in peripheral blood cells relative to that found in control mice. IL-2IC treatment significantly inhibited arthritis in CIA mice. Histopathological examination of joints revealed inhibited synovial cell proliferation and IL-17, IL-6, and TNF-α levels but increased Foxp3+ Tregs after IL-2IC treatment. Flow cytometric examination of spleen cells revealed reduced IFN-γ– and IL-17–producing cells and increased IL-10–producing Tregs after IL-2IC treatment. The suppressive activities of CD4+CD25+ Tregs induced by IL-2ICs were stronger than those in untreated mice. IL-2ICs inhibited arthritis by augmenting not only Treg numbers but also Treg functions, which play regulatory roles in autoimmune arthritis.

抗ARS抗体症候群に血球貪食症候群(HPS)が合併した1例

A 48-year-old woman had suffered from a fever and general fatigue, and visited the other hospital for fever elevation in November 2013, at which time interstitial lung disease was revealed. In January 2014, she experienced an eruption in the hand and developed peripheral blood flow damage. Under a diagnosis of adult Stills disease, the patient was administered 0.5 mg of betamethasone as well as cyclosporin at 75 mg/day. In November 2014, general fatigue, fever, and headache were noted, while MRI revealed an enlarged hypophysis and laboratory findings were positive for the anti-pituitary cell antibody, thus a diagnosis of autoimmune hypophysitis was made. Although disease activity was low, she requested hospitalization and was admitted by the Division of Endocrinology and Metabolism at our hospital in May 2015, though only observed. Fever developed again, along with interstitial lung disease, Raynauds phenomenon, and pain in the crural area again, and we considered the possibility of another disease. After stopping administration of betamethasone and cyclosporin, we made a diagnosis of anti-aminoacyl tRNA synthetase antibody syndrome, and administered methylprednisolone at 500 mg for 3 days as well as prednisolone at 35 mg/day following steroid pulse therapy. Although her condition soon improved, fever, muscle pain, and pancytopenia returned after 3 days. Bone marrow findings revealed the existence of hemophagocytosis, for which we again gave methylprednisolone at 500 mg for 3 days and cyclosporin at 125 mg/day. Thereafter, the patient recovered and was discharged from the hospital.

SLE（抗リン脂質抗体症候群）合併妊娠34週にHELLP症候群を発症した一例；VW因子測定の有用性

SUMMARY A 39-year-old woman was diagnosed with Systemic lupus erthymatosus (SLE) in 1993, and initially received 30 mg of prednisolone (PSL) daily as treatment. In 2012, the patient was diagnosed with pregnancy-induced hypertension (PIH) complecated with proteinurea, hypertension and pretibial edema at 24 weeks of gestation. At onset, protein urea was 1.6 g/day and she was given bed rest in the hospital with a protein-restricted and low salt diet, which led to a decrease in protein urea to approximately 1 g/day. At 34 weeks of gestation epigastric pain developed, and laboratory examinations showed liver dysfunction and low platelets. We made a diagnosis of hemolysis, elevated liver enzymes, low platelet (HELLP) syndrome and performed an emergency cesarean procedure. Thereafter blood pressure was elevated, protein urea was 3.2 g/daily, anti-ds-DNA antibody level was elevated and serum C3/C4/CH50 was reduced, thus we gave. plasma exchange therapy, along with immunoadsorption and steroid pulse therapy (methyl-prednisolone 500 mg/daily for 3 days), as well as PSL at 30 mg/day. Overtime clinical symptoms and laboratory data gradually improved. CONCLUSION Some reports suggest that SLE during pregnancy is a risk factor for hypertension, nephritis, SLE relapse and HELLP syndrome. In the patient, ADAMTS13 activity did not decrease, while there was an increase in VW factor level. We assessed this case was as atypical thrombotic microangiopathy. And herein report HELLP syndrome during pregnancy associated with SLE in our patient.

Marked efficacy of adalimumab for secondary gastrointestinal amyloidosis accompanied with ankylosing spondylitis

A 39-year-old man with seronegative rheumatoid arthritis which was refractory to methotrexate and prednisolone therapy complained of epigastralgia, melena and diarrhea. Diffuse mucosal damage was observed on endoscopic examination, and histological findings of the gastric and colonal mucosa showed AA type amyloidosis. He was diagnosed with ankylosing spondylitis (AS) on the basis of the clinical feature such as the limitation in range of motion of lumber spine, and sacroiliitis on MR imaging. Although digestive symptom ameliorated by fasting and antibiotic therapy, laboratory findings continued to reveal an elevation of serum C-reactive protein (CRP) value and arthritis worsened. However, after the initiation of the treatment with adalimumab (ADA), not only his manifestation but also serum levels of CRP became normalized promptly. As far as we could evaluated, follow-up colonoscopic examination showed normal mucosal findings and histologic examination proved that amyloid protein disappeared. Secondary gastrointestinal amyloidosis is ralely associated with AS. Therefore standard therapy is not established. This case might indicate an efficacy of ADA for secondary gastrointestinal amyloidosis accompanied with AS.

SAT0158 Comparison of Early Effect on Bone Metabolism in Patients with Active Rheumatoid Arthritis After Tocilizumab or Abatacept Therapy: Results from Propensity Score Analysis

Background Biological disease-modifying antirheumatic drugs (bDMARDs) inhibit progression of structural damage in rheumatoid arthritis (RA). These results suggest the possibility that bDMARDs improve osteoclastic bone destruction of RA. However, the detailed mechanism of bDMARDs for bone metabolism in RA is poorly understood. Objectives To clarify the mechanism of tocilizumab (TCZ) or abatacept (ABT) for bone metabolism in active RA. Methods We selected 80 female patients with active RA, 44 patients were treated with TCZ and 36 patients were treated with ABT intravenously. Next, Circulating levels of type I collagen cross-linked N-telopeptides (NTx), osteocalcin (OC), soluble receptor activator of NF-kappa B ligand (sRANKL), osteoprotegerin (OPG), Dicckopf-1 (DKK-1), and osteopontin (OPN) were examined by ELISA at baseline and after 12 weeks of each treatment. Results Matching of patients according to propensity score resulted in a cohort that consisted of 28 patients in TCZ group and 28 patients in ABT group. Patients background between TCZ group and ABT group, including age, prednisolone or methotrexate dose, and baseline of DAS-28 was matched. In TCZ group, average of NTx, DKK-1 and OPN levels at 12 weeks decreased significantly from the baseline (24.4 vs 21.5 nmol BCE/L; p<0.05, 2743 vs 2138 pg/mL; p<0.01, 90 vs 60 pg/mL; p<0.01 respectively). Average of OC levels at 12 weeks increased significantly from the baseline (8.6 vs 10.1 ng/mL; p<0.01). Average of sRANKL and sRANKL/OPG levels at 12 weeks tended to decrease from the baseline (0.47 vs 0.41 pmol/L, 0.13 vs 0.10% respectively). Interestingly, average of OPG levels at 12 weeks tended to increase from the baseline (5.03 vs 5.23 pmol/L). In ABT group, similarly, average of NTx and OPN levels at 12 weeks decreased significantly from the baseline (16.1 vs 14.7 nmol BCE/L; p<0.05, 86 vs 71 pg/mL; p<0.05 respectively). OC levels tended to increase (6.4 vs 6.8 ng/mL). However, sRANKL, OPG and sRANKL/OPG levels were not changed. In contrast, average of DKK-1 levels at 12 weeks increased significantly from the baseline (2336 vs 2558 pg/mL; p<0.05). In comparison of the rate of change from the baseline (%change) of these biomarkers between TCZ group and ABT group, %change of OPG in TCZ group increased significantly compared with ABT group (5.56 vs -1.77%; p<0.05) and %change of DKK-1 in TCZ group decreased significantly compared with ABT group (-18.2 vs 10.4%; p<0.01). Conclusions TCZ or ABT has improved inflammatory bone destruction of RA. However, the main mechanism of TCZ and ABT is different. These results suggest that TCZ has improved bone metabolism in RA through the control of osteoclastogeneis via RANKL/OPG balance. Especially, the promotion of osteoblastogenesis via the inhibition of DKK-1 may be a specific effect in TCZ compared with ABT. On the other hands, In ABT, it is suggested that the suppression mechanism involved in osteoclastogenesis which does not pass control of RANKL/OPG balance exists. This mechanism may be a direct inhibiting effect of osteoclast precursors. Disclosure of Interest None declared

SAT0119 Effect of Abatacept on Bone Homeostasis and Osteopontin in Rheumatoid Arthritis

Background Abatacept (CTLA4-Ig) is a new therapeutic agent used for rheumatoid arthritis (RA). Recently, it is reported that CTLA-4 directly inhibits osteoclast formation. On the other hand, Osteopontin (OPN) is produced by activated T lymphocytes and has been recognized as one of the key molecules for osteoclastic bone-resorption in RA. However, the effect of abatacept on bone homeostasis and OPN production in RA is poorly understood. In this study, we investigated the effects of abatacept on biochemical markers of bone, serum soluble receptor activator of NF-kappa B ligand (sRANKL), osteoprotegerin (OPG), and plasma osteopontin (OPN) in patients with RA. Objectives To demonstrate the effect of abatacept on bone homeostasis in RA. Methods 24 patients with RA (19 females, 5 males; age 59.8±14.7 years; disease duration 6.1±8.0 years; stage 2.0±1.2; class 1.8±0.6; DAS28-CRP 4.6±1.4; SDAI 26.7±12.8; use of MTX 83%; average dose of MTX 5.9±3.3mg/week; use of PSL 71%; average dose of PSL 3.9±3.2mg/day) were started on treatment with abatacept for 24 weeks. All patients were biologics naïve. In addition, circulating levels of type I collagen cross-linked N-telopeptides (NTx), osteocalcin, sRANKL, OPG, and plasma OPNwere examined by ELISA at baseline and after 12 and 24 weeks. Results After 24 weeks of abatacepttreatment, DAS28-CRP and SDAI decreased significantly from the baseline (4.6±1.4 vs 2.5±0.9; p<0.01, 26.7±12.8 vs 8.6±6.0; p<0.01, respectively), so that 14 patients achieved DAS28-CRP remission. After 12 weeks, average of NTx levels decreased significantly from the baseline (16.27±5.81 vs 14.23±3.48 nmol BCE/l; p<0.01). After 24 weeks, average of osteocalcin levels increased significantly (5.80±3.02vs 6.45±2.61 ng/ml; p<0.05) and average of OPN levels decreased significantly from the baseline (101.57±57.40 vs 71.76±29.49 pg/ml; p<0.01). Average of RANKL levels tended to decrease from the baseline ((0.22±0.39 vs 0.12±0.20 pmol/l; p=0.06), whereas average of OPG levels did not change significantly from the baseline (4.67±1.96 vs 4.90±2.44 pmol/L; p=0.17). Conclusions These findings suggest that abatacept improves systemic bone metabolism in patient with RA through the increase of bone formation markers and the decrease of bone degradation markers. We consider that these mechanism result from the regulation of OPN and RANKL expression in activated T lymphocytes. Consequently, abatacept may control osteoclastic-bone destruction in RA via the suppression of RANKL induced-osteoclastogenesis and OPN induced-osteoclast attachment of bone surface. Disclosure of Interest None Declared