Jin Kyun Park

HM71224, a novel Bruton’s tyrosine kinase inhibitor, suppresses B cell and monocyte activation and ameliorates arthritis in a mouse model: a potential drug for rheumatoid arthritis

BackgroundBruton’s tyrosine kinase (Btk) is critical for activation of B cells and myeloid cells. This study aimed to characterize the effects of HM71224, a novel Btk inhibitor, both in vitro and in a mouse model of experimental arthritis.MethodsThe kinase inhibition profile of HM71224 was analyzed. The in vitro effects of HM71224 on B cells and monocytes were analyzed by examining phosphorylation of Btk and its downstream signaling molecules, along with cytokine production and osteoclast formation. The in vivo effects of HM71224 were investigated in a mouse model of collagen-induced arthritis (CIA).ResultsHM71224 irreversibly bound to and inhibited Btk (IC50 = 1.95 nM). The compound also inhibited the phosphorylation of Btk and its downstream molecules such as PLCγ2, in activated Ramos B lymphoma cells and primary human B cells in a dose-dependent manner. Furthermore, HM71224 effectively inhibited the production of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β by human monocytes, and osteoclast formation by human monocytes. Finally, HM71224 improved experimental arthritis and prevented joint destruction in a murine model of CIA.ConclusionsHM71224 inhibits Btk in B cells and monocytes and ameliorates experimental arthritis in a mouse model. Thus, HM71224 is a potential novel therapeutic agent for rheumatoid arthritis in humans.

Comparison of cancer incidence among patients with rheumatic disease: a retrospective cohort study

IntroductionRheumatic diseases (RDs) are associated with different cancers; however, it is unclear whether particular cancers are more prevalent in certain RDs. In the present study, we examined the relative incidence of several cancers in a single homogeneous cohort of patients with different RDs.MethodsPatients (N = 3,586) diagnosed with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc), dermatomyositis (DM) or polymyositis were included. Cancer diagnosis was based on histopathology. The 2008 Korean National Cancer Registry served as the reference for calculating standardized incidence ratios (SIRs).ResultsDuring the follow-up period of 31,064 person-years, 187 patients developed cancer. RA and SLE patients showed an increased risk of non-Hodgkin’s lymphoma (SIR for RA patients = 3.387, 95% confidence interval (CI) = 1.462 to 6.673; SIR for SLE patients = 7.408, 95% CI = 2.405 to 17.287). SLE patients also had a higher risk of cervical cancer (SIR = 4.282, 95% CI = 1.722 to 8.824). SSc patients showed a higher risk of lung cancer (SIR = 4.917, 95% CI = 1.977 to 10.131). Endometrial cancer was increased only in patients with DM (SIR = 30.529, 95% CI = 3.697 to 110.283). RA patients had a lower risk for gastric cancer (SIR = 0.663, 95% CI = 0.327 to 0.998). The mean time between the RD and cancer diagnoses ranged from 0.1 to 16.6 years, with the shortest time observed in patients with DM (2.0 ± 2.1 years).ConclusionsDifferent RDs are associated with particular cancers. Thus, cancer surveillance tailored to specific RDs might be beneficial.

Head-to-head comparison of udenafil vs amlodipine in the treatment of secondary Raynaud’s phenomenon: a double-blind, randomized, cross-over study

OBJECTIVE RP is a reversible vasoconstriction of digital arteries that causes pain and skin discoloration. This study compared the efficacy of the new phosphodiesterase type 5 inhibitor udenafil with that of the calcium channel blocker amlodipine in the treatment of secondary RP. METHODS A total of 29 patients with secondary RP associated with connective tissue diseases were enrolled in this double-blind, randomized, cross-over study. The patients were randomized to receive udenafil 100 mg/day or amlodipine 10 mg/day for 4 weeks. After a washout period they were crossed over to the other drug for another 4 weeks. The primary outcome was RP frequency before and after treatment. The secondary outcomes were RP condition scores, RP duration, number of digital ulcers, HAQ, physician global assessment and digital artery flow before and after treatment. RESULTS Amlodipine and udenafil both decreased the rate of RP attack significantly. The drugs did not differ in terms of RP frequency or any of the secondary outcomes except for digital blood flow; udenafil improved it significantly better than amlodipine (P = 0.021). Udenafil was well tolerated without serious adverse effects. CONCLUSION Udenafil and amlodipine have comparable efficacy in improving RP attacks. In addition, udenafil improves the blood flow in digital arteries compared with amlodipine. TRIAL REGISTRATION www.clinicaltrials.gov, protocol number NCT01280266.

Patients with Rheumatoid Arthritis Show Altered Lipoprotein Profiles with Dysfunctional High-Density Lipoproteins that Can Exacerbate Inflammatory and Atherogenic Process.

Objective In order to identify putative biomarkers in lipoprotein, we compared lipid and lipoprotein properties between rheumatoid arthritis (RA) patients and control with similar age. Methods We analyzed four classes of lipoproteins (VLDL, LDL, HDL2, HDL3) from both male (n = 8, 69±4 year-old) and female (n = 25, 53±7 year-old) rheumatoid arthritis (RA) patients as well as controls with similar age (n = 13). Results Although RA group showed normal levels of total cholesterol (TC), low-density lipoprotein (LDL)-cholesterol, and glucose, however, the RA group showed significantly reduced high-density lipoprotein (HDL)-C level and ratio of HDL-C/TC. The RA group showed significantly elevated levels of blood triglyceride (TG), uric acid, and cholesteryl ester transfer protein (CETP) activity. The RA group also showed elevated levels of advanced glycated end (AGE) products in all lipoproteins and severe aggregation of apoA-I in HDL. As CETP activity and TG contents were 2-fold increased in HDL from RA group, paraoxonase activity was reduced upto 20%. Electron microscopy revealed that RA group showed much less HDL2 particle number than control. LDL from the RA group was severely oxidized and glycated with greater fragmentation of apo-B, especially in female group, it was more atherogenic via phagocytosis. Conclusion Lipoproteins from the RA patients showed severely altered structure with impaired functionality, which is very similar to that observed in coronary heart patients. These dysfunctional properties in lipoproteins from the RA patients might be associated with high incidence of cardiovascular events in RA patients.

Circulating exosomes from patients with systemic lupus erythematosus induce a proinflammatory immune response

BackgroundExosomes are involved in intercellular communication. The aim of this study was to investigate whether circulating exosomes effectively contribute to the inflammatory response in systemic lupus erythematosus (SLE).MethodsExosomes were purified from SLE patients and healthy controls (HCs). Healthy peripheral blood mononuclear cells (PBMCs) were stimulated with exosomes isolated from SLE patients and HCs in the presence or absence of Toll-like receptor (TLR) inhibitors. Production of interferon (IFN)-α, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 were measured. Correlation between exosome levels and SLE disease activity was examined.ResultsThe serum exosomes levels were significantly higher in SLE patients than in HCs. SLE exosomes induced a higher production of IFN-α, TNF-α, IL-1β, and IL-6 compared to healthy exosomes. SLE serum that was depleted of exosomes and SLE exosomes that were mechanically disrupted failed to induce any significant cytokine production. Exosome-mediated production of TNF-α, IL-1β, and IL-6 was decreased by the TLR4 antagonist, whereas that of IFN-α was suppressed by the TLR1/2, TLR7, and TLR9 antagonists. Exosome levels correlated with disease activity in SLE patients (rho = 0.846, p = 0.008).ConclusionsThe circulating exosomes are immunologically active and their levels correlate with disease activity in SLE patients. The circulating exosomes might serve as novel biomarkers of SLE disease activity.

Cytokine signaling-1 suppressor is inducible by IL-1beta and inhibits the catabolic effects of IL-1beta in chondrocytes: its implication in the paradoxical joint-protective role of IL-1beta.

IntroductionAlthough IL-1β is believed to be crucial in the pathogenesis of osteoarthritis (OA), the IL-1β blockade brings no therapeutic benefit in human OA and results in OA aggravation in several animal models. We explored the role of a cytokine signaling 1 (SOCS1) suppressor as a regulatory modulator of IL-1β signaling in chondrocytes.MethodsCartilage samples were obtained from patients with knee OA and those without OA who underwent surgery for femur-neck fracture. SOCS1 expression in cartilage was assessed with immunohistochemistry. IL-1β-induced SOCS1 expression in chondrocytes was analyzed with quantitative polymerase chain reaction and immunoblot. The effect of SOCS1 on IL-1β signaling pathways and the synthesis of matrix metalloproteinases (MMPs) and aggrecanase-1 was investigated in SOCS1-overexpressing or -knockdown chondrocytes.ResultsSOCS1 expression was significantly increased in OA cartilage, especially in areas of severe damage (P < 0.01). IL-1β stimulated SOCS1 mRNA expression in a dose-dependent pattern (P < 0.01). The IL-1β-induced production of MMP-1, MMP-3, MMP-13, and ADAMTS-4 (aggrecanase-1, a disintegrin and metalloproteinase with thrombospondin motifs 4) was affected by SOCS1 overexpression or knockdown in both SW1353 cells and primary human articular chondrocytes (all P values < 0.05). The inhibitory effects of SOCS1 were mediated by blocking p38, c-Jun N-terminal kinase (JNK), and nuclear factor κB (NF-κB) activation, and by downregulating transforming growth factor-β-activated kinase 1 (TAK1) expression.ConclusionsOur results show that SOCS1 is induced by IL1-β in OA chondrocytes and suppresses the IL-1β-induced synthesis of matrix-degrading enzymes by inhibiting IL-1β signaling at multiple levels. It suggests that the IL-1β-inducible SOCS1 acts as a negative regulator of the IL-1β response in OA cartilage.

Clinical factors and treatment outcomes associated with failure in the detection of urate crystal in patients with acute gouty arthritis.

Background/Aims To investigate the rate of detection of monosodium urate (MSU) crystals in the synovial fluid (SF) of patients with acute gouty arthritis and factors associated with false-negative results. Methods A total of 179 patients with acute gouty arthritis who had undergone SF crystal examination were identified from the data warehouse of two university hospitals. Clinical and laboratory data were obtained from the medical records. Results The overall rate of detection of MSU crystals was 78.8%. In univariate analyses, the only significant differences between the variables of crystal-negative and crystal-positive patients were a lower C-reactive protein level (p = 0.040) and fewer patients undergoing emergent surgery in the crystal-positive group (p = 4.5 × 10-6). In logistic regression analyses, MSU crystal-negative results were significantly associated with the interval from arthritis onset to crystal examination (p = 0.042), and this was the most significant risk factor for arthroscopic surgery (p = 2.1 × 10-4). Seventeen patients who underwent arthroscopic surgery had a significantly longer hospital stay (p = 0.007) and a significant delay in gout treatment (p = 8.74 × 10-5). The distribution of crystal-negative patients differed significantly between the SF samples that were evaluated by both the laboratory medicine and the rheumatology departments (p = 1.2 × 10-14), and the κ value was 0.108. Conclusions Although several clinical features were associated with detection failure, SF MSU crystal identification was critically dependent on the observer. Considering the impact on the treatment outcomes, implementation of a quality control program is essential.

Certain Autoimmune Manifestations Are Associated With Distinctive Karyotypes and Outcomes in Patients With Myelodysplastic Syndrome: A Retrospective Cohort Study

AbstractAutoimmune manifestations (AIMs) are common in patients with myelodysplastic syndrome (MDS). This study aimed to investigate whether AIMs are associated with a specific cytogenetic abnormalities and worse survival in patients with MDS.A total of 67 MDS patients with AIMs and 134 age- and sex-matched MDS patients without AIMs, all of whom received medical care at Seoul National University Hospital from January 2000 through July 2014, were enrolled. The clinical features, chromosomal abnormalities, and outcomes were examined. The effect of AIMs on mortality was estimated after adjusting for age, sex, and the International Prognostic Scoring System.The mean age (±SD) at the time of MDS diagnosis was 54.5 ± 17.1 years, and 44.8% of patients were male. Neutrophilic dermatosis (ND; Sweet syndrome and pyoderma gangrenosum) was the most prevalent AIM (n = 24 36%]), followed by Behcet disease (10 [15%]), rheumatoid arthritis (9 [13%]), vasculitis (8 [12%]), myositis (3 [4%]), spondyloarthropathy (3 [4%]), and systemic lupus erythematous (2 [3%]). ND and vasculitis occurred at the time of MDS diagnosis, whereas other AIMs occurred years after MDS diagnosis. Deletion of 5q was associated with ND (P = 0.001), whereas trisomy 8 was associated with Behcet disease (P = 0.015). Strikingly, ND was associated with a 1.8-fold increase in mortality (95% CI 1.033–3.093; P = 0.038).Certain AIMs in MDS patients are associated with distinctive karyotypes and worse survival. A larger study is needed to confirm whether the presence of AIMs influences disease outcome in MDS.

Serum 25-Hydroxyvitamin D3 and BAFF Levels Are Associated with Disease Activity in Primary Sjogren’s Syndrome

The study investigated the association between disease activity and serum 25-hydroxyvitamin D3 (25(OH)-D3), B cell activation of the tumor necrosis factor family (BAFF), or β 2 microglobulin in patients with primary Sjogrens syndrome (SS). Sixty-nine primary SS patients and 22 sicca control patients were included in the study. Disease activity was measured with EULAR Sjogrens syndrome disease activity index (ESSDAI). Serum levels of 25(OH)-D3 and β 2 microglobulin were measured by radioimmunoassay and BAFF was measured by an enzyme-linked immunosorbent assay. Serum levels of 25(OH)-D3 were significantly lower in SS patients compared to the sicca controls (p = 0.036). Serum levels of BAFF tended to be higher (p = 0.225) and those of β 2 microglobulin were significantly higher in patients with SS than in sicca controls (p = 0.023). In univariate regression analyses, ESSDAI was significantly associated with serum levels of 25(OH)-D3, BAFF, and β 2 microglobulin. After stepwise backward multivariate linear regression analyses including age and acute phase reactants, ESSDAI was associated with 25(OH)-D3 (β = −0.042, p = 0.015) and BAFF (β = 0.001, p = 0.015) in SS patients. In SS patients, ESSDAI is negatively associated with serum levels of 25(OH)-D3 and positively associated with BAFF.

THU0499 Hm71224, A Novel Oral BTK Inhibitor, Inhibits Human Immune Cell Activation: New Drug Candidate to Treat B-Cell Associated Autoimmune Diseases

Background Bruton tyrosine kinase (BTK), a Tec family kinase, is involved in B cell activation and osteoclast formation. As BTK plays a central role in B cell receptor (BCR) signaling and B cell development, BTK might be an attractive therapeutic target for autoimmune diseases including rheumatoid arthritis (RA) [1–3]. Objectives To investigate the effects of HM7122, a novel BTK inhibitor, on human B cell activation and osteoclast formation. Methods In vitro biochemical inhibition assay was performed using Invitrogen kinase assay. Peripheral blood mononuclear cells (PBMCs) from healthy controls were activated with anti-human IgM in increasing concentrations of HM71224. Phosphorylationof BTK and its down-stream signaling molecules PLCγ2 and ERK were examined using phospho-flow and phospho-blots. The BTK occupancy was measured in PBMCs using ELISA. The expression of B cell activation marker CD40, CD69 and CD86 were examined by flow cytometry. Osteoclasts were generated from isolated monocytes in the presence of M-CSF and RANKL and the inhibition of osteoclast generation by HM71224 was examined. Results In vitro, HM71224 effectively bound to BTK (IC50 =2nM) but not to STAT5 (IC50 >1000 nM), STAT6 (IC50 =445 nM) and EGFR (IC50 =800 nM). HM71224 blocked phosphorylation of BTK, PLCγ2 and ERK (IC50 =1nM, 1nM, and 100 nM, respectively). The BTK occupancy in human PBMCs showed an effective binding of HM71224 to BTK protein (IC50 =69.9±14 nM). Upregulation of the activation marker CD40, CD69 and CD86 on stimulated human B cells were inhibited by HM71224 in a dose-dependent manner (Figure A). Furthermore, osteoclast formation was suppressed in the presence of HM71224 as well (Figure B). Conclusions HM71224 is a novel BTK inhibitor that effectively inhibits B cell activation and osteoclastogenesis. HM71224 might offer a new therapeutic option to treat autoimmune diseases associated with B cell activation. References Edwards J.C.W. et al, B-cell targeting in rheumatoid arthritis and other autoimmune diseases. Nature Reviews Immunology, 2006, 6: 394-403. Rickert R.C. New insights into pre-BCR and BCR signaling with relevance to B cell malignancies. Nature Reviews Immunology, 2013, 13:578-591. Swanson D.C. et al, Tyrosine kinases as targets for the treatment of rheumatoid arthritis. Nature Reviews Rheumatology, 2009, 5: 317-324. Disclosure of Interest : J. K. Park: None declared, J. A. Park: None declared, Y. J. Lee: None declared, J. Song: None declared, J. I. Oh: None declared, Y.-M. Lee: None declared, K. H. Suh: None declared, J. Son: None declared, E. B. Lee Grant/research support: Hanmi Pharm Co Ltd DOI 10.1136/annrheumdis-2014-eular.2783