Dysfunction of TRIM21 in interferon signature of systemic lupus erythematosus.

OBJECTIVES: TRIM21 is an E3 ubiquitin ligase for interferon regulatory factors (IRFs) that are involved in innate and acquired immunity. Here, we evaluated the role of TRIM21 in the interferon (IFN) signature of systemic lupus erythematosus (SLE). METHODS: Twenty SLE patients and 24 healthy controls were enrolled in this study. We analyzed mRNA expression of TRIM21, type I IFN, and IFN-inducible genes in peripheral blood mononuclear cell (PBMC). The protein levels of IRFs were assessed by Western blotting in PBMCs cultured with or without MG-132. RESULTS: The expression of TRIM21 mRNA and protein was significantly higher in SLE PBMCs as compared to healthy controls. There was a correlation between TRIM21 mRNA expression and SLE activities. In contrast to a negative correlation between mRNA expression level of TRIM21 and those of type I IFNs in healthy controls, we found a positive correlation between them in anti-TRIM21 antibody-positive SLE patients. Neither positive nor negative correlation was observed in the autoantibody-negative SLE patients. Western-blotting analysis revealed impaired ubiquitin-dependent proteasomal degradation of IRFs in SLE PBMCs. CONCLUSION: Our study showed ubiquitin-dependent proteasomal degradation of IRFs was impaired in anti-TRIM21 antibody-dependent and -independent fashions, leading to amplification of IFN signature in SLE.

(18)F-FDG and (18)F-NaF PET/CT demonstrate coupling of inflammation and accelerated bone turnover in rheumatoid arthritis.

OBJECTIVE: To compare the findings in rheumatoid arthritis (RA)-affected joints between (18)F-fluorodeoxyglucose (FDG) and (18)F-fluoride (NaF) positron emission tomography (PET)/computed tomography (CT). METHODS: We enrolled twelve RA patients who started a new biologic agent (naïve 9 and switch 3). At entry, both hands were examined by (18)F-FDG PET/CT, (18)F-NaF PET/CT, and X-ray. Intensity of PET signals was determined by standardized uptake value max (SUVmax) in metacarpophalangeal (MCP), proximal interphalangeal (PIP), and ulnar, medial, and radial regions of the wrists. Hand X-rays were evaluated according to the Genant-modified Sharp score at baseline and 6 months. RESULTS: Both (18)F-FDG and (18)F-NaF accumulated in RA-affected joints. The SUVmax of (18)F-FDG correlated with that of (18)F-NaF in individual joints (r = 0.65), though detail distribution was different between two tracers. (18)F-NaF and (18)F-FDG signals were mainly located in the bone and the surrounding soft tissues, respectively. The sum of SUVmax of (18)F-NaF correlated with disease activity score in 28 joint (DAS28), modified health assessment questionnaire (MHAQ), and radiographic progression. (18)F-FDG and (18)F-NaF signals were associated with the presence of erosions, particularly progressive ones. CONCLUSION: Our data show that both (18)F-FDG and (18)F-NaF PET signals were associated with RA-affected joints, especially those with ongoing erosive changes.

A novel 8-joint ultrasound score is useful in daily practice for rheumatoid arthritis.

OBJECTIVES: To investigate the optimal number and combination of joints to be assessed by power Doppler ultrasonography (PDUS) in daily practice for rheumatoid arthritis (RA). METHODS: PDUS were performed in 24 joints, including all proximal interphalangeal, metacarpophalangeal (MCP), and bilateral wrist and knee joints in 234 patients with RA. PD signals were scored semiquantitatively from 0 to 3 in each joint, and total PD score-24 was calculated by summing them up as comprehensive assessment. RESULTS: Positive PD signals were more frequently found in bilateral wrist, knee, and the second and third MCP joints than the other joints. The individual PD scores of these 8 joints also showed higher correlation coefficients with total PD score-24 (rs ≥ 0.4). Among the sum PD scores of various selected joint combinations, the score of the combination of 8 joints (total PD score-8), including bilateral second and third MCP, wrist, and knee joints, showed the highest sensitivity and negative predictive value (98.1% and 96.2%, respectively). Total PD score-8 showed high correlation with the total PD score-24 (rs = 0.97, p < 0.01). CONCLUSIONS: Total PD score-8 is simple and efficient enough for monitoring disease activity and judging imaging remission of RA in daily practice.

Predicting joint destruction in rheumatoid arthritis with power Doppler, anti-citrullinated peptide antibody, and joint swelling.

OBJECTIVE: To determine combined evaluation of musculoskeletal ultrasonography (MSUS) and power Doppler (PD) signals, anti-citrullinated peptide antibody (ACPA), and other clinical findings improve the prediction of joint destruction in rheumatoid arthritis (RA). METHODS: We performed a retrospective study of 331 RA patients (female n = 280 and male n = 51, mean age: 57.9 ± 13.2 years) who underwent MSUS from 2002 to 2012. Correlations with progression of joint destructions in 1,308 2nd and 3rd metacarpophalangeal (MCP) joints and various factors including PD signals of the same joints, clinical findings, age, disease duration at the study entry, gender, observation period, radiographic bone scores according to modified Sharp-van der Heijde methods, ACPA, and rheumatoid factor (RF) were analyzed in patient- and joint-based fashions, using univariate and multivariate logistic regression analyses and generalized linear mixed model. RESULTS: Patients' characteristics were as follows: mean disease duration: 5.7 ± 7.5 years, observation period: 4.6 ± 2.6 years, RF positivity: 79.9%, and ACPA positivity: 77.5%. PD-positive 2nd and 3rd joints showed higher rate of joint destruction, especially in ACPA-positive patients. Moreover, PD-positive joints in ACPA-positive patients showed joint destruction even in joints without swelling. Multivariate analysis determined PD, swollen joint (SJ), observation period, basal radiographic bone scores, and ACPA as independent risks for joint destruction. CONCLUSION: PD, SJ, basal radiographic bone scores, and ACPA are independent predictors for the joint destruction of 2nd and 3rd MCPs in RA; thus, considering these factors would be useful in daily practice.

Ultrasonography predicts achievement of Boolean remission after DAS28-based clinical remission of rheumatoid arthritis.

OBJECTIVES: To determine whether ultrasonography (US) predicts Boolean remission in rheumatoid arthritis (RA) patients who had achieved disease activity score in 28 joints (DAS28)-based remission criteria. METHODS: Thirty-one RA patients in DAS28-based clinical remission were recruited. US semiquantitatively determined Gray scale (GS) and power Doppler (PD) signal scores in the bilateral wrists and all metacarpophalangeals and proximal interphalangeals. Total GS score and total PD score were calculated as the sum of individual scores for each joint. RESULTS: Among 22 RA patients, who maintained DAS28 remission for 2 years, 16 met Boolean remission criteria at the end of study. Both total GS and total PD scores at baseline were significantly lower in Boolean remission group than non-remission group. There was no significant difference in other baseline parameters, including duration of disease, duration of remission, mTSS, and disease activity composite parameters between the two groups. Among the factors for Boolean remission criteria at 2 years, patient global assessment score was associated with total GS score at the entry, while swollen joint count was related to total PD score. CONCLUSIONS: Null or low grade of GS and PD findings in US are associated with achieving Boolean remission. Thus, US is essential for assessment and prediction of "deeper remission" of RA.

Pob1 ensures cylindrical cell shape by coupling two distinct rho signaling events during secretory vesicle targeting.

Proper cell morphogenesis requires the co-ordination of cell polarity, cytoskeletal organization and vesicle trafficking. The Schizosaccharomyces pombe mutant pob1-664 has a curious lemon-like shape, the basis of which is not understood. Here, we found abundant vesicle accumulation in these cells, suggesting that Pob1 plays a role in vesicle trafficking. We identified Rho3 as a multicopy suppressor of this phenotype. Because Rho3 function is related to For3, an actin-polymerizing protein, and Sec8, a component of the exocyst complex, we analyzed their functional relationship with Pob1. Pob1 was essential for the formation of actin cables (by interacting with For3) and for the polarized localization of Sec8. Although neither For3 nor Sec8 is essential for polarized growth, their simultaneous disruption prevented tip growth and yielded a lemon-like cell morphology similar to pob1-664. Thus, Pob1 may ensure cylindrical cell shape of S. pombe by coupling actin-mediated vesicle transport and exocyst-mediated vesicle tethering during secretory vesicle targeting.

Changes in the proportion of clinical clusters contribute to the phenotypic evolution of Behçet's disease in Japan.

BACKGROUND: We hypothesized that Behçet's disease (BD) consists of several clinical subtypes with different severity, resulting in heterogeneity of the disease. Here, we conducted a study to identify clinical clusters of BD. METHODS: A total of 657 patients registered in the Yokohama City University (YCU) regional BD registry between 1990 and 2018, as well as 6754 patients who were initially registered in the Japanese Ministry of Health, Labour and Welfare (MHLW) database between 2003 and 2014, were investigated. The YCU registry data regarding the clinical manifestations of BD, human leukocyte antigen (HLA) status, treatments, and hospitalizations were analyzed first, followed by similar analyses of the MHLW for validation. A hierarchical cluster analysis was independently performed in both patient groups. RESULTS: A hierarchical cluster analysis determined five independent clinical clusters in the YCU cohort. Individual counterparts of the YCU clusters were confirmed in the MHLW registry. Recent phenotypical evolutions of BD in Japan, such as increased gastrointestinal (GI) involvement, reduced complete type according to the Japan Criteria, and reduced HLA-B51 positivity were associated with chronologically changing proportions of the clinical clusters. CONCLUSIONS: In this study, we identified independent clinical clusters among BD patients in Japan and found that the proportion of each cluster varied over time. We propose five independent clusters namely "mucocutaneous", "mucocutaneous with arthritis", "neuro", "GI", and "eye."

CC chemokine receptor-1 activates intimal smooth muscle-like cells in graft arterial disease.

BACKGROUND: Graft arterial disease (GAD) limits long-term solid-organ allograft survival. The thickened intima in GAD contains smooth muscle-like cells (SMLCs), leukocytes, and extracellular matrix. The intimal SMLCs in mouse GAD lesions differ from medial smooth muscle cells in their function and phenotype. Although intimal SMLCs may originate by migration and modulation of donor medial cells or by recruitment of host-derived precursors, the mechanisms that underlie their localization within grafts and the factors that drive these processes remain unclear. METHODS AND RESULTS: This study of aortic transplantation in mice demonstrated an important function for chemokines beyond their traditional role in leukocyte recruitment and activation. Intimal SMLCs, but not medial smooth muscle cells, express functional CC chemokine receptor-1 (CCR1) and respond to RANTES by increased migration and proliferation. Although RANTES infusion in vivo promoted inflammatory cell accumulation in the adventitia of aortic allografts of wild-type and CCR1-deficient recipients, it increased GAD intimal thickening with SMLC proliferation in only the wild-type hosts. Aortic allografts transplanted into CCR1-deficient mice after wild-type bone marrow transplantation did not develop intimal lesions, which indicates that CCR1-bearing inflammatory cells do not contribute to intimal lesion formation. Moreover, RANTES induced SMLC proliferation in vitro but did not promote medial smooth muscle cell growth. Blockade of CCR5 attenuated RANTES-induced T-cell and monocyte/macrophage proliferation but did not affect RANTES-induced SMLC proliferation, consistent with a larger role of CCR1-binding chemokines in SMLC migration and proliferation and GAD development. CONCLUSIONS: These studies provide a novel mechanistic insight into the formation of vascular intimal hyperplasia and suggest a novel therapeutic strategy for preventing allograft arteriopathy.

Continuous evolution of clinical phenotype in 578 Japanese patients with Behçet's disease: a retrospective observational study.

BACKGROUND: It has been suggested that the phenotypes of Behçet's disease (BD) in Japan are changing. To ask whether the evolution of BD holds true in recent-onset cases in Japan, we performed a retrospective study. METHODS: We reviewed the records of 578 patients with BD who met the 1987 revised diagnostic criteria of the Behçet's disease research committee of Japan. The patients were divided into three groups based on the date of disease onset. We compared the demography, clinical features, and treatments among them with or without adjustment for the observation period. Patients having oral ulcers, genital ulcers, regional skin involvement, and uveitis are categorized as having complete-type BD, and the associated factors were determined by univariate and multivariate logistic regression analyses. RESULTS: Male patients had a higher propensity for uveitis and central nervous system (CNS) involvement, whereas female patients had higher rates of genital ulcers and arthritis. We found a significant trend in reduction of complete-type, genital ulcer, HLA-B51 carriers, and increment of gastrointestinal BD over time. Multiple regression analysis identified HLA-B51 positivity, earlier date of disease onset, and younger age of onset as independently associated with complete-type BD. Although treatments had been also chronologically changed, the causative relationship between therapeutic agents and phenotypical changes was not determined from the study. CONCLUSION: The present study revealed that phenotypical evolution was characterized by decreased incidence of the complete type and increment of gastrointestinal involvement in Japanese patients with BD during the last 30 years.