Daiki Nakagomi

Prediction of Relapse After Discontinuation of Biologic Agents by Ultrasonographic Assessment in Patients With Rheumatoid Arthritis in Clinical Remission: High Predictive Values of Total Gray‐Scale and Power Doppler Scores That Represent Residual Synovial Inflammation Before Discontinuation

This prospective study aimed to determine whether the comprehensive ultrasonographic assessment of synovial inflammation predicts relapse after discontinuation of treatment with a biologic agent in patients with rheumatoid arthritis (RA) in clinical remission.

[18F]FDG uptake in proximal muscles assessed by PET/CT reflects both global and local muscular inflammation and provides useful information in the management of patients with polymyositis/dermatomyositis

OBJECTIVE This study aimed to determine whether [(18)F]fluorodeoxyglucose-PET/CT ([(18)F]FDG-PET/CT) discriminates PM/DM from non-muscular diseases and also whether FDG uptake in proximal muscles reflects the activity and severity of muscular inflammation in PM/DM. METHODS Twenty treatment-naïve PM/DM patients who underwent [(18)F]FDG-PET/CT were retrospectively identified by reviewing medical records. The same number of age- and sex-matched control patients with non-muscular diseases were also identified. Standardized uptake value (SUV) was calculated for each of the seven proximal muscles. For patient-based assessment, mean proximal muscle SUV was calculated by averaging the SUVs for these proximal muscles bilaterally. RESULTS Mean proximal muscle SUVs were significantly greater in PM/DM patients than in control patients (median 1.05 vs 0.69, P < 0.001). Mean proximal muscle SUVs significantly correlated with mean proximal manual muscle test scores (ρ = 0.49, P = 0.028) and serum levels of creatine kinase (ρ = 0.54, P = 0.015) and aldolase (ρ = 0.64, P = 0.002). Furthermore, SUVs in proximal muscles from which biopsy specimens were obtained significantly correlated with histological grade for inflammatory cell infiltration (ρ = 0.66, P = 0.002). CONCLUSION Our results suggest that [(18)F]FDG-PET/CT is useful in the diagnosis of PM/DM when inflammation in proximal muscles is globally assessed with quantitative measurements. Our results also indicate that local FDG uptake in a proximal muscle reflects the activity of inflammation in the same muscle and provides useful information in determining the region for muscle biopsy.

Correlation of Radiographic Progression with the Cumulative Activity of Synovitis Estimated by Power Doppler Ultrasound in Rheumatoid Arthritis: Difference Between Patients Treated with Methotrexate and Those Treated with Biological Agents

Objective. Our prospective study aimed to demonstrate that the cumulative synovial power Doppler (PD) ultrasound scores correlate with radiographic progression better than conventional measures in patients with rheumatoid arthritis (RA). We also investigated the difference between antirheumatic agents. Methods. Sixty-nine patients with RA who had recently received either methotrexate (MTX; n = 23), tumor necrosis factor (TNF) antagonists (n = 28), or tocilizumab (TCZ; n = 18) were enrolled. Patients underwent clinical, laboratory, and ultrasonographic assessment at baseline, 12 weeks, and 24 weeks. Radiographic damage was evaluated using van der Heijde modified total Sharp score (TSS) at baseline and 24 weeks. Results. Fifty-seven patients continued the same treatment regimen for 24 weeks and completed the study, and 21 patients (36.8%) showed radiographic progression during the study period. In all patients, ΔTSS significantly correlated both with cumulative 28-joint Disease Activity Score–C-reactive protein (DAS28-CRP; ρ = 0.342, p = 0.009) and cumulative total PD scores (ρ = 0.357, p = 0.006). In MTX-treated patients, cumulative total PD scores significantly correlated with ΔTSS (ρ = 0.679, p = 0.004), whereas cumulative DAS28-CRP did not (ρ = 0.487, p = 0.056). However, cumulative total PD scores did not correlate with ΔTSS in TNF antagonist–treated or TCZ-treated patients. Conclusion. Our data confirm the evidence that synovial PD activity more accurately reflects active synovial inflammation (which actually causes joint destruction) than do conventional measures in patients treated with MTX. Our data also indicate that TNF antagonists can inhibit short-term radiographic progression in the presence of active synovitis.

Erratum to: Bucillamine-induced yellow nail in Japanese patients with rheumatoid arthritis: two case reports and a review of 36 reported cases

Yellow nail syndrome is an idiopathic condition characterized by a triad consisting of yellow nail, lymphedema, and pulmonary manifestations. Thiol compounds such as D-penicillamine have been reported to be the major cause of drug-induced yellow nail syndrome in patients with rheumatoid arthritis (RA). We recently experienced two Japanese cases with RA who developed yellow nail under treatment with bucillamine, a thiol-containing anti-rheumatic drug developed and approved in Japan. We reviewed the literature for similar cases and identified 36 RA cases with bucillamine-induced yellow nail, mostly in Japanese medical journals. Most of these cases (90.3%) showed improvement of yellow nail after discontinuation of bucillamine, whereas lymphedema and pulmonary manifestations improved only in 30.8 and 35.0% of the patients, respectively.

Prevalence and Responsiveness to Treatment of Lung Abnormalities on Chest Computed Tomography in Patients With Microscopic Polyangiitis: A Multicenter, Longitudinal, Retrospective Study of One Hundred Fifty Consecutive Hospital-Based Japanese Patients.

To determine the prevalence of lung abnormalities on chest computed tomography (CT) in patients with microscopic polyangiitis (MPA), to assess the responsiveness of such abnormalities to initial treatment, and to assess associations between these abnormalities and patient and disease characteristics and mortality.

Efficacy of abatacept for arthritis in patients with an overlap syndrome between rheumatoid arthritis and systemic lupus erythematosus.

Introduction. This study aimed to investigate the efficacy of abatacept for arthritis in patients with rhupus, an overlap syndrome between rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Methods. Patients who fulfilled both the 2010 ACR/EULAR criteria for RA classification and the 1997 ACR revised criteria for classification of SLE and received abatacept treatment for arthritis were retrospectively studied. Results. Six rhupus patients who fulfilled the inclusion criteria above were identified. All patients had active arthritis despite receiving antirheumatic drugs including methotrexate when abatacept was initiated. Clinical Disease Activity Index (CDAI) significantly decreased between baseline and 12 weeks (P = 0.028) and remained low through 24 weeks. All patients achieved either a good or moderate response according to the EULAR response criteria at 24 weeks. Health Assessment Questionnaire-Disability Index (HAQ-DI) also significantly decreased between baseline and 24 weeks (P = 0.043). In addition, the levels of immunoglobulin G and anti-DNA antibody significantly decreased between baseline and 24 weeks (P = 0.028 and P = 0.043, resp.). Conclusions. Treatment with abatacept is likely to be efficacious in patients with rhupus whose arthritis is refractory to methotrexate. In addition, abatacept may have a moderate effect on abnormal antibody production in rhupus patients.

Prevalence and responsiveness to treatment of lung abnormalities on chest computed tomography in patients with microscopic polyangiitis – a multicenter, longitudinal, retrospective study of 150 hospital‐based consecutive Japanese patients

To determine the prevalence of lung abnormalities on chest computed tomography (CT) in patients with microscopic polyangiitis (MPA), to assess the responsiveness of such abnormalities to initial treatment, and to assess associations between these abnormalities and patient and disease characteristics and mortality.

Critical Roles of IĸB Kinase Subunits in Mast Cell Degranulation

The IĸB kinase (IKK) complex plays a crucial role in the activation of the transcription factor NF-ĸB by phosphorylating an inhibitory molecule IĸBα. Recently, we showed that IKK2 (also called IKKβ), a catalytic subunit of the IKK complex, induces immunoglobulin E-mediated degranulation in mast cells by phosphorylating SNAP-23, the target-membrane soluble N-ethylmaleimide-sensitive fusion factor attachment protein receptor (SNARE). In addition to IKK2, a recent study has shown that ELKS, a regulatory subunit of the IKK complex, also induces the degranulation of rat basophilic leukemia cells. These findings indicate that the two subunits of the IKK complex, IKK2 and ELKS, function not only in NF-ĸB-dependent transcriptional activation but also in NF-ĸB-independent pathways. This review focuses on the functions of IKK2 and ELKS in mast cell degranulation.

STAT4 Is Required for IFN-β-Induced MCP-1 mRNA Expression in Murine Mast Cells

Background: Mast cells are immunocompetent cells that are found in almost all tissues and function as sentinels of immune responses. Recently, it has been shown that mast cells play significant roles in innate immune responses. However, it is still largely unknown whether signal transducers and activators of transcription 4 (STAT4), one of the STAT proteins under type I IFN signaling, is involved in type I IFN-mediated gene expression in mast cells. Methods: We investigated the role of STAT4 in IFN-β-induced gene expression in mast cells by using STAT4-deficient (STAT4–/–) bone marrow-derived mast cells (BMMCs). Results: STAT4 was expressed in BMMCs and activated in response to IFN-β but not to IL-12 or IL-23. The development of BMMCs as well as IgE-induced degranulation of BMMCs was normal in STAT4–/– mice. On the other hand, while IFN-β-induced mRNA expression of interferon-induced protein with tetratricopeptide repeats 1 (IFIT-1), protein kinase interferon-inducible double stranded RNA dependent (PKR), and myxovirus resistance 1 (Mx1) was similar between STAT4–/– BMMCs and wild-type (WT) BMMCs, IFN-β-induced MCP-1 mRNA expression was severely diminished in STAT4–/– BMMCs as compared with WT BMMCs. Conclusions: STAT4 plays an essential role in IFN-β-induced MCP-1 mRNA expression in mast cells.

Analysis of the factors which influence the measurement of synovial power Doppler signals with semi-quantitative and quantitative measures - a pilot multicenter exercise in Japan.

Abstract Objectives. This pilot multicenter exercise aimed to evaluate the inter-observer reproducibility of synovial power Doppler (PD) signals in rheumatoid arthritis (RA) patients and to determine the factors influencing the measurements. Methods. Two representative RA patients were assessed by four independent experienced sonographers. The influence of machine difference, deterioration of the transducer and pulse repetition frequency (PRF) on the assessment of synovial PD signals was investigated. Results. Intra-class correlation coefficient (ICC) for the scanner–reader reproducibility of semi-quantitative PD score was high (0.867). ICC for the inter-scanner reproducibility of synovial PD pixel count was higher than that of semi-quantitative PD score. The assessment of PD signals significantly differed between two machines with quantitative measurements but did not with semi-quantitative score. The assessment of PD signals with a deteriorated transducer was much less sensitive than that with an intact one. The semi-quantitative scores for PD signals were comparable between three different PRFs (500/800/1,300 Hz), whereas the pixel count was significantly lower with the highest one in the knee joint. Conclusions. Measurement of PD signal can be substantially affected by deteriorated quality of the transducer, whereas the differences are relatively modest between machines with similar specifications and also between PRF settings within a low range.