Structural deterioration of finger joints with ultrasonographic synovitis in rheumatoid arthritis patients with clinical low disease activity.

OBJECTIVE: In this study we investigated the relationship between synovial vascularity (SV) and structural alteration of finger joints in patients with RA and long-term sustained clinical low disease activity (CLDA). METHODS: RA patients with CLDA of >2 years (minimum 1 year of CLDA for study entry plus 1 year of observation) were analysed. Quantitative SV values were sequentially measured in each finger joint using power Doppler ultrasonography (0, 8, 20 and 52 weeks). Radiological progression of local finger joints was evaluated according to the Genant-modified Sharp score (0-52 weeks). RESULTS: Of the 25 patients enrolled, 15 patients were finally analysed after excluding 10 patients who failed to maintain CLDA during the observational period. Changes in radiological progression of MCP and PIP joints with positive SV were significantly greater than those in joints with negative SV. Joint space narrowing (JSN) was strongly related to structural alteration of finger joints. In joints with positive SV, changes in structural alteration did not relate to total SV values, which reflect total exposure to inflammation in an observational period. CONCLUSION: Even in patients with a long period of CLDA, finger joints with positive SV showed structural alteration, especially in the progression of JSN. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry, http://www.umin.ac.jp/ctr/, UMIN000007305.

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.

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.

Positive synovial vascularity in patients with low disease activity indicates smouldering inflammation leading to joint damage in rheumatoid arthritis: time-integrated joint inflammation estimated by synovial vascularity in each finger joint.

OBJECTIVE: To investigate the relationship between synovial vascularity and joint damage progression in each finger joint of patients with RA under low disease activity during treatment with biologic agents. METHODS: We studied 310 MCP and 310 PIP joints of 31 patients with active RA who were administered adalimumab (ADA) or tocilizumab (TCZ). Patients were examined with clinical and laboratory assessments. Power Doppler sonography was performed at baseline and at weeks 8, 20 and 40. Synovial vascularity was evaluated according to quantitative measurement. Hand and foot radiography was performed at baseline and at week 50. RESULTS: Composite scores of the DAS with 28 joints and the Simplified Disease Activity Index (SDAI) were significantly decreased from baseline to week 8, being sustained at a low level by biologic agents during the observational period. MCP and PIP joints with positive synovial vascularity after week 8 showed more subsequent joint damage progression than joints without synovial vascularity throughout the follow-up. The changes in radiographic progression in these joints were independent of the sum of synovial vascularity from baseline to week 40 or the occasional occurrence of positive synovial vascularity. CONCLUSION: Smouldering inflammation reflected by positive synovial vascularity under low disease activity was linked to joint damage. The damage progressed irrespective of the severity of positive synovial vascularity. Even with a favourable overall therapeutic response, monitoring of synovial vascularity has the potential to provide useful joint information to tailor treatment strategies. Trial registration. University Hospital Medical Information Network Clinical Trials Registry; http://www.umin.ac.jp/ctr/; UMIN000004476.

Convolutional neural network for classification of two-dimensional array images generated from clinical information may support diagnosis of rheumatoid arthritis.

This research aimed to study the application of deep learning to the diagnosis of rheumatoid arthritis (RA). Definite criteria or direct markers for diagnosing RA are lacking. Rheumatologists diagnose RA according to an integrated assessment based on scientific evidence and clinical experience. Our novel idea was to convert various clinical information from patients into simple two-dimensional images and then use them to fine-tune a convolutional neural network (CNN) to classify RA or nonRA. We semi-quantitatively converted each type of clinical information to four coloured square images and arranged them as one image for each patient. One rheumatologist modified each patient's clinical information to increase learning data. In total, 1037 images (252 RA, 785 nonRA) were used to fine-tune a pretrained CNN with transfer learning. For clinical data (10 RA, 40 nonRA), which were independent of the learning data and were used as testing data, we compared the classification ability of the fine-tuned CNN with that of three expert rheumatologists. Our simple system could potentially support RA diagnosis and therefore might be useful for screening RA in both specialised hospitals and general clinics. This study paves the way to enabling deep learning in the diagnosis of RA.

Cobalt concentration in urine as an indicator of occupational exposure to low level cobalt oxide.

The aim of this study was to verify the relationship between the cobalt oxide concentration in air and the cobalt concentration in urine. In the first study, we measured the cobalt concentration in the urine of 16 workers exposed to cobalt oxide in a Digital Video Cassette manufacturing plant at the beginning and end of their workshift during 2 working cycles. In the second study, we measured the exposure level to cobalt oxide and the cobalt concentration in urine at the end of the workshift of other 16 workers on 3 out of 5 consecutive work days (Monday, Wednesday and Friday). Four workers among the 16 participated twice. In the first study, the cobalt concentration in the urine increased about 1.5-3 fold during each workshift and then tended to decrease rapidly to the control value before the next workshift. In the second study, we examined the relationship between air and urine concentration using 22 samples after excluding data from workers with dust respirators. Comparing the air and urine concentrations for samples under 30 microg/m3 (n = 20), a significant correlation was found (r = 0.76). These results indicate that most of the inhaled cobalt oxide was excreted rapidly, and a good relationship was found between air and urine concentrations at the end of the workshift when the exposure level was under 30 microg/m3. Therefore, the cobalt concentration in urine at the end of a workshift can be used as an indicator of one-day exposure to cobalt oxide when the exposure is low level.

Active synovitis in the presence of osteitis predicts residual synovitis in patients with rheumatoid arthritis with a clinical response to treatment.

AIM: To clarify the relationship between active synovitis/osteitis and subsequent residual synovitis (R-synovitis) in patients with rheumatoid arthritis (RA). METHODS: Three hundred and twenty finger joints of 16 patients with active RA at baseline (Disease Activity Score with 28 joints - erythrocyte sedimentation rate > 3.2) who subsequently achieved clinical low disease activity or remission afterwards were analyzed. Synovial vascularity (SV) was assessed according to a semi-quantitative ultrasound score (grades 0-3). Active synovitis was defined by SV positivity at baseline. R-synovitis was defined by the presence of grade > 2 SV at the 24th week. Osteitis was detected by magnetic resonance imaging (MRI) at baseline as trabecular bone lesions with water content and indistinct margins. RESULTS: Ultrasonography detected active synovitis in 116 joints at baseline. Forty-seven joints had R-synovitis at the 24th week. MRI detected osteitis in 12 joints at baseline. The presence of active synovitis with osteitis at baseline was significantly correlated with R-synovitis at the 24th week. CONCLUSIONS: Active synovitis in the presence of osteitis predicted R-synovitis regardless of whether there was a clinical improvement in RA.

Centrally administered orexin-A activates corticotropin-releasing factor-containing neurons in the hypothalamic paraventricular nucleus and central amygdaloid nucleus of rats: possible involvement of central orexins on stress-activated central CRF neurons.

We examined the effects of centrally administered orexin-A on corticotropin-releasing factor (CRF)-containing neurons in the hypothalamic paraventricular nucleus (PVN) and the central amygdaloid nucleus (CeA) of rats, using dual immunostaining for CRF and Fos. Ninety minutes after intracerebroventricular administration of orexin-A, approximately 96% and 45% of CRF-containing neurons expressed Fos-like immunoreactivity (LI) in the PVN and the CeA, respectively. We also examined the effects of immobilized stress and cold exposure on orexin-A-containing neurons in the rat hypothalamus using dual immunostaining for orexin-A and Fos. After immobilized stress for 20 min and cold exposure at 4 degrees C for 30 min, approximately 24% and 15% of orexin-A-containing neurons expressed Fos-LI, respectively. These results suggest that orexins in the central nervous system may be involved in the activation of central CRF neurons induced by stress.

Radiographic prognosis of finger joint damage predicted by early alteration in synovial vascularity in patients with rheumatoid arthritis: Potential utility of power doppler sonography in clinical practice.

OBJECTIVE: To investigate the relationship between synovial vascularity and progression of structural bone damage in each finger joint in patients with rheumatoid arthritis (RA) and to demonstrate synovial vascularity as a potential therapeutic marker. METHODS: We studied 250 metacarpophalangeal (MCP) and 250 proximal interphalangeal (PIP) joints of 25 patients with active RA who were administered adalimumab or tocilizumab. Patients were examined with clinical and laboratory assessments. Power Doppler sonography was performed at baseline and at the fourth and eighth weeks. Synovial vascularity was evaluated according to quantitative measurement. Hand and foot radiography was performed at baseline and the twentieth week. RESULTS: Clinical indices such as the 28-joint Disease Activity Score, the Clinical Disease Activity Index, and the Simplified Disease Activity Index were significantly decreased by biologic agents. The MCP and PIP joints with no response in synovial vascularity between baseline and the eighth week (vascularity improvement of ≤70% at the eighth week) showed a higher risk of radiographic progression compared with responsive joints (vascularity improvement of >70% at the eighth week; relative risk 2.33-9). Radiographic progression at the twentieth week was significantly lower in responsive joints than in nonresponsive joints. CONCLUSION: The improvement of synovial vascularity following treatment with biologic agents led to suppression of radiographic progression of RA in each finger joint. The alteration in synovial vascularity numerically reflected therapeutic efficacy. Using vascularity as a marker to determine the most suitable therapeutic approach would be beneficial for patients with active RA.

Change of synovial vascularity in a single finger joint assessed by power doppler sonography correlated with radiographic change in rheumatoid arthritis: comparative study of a novel quantitative score with a semiquantitative score.

OBJECTIVE: To investigate the relationship between synovial vascularity assessed by quantitative power Doppler sonography (PDS) and progression of structural bone damage in a single finger joint in patients with rheumatoid arthritis (RA). METHODS: We studied 190 metacarpophalangeal (MCP) joints and 190 proximal interphalangeal (PIP) joints of 19 patients with active RA who had initial treatment with disease-modifying antirheumatic drugs (DMARDs). Patients were examined by clinical and laboratory assessments throughout the study. Hand and foot radiography was performed at baseline and the twentieth week. Magnetic resonance imaging (MRI) was performed at baseline. PDS was performed at baseline and the eighth week. Synovial vascularity was evaluated according to both quantitative and semiquantitative methods. RESULTS: Quantitative PDS was significantly correlated with the enhancement rate of MRI in each single finger joint. Comparing quantitative synovial vascularity and radiographic change in single MCP or PIP joints, the level of vascularity at baseline showed a significant positive correlation with radiographic progression at the twentieth week. The change of vascularity in response to DMARDs, defined as the percentage change in vascularity by the eighth week from baseline, was inversely correlated with radiographic progression in each MCP joint. The quantitative PDS method was more useful than the semiquantitative method for the evaluation of synovial vascularity in a single finger joint. CONCLUSION: The change of synovial vascularity in a single finger joint determined by quantitative PDS could numerically predict its radiographic progression. Using vascularity as a guide to consider a therapeutic approach would have benefits for patients with active RA.

Power Doppler ultrasound of rheumatoid synovitis: quantification of vascular signal and analysis of interobserver variability.

OBJECTIVE: The objective of this study was to assess interobserver uncertainties in power Doppler (PD) examination of the fingers of patients with rheumatoid arthritis (RA), by separating the source of the discrepancy into (1) acquisition of the images and (2) criteria for assessment of the images. MATERIALS AND METHODS: Twenty patients who had been diagnosed with RA were enrolled in this study. Ultrasound examinations were performed by one inexperienced and two experienced sonographers. Interobserver variation was measured using a conventional semiquantitative image grading scale. Interobserver variation of the quantitative PD (QPD) index (the summation of the colored pixels in a region of interest) was also assessed. RESULTS: The agreement was higher between the two experienced sonographers (kappa value of 0.8) than between experienced and inexperienced sonographers (kappa value, 0.6-0.7) in the semiquantitative image grading scale. Results suggest that the difference in the assessment on the image grading scale was due more to the difference in the acquisition of the images than to variations in the grading criteria between sonographers. An excellent relationship was noted between the image grading scale and the QPD index for Doppler signal with a Spearman's coefficient of rank correlation of 0.83 (P < 0.0001). CONCLUSIONS: Interobserver discrepancies in the image grading and QPD index methods were due more to the difference in the acquisition of the image than to the grading criteria used. The QPD index seems to be as reliable as the image grading scale with reasonable interobserver agreement between experienced sonographers.

Fos expression in CRF-containing neurons in the rat paraventricular nucleus after central administration of neuromedin U.

We examined the effects of centrally administered neuromedin U (NMU) on corticotrophin-releasing factor (CRF)-containing neurons in the hypothalamic paraventricular nucleus (PVN) of rats, using double immunohistochemistry for CRF and Fos. Almost all CRF-containing neurons in the parvocellular divisions of the PVN expressed Fos-like immunoreactivity 90 min after intracerebroventricular administration of NMU (3 nmol/rat). This results suggest the possibility that central NMU may be involved in stress-induced activation of CRF-containing neurons in the PVN.