Katsumi Eguchi

A prediction rule for disease outcome in patients with undifferentiated arthritis using magnetic resonance imaging of the wrists and finger joints and serologic autoantibodies

OBJECTIVEnTo evaluate whether magnetic resonance imaging (MRI) of the wrists and finger joints and an analysis of serologic autoantibodies are clinically meaningful for the subsequent development of rheumatoid arthritis (RA) in patients with undifferentiated arthritis (UA).nnnMETHODSnA total of 129 patients with UA, a disease status formally confirmed by a rheumatologist over a period of at least 1 year, were included. Gadolinium-diethylenetriamine-enhanced MRI of both wrists and finger joints and serologic variables were examined upon admission to our Early Arthritis Clinic at Nagasaki University. After a prospective followup of 1 year, a predictive value for the development of RA was determined for each patient.nnnRESULTSnThe subjects were evaluated for their positive or negative status with respect to 3 objective measures at study entry: anti-cyclic citrullinated peptide (anti-CCP) antibodies and/or IgM-rheumatoid factor, MRI-proven symmetric synovitis, and MRI-proven bone edema and/or bone erosion. The patients who were positive for at least 2 of these measures progressed to RA at 1 year with a 79.7% positive predictive value (PPV), 63.0% negative predictive value, 75.9% specificity, 68.0% sensitivity, and 71.3% accuracy. Furthermore, in 22 UA patients positive for both anti-CCP antibodies and MRI-proven bone edema who were considered to have progressed to RA at 1 year, the PPV was increased to 100%. A close correlation was found between the present rule and that established in the Leiden Early Arthritis Cohort.nnnCONCLUSIONnMRI-proven early joint damage in conjunction with serologic autoantibodies is efficient in predicting progression from UA to RA. This method can be used to identify patients who would benefit from early treatment with disease-modifying antirheumatic drugs.

The power Doppler ultrasonography score from 24 synovial sites or 6 simplified synovial sites, including the metacarpophalangeal joints, reflects the clinical disease activity and level of serum biomarkers in patients with rheumatoid arthritis

OBJECTIVEnWe evaluated the significance of the power Doppler ultrasonography (PDUS) score by comparing it with serum biomarkers and clinical disease activity.nnnMETHODSnWe measured the PDUS scores of 24 synovial sites in 12 joints in 22 RA patients. For convenience, the PDUS scores of six synovial sites in six joints were also examined. Each joint was scored for a power Doppler (PD) signal on a scale from 0 to 3. The PDUS scores are the sums of the PD signal scores for the 24 synovial sites or the 6 synovial sites. On the same day, serum variables as well as clinical disease activity were evaluated.nnnRESULTSnThe PDUS scores from the 24 joint sites were significantly positively correlated with DAS of 28 joints (DAS-28), simplified disease activity index (SDAI), clinical disease activity index (CDAI) and serum biomarkers including MMP-3, VEGF and tissue inhibitor of metalloproteinases-1 (TIMP-1). Accordingly, the PDUS scores from the six synovial sites greatly correlated with those from the 24 joint sites. Clinical disease activities as well as serum variables were also clearly correlated with the PDUS scores from the six synovial sites.nnnCONCLUSIONnThe standard as well as the simplified PDUS scores well reflected clinical disease activity and serum variables, including angiogenic factors. Our data reaffirm the utility of ultrasonography for monitoring disease activity in patients with RA.

Association between anti-ZnT8 autoantibody specificities and SLC30A8 Arg325Trp variant in Japanese patients with type 1 diabetes.

Aims/hypothesisWe analysed the association between humoral autoreactivity to zinc transporter-8 (ZnT8) and the SLC30A8 rs13266634 polymorphism (Arg325Trp), which is located at the most distal loop in the ZnT8 protein.MethodsAutoantibodies to ZnT8 were determined by RIA in 270 patients with type 1 diabetes using ZnT8 carboxy-terminal constructs (amino acids 268–369) carrying 325Trp(CW) and 325Arg(CR) and a hybrid construct (CW-CR). Forty-four ZnT8 autoantibody-positive sera with genomic DNA were used to examine the association between reactivity to ZnT8 constructs and the rs13266634 genotype.ResultsSeventy-five patients reacted to the CW-CR hybrid construct, whereas 37 and 36 patients reacted to the CW and CR constructs, respectively. All sera positive for either CW or CR autoantibodies were positive for CW-CR autoantibodies. Among 19 patients with a 325Arg(CC) genotype, 5% had CW-specific autoantibodies, 42% had CR-specific autoantibodies and 32% had dual reactivity. Conversely, 73% of 15 patients with the 325Trp(TT) genotype had CW-specific autoantibodies, no patients had CR-specific autoantibodies and 13% had dual reactivity. Nine of the ten patients (90%) with the CT genotype reacted with either CR or CW constructs. The titre of CR autoantibodies in patients carrying the C allele was significantly higher than that in TT homozygotes (pu2009<u20090.0001). In contrast, the titre of CW autoantibodies in patients carrying a T allele was significantly higher than that in CC homozygotes (pu2009<u20090.005). No evidence of an association between rs13266634 and type 1 diabetes was observed.Conclusions/interpretationThese results indicate that variant residue at amino acid 325 is a key determinant of humoral autoreactivity to ZnT8 and that the SLC30A8 genotype is an important determinant of autoantibody specificity.

A significantly impaired natural killer cell activity due to a low activity on a per-cell basis in rheumatoid arthritis.

To elucidate the characterization of peripheral natural killer (NK) cells in patients with rheumatoid arthritis (RA), we investigated the NK cell activity, the expression of NK cell activating receptors and intracellular molecules. The NK activity was analyzed in 27 RA patients, 22 primary Sjögren’s syndrome (SS) patients, and 15 healthy individuals using the 51Chrominium release assay. The expression of NK cell activating receptors (NKG2D, CD244, CD2, and CD16) and intracellular molecules (granzyme B, perforin, and TCR ζ chain) in CD3-CD56+ cells were characterized by flow cytometry. The serum cytokine levels (IL-6, TNFα, and IL-18) were measured using ELISA. Both the NK cell activity and the activity on a per-cell basis were observed to significantly decrease in the RA patients in comparison to the controls. The expression of NKG2D and CD244 also significantly decreased in both the RA and primary SS patients, whereas the significant decrease in the CD16 expression was only observed in the RA patients. The titer of the serum IL-6, TNFα, and IL-18 was significantly higher in the RA patients than in the controls. These data suggest that a low NK activity on a per-cell basis might therefore contribute to an impaired NK activity in the patients with RA.

Musculoskeletal ultrasonography assists the diagnostic performance of the 2010 classification criteria for rheumatoid arthritis

ObjectiveWe investigated whether musculoskeletal ultrasonography (MSKUS) assists the diagnostic performance of the 2010 rheumatoid arthritis (RA) classification criteria.MethodsSixty-nine early arthritis patients were consecutively enrolled. None of the patients had been treated. In MSKUS of bilateral wrist and finger joints from 22 sites, the findings obtained by gray-scale and power Doppler (PD) assessment were graded on a semiquantitative scale from 0 to 3. Plain magnetic resonance imaging (MRI) of both wrist and finger joints was also examined. Diagnosis of RA was defined by the initiation of disease-modifying antirheumatic drugs within the first 3xa0months. The diagnostic performance of the patients was evaluated at entry using 2010 RA classification criteria in conjunction with MSKUS.ResultsThe indispensable MSKUS finding for differentiating RA was the presence of a PD grade 2 or 3 that was superior to 2010 RA classification criteria or MRI-proven bone edema. We propose that the decision tree algorithm of 2010 RA classification criteria with PD grade 2 or 3 reveals the best discriminative ability.ConclusionMSKUS, especially with a strong PD signal, is very useful to assist the diagnostic performance of the 2010 RA classification criteria in the early recognition of RA.

Autoantibodies to Insulin, Insulinoma-Associated Antigen-2, and Zinc Transporter 8 Improve the Prediction of Early Insulin Requirement in Adult-Onset Autoimmune Diabetes

OBJECTIVEnThe aim of this study was to identify the predictive marker for early insulin requirement in adult-onset autoimmune diabetes in the Japanese populations.nnnDESIGN/PATIENTSnWe analyzed insulin autoantibodies (IAA), insulinoma-associated antigen-2 (IA-2) autoantibodies (IA-2icA), and zinc transporter 8 (ZnT8) autoantibodies (ZnT8A) by radioimmunoassay in 47 Japanese patients with adult-onset autoimmune diabetes who were identified by native GAD autoantibody (nGADA) screening of approximately 3000 non-insulin-requiring diabetes patients and 302 nGADA-negative type 2 diabetes patients. Furthermore, GAD65 autoantibody-specific epitopes were also analyzed using GAD65/GAD67 chimeric constructs.nnnRESULTSnThe prevalence of IAA, IA-2icA, and ZnT8A in nGADA-positive patients was 26, 15, and 19%, respectively, which was significantly higher than that in nGADA-negative type 2 diabetes (2, 2, and 2%; P < 0.0001). Among nGADA-positive patients, 38% had one or more of IAA, IA-2icA, or ZnT8A, and 15% had two or more of these autoantibodies, compared with none of the nGADA-negative patients (P < 0.0001). Thirty-six percent of nGADA-positive patients subsequently required insulin therapy; and high nGADA titer (log-rank P = 0.003), middle epitope recognition of GAD65A (P = 0.002), and the presence of one or more of IAA, IA-2icA, or ZnT8A (P = 0.002) at diagnosis marked the risk for early requirement of insulin therapy. Multivariate logistic regression analysis showed the multiple islet autoantibodies to be independently associated with the risk for insulin requirement (odds ratio = 13.77; 95% confidence interval, 2.77-68.45; P = 0.001).nnnCONCLUSIONSnThese results indicate that the determination of IAA, IA-2icA, and ZnT8A improves the prediction of a future insulin insufficiency in adult-onset autoimmune diabetes, which appears to be superior to GADA titer and GAD65A-specific epitopes.

Proinflammatory Cytokines Synergistically Enhance the Production of Chemokine Ligand 20 (CCL20) from Rheumatoid Fibroblast-like Synovial Cells in vitro and Serum CCL20 Is Reduced in vivo by Biologic Disease-modifying Antirheumatic Drugs

Objective. Chemokine ligand 20 (CCL20) is a selective ligand for chemokine receptor 6 (CCR6). We investigated, both in vitro and in vivo, whether CCL20 is critically involved in the disease process of rheumatoid arthritis (RA). Methods. In vitro study investigated the effect of proinflammatory cytokines and biologic disease-modifying antirheumatic drugs (DMARD) on the production of CCL20 by rheumatoid fibroblast-like synovial cells (FLS). The in vivo role of CCL20 was studied by screening for serum CCL20 concentration in patients with RA during the therapeutic course of biologic DMARD, i.e., infliximab, etanercept, and tocilizumab. Results. Spontaneous CCL20 production from rheumatoid FLS was minimal; however, its production was significantly stimulated by interleukin 1ß (IL-1ß), tumor necrosis factor-α (TNF-α), or IL-17. IL-1ß was the most potent for stimulating the production of CCL20. CCL20 production was synergistically augmented by a combination of IL-1ß, TNF-α, and IL-17. In contrast, interferon-γ suppressed IL-1ß-induced CCL20 production. IL-6, in combination with soluble IL-6 receptor (sIL-6R), did not modulate CCL20 production, whereas IL-1ß-induced, TNF-α-induced, and IL-17-induced production were increased by IL-6. These production levels were clearly suppressed by biologic DMARD in vitro. Serum CCL20 was significantly higher in RA than in control subjects, and was clearly decreased by the treatment with infliximab, etanercept, and tocilizumab. Conclusion. Proinflammatory cytokines modulate the production of CCL20 from FLS. Our data suggest that therapeutic efficacy of biologic DMARD may result from the inhibition of CCL20 production in rheumatoid synovium.

Ultrasonographic examination of rheumatoid arthritis patients who are free of physical synovitis: power Doppler subclinical synovitis is associated with bone erosion

OBJECTIVEnThe aim of this study was to investigate the characteristics of power Doppler (PD) subclinical synovitis in patients with RA who achieve clinical remission free from physical synovitis.nnnMETHODSnTwenty-nine RA patients were consecutively enrolled. All of the patients had achieved clinical remission [simplified disease activity index (SDAI) 3.3] for at least 6 months at the musculoskeletal ultrasound (MSKUS) examination. Additionally, none of the patients exhibited tender joints at 68 sites or swollen joints at 66 sites. MSKUS of bilateral wrist and finger joints, including the first to fifth MCP joints, the first IP joint and the second to fifth PIP joints, was performed and the findings obtained by grey scale (GS) and PD were graded on a semi-quantitative scale from 0 to 3.nnnRESULTSnThe median disease duration upon the introduction of DMARDs was 3 months and that at MSKUS examination was 21 months. The percentages of patients with PD synovitis in at least one joint were PD grade 1, 58.6%; PD grade 2, 31.0% and PD grade 3, 6.9%. The use of biological agents was low in patients with PD synovitis grade 2 (P < 0.05). The presence of US bone erosion was high by patient (P < 0.05) and by joint (P < 0.0001) with PD synovitis as compared with those without PD synovitis. However, no correlations were found between PD synovitis measures and serum biomarkers, including angiogenesis factors.nnnCONCLUSIONnPD subclinical synovitis correlates with several clinical characteristics, whereas conventional serum biomarkers are not useful for indicating the presence of subclinical PD synovitis.

CD4+CD25(high)CD127(low/-) Treg cell frequency from peripheral blood correlates with disease activity in patients with rheumatoid arthritis.

Objective. To investigate whether the frequency of peripheral blood (PB) regulatory T cells (Treg) correlates with the clinical disease activity of rheumatoid arthritis (RA). Methods. PB Treg cells, defined as the CD4+CD25highCD127low/- population, were examined by flow cytometry in 48 patients with RA, including 13 who had never received disease-modifying antirheumatic drugs (DMARD), 19 with active disease who were receiving (n = 14) or had received (n = 5) DMARD, and 16 receiving DMARD whose disease was in remission. The clinical disease activity of the patients was defined by the 28-joint Disease Activity Score (DAS28). The association of DAS28, C-reactive protein (CRP), or erythrocyte sedimentation rate (ESR) with the frequency of PB Treg cells was examined. Results. The frequency of PB Treg cells in patients with RA was significantly low compared with that of healthy controls (n = 14). Among the 3 populations of patients with RA, Treg cell frequency was lowest in patients with active RA. In contrast, the Treg cell frequency of patients with RA in remission was similar to that of healthy controls. Accordingly, the frequency of CD4+CD25highCD127low/- Treg cells negatively correlated with DAS28, CRP, and ESR in patients with RA. Conclusion. The data suggest that Treg cells, defined as the CD4+CD25highCD127low/- population, may contribute to the pathogenesis of RA and be an indicator of disease activity.

Differences in the humoral autoreactivity to zinc transporter 8 between childhood- and adult-onset type 1 diabetes in Japanese patients

The aim of this study was to evaluate the humoral autoreactivity to zinc transporter 8 (ZnT8) depending on the clinical phenotype of type 1 diabetes (T1D). ZnT8 autoantibodies (ZnT8A) were determined by radioimmunoassay using carboxy-terminal ZnT8 constructs in 57 childhood-onset, 97 adult-onset, and 85 fulminant T1D. The ZnT8A frequency was higher in childhood-onset patients and decreased with increasing age of onset from 70% to 24% (P(trend)<0.005). None of the patients with fulminant T1D was positive for ZnT8A. There were at least two distinct ZnT8A epitope patterns associated with the aa325-restriction, childhood-onset patients have aa325-nonrestricted response more frequently compared to the adult-onset group (P<0.05). The level of ZnT8A was inversely associated with the copy number of HLA-DR4 allele (P<0.05). These results suggest differences in the humoral autoreactivity to ZnT8 depending on the clinical phenotype, which should provide strategy for autoantibody measurement in subjects to allow early diagnosis of autoimmune T1D.