Asami Abe

Procalcitonin is a specific marker for detecting bacterial infection in patients with rheumatoid arthritis.

Objective. Rheumatoid arthritis (RA) is a chronic inflammatory disease accompanied by many complications, and serious infections are associated with many of the advanced therapeutics used to treat it. We assessed serum procalcitonin (PCT) levels to distinguish bacterial infection from other complications in patients with RA. Methods. One hundred eighteen patients experiencing an RA flare, noninfectious complication of RA or its treatment, nonbacterial infection, or bacterial infection were studied. Serum PCT concentrations were determined with a chemiluminescent enzyme immunoassay. Results. All patients experiencing an RA flare showed negative PCT levels (≤ 0.1 ng/ml; n = 18). The PCT level was higher in the bacterial infection group (25.8% had levels ≥ 0.5 ng/ml) than in the other 3 groups (0.0–4.3% had levels ≥ 0.5 ng/ml) and the difference was significant among groups (p = 0.003). Conversely, no statistically significant difference was observed among the groups with C-reactive protein (CRP) concentration ≥ 0.3 mg/dl (p = 0.513), white blood cell (WBC) count > 8500/mm3 (p = 0.053), or erythrocyte sedimentation rate (ESR) > 15 mm/h (p = 0.328). The OR of high PCT level (≥ 0.5 ng/ml) for detection of bacterial infection was 19.13 (95% CI 2.44–149.78, p = 0.005). Specificity and positive likelihood ratio of PCT ≥ 0.5 ng/ml were highest (98.2% and 14.33, respectively) for detection of bacterial infection, although the sensitivity was low (25.8%). Conclusion. Serum PCT level is a more specific marker for detection of bacterial infection than either CRP, ESR, or WBC count in patients with RA. High PCT levels (≥ 0.5 ng/ml) strongly suggest bacterial infection. However, PCT < 0.5 ng/ml, even if < 0.2 ng/ml, does not rule out bacterial infection and physicians should treat appropriately.

The Role of the Thymus in Development of Necrotizing Arteritis in Transgenic Rats Carrying the env-pX Gene of Human T-Cell Leukemia Virus Type-I

Necrotizing arteritis mimicking polyarteritis nodosa occurred in transgenic rats carrying the env-pX gene of human T-cell leukemia virus type I. To investigate the pathogenesis of necrotizing arteritis in these rats (env-pX rats), adoptive transfers of spleen cells and bone marrow cells were done from env-pX rats before they developed arteritis to nontransgenic rats. Necrotizing arteritis occurred in lethally irradiated nontransgenic rats reconstituted by env-pX spleen cells, thus indicating that the env-pX transgene in affected vessels may not be essential for the development of arteritis. In contrast, arteritis was not induced in nontransgenic recipients by adoptive transfers of env-pX bone marrow cells, which suggested that T cells derived from the env-pX thymus may play a role in the development of arteritis. To clarify if the process of differentiation of T cells in the env-pX thymus is crucial to develop necrotizing arteritis, reciprocal exchange of thymus frameworks was done between env-pX and nontransgenic rats. Necrotizing arteritis occurred in nontransgenic rats with an env-pX thymus framework, whereas development of arteritis was suppressed in env-pX rats in which the thymus framework was replaced with a nontransgenic one. This collective evidence shows that the thymus is directly associated with the development of necrotizing arteritis in env-pX rats.

Functional alteration of peripheral CD25(+)CD4(+)immunoregulatory T cells in a transgenic rat model of autoimmune diseases.

Transgenic rats carrying the env-pX gene of human T cell leukemia virus type-I (env-pX rats) develop various collagen vascular diseases. Since autoantibodies are present in their sera, env-pX rats are considered to be a prototype model for autoimmune diseases. Adoptive transfers of spleen cells from syngenic non-transgenic rats decreased the incidence of diseases in env-pX rats, thus suggesting that normal spleen contains cells, which suppress autoimmune diseases. Murine peripheral CD25(+)CD4(+)T cells play roles in maintaining immunological self-tolerance. To examine if alterations of immunoregulatory cells may be evident in env-pX rats, quantitative and qualitative analyses of splenic CD25(+)CD4(+)T cells were done before these rats developed autoimmune diseases. Env-pX and non-transgenic rats had equivalent number of CD25(+)CD4(+)T cells. However, CD25(+)CD4(+)T cells from env-pX rats did not suppress proliferation of T cells stimulated by anti-CD3 antibodies (Ab) in vitro, whereas those from non-transgenic rats did. Additionally, env-pX CD25(+)CD4(+)T cells showed autologous and anti-CD3 Ab-mediated proliferation, in contrast to the anergic features in non-transgenic rats. These findings appear to be the first evidence that CD25(+)CD4(+)immunoregulatory T cells are altered in animal models, which naturally develop autoimmune diseases.

A comparison of the ultrasonography images of the joints of patients with rheumatoid arthritis and the corresponding synovial histological findings.

Abstract Objectives: The objective of this study is to investigate whether ultrasonography (US) images of joints that underwent surgery reflected the synovial histological findings or clinical indicators and to compare the results of the findings related to large joints (LJs) with those of small joints (SJs). Methods: The operations were performed on 215 joints in 177 patients with rheumatoid arthritis (RA). The 215 joints included 64 LJs and 151 SJs. The joints with the power Doppler (PD) signal grades 0 and 1 were assigned to group L, while those with grades 2 and 3 were assigned to group H. The Rooney score, Disease Activity Score-erythrocyte sedimentation rate (DAS28), serum matrix metallopeptidase 3 (MMP-3), and C-reactive protein (CRP) levels were determined. Results: The Rooney score, DAS28, MMP-3, and CRP levels of the LJs were significantly lower in group L than in group H. In group H, similar results were found in the LJs and SJs, with a significant increase in the disease activity, CRP and MMP-3 levels and the histological findings in comparison to group L. Conclusions: The PD signal grade was one of the indicators that reflected the degree of synovitis in the histological findings of the active joints of RA patients.

Serum Fibroblast Growth Factor 23 (FGF23) in Patients with Rheumatoid Arthritis

Objective Rheumatoid arthritis (RA) is a chronic inflammatory disease accompanied by periarticular and systemic osteoporosis. Fibroblast growth factor 23 (FGF23), which is mainly produced by osteocytes, circulates to the kidneys and regulates bone metabolism. We herein assessed serum FGF23 and its relationship to inflammation and osteoporosis in patients with RA. Methods Sixty-one patients with RA were included. Serum concentrations of FGF23 were determined using a sandwich enzyme-linked immunosorbent assay. Results The mean (± standard deviation) serum FGF23 concentration was 34.9±9.2 (range, 21.0-61.0) pg/mL. The serum FGF23 level was significantly and positively correlated with the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) levels, disease activity score-28 based on the ESR (DAS-28 ESR) and DAS-28 CRP (r=0.261, p=0.044, r=0.280, p=0.029, r=0.409, p=0.001 and r=0.421, p=0.001, respectively). The serum matrix metalloproteinase-3 level was also significantly and positively correlated with the serum FGF23 level (r=0.331, p=0.015). Concentrations of type I collagen cross-linked N-telopeptide in the serum was significantly correlated with the serum FGF23 level (r=0.272, p=0.034). Neither the bone mineral density in the femoral neck nor lumbar was significantly correlated with the serum FGF23 level. Serum phosphate, calcium, 25-hydroxy vitamin D, and intact parathyroid hormone were not related to the serum FGF23 level. Conclusion In patients with RA, serum FGF23 is correlated with inflammation, the disease activity of RA, and bone absorption markers. Serum FGF23 may be associated with abnormal bone absorption related to RA inflammation. Further studies are necessary to clarify the mechanism underlying this association.

The Rate of Decrease in the Disease Activity of Rheumatoid Arthritis during Treatment with Adalimumab Depends on the Dose of Methotrexate

OBJECTIVE The aim of this study was to analyze the efficacy of adalimumab (ADA) in patients with rheumatoid arthritis treated with or without methotrexate (MTX) and determine impact of the MTX dose. METHODS Pearsons product-moment correlation coefficient was used to assess the correlations between the improvement in the Disease Activity Score (DAS) 28- erythrocyte sedimentation rate (ESR) score and the MTX dose in patients receiving treatment with MTX at a dose of <8 mg/week, 8 mg/week and >8 mg/week. PATIENTS ADA therapy was initiated in 68 rheumatoid arthritis patients between July 2008 and June 2013. The mean MTX dose was 9.6 ± 2.6 mg/week, and the patients were followed for 24 weeks. RESULTS The mean DAS28-ESR scores at baseline and week 24 were 4.6 ± 1.3 and 2.7 ± 1.2 in the 60 patients treated with MTX and 4.5 ± 1.0 and 4.2 ± 1.5 in the eight patients treated without MTX, respectively. Clinical remission was achieved in 48% and 25% of the patients, respectively, by week 24. Moreover, 90.0% of the patients taking MTX continued to receive ADA until week 24, while 50.0% of the patients not taking MTX continued to receive ADA until week 24. Among the 35 patients receiving MTX at a dose of >8 mg/week, the DAS28-ESR scores decreased rapidly from 4.4 ± 1.2 at baseline to 3.2 ± 1.1 at week 4 and further decreased to 2.4 ± 1.0 at week 24. Meanwhile, clinical remission was achieved in 57% of the patients receiving MTX at a dose of >8 mg/week and 36% of those receiving MTX at a dose of ≤8 mg/week. A significant correlation was noted between the improvement in the DAS-ESR score and the MTX dose. CONCLUSION In this study population, enhanced clinical efficacy of ADA was achieved in combination with the administration of a sufficient dose of MTX, determined to be >8 mg/week.

Extensor tendon rupture and three-dimensional computed tomography imaging of the rheumatoid wrist

PurposeExtensor tendon rupture on the dorsum of the wrist is commonly seen in patients with rheumatoid arthritis (RA). The diagnosis of tendon rupture is usually straightforward, but it is sometimes difficult in the hand with complex deformity. The purposes of this study were to investigate the reliability of three-dimensional computed tomography (3DCT) imaging of extensor tendons in the rheumatoid wrist and in the normal wrist and to clarify the validity of its clinical application to the diagnosis of tendon rupture in the rheumatoid wrist.MethodsPreoperative 3DCT images of 48 wrists of 45 patients with RA and 3DCT images of 38 wrists of 38 healthy volunteers were reviewed retrospectively by six orthopaedic surgeons who were unaware of all other study data. Extensor tendon rupture was verified by operation on 20 rheumatoid wrists.ResultsRegarding interobserver and intra-observer reliabilities of 3DCT imaging of the extensor tendons, agreement with respect to tendon rupture in this study group was high, and Cohens kappa (κ) coefficient was variable, depending on the individual tendon. Positive predictive value (PPV) of tendon rupture in the extensor digiti minimi (EDM), extensor digitorum communis (EDC) V and IV and extensor pollicis longs (EPL) tendons was more than 60%, but those for the other extensor tendons were less than 50%. Negative predictive value (NPV) was more than 96% in all extensor tendons, in both rheumatoid and normal wrists.ConclusionsExtensor tendons in normal and rheumatoid wrists were well depicted by 3DCT imaging. In the rheumatoid wrists, extensors of the ring and little fingers and the thumb were depicted more accurately than those to the other fingers. 3DCT imaging was clinically applicable to wrists for which it was difficult to diagnose by physical examination a definite cause for the loss of extension of the fingers.

Cyclic AMP response element-binding protein is implicated in IL-6 production from arthritic synovial cells

Overproduction of interleukin (IL)-6 from synovial cells is critically involved in the pathogenesis of rheumatoid arthritis (RA). Cyclic adenosine monophosphate (AMP) response element-binding protein (CREB), a leucine zipper transcription factor, is expressed at a high level in synovial cells of patients with RA. Although CREB transactivates IL-6 expression in vascular smooth muscle cells, the relation between CREB expression and IL-6 production from arthritic synovial cells remains unclear. In this study, to determine whether CREB is implicated in IL-6 production from arthritic synovial cells, a dominant negative molecule of activation transcription factor 1 (ATF-1) was transfected into synovial cells obtained from arthritic joints of env-pX rats. These transgenic rats carrying the env-pX gene of human T-cell leukemia virus type-1 develop destructive arthritis with high titers of serum rheumatoid factor and are thus regarded as a suitable model of RA. The dominant negative ATF-1 (ATF-1DN) constitutes a heterodimer with CREB and inhibits CREB function, as CREB/ATF-1DN heterodimers no longer bind to the target sequence of CREB. We showed that transfection of ATF-1DN significantly reduced IL-6 production from arthritic synovial cells. These findings suggest that CREB is implicated in IL-6 production from synovial cells and plays an important role in RA pathogenesis.

Bone marrow cells carrying the env-pX transgene play a role in the severity but not prolongation of arthritis in human T-cell leukaemia virus type-I transgenic rats: a possible role of articular tissues carrying the transgene in the prolongation of arthritis

Transgenic rats carrying the env‐pX gene of human T‐cell leukaemia virus type‐I (env‐pX rats) were immunized with type II collagen (CII), and chronological alterations of arthritis were compared with findings of collagen‐induced arthritis (CIA) in wildtype Wistar–King–Aptekman–Hokudai (WKAH) rats. Arthritis induced by CII in env‐pX rats was more severe and persisted longer than CIA in WKAH rats. To determine whether the phenomenon is caused mainly by the transgene‐carrying lymphocytes or articular tissues, we immunized lethally irradiated env‐pX and WKAH rats with reciprocal bone marrow cell (BMC) transplantation. A severe but transient arthritis was induced by CII in WKAH rats reconstituted by env‐pX BMC (w/tB/CII rats). On the other hand, in env‐pX rats reconstituted by WKAH BMC, arthritis persisted longer than in w/tB/CII rats, although the degree was less at an early phase after CII immunization. These findings suggest that articular tissues rather than the BMCs carrying the env‐pX transgene play a role in the prolongation of arthritis in env‐pX rats, although BMCs carrying the transgene are associated with the severity of arthritis. When inflammatory cytokines in synovial cells isolated from env‐pX rats before they developed arthritis were examined, interleukin‐6 (IL‐6) was detected at a higher level than in synovial cells from WKAH rats, thus suggesting the critical role of IL‐6 in env‐pX arthritis.

A case of rheumatoid arthritis with methotrexate related lymphoproliferative diseases of the knee

Abstract Methotrexate (MTX) is the first choice disease-modifying antirheumatic drug (DMARD) for rheumatoid arthritis (RA) and is referred to as an “anchor drug”; its use has been steadily increasing annually. However, MTX-related lymphoproliferative diseases (MTX-LPDs) have emerged as important complications in the patients with RA. There have been no reports of intra-articular MTX-LPDs of the patients with RA. Atypical cells were found in the patient’s joint fluid by cytological examinations, and MTX-LPDs were suspected. The patient discontinued MTX and open synovectomy was performed. The histological findings and immunohistochemical staining of the specimens confirmed the diagnosis of diffuse large B-cell lymphoma (DLBCL) of MTX-LPDs. After the operation of the patient’s left knee joint, pains and swollen joint disappeared with no relapse. The cytological examinations of the synovial fluid followed by knee operation were effective for early diagnosis of MTX-LPD. MTX discontinuation with no chemotherapy followed up with a knee operation improved the recovery of the MTX-LPD.