Plasma platelet-derived microparticles in patients with connective tissue diseases.

OBJECTIVE: To clarify the role of platelet-derived microparticles (PDMP), which are small vesicles with thrombotic and immunological properties, in systemic lupus erythematosus (SLE), systemic sclerosis (SSc), dermatomyositis/polymyositis (PM/DM), and mixed connective tissue disease (MCTD). METHODS: Plasma levels of PDMP were measured by ELISA, and compared among patients with one of the 4 diseases. Association of PDMP levels with clinical characteristics and medication of the patients was also examined. RESULTS: PDMP levels were higher in patients with MCTD and SSc than in controls. Multiple linear regression analysis revealed that patients with Raynaud's phenomenon (RP) showed higher PDMP levels than those without. PDMP levels in individual patients did not fluctuate significantly over several months. CONCLUSION: PDMP level is associated with MCTD, SSc, and RP, and could be a novel marker for RP.

Serum matrix metalloproteinase-3 as predictor of joint destruction in rheumatoid arthritis, treated with non-biological disease modifying anti-rheumatic drugs.

BACKGROUND: Rheumatoid factor (RF), anti-citrullinated peptide antibody (ACPA), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) have been studied extensively as prognostic markers of rheumatoid arthritis (RA). However, despite the fact that matrix metalloproteinase-3 (MMP-3) is linked to RA activity, few studies have evaluated MMP-3 as prognostic marker. OBJECTIVE: To evaluate the performance of MMP-3 as predictor of joint destruction in RA treated with non-biological disease modifying anti-rheumatic drugs. METHODS: In a retrospective study of 58 early to moderate stage RA patients who consulted the Department of Clinical Pathology and Immunology, Kobe University Hospital between May 2002 and April 2009, we evaluated the performance of MMP-3 and other biomarkers as predictors of joint destruction, by comparing them between radiographically progressive and non-progressive group. RESULTS: Serum levels of RF at entry and ACPA, but not MMP-3 at entry, were significantly higher for the progressive group. Ratios of patients with MMP-3 levels higher than healthy control were not significantly different for the two groups. However, cutoff values determined through receiver operating characteristic analysis showed that the ratio of patients with elevated RF was significantly higher in the progressive group (p=0.001), while MMP-3 (p=0.092), ACPA (p=0.052), CRP (p=0.056), and ESR (p=0.069) tended to be more elevated in the progressive group. Multiple logistic regression analysis using the cutoff value identified MMP-3 positive and RF positive, but not ACPA, CRP or ESR, as significant factors for radiographic progression (OR 16.79 [95% CI: 1.34-414.19]). CONCLUSION: MMP-3 can be a useful marker for prediction of joint destruction.

Prevalence of disease-specific antinuclear antibodies in general population: estimates from annual physical examinations of residents of a small town over a 5-year period.

The aim of this study was to investigate the types and prevalence of disease-specific antinuclear antibodies (ANAs) and their relationship to rheumatic diseases in the general Japanese population. An immunofluorescence (IF) method was used for the first screening of ANA levels in serum samples obtained from 2181 residents of a small Japanese town. Individuals positive for IF-ANA were then further tested for disease-specific ANAs using eight enzyme immunoassays. Physical status and the presence of illness were determined by means of questionnaires and medical examinations. Based on the result of the IF-ANA assay, the rates of positive samples at 1:40 and 1:160 dilutions were 26.0 and 9.5%, respectively, with females have significantly higher positivity rates than males (P < 0.0001). Among 566 IF-ANA-positive individuals, 100 individuals were found to have 114 disease-specific ANAs. Anti-SSA/Ro, anti-centromere, and anti-U1RNP antibodies were detected in 58, 30, and 11 individuals, respectively, but anti-Sm, anti-Scl-70, and anti-Jo-1 antibodies were undetectable. Questionnaires and medical examinations revealed that among 60 disease-specific ANA-positive individuals that were available for testing, six had Sjögren's syndrome (SS), five were suspected of having SS, and five had rheumatoid arthritis. Surprisingly, 34 (57%) of the disease-specific ANA-positive individuals were clinically healthy. Anti-SSA/Ro, anti-centromere, and anti-U1RNP antibodies were quite frequent among clinically healthy Japanese subjects, although anti-Sm, anti-Scl-70, and anti-Jo-1 antibodies were not. Of the 60 individuals who tested positive for disease-specific ANAs, 30% (18/60) actually manifested systemic rheumatic diseases, while 50% showed no detectable signs or symptoms of rheumatic diseases.

[Usefulness of anti-cyclic citrullinated peptide antibodies (anti-CCP) for the diagnosis of rheumatoid arthritis].

Rheumatoid factor (RF) has been commonly used as a marker of rheumatoid arthritis (RA). RF can be detected in 60-80% of RA patients, but the specificity is low against other rheumatic diseases patients. We evaluated the diagnostic accuracy of anti-cyclic citrullinated peptide antibody (anti-CCP), a new diagnostic test for RA. Anti-CCP demonstrated higher sensitivity (81.0%) and specificity (92.4%). By the receiver operating characteristic (ROC) curve analysis, anti-CCP was superior to other markers (ie. RF, CARF, IgG-RF, and MMP-3). In early RA patients (RA patients who had had disease symptoms for < 2 years), sensitivity was 68.8%. Positivities of anti-CCP in RA patients became higher as the advance of stage defined by the Steinbrocker classification. We concluded that anti-CCP is a very valuable tool for the diagnosis of RA. Moreover, anti-CCP is a useful for finding RA of recent onset.

CD4+ PD-1+ T cells accumulate as unique anergic cells in rheumatoid arthritis synovial fluid.

OBJECTIVE: The PD-1 receptor, whose deficiency in mice causes autoimmune diseases such as arthritis, is considered to be a negative regulator of activated T cells and to play a crucial role in peripheral tolerance. To clarify the involvement of the PD-1 system in rheumatoid arthritis (RA), we investigated PD-1 expression on synovial fluid (SF) T cells from patients with RA. METHODS: FACS analysis for PD-1 was performed on SF T cells from 44 patients with RA and 6 with osteoarthritis (OA), and also on peripheral blood (PB) T cells from 12 RA patients and 7 healthy controls. Two-color analysis of cell surface PD-1 expression and the intracellular concentration of cytokine production was used to investigate CD4+ T cells from SF of patients with RA and PB from controls. RESULTS: Scarcely any PD-1 expression was detected on control PB T or OA SF T cells. In contrast, PD-1+ cells made up 20.9 +/- 8.6% (mean +/- SD) of RA SF T cells. In RA SF, PD-1 was expressed more predominantly on CD4+ T cells than on CD8+ T cells. As well as expressing CD45RO and CXCR3, CD4+ PD-1+ T cells were mostly CTLA-4 positive and CD26 negative, and were enriched in CD45RB(low) cells. Intracellular cytokine staining revealed that CD4+ PD-1+, but not CD4+ PD-1-, T cells produced interleukin 10 (IL-10), and that CD4+ PD-1+ T cells produced less IL-2 than CD4+ PD-1- T cells. CONCLUSION: PD-1+ T cells in RA SF are enriched, and phenotypic analysis suggests that these cells constitute a unique anergic T cell subset in RA SF.

[The clinical benefits to bone mineral density were shown by cyclical oral etidronate administration in steroid induced osteoporosis].

PURPOSE: To compare the bone-mass effects of intermittent cyclic etidronate administration in patients of various rheumatic disease patients with corticosteroid-induced osteoporosis. PATIENTS AND METHODS: We evaluated bone mineral density (BMD) of lumbar spine in 34 female patients (mean age: 46.4 +/- 13.7 y. o. 17-71) treated with long term corticosteroid (> 6 months). Eighteen patients cyclically received etidronate orally (400 mg or 200 mg etidronate daily for 2 weeks, followed by 10-12 weeks drug-free periods). Twelve in these 18 patients received 400 mg (group A) and another 6 patients were treated with 200 mg/day (group B). Sixteen patients free from etidronate administrations were analysed as a control group. RESULTS: Cyclical etidronate therapy showed significant increase in BMD. The BMD of lumbar spine increased from 0.760 +/- 0.10 g/cm 2 to 0.783 +/- 0.11 g/cm 2 (%change from baseline 2.91 +/- 2.56%/year) in group A treated patients after 12 months. Reduced BMD (%change from baseline 1.55 +/- 2.48%) was observed in 16 control group patients (P < 0.0012). The BMD in group A was significantly high compared to group B or control after the etidronate treatment. In 7 of group A, BMD increased significantly on 6 months but no more significant increase was shown on 12 months compared to the value on 6 months. On the other hand the BMD tend to increased for after 2 years in intermittent cyclic etidronate treatment in 8 cases of group A. There were no adverse effects and abnormal laboratory data related to the administration of etidronate. Although only 2 cases of group A showed the findings of compression fracture before the study, but no new compression fracture appeared in any group during this study. CONCLUSION: It was shown that cyclical etidronate therapy is effective for steroid induced osteoporosis.

Thioredoxin as a biomarker for oxidative stress in patients with rheumatoid arthritis.

There is no doubt that oxidative stress occurs in patients with rheumatoid arthritis (RA) and play an important role in both inflammation and destruction of RA joints. Thioredoxin (TRX) is a ubiquitous redox-active protein and is known to be induced in several cells against oxidative stress and to be secreted extracellularly. To clarify whether plasma thioredoxin levels could be a marker for oxidative stress in patients with RA, we measured plasma TRX levels in patients with RA using a sensitive sandwich enzyme-linked immunosorbent assay (ELISA) and investigated its relationship to TRX concentrations in the inflammatory joints. We have found that the plasma TRX levels of RA patients were significantly higher than those of normal subjects (86.8 +/-54.1 ng/ml versus 38.6 +/-18.5 ng/ml, P<0.0001). The plasma levels were correlated with the disease activity of RA and also with serum C-reactive protein (CRP) values (P<0.01). The concentration of TRX in synovial fluid (SF) from RA was 353.3 +/- 220.1 ng/ml (mean +/- S.D.) which was significantly higher than that in SF from osteoarthritis patients (70.6 +/- 31.0 ng/ml, P<0.0001). The SF TRX concentration was significantly correlated with the number of leukocytes infiltrating in SF and with the serum CRP levels. The serum TRX levels were significantly positively correlated with the SF TRX concentrations in RA patients (P<0.05). By the histological examination for synovial tissue of RA patients, TRX was shown to be present on the surface of synovial lining layer as well as in the leukocytes.Moreover, urinary excretion of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of oxidative DNA damage by endogenously generated oxygen radicals, was significantly higher in RA patients than in healthy subjects (11.55 +/- 4.71 versus 7.76 +/- 2.26 ng/mg creatinine, P<0.0001). Plasma TRX levels were significantly correlated with urinary excretion of 8-OHdG (P<0.005). We concluded that plasma TRX level is a new biomarker for the disease activity of RA and may reflect higher levels of oxidative stress in RA patients.