Biomedical subjects

Shinichi Sato

Publications and source records attributed to Shinichi Sato.

At least 73 records · Page 4Linked to original sources

PubMed2005

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (2003). III. Secular changes in susceptibility].

The bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa) isolated from 565 patients diagnosed as urinary tract infections (UTIs) in 14 institutions in Japan were collected between August 2003 and July 2004. The susceptibilities of these bacteria to various antimicrobial agents were examined. The bacteria were divided into 2 groups consisting of uncomplicated UTIs and complicated UTIs (with and without indwelling catheter) based on their isolation origins. The results were compared with those obtained between 1994 and 2002. The drug sensitivity of S. aureus in this year was similar to those in up to the previous years and S. aureus showed the best susceptibility to vancomycin. The drug sensitivity of E. faecalis in this year also was similar to those in up to the previous years. The drug sensitivity of E. coli in this year was generally good except penicillins and was similar to those in up to the previous years. Among cephems, cefozopran (CZOP) and cefpirome (CPR) showed the highest potency activity (MIC90: < or = 0.125 microg/mL). An antibacterial activity of cefotiam (CTM) was stable for 10 years and was fine (MIC0: < or = 0.5 microg/mL). The sensitivity of E. coli to carbapenems and carumonam (CRMN) also was good like to CZOP. The sensitivity of the complicated UTIs group to quinolones, however, has decreased after 2000 and it was suggested that the resistance to the drug has developed. Kiebsiella spp. showed a decrease in the susceptibility to some of cephems. The drugs indicating a big decrease in the sensitivity were cefazolin, CTM, cefaclor, and cefpodoxime. Imipenem, carbapenems, also indicated a decrease in the sensitivity. The susceptibility of the strain to the other drugs was similar to that in up to the previous years. Among them, CZOP maintained good susceptibility (MIC90: > or = 0.125 microg/mL against uncomplicated UTIs, 0.25 microg/mL against complicated UTIs) like meropenem. The drug sensitivity of P. aeruginosa was generally low and was not much different from that in up to the previous years.

Anti-Infective Agents↗

PubMed2004

Carotid intima-media thickness and plaque characteristics as a risk factor for stroke in Japanese elderly men.

BACKGROUND AND PURPOSE: Few cohort studies have examined the association of carotid intima-media thickness (IMT) and plaque characteristics with the risk of stroke in apparently healthy persons. We examined the relationship of carotid IMT and the surface, morphology, and calcification of carotid plaques with the incidence of stroke among Japanese men. METHODS: Carotid IMT and plaque were evaluated bilaterally with ultrasonography in 1289 men aged 60 to 74 years without a previous stroke or coronary heart disease. In this cohort, the subsequent incidence of stroke was investigated. RESULTS: During the 4.5-year follow-up, 34 strokes occurred. The multivariate-adjusted relative risk (95% CI) for the highest versus lowest quartiles of maximum IMT of the common carotid artery (CCA; > or =1.07 versus < or =0.77 mm) was 3.0 (1.1 to 8.3) for stroke. The combination of CCA and internal carotid artery (ICA) wall thickness was a better predictor of the risk of stroke than was CCA wall thickness alone. Men with a plaque, defined as a focal wall thickness of > or =1.5 mm, in the ICA had a 3-fold higher risk of stroke than those without a plaque, and the plaque surface irregularity further increased the stroke risk. A significant excess risk of stroke was confined to men with an uncalcified plaque. CONCLUSIONS: Increased IMT of the CCA and an uncalcified plaque in the ICA, as assessed by ultrasonography, are risk factors for stroke in elderly Japanese men.

Aged↗

PubMed2004

Serum total homocysteine concentrations and risk of stroke and its subtypes in Japanese.

BACKGROUND: To date, no prospective studies have examined the association between serum homocysteine levels and the risk of stroke and stroke subtypes in Asian populations. METHODS AND RESULTS: A prospective, nested, case-control study of Japanese subjects 40 to 85 years of age was conducted by using frozen serum samples from 11 846 participants in cardiovascular risk surveys collected from 1984 to 1995 for one community and 1989 to 1995 for the other two communities. By the end of 2000, we identified 150 incident strokes, the subtypes of which were confirmed by imaging studies. Three control subjects per case were selected by matching for sex, age, community, year of serum storage, and fasting status. Serum total homocysteine levels were measured by high-performance liquid chromatography. Compared with control subjects, total (n=150), hemorrhagic (n=52), and ischemic (n=98) strokes had higher geometric mean values of total homocysteine and higher proportions of homocysteine > or =11.0 micromol/L. The multivariate odds ratios (95% CI) for highest (> or =11.0 micromol/L) versus lowest quartiles (<7.0 micromol/L) of homocysteine after adjustment for body mass index, smoking, alcohol intake, hypertension, serum total cholesterol, and other cardiovascular risk factors were 2.99 (1.51 to 5.93) for total stroke, 3.89 (1.60 to 9.46) for ischemic stroke, 3.36 (1.27 to 8.90) for lacunar infarction, and 1.63 (0.44 to 6.00) for hemorrhagic stroke. The respective multivariate odds ratios associated with a 5-micromol/L increase in homocysteine were 1.40 (1.09 to 1.80), 1.52 (1.07 to 2.14), 1.48 (1.01 to 2.18), and 1.10 (0.76 to 1.59). The excess risk of total and ischemic strokes did not vary significantly according to sex, age, smoking status, or hypertensive status. CONCLUSIONS: High total homocysteine concentrations were associated with the increased risk of total stroke, more specifically ischemic stroke and lacunar infarction, among Japanese men and women.

Adult↗

PubMed2004

Augmented production of transforming growth factor-beta by cultured peripheral blood mononuclear cells from patients with systemic sclerosis.

We sought to determine whether the spontaneous production of transforming growth factor-beta (TGF-beta) by peripheral blood mononuclear cells (PBMC) is increased in patients with systemic sclerosis (SSc). Culture supernatants of PBMC from SSc patients (n = 88) and healthy controls (n = 44) were analyzed by enzyme-linked immunosorbent assay. The production of active TGF-beta1 and total (active and latent) TGF-beta1 by PBMC from patients with limited cutaneous SSc (lSSc) and by PBMC from patients with diffuse cutaneous SSc (dSSc) was significantly elevated compared to the production by PBMC from normal controls. Production of active TGF-beta1 by dSSc PBMC was higher than that by lSSc PBMC, although not significantly. Patients with PBMC with increased active or total TGF-beta1 production showed significantly shorter disease duration than patients with PBMC with normal production levels. PBMC from patients without anticentromere antibody showed enhanced active TGF-beta1 production more frequently than those from patients with anticentromere antibody. PBMC from SSc patients more frequently showed enhanced total TGF-beta2 production than PBMC from normal controls. Among each leukocyte subset, spontaneous production of total TGF-beta1 was significantly higher in cultured peripheral monocytes/macrophages, but not in T cells, B cells, or NK cells, from patients than from normal controls. Thus, the enhanced production of TGF-beta by PBMC may contribute to the disease process in SSc

Adult↗

PubMed2004

P-selectin glycoprotein ligand-1 is required for the development of cutaneous vasculitis induced by immune complex deposition.

Immune complex (IC)-induced tissue injury is mediated by inflammatory cell infiltration that is highly regulated by various adhesion molecules. To assess the contribution of P-selectin glycoprotein ligand-1 (PSGL-1) and selectins in the pathogenetic process, the cutaneous reverse-passive Arthus reaction was examined in mice treated with monoclonal antibodies (mAb) to PSGL-1 or P- and/or E-selectin. Edema and hemorrhage were significantly reduced in mice treated with anti-P-selectin mAb compared with control mice while they were not inhibited in mice treated with anti-E-selectin mAb. It is remarkable that blocking PSGL-1 by mAb resulted in significant, further reduction in edema and hemorrhage compared with blocking anti-P- or anti-E-selectin. However, blockade of E- and P-selectins exhibited more significant reduction relative to PSGL-1 blockade. The inhibited edema and hemorrhage paralleled reduced infiltration of neutrophils and mast cells. Reduced infiltration of neutrophils and mast cells was observed in the peritoneal Arthus reaction and was associated with the decreased production of tumor necrosis factor alpha and interleukin-6. The results of this study indicate that PSGL-1 contributes to the Arthus reaction mainly as a ligand of P-selectin and partly as a ligand of E- and/or L-selectin by regulating neutrophil and mast-cell recruitment and that PSGL-1 would be a therapeutic target for human IC-mediated diseases.

Animals↗

PubMed2004

A case of scleroderma spectrum disorder with anticentriole antibody and pulmonary hypertension.

We describe the case of a patient with anticentriole antibody-positive scleroderma spectrum disorder (SSD) who developed pulmonary hypertension. A 54-year-old woman had noticed Raynaud's phenomenon and digital ulcers during the winter for the past 10 years. Although sclerodactyly was not present, digital ulcers, swelling of her hands, and phalangeal contracture were observed. An indirect immunofluorescence test revealed anticentriole antibody. Other SSc-specific antoantibodies were negative. An echocardiogram demonstrated that the estimated right ventricular systolic pressure was increased to 51 mmHg. She was diagnosed as SSD with pulmonary hypertension. This is the first case of SSD with anticentriole antibody to develop pulmonary hypertension.

Autoantibodies↗

PubMed2004

Improvement of skin sclerosis after occurrence of anticentromere antibody in a patient with diffuse cutaneous systemic sclerosis.

A 38-year-old woman had noticed sclerodactylia and Raynaud's phenomenon 10 months before consultation. She was diagnosed as having systemic sclerosis (SSc) based on the skin sclerosis of her arms, chest, and face. Antinuclear antibody (ANA) level was 1:1280 with a speckled pattern, but specific autoantibodies were negative. Following the treatment with oral prednisolone and D-penicillamine, her skin sclerosis gradually improved. Three months after initiation of prednisolone, she presented Pneumocystis carinii pneumonia. About 1 year after the first admission, the pattern of indirect immunofluorescence staining changed from the speckled pattern to the discrete speckled pattern, and simultaneously anticentromere antibody (ACA) was detected by enzyme-linked immunosorbent assay. Her skin sclerosis rapidly and remarkably improved after appearance of ACA. It is generally considered that once certain SSc-specific autoantibody occurs, it does not disappear and change into other specificity of autoantibody thereafter. This case suggests that the presence of ACA closely correlates with clinical features and also suggests that clinical features may change during the clinical course with the appearance of another specific ANA. This case is very rare because such a case was not reported previously.

Administration, Oral↗

PubMed2004

Anti-DNA topoisomerase IIalpha autoantibodies in localized scleroderma.

OBJECTIVE: To determine the prevalence and clinical correlation of anti-DNA topoisomerase IIalpha (anti-topo IIalpha) antibody in patients with localized scleroderma. METHODS: Anti-topo IIalpha antibodies or anti-DNA topoisomerase I (topo I) antibodies were determined by enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Inhibition of topo IIalpha enzymatic activity by the antibodies was evaluated by decatenation assays using kinetoplast DNA as a substrate. RESULTS: IgG or IgM anti-topo IIalpha antibody was detected in 76% (35 of 46) of patients with localized scleroderma, and in 85% (11 of 13) of patients with generalized morphea, the severest form of localized scleroderma. This prevalence of the antibody in patients with localized scleroderma was much higher than that found in patients with systemic sclerosis (SSc) (5 of 37 [14%]), systemic lupus erythematosus (2 of 26 [8%]), dermatomyositis (2 of 20 [10%]), and in healthy controls (3 of 42 [7%]). Immunoblotting confirmed the presence of IgG anti-topo IIalpha antibody in sera from patients with localized scleroderma and showed no cross-reactivity of anti-topo IIalpha antibody with topo I. Anti-topo I antibody was not detected by ELISA in any sera from patients with localized scleroderma. In addition, anti-topo I antibody from SSc patients did not cross-react with topo IIalpha. The presence of anti-topo IIalpha antibody was associated with a greater total number of sclerotic lesions and number of plaque lesions in patients with localized scleroderma. Furthermore, anti-topo IIalpha antibody was able to inhibit topo IIalpha enzymatic activity. CONCLUSION: The results of the present study indicate that anti-topo IIalpha is a major autoantibody in localized scleroderma, and is distinct from anti-topo I antibody in SSc.

Adolescent↗

PubMed2004

Altered blood B lymphocyte homeostasis in systemic sclerosis: expanded naive B cells and diminished but activated memory B cells.

OBJECTIVE: To determine phenotypic and functional abnormalities of blood B cell subsets in patients with systemic sclerosis (SSc). METHODS: Cell surface marker expression was determined by flow cytometry. Spontaneous apoptosis was evaluated by annexin V expression with flow cytometric analysis. IgG production by isolated IgD- memory B cells was examined by enzyme-linked immunosorbent assay. RESULTS: The numbers of blood CD27- naive B cells from SSc patients were increased compared with normal control cells, while memory B cells expressing medium levels of CD27 and plasmablasts expressing high levels of CD27 were reduced. In contrast, plasmablasts were the predominant population in patients with systemic lupus erythematosus (SLE). Memory B cells in SSc showed increased expression of activation markers, including CD80, CD86, and CD95, relative to normal controls. Consistent with CD95 up-regulation, SSc memory B cells exhibited augmented spontaneous apoptosis after 24-hour incubation; augmented apoptosis may explain the reduced memory B cell number. Nonetheless, isolated IgD- SSc memory B cells treated with stimuli had an enhanced ability to produce IgG. Furthermore, expression of CD19, a critical signal transduction molecule of B cells that regulates autoantibody production, was significantly increased in memory B cells as well as in naive B cells in SSc. In contrast, CD19 expression was decreased in SLE B cells. CONCLUSION: SSc patients have distinct abnormalities of blood homeostasis and B cell compartments, characterized by expanded naive B cells and activated but diminished memory B cells. Our results suggest that CD19 overexpression in SSc memory B cells is related to their hyperreactivity.

Adult↗

PubMed2004

Association of a functional CD19 polymorphism with susceptibility to systemic sclerosis.

OBJECTIVE: CD19 is overexpressed in B cells from patients with systemic sclerosis (SSc), and plays a crucial role not only for autoantibody production, but also for skin fibrosis in mouse models. We previously reported the association of a GT repeat polymorphism in the 3'-untranslated region (3'-UTR) of CD19 with human systemic lupus erythematosus. In this study, we examined whether CD19 polymorphisms are associated with genetic susceptibility to SSc. METHODS: A case-control association study was performed for CD19 polymorphisms, -499G>T in the promoter region and a GT repeat polymorphism in the 3'-UTR, in 134 patients with SSc and 96 healthy individuals recruited at Kanazawa University. CD19 expression levels in the peripheral blood naive and memory B cells from SSc patients were examined by 2-color flow cytometry. RESULTS: Carrier frequencies of the -499T allele in the promoter (odds ratio [OR] 2.18, 95% confidence interval [95% CI] 1.31-3.86, P = 0.003) and of the (GT)(14) allele in the 3'-UTR (OR 1.86, 95% CI 1.05-3.28, P = 0.03) were significantly increased in SSc patients compared with healthy controls. Association was particularly evident in patients with limited cutaneous SSc with anticentromere antibodies. These alleles were in linkage disequilibrium, but the -499T allele seemed to play a primary role. CD19 expression levels in peripheral blood B cells were significantly elevated in both naive (P = 0.0029) and memory (P = 0.0022) B cells from patients with SSc who had the -499T allele as compared with those without the -499T allele. CONCLUSION: The CD19 -499G>T polymorphism is associated with higher CD19 expression in B cells, and with susceptibility to SSc.

Adult↗

PubMed2004

Role of C-C chemokine receptors 1 and 5 and CCL3/macrophage inflammatory protein-1alpha in the cutaneous Arthus reaction: possible attenuation of their inhibitory effects by compensatory chemokine production.

The deposition of immune complexes induces an acute inflammatory response with tissue injury. Immune complex-induced tissue injury is mediated by inflammatory cell infiltration that is highly regulated by multiple chemokines. To assess the role of the chemokine receptors CCR1 and CCR5, and a ligand for these receptors CCL3/macrophage inflammatory protein-1alpha, in this pathogenic process, the reverse passive cutaneous Arthus reaction was induced in mice lacking CCR1, CCR5, or CCL3. Edema was significantly attenuated in CCR1-deficient (CCR1(-/-)) and CCL3(-/-) mice but not CCR5(-/-) mice, compared with wild-type mice. Numbers of infiltrating neutrophils and mast cells were reduced in CCL3(-/-) and CCR1(-/-) mice, respectively, compared with wild-type mice. CCR1 and CCR5 were expressed on neutrophils and mast cells. Remarkably, the intradermal mRNA expression of CCL5/RANTES, another ligand for CCR1 and CCR5, was increased in CCR5(-/-) and CCL3(-/-) mice, compared with wild-type mice, while the cutaneous CCL3 mRNA expression was augmented in CCR1(-/-) and CCR5(-/-) mice. These results indicate that CCR1, CCR5, and CCL3 cooperatively contribute to the cutaneous Arthus reaction, and also suggest that enhanced expression of CCL3 and CCL5 compensates for the loss of CCR1, CCR5, and CCL3 in the reaction.

Animals↗

PubMed2004

Prevalence and correlates of carotid atherosclerosis among elderly Japanese men.

We determined intima-media thickness (IMT) and diameter of carotid artery and estimated their correlations with cardiovascular risk factors in 1129 men aged 60-74 years, who participated in a cardiovascular risk survey in three Japanese communities. The multivariate odds ratios (95% confidence interval) for the maximum IMT > or = 1.1 mm in the common carotid artery (CCA) were 1.3 (1.1-1.5) per 4 years of age, 1.8 (1.4-2.5) for hypertension, 1.4 (1.2-1.7) for a 34.4 mg/dl increase in serum total cholesterol, 0.7 (0.6-0.8) for a 14.7 mg/dl increase in serum HDL-cholesterol, and 2.4 (1.1-5.0) for history of stroke, while the maximum IMT > or = 1.5mm in the internal carotid artery (ICA) were 1.6 (1.4-1.8) per 4 years of age, 1.9 (1.5-2.4) for hypertension, 1.6 (1.2-2.1) for current smoking, and 3.5 (1.6-7.6) for history of stroke. Age, height, hypertension, current smoking, ethanol intake and history of coronary heart disease were independent determinants of both the outer and inner CCA diameter. Maximum IMT correlated positively with the outer diameter and inversely with the inner diameter in the CCA. Carotid atherosclerosis suggests to be a risk factor for stroke among Japanese elderly men, although future prospective studies are required to confirm this finding.

Age Factors↗

PubMed2004

Randomized, controlled trial of secondary prevention of coronary sclerosis in normocholesterolemic patients using pravastatin: final 5-year angiographic follow-up of the Prevention of Coronary Sclerosis (PCS) study.

BACKGROUND: The potential benefit of cholesterol-lowering therapy for normocholesterolemic patients with coronary artery disease (CAD) has not been clarified. The Prevention of Coronary Sclerosis (PCS) Study was designed to evaluate the effect of pravastatin on secondary prevention of progression of CAD in normocholesterolemic patients for a period of 5 years. METHODS: A total of 329 patients with CAD were enrolled. Normocholesterolemic patients were defined by a serum total cholesterol (TC) level of 180-219 mg/dl. Patients in this group were randomized into pravastatin and dietary control groups. Patients whose serum TC level fell outside the normal range were divided into a high-cholesterol reference group (TC > or = 220 mg/dl) and a low-cholesterol reference group (TC < 180 mg/dl). Patients in the pravastatin and high-cholesterol groups received pravastatin 10 mg/day. Coronary angiography was performed at baseline, 2 years, and 5 years and analyzed by quantitative coronary arteriography. Angiographic coronary progression was evaluated by minimum obstruction diameter (MOD) and mean segment diameter (MSD). RESULTS: At 5 years, change in MOD was significantly (change, P=0.033; change/years, P=0.032) less in the pravastatin group (-0.04 +/- 0.17 mm) than in the dietary control group (-0.16 +/- 0.27 mm). Although a similar trend was observed in the MSD results, the differences were not significant. CONCLUSION: Long-term angiographic data show that cholesterol-lowering therapy by pravastatin prevents progression of coronary atherosclerosis in normocholesterolemic patients with CAD.

Adult↗

PubMed2004

Expression of fractalkine and its receptor, CX3CR1, in atopic dermatitis: possible contribution to skin inflammation.

BACKGROUND: Fractalkine (FKN) induces activation and adhesion of leukocytes expressing its receptor, CX(3)CR1. FKN is released from the cell surface through proteolytic cleavage as soluble FKN (sFKN). OBJECTIVE: We sought to assess FKN and CX(3)CR1 expression in the skin, serum sFKN levels, and CX(3)CR1 expression on blood leukocytes in patients with atopic dermatitis (AD). METHODS: FKN and CX(3)CR1 expression in the skin was examined immunohistochemically. mRNA expression of FKN, thymus and activation-regulated chemokine, and macrophage-derived chemokine in the skin was assessed by means of real-time RT-PCR. Serum sFKN levels were assessed by using ELISA. Blood leukocytes were stained for CX(3)CR1 by means of flow cytometric analysis. RESULTS: FKN was strongly expressed on endothelial cells in skin lesions of patients with AD and psoriasis but not in normal skin. FKN mRNA levels in AD lesional skin increased to a similar extent to thymus and activation-regulated chemokine and macrophage-derived chemokine mRNA levels. CX(3)CR1-expressing cells in the affected skin of patients with AD or psoriasis increased compared with those in normal skin. Serum sFKN levels were increased in patients with AD but not in patients with psoriasis relative to levels in healthy control subjects. Serum sFKN levels were associated with the disease severity and decreased with the improvement of skin lesions in patients with AD. CX(3)CR1(+) cell frequencies and CX(3)CR1 expression levels were decreased in CD8(+) T cells, monocytes, and natural killer cells from patients with AD, but this was not observed in patients with psoriasis. CONCLUSIONS: These results suggest that through functions in both membrane-bound and soluble forms, FKN plays an important role in the trafficking of CX(3)CR1(+) leukocytes during the inflammation caused by AD.

Adolescent↗

PubMed2004

Both Th2 and Th1 chemokines (TARC/CCL17, MDC/CCL22, and Mig/CXCL9) are elevated in sera from patients with atopic dermatitis.

BACKGROUND: Chemokines and their receptors are important elements for the selective attraction and activation of various subsets of leukocytes. Expression of CXCR3 ligands, such as monokine induced by IFN-gamma (Mig) leads to preferential Th1 recruitment, whereas CCR4 ligands, thymus and activation regulated chemokine (TARC) or macrophage derived chemokine (MDC), mediate preferential Th2 recruitment. Although atopic dermatitis (AD) has been shown to be a Th2-type disease, recent studies have revealed that Th1-type cytokines, such as IFN-gamma, especially in chronic skin lesions, play important roles in pathogenesis of AD. OBJECTIVE: The purpose of this study was to investigate serum levels of Th2 chemokines TARC and MDC and a Th1 chemokine Mig in the same samples from patients with AD and their clinical correlation. METHODS: Serum chemokine levels in patients with AD (n = 55), contact dermatitis (CD; n = 15), and normal controls (n = 30) were examined by ELISA. RESULTS: Serum levels of TARC and MDC in AD patients and CD patients were significantly higher than those found in normal controls. Serum levels of these chemokines were similar for AD patients and CD patients. Furthermore, these levels correlated positively with disease severity, total IgE levels, and peripheral eosinophilia in AD patients. Serum Mig levels in AD patients and CD patients were significantly higher than those in control subjects. However, serum Mig levels were significantly elevated in CD patients relative to AD patients. Furthermore, serum Mig levels correlated positively with levels of both TARC and MDC in AD patients. CONCLUSION: These results suggest that both Th2 and Th1 chemokines may play roles in the development of AD.

Adolescent↗

PubMed2004

Serum levels of a Th1 chemoattractant IP-10 and Th2 chemoattractants, TARC and MDC, are elevated in patients with systemic sclerosis.

BACKGROUND: Although abnormalities of various chemokines are detected in systemic sclerosis (SSc), there are few findings concerning Th1 or Th2 chemoattractants. OBJECTIVE: To determine whether serum levels of chemokines preferentially chemotactic for Th1 cells (IP-10 and MIG) and predominantly chemotactic for Th2 cells (TARC and MDC) are elevated and whether they correlate with clinical features in patients with SSc. METHODS: Serum samples from patients with diffuse cutaneous SSc (dSSc; n = 34), limited cutaneous SSc (lSSc; n = 30), dermatomyositis (DM; n = 15), systemic lupus erythematosus (SLE; n = 22), and normal controls (n = 30) were examined by sandwich ELISA. RESULTS: Serum TARC levels were significantly elevated in dSSc patients (P < 0.0002) and lSSc patients (P < 0.0001) compared with normal controls. Similarly, serum MDC levels were significantly increased in patients with dSSc (P < 0.02) or lSSc (P < 0.05) relative to normal controls. In addition, serum IP-10 was detected significantly more frequently in patients with dSSc (44%), lSSc (30%), or DM (53%) than normal controls (0%) and patients with SLE (0%). Furthermore, elevated TARC levels correlated with the presence of pitting scars and anti-topoisomerase I antibody, increased titers of anti-topoisomerase I and antinuclear antibody, and decreased glomerular filtration rate. Increased MDC levels were associated with pitting scars and younger ages at onset. CONCLUSION: These results suggest that both Th2 chemoattractants, TARC and MDC, and a Th1 chemoattractant IP-10 play a role in the development of SSc.

Adolescent↗

PubMed2004

Elevated expression of CD23 on peripheral blood B lymphocytes from patients with bullous pemphigoid: correlation with increased serum IgE.

BACKGROUND: Increased serum IgE levels are occasionally found in patients with severe bullous pemphigoid (BP). CD23, a low affinity Fc receptor for IgE, is mainly expressed on mature B lymphocytes. Studies have suggested that serum levels of soluble CD23 (sCD23) correlate with serum IgE levels and disease severity in BP. OBJECTIVE: The purpose of our study is to examine whether the expression of CD23 is elevated in BP and whether this expression correlates with serum IgE levels and disease severity. METHODS: We measured CD23 expression on B cells from patients with active BP, pemphigus vulgaris, pemphigus foliaceus, and atopic dermatitis (AD), as well as healthy control subjects, using a flow cytometer. Serum levels of IgE and sCD23 were also measured. RESULTS: The expression of CD23 was significantly higher in BP patients compared with healthy control subjects (P < 0.05), whereas the levels were normal in the other bullous diseases. CD23 expression tended to be higher in severe BP compared with moderate BP, and the levels in severe BP were comparable to the levels in AD. Furthermore, CD23 expression correlated positively with serum IgE levels (P < 0.002), and the IgE levels were significantly higher in severe BP than in moderate BP (P < 0.01 ). CD23 expression in BP did not correlate with sCD23 levels. CONCLUSIONS: These results suggest that the up-regulated surface CD23 on B cells may be involved in IgE synthesis and inflammatory events in BP.

Adult↗

PubMed2004

Altered B lymphocyte function induces systemic autoimmunity in systemic sclerosis.

Systemic sclerosis (SSc) is a connective tissue disease characterized by excessive extracellular matrix deposition in the skin and visceral organs. SSc is associated with immune activation characterized by autoantibody production, lymphocyte activation, and release of various cytokines. The presence of autoantibodies is a central feature of immune activation in SSc. Although autoantibodies are thought to be closely linked to the pathogenesis of SSc, the pathogenic relationship between systemic autoimmunity and the clinical manifestations of SSc, including skin fibrosis, remains unknown. Recent studies have revealed that B cells play a critical role in systemic autoimmunity and disease expression through various functions, including cytokine production in addition to autoantibody production. The B cell signaling thresholds are regulated by response regulators that augment or diminish B cell signals during responses to self and foreign antigens. Abnormal regulation of the response regulator function and expression may result in autoantibody production. Among these response regulators, CD19, which is a critical cell-surface signal transduction molecule of B cells, is the most potent positive regulator. Transgenic mice that overexpress CD19 by approximately 3-fold lose tolerance and generate autoantibodies spontaneously. B cells from SSc patients exhibit a 20%-increase in CD19 expression that induces SSc-specific autoantibody production in transgenic mice. Furthermore, SSc patients have intrinsic B cell abnormalities characterized by expanded naive B cells, activated but diminished memory B cells, and chronic hyper-reactivity of memory B cells, possibly due to CD19 overexpression. Similarly, B cells from a tight-skin mouse, a model of SSc, show augmented CD19 signaling and chronic hyper-reactivity. Remarkably, CD19 loss results in inhibition of chronic B cell hyper-reactivity and elimination of autoantibody production, which is associated with improvement in skin fibrosis and a parallel decrease in IL-6 production by B cells. Thus, chronic B cell activation resulting from augmented CD19 signaling leads to skin fibrosis possibly through IL-6 overproduction, as well as autoantibody production, in tight-skin mice and SSc patients.

Animals↗