Roles of CCR2 and CXCR3 in the T cell-mediated response occurring during lupus flares

OBJECTIVE: Infiltrating lymphocytes have been demonstrated to play an important role in the tissue injury that occurs in systemic lupus erythematosus (SLE). Inflammatory chemokines control lymphocyte traffic through their interaction with T cell chemokine receptors. In this study we assessed the expression of chemokine receptors on T cell subsets of patients with active or inactive SLE. METHODS: Forty-four SLE patients (40 women and 4 men) were included in the study. The patients were divided according to their SLE Disease Activity Index (SLEDAI), which resulted in a group of patients with inactive SLE (n = 27) and a group with active SLE (n = 17). The control group was composed of 22 healthy blood donors. A disease control group consisted of 18 patients infected with human immunodeficiency virus. Expression of chemokine receptors CCR1, CCR2, CCR5, CXCR3, CXCR4, and CX3CR1 was assessed on whole blood samples by immunofluorescence analysis. RESULTS: On T lymphocytes, significant differences between the SLE patients and controls were observed only in the expression of CCR2 and CXCR3. On monocytes, no significant differences in CCR2 expression were observed between the healthy controls and the SLE patients. The proportion of CD8+,CCR2+ T cells was significantly lower in the SLE patients compared with the controls (mean +/- SD 2.3 +/- 1.3% and 3.5 +/- 3.2% in the active and inactive SLE groups, respectively, versus 21 +/- 24% in controls; P < 0.0001 for both). The CD4+,CCR2+ subset was represented similarly among the controls and patients with inactive SLE (16.7 +/- 5.8% and 12.8 +/- 8.1%, respectively) but was depleted in patients with active SLE (7.1 +/- 4.4%; P < 0.0001 versus controls). The active SLE group expressed significantly lower circulating levels of CD4+,CCR2+ T cells than did the inactive disease group (P = 0.007). A negative correlation was found between the proportion of CD4+,CCR2+ T cells and the SLEDAI (r = -0.43, P = 0.005, by Spearman's correlation). Proportions of CD8+,CXCR3+ T cells were similar between the SLE groups and the control group (58 +/- 22.6% in active SLE, 47.1 +/- 20% in inactive SLE, and 59.4 +/- 17.3% in controls). The proportion of CXCR3-expressing CD4+ T cells was decreased in the active disease group (23.5 +/- 3.2% versus 39.9 +/- 12.5% in controls; P = 0.008) but not in the inactive disease group (34.8 +/- 9.5%). A trend toward a significant negative correlation was observed between the decreased proportion of CD4+,CXCR3+ T cells and the SLEDAI (P = 0.08). Following in vitro activation of purified CD4 T cells, only CCR2 was internalized, whereas expression of CXCR3 was retained in activated CD4 cells. CONCLUSION: The numbers of circulating CD4+,CXCR3+ and CD4+,CCR2+ T cells are selectively decreased during SLE flares. A decrease in the number of circulating CD4+ T cells expressing CCR2 and/or CXCR3 could serve as a biomarker of the SLE flare.     

Low number of complement C3b/C4b receptors (CR1) on erythrocytes from patients with essential mixed cryoglobulinemia, systemic lupus erythematosus and rheumatoid arthritis: relationship with disease activity, anticardiolipin antibodies, complement activation and therapy.

Our aim was to assess whether the amount of complement C3b/C4b receptors (CR1) on erythrocytes shows a correlation to disease activity in various connective tissue diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and essential mixed cryoglobulinemia (EMC). Using an anti-CR1 monoclonal antibody, 26 patients with SLE, 34 with RA and 22 patients with EMC were investigated for erythrocyte CR1 expression. The control group consisted of 30 healthy individuals. The mean number of CR1/erythrocyte in the control group was 568 +/- 197 (range 174-1060), significantly higher than studied (EMC:379 +/- 248; p = 0.0005;SLE 147 +/- 56, p less than 0.0001; RA 298 +/- 177, p less than 0.0001). In patients with RA and in SLE, but not in patients with EMC, the number of CR1 numbers and anticardiolipin antibody (aCl) titers (r2 = 0.493; p = 0.034). A statistically significant correlation between CR1 numbers and CH50 values was found in patients with SLE, while in 3 patients with RA 4 months of therapy with cyclosporine A led to a further 30% reduction in CR1 number. Our conclusions are that (a) the decreased expression of erythrocyte CR1 is apparently a common feature of patients with various connective tissue diseases; (b) several acquired factors such as disease activity, complement activation, aCl and drugs may contribute to the loss of CR1 from erythrocytes; (c) in patients with RA and SLE, but not in patients with EMC, CR1 enumeration on erythrocytes may serve as a variable for clinical monitoring.     

Oxidative stress in systemic lupus erythematosus: relationship to disease activity and symptoms

Oxidative stress may play a role in the pathogenesis of systemic lupus erythematosus (SLE). We examined the hypothesis that oxidative stress was associated with indices of lupus disease activity and severity of symptoms. Urinary F2 isoprostane excretion, a validated marker of oxidative stress, was measured in 95 patients with SLE and 103 healthy controls. Outcome measures included SLEDAI and SLICC scores, the modified health assessment questionnaire, the fatigue severity scale (FSS), and visual analogue scales (VAS) for fatigue, pain and overall disease activity. F2 isoprostane excretion was compared in patients and controls, and its relationship with clinical variables in SLE examined. F2 isoprostane excretion did not differ significantly among patients with lupus (2.7 +/- 2.3 ng/mg Cr) and control subjects (2.2 +/- 1.4 ng/mg Cr) (P = 0.70). In patients with lupus, F2 isoprostane concentrations were independently associated with higher patient reported disease activity (VAS) (OR = 1.52, P = 0.01), fatigue (FSS, OR = 1.52, P = 0.03) and lower quality of life (OR = 0.73, P = 0.05), but not with objective markers or inflammation or disease activity. In conclusion, F2 isoprostane excretion is associated with patient-reported symptoms in SLE but not with measures of inflammation, SLEDAI or SLICC. Oxidative stress may contribute to debilitating symptoms such as fatigue in SLE.     

Purified protein derivative reaction in systemic lupus erythematosus patients. Indirect study of cellular immunity

Cutaneous anergy in SLE patients results from disease activity and/or immunosuppressive treatment (IT). The aim of this study was to evaluate purified protein derivative (PPD) reaction in SLE patients. A total of 145 patients and 20 controls were studied. Five units of PPD were applied on day 0, and skin reaction was measured after 3 (PPD1) and 6 (PPD2) days. A booster was applied (day 14), and the reaction was measured after 3 (PPD3) and 6 (PPD4) days. Non-parametric ANOVA test and unpaired Student's t-test were performed. Forty patients (group I) were inactive (MexSLEDAI < 3), receiving no IT (at least 3 months previous to the PPD test); 39 (group II) were inactive receiving IT; 24 (group III) were active without IT, and 42 (group IV) were active with IT. Active patients had lower PPD1 (group III, 1.4 +/- 0.9; group IV, 0.6 +/- 0.5) than inactive patients (group I, 8.4 +/- 2.3; group II, 5.1 +/- 1.9) and than controls (9.4 +/- 3; P < or = 0.001). Group IV had lower delayed response (PPD2 = 0.3 +/- 0.3) than inactive groups (group I, 2.6 +/- 0.9; group II, 3.1 +/- 0.8) and than controls (7.9 +/- 2.5; P < or = 0.001). Group III had lower delayed reaction (PPD2 = 1.2 +/- 0.8) than controls (P < or = 0.001). Active SLE patients, receiving or not receiving IT, had lower skin response to PPD than inactive patients and controls.     

Myocardial tissue characterization in systemic lupus erythematosus: value of a comprehensive cardiovascular magnetic resonance approach

Systemic lupus erythematosus (SLE) is a multi-organ inflammatory disorder mainly affecting women and is associated with high cardiovascular morbidity and mortality. We tested the utility of a comprehensive cardiovascular magnetic resonance approach to assess myocardial involvement and to determine its relation to disease activity in SLE patients. We studied 20 SLE patients (19 females, 35+/-10 years) and 13 healthy volunteers (nine females, 28+/-11 years). Classification followed the criteria of the American College of Rheumatology and assessment of SLE activity was based on the European Consensus Lupus Activity Measurement index. Cardiovascular magnetic resonance (CMR) was performed on a 1.5T scanner and included the following sequences: steady-state free precession, T2-weighted, early and late T1-weighted after gadolinium-DTPA injection. Ejection fraction was not significantly different between groups (controls: 63+/-6, inactive SLE: 67+/-7, active SLE 64+/-8; P=0.003 for all groups). In contrast, relative T2 ratio (myocardium to skeletal muscle) was significantly higher in active SLE than in the other groups (controls: 1.7+/-0.3, inactive: 1.8+/-0.2, active: 2.1+/-0.2; P=0.003). Similarly, early enhancement ratio was significantly higher in active SLE (controls: 2.4+/-1.4, inactive: 2.8+/-1.1, active: 4.5+/-2.0, P=0.39). Both relative T2 and early enhancement ratios significantly correlated with disease activity. Intramural foci of late enhancement were observed in three of eight patients (all with active SLE). Of the five patients with no late enhancement, only one had active disease. An imaging approach combining T2-weighted, early and late enhancement imaging is a useful tool to assess possible myocardial involvement in SLE. CMR parameters of global myocardial involvement correlate well with disease activity, but not with usual clinical signs as summarized in a cardiac score.     

Endothelial cell apoptosis in systemic lupus erythematosus: a common pathway for abnormal vascular function and thrombosis propensity

Women with systemic lupus erythematosus (SLE) are at risk for premature atherothrombosis independent of Framingham risk factors. We investigated whether endothelial cell (EC) apoptosis predicts abnormal vasomotor tone and contributes to circulating tissue factor (TF) levels in this disease. Brachial artery flow-mediated dilation (FMD) and nitroglycerin-mediated dilation were determined in women with SLE, healthy control subjects, and subjects with coronary artery disease (CAD) (n = 43/group). Quantification of circulating apoptotic ECs was performed by flow cytometry (CD146(+) cells that stained for Annexin V [CD146(AnnV+)]) and immunofluorescent microscopy. Plasma TF was measured by enzyme-linked immunosorbent assay (ELISA). Compared with healthy control and CAD subjects, patients with SLE had higher numbers of circulating CD146(AnnV+) cells (10 +/- 3, 18 +/- 5, and 89 +/- 32 cells/mL, respectively, mean +/- SEM; P <.01). Increased CD146(AnnV+) cells correlated strongly with abnormal vascular function (P =.037). After adjusting for known predictors of endothelial function, CD146(AnnV+) was the only variable that predicted FMD (beta = -4.5, P <.001). Increased CD146(AnnV+) was strongly associated with elevated levels of circulating TF (r =.46, P =.002). Circulating apoptotic ECs are elevated in young women with SLE and strongly correlate with markedly abnormal vascular function and elevated TF levels. Heightened endothelial apoptosis may represent an important mechanism for development of atherothrombosis in SLE.     

Preclinical vascular disease in systemic lupus erythematosus and primary antiphospholipid syndrome

OBJECTIVE: To determine the prevalence of preclinical vascular disease and associated risk factors in patients with systemic lupus erythematosus (SLE) or primary antiphospholipid syndrome (APS). METHODS: We consecutively studied 70 SLE patients and 25 primary APS patients without clinical coronary artery disease. The control group included 40 healthy women. Carotid ultrasound was performed and the intima-media wall thickness (IMT) and presence of plaque was investigated in all patients and controls. Traditional vascular risk factors and SLE-disease and treatment related factors were also analysed. RESULTS: SLE patients had a higher prevalence of traditional atherosclerosis risk factors: hypertension (P<0.005) and dyslipidaemia (P<0.05) and higher levels of total cholesterol (P = 0.03), triglycerides (P = 0.004) and apolipoprotein B (P = 0.04). The prevalence of carotid plaque was higher and appeared earlier in SLE patients than in the primary APS patients or controls (P<0.001). The IMT was similar in the three groups. SLE patients with secondary APS had a higher prevalence of carotid plaque than patients with primary APS (37.5% vs 8%, P = 0.03). The presence of plaque in SLE patients was associated with a higher SLICC score (2.40 +/- 1.78 vs 1.02 +/- 1.18, P = 0.002), higher ECLAM score (3.10 +/- 2.32 vs 1.84 +/- 1.59, P = 0.02) and older age (47.3 +/- 8.44 vs 37.38 +/- 11.28, P = 0.003) at the time of carotid ultrasound study. CONCLUSION: Plaque prevalence in patients with primary APS is similar to that of controls and inferior to that of SLE patients with secondary APS. SLE patients have a high prevalence of early carotid atherosclerosis that is associated with cumulative disease damage and disease activity.     

Molecular characterization of rectal mucosa-associated bacterial flora in inflammatory bowel disease

BACKGROUND: Colorectal bacteria may play a role in the pathogenesis of inflammatory bowel disease (IBD). To test the hypothesis that, in affected patients, the numbers of potentially protective mucosal bacteria might be reduced and pathogenic species increased, we compared rectal mucosa-associated flora in patients with IBD and normal controls. METHODS: Snap-frozen rectal biopsies taken at routine diagnostic colonoscopy from 33 patients with ulcerative colitis, 6 patients with Crohn's disease, and 14 controls with normal colonoscopy were processed, and individual bacterial groups were counted using fluorescent in situ hybridization. RESULTS: Bacteria were mostly found apposed to the epithelial surface and within crypts. Epithelium-associated counts of bifidobacteria in active [median 15/mm of epithelial surface (range, 4-56), n = 14] and quiescent ulcerative colitis [26/mm (range, 11-140), n = 19] were lower than in controls [56/mm (range, 0-144), n = 14; P = 0.006 and P = 0.03, respectively]. Conversely, epithelium-associated Escherichia coli counts were higher in active [82/mm (range, 56-136)] than inactive ulcerative colitis [6/mm (range, 0-136), P = 0.0001] or controls [0/mm (range, 0-16), P < 0.0001]. Epithelium-associated clostridia counts were also higher in active [3/mm (range, 0-9)] than inactive colitis [0/mm (range, 0-9), P = 0.03] or controls [0/mm (range, 0-1); P = 0.0007]. Epithelium-associated E. coli counts were higher in Crohn's disease [42/mm (range, 3-90), n = 6] than controls (P = 0.0006). E. coli were also found as individual bacteria and in clusters in the lamina propria in ulcerative colitis and Crohn's disease but in none of the controls (P < 0.01). Numbers of Lactobacillus and Bacteroides showed no differences between patient groups. CONCLUSIONS: The reduction in mucosa-associated bifidobacteria and increase in E. coli and clostridia in patients with IBD supports the hypothesis that an imbalance between potentially beneficial and pathogenic bacteria may contribute to its pathogenesis.     

Impairment of left ventricular diastolic function in systemic lupus erythematosus.

Left ventricular (LV) diastolic performance was evaluated with pulsed-wave Doppler echocardiography in a cross-sectional population of patients with systemic lupus erythematosus (SLE) in search of subclinical myocardial involvement. Such involvement is reported to occur infrequently, despite pathohistologic evidence of myocarditis in up to 70% of patients with SLE. Thirty-five consecutive patients with SLE were evaluated, 14 with active and 21 with inactive disease, and were compared with 30 age-matched healthy control subjects. Twenty-six patients were restudied at 7 months. All had normal LV systolic function, normal pericardial and valvular structures, and no significant valvular regurgitation on Doppler echocardiography. In SLE patients with active disease, indexes of LV diastolic function differed significantly from the inactive group and from control subjects, with marked prolongation of isovolumic relaxation time (104 +/- 18 vs 74 +/- 13 ms, p = 0.0001), as well as reduced peak early diastolic filling velocity (E) (0.69 +/- 0.19 vs 0.83 +/- 0.17 ms, p = 0.01), reduced ratio of early to late diastolic flow velocity (E/A) (1.15 +/- 0.53 vs 1.47 +/- 0.35, p = 0.02), and prolonged mitral pressure halftime (74 +/- 14 vs 65 +/- 8 ms p = 0.01). Similar significant differences were found between the active and inactive SLE patient groups. SLE patients with inactive disease differed from control subjects in only mild prolongation of mitral pressure halftime. Abnormal prolongation of isovolumic relaxation (greater than 100 ms) was found to be the most useful marker of diastolic impairment, being present in 64% of SLE patients with active disease and in 14% of patients with inactive disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

Th1/Th2 cytokines in patients with systemic lupus erythematosus: is tumor necrosis factor alpha protective?

OBJECTIVES: To determine the circulating levels of Th1 and Th2 cytokines in patients with systemic lupus erythematosus (SLE) and to elucidate their association with disease activity and autoimmune response. METHODS: We included 52 patients and 25 healthy controls. Serum levels of tumor necrosis factor (TNF) alpha, interferon (IFN) gamma, interleukin (IL)-12p70, IL-10, and IL-4, as well as anti-DNA, -Ro, -La, -RNP, and -Sm antibodies were determined by enzyme-linked immunosorbent assay. Disease activity was recorded according to the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and classified as very active (SLEDAI > or = 13), moderately active (SLEDAI: 3-12), or inactive (SLEDAI < or = 2). RESULTS: The mean age of the patients was 34.2 +/- 12.6 years, and the mean duration of disease was 4.9 +/- 7.6 years. Twelve patients (23%), 20 patients (34.5%), and 20 patients (34.5%) had highly, moderately, and inactive SLE, respectively. Levels of IFN-gamma, TNF-alpha, and IL-12 were significantly higher in patients than in healthy controls (P <.03), as well as the IL-12/IL-10, IL-12/IL-4, IFN/IL-10, IFN/IL-4, TNF/IL-10, and TNF/IL-4 ratios (P <.01), suggesting a major participation of Th1 over Th2 cytokines. Nevertheless, a direct correlation between Th1 (IFN-gamma and TNF-alpha) and Th2 (IL-4 and IL-10) cytokines was observed in patients (r >.5, P <.01), indicating a mutual Th1-Th2 participation. TNF-alpha levels and the TNF/IL-10 ratio were higher in patients with inactive disease compared with patients with very active disease and controls (P <.04). IL-12 levels and IL-12/IL-4, as well as IL-12/IL-10, ratios were higher in patients with very active disease than in those with inactive SLE and controls (P <.01). IL-10 levels were associated with anti-DNA, anti-Ro, and anti-La response (P <.01). CONCLUSION: Our results suggest that TNF-alpha could be a protective factor in SLE patients, whereas IL-12p70 participates in disease activity and IL-10 influences the autoimmune response (autoantibody production).     

Chylomicron metabolism is markedly altered in systemic lupus erythematosus

OBJECTIVE: To verify the in vivo status of chylomicron metabolism in systemic lupus erythematosus (SLE) since there is a high incidence of atherosclerosis in this disease and chylomicrons may have an important role in atherogenesis. METHODS: A chylomicron-like emulsion labeled with 14C-cholesteryl esters and 3H-triglycerides was injected intravenously into 10 female patients with inactive SLE and 10 healthy age- and sex-matched control subjects to determine the plasma kinetics of the emulsion lipids from consecutive plasma samples taken at regular intervals for 1 hour. Lipolytic activity was determined in vitro after incubation of the labeled emulsion with postheparin plasma. RESULTS: The decay curves for the emulsion were markedly slowed in SLE. Chylomicron lipolysis, indicated by the fractional clearance rate (FCR) of emulsion 3H-triglyceride, was 2-fold smaller in SLE patients than in controls (mean +/- SD 0.023 +/- 0.011 versus 0.047 +/-0.015 minute(-1); P = 0.010). Chylomicron removal, indicated by emulsion 14C-cholesteryl ester FCR, was 3-fold smaller in SLE patients than in controls (0.007 +/-0.007 versus 0.023 +/- 0.011 minute(-1); P = 0.009). In vitro lipolysis in SLE patients was nearly half that of the controls (mean +/- SD 10,199 +/- 2,959 versus 6,598 +/-2,215; P = 0.014). Higher levels of very-low-density lipoprotein cholesterol and triglycerides and lower levels of high-density lipoprotein cholesterol and apolipoprotein A-I were also observed in the SLE patients. CONCLUSION: SLE patients have disturbances in chylomicron metabolism that are characterized by decreased lipolysis and chylomicron remnant removal from the plasma. This finding, together with other alterations in lipid profiles that were confirmed in the present study, is largely accountable for the accelerated atherosclerotic process of the disease.     

Association of increased interferon-inducible gene expression with disease activity and lupus nephritis in patients with systemic lupus erythematosus

OBJECTIVE: To study 5 type I interferon (IFN)-inducible genes (LY6E, OAS1, OASL, MX1, and ISG15) in patients with systemic lupus erythematosus (SLE) and to correlate expression levels with disease activity and/or clinical manifestations. METHODS: Peripheral blood cells were obtained from 48 SLE patients, 48 normal controls, and 22 rheumatic disease controls, and total RNA was extracted and reverse transcribed into complementary DNA. Gene expression levels were measured by real-time polymerase chain reaction, standardized to a housekeeping gene, and summed to an IFN score. Disease activity was determined by the Safety of Estrogens in Lupus Erythematosus: National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) composite. RESULTS: Each gene was highly expressed in SLE patients compared with normal controls (P < or = 0.0003) or disease controls (P < or = 0.0008 except for MX1). IFN scores were positively associated with the SELENA-SLEDAI instrument score (P = 0.001), the SELENA-SLEDAI flare score (P = 0.03), and the physician's global assessment score (P = 0.005). Compared with patients without nephritis, lupus nephritis patients had higher IFN scores (overall P < 0.0001), especially during active renal disease. IFN scores were weakly associated with neurologic manifestations. Elevated IFN scores were positively associated with the current presence of anti-double-stranded DNA (anti-dsDNA) antibodies (P = 0.007) or hypocomplementemia (P = 0.007). LY6E expression levels distinguished active from inactive lupus nephritis (P = 0.02) and were positively associated with proteinuria (P = 0.009). CONCLUSION: The 5 IFN-inducible genes were highly expressed in SLE patients, and increased levels were correlated with disease activity defined by several methods. IFN scores, or LY6E levels, were elevated in lupus nephritis patients, especially during active renal disease, and in patients with anti-dsDNA antibody positivity and hypocomplementemia. IFN scores, or LY6E levels, may be useful as a biomarker for lupus nephritis therapy.     

Raloxifene for postmenopausal women with systemic lupus erythematosus: a pilot randomized controlled study

OBJECTIVE: To study the effects of raloxifene on disease activity and bone mineral density (BMD) in postmenopausal women with systemic lupus erythematosus (SLE). METHODS: Postmenopausal women with osteopenia and inactive SLE were randomly assigned to receive either raloxifene (60 mg/day) plus elemental calcium (1,200 mg/day) or elemental calcium alone (control). Patients with a history of thromboembolism or antiphospholipid antibody positivity were excluded. BMD at various sites was serially measured, and lupus activity was serially assessed using the Safety of Estrogens in Lupus Erythematosus: National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI). RESULTS: The study group comprised 33 patients (16 assigned to receive raloxifene and 17 controls, mean +/- SD age 53.8 +/- 5.3 years). Age, body mass index, and baseline BMD values did not differ significantly between the 2 groups of patients. All patients were receiving low-dose prednisolone. After 12 months, femoral neck BMD (mean +/- SD -2.6 +/- 1.0%; P = 0.02) and lumbar spine BMD (-3.3 +/- 0.8%; P = 0.001) decreased significantly in the controls but not in the raloxifene group. No patient had a major flare of lupus, but mild/moderate flares occurred in 4 raloxifene-treated and 6 control patients (P = 0.79). The total area under the curve of SELENA-SLEDAI scores was not significantly different between the 2 groups. A significant increase in the high-density lipoprotein cholesterol level and a reduction in the low-density lipoprotein cholesterol level were observed in the raloxifene group but not in controls. One patient in the raloxifene group (6%) withdrew from the study because of hot flushes. No thromboembolic events were reported. CONCLUSION: Raloxifene was well tolerated in Chinese patients with SLE who had inactive disease and in whom hypercoagulability was not identified. Raloxifene maintained femoral neck and spinal BMD in patients receiving corticosteroids.     

Expansion of toll-like receptor 9-expressing B cells in active systemic lupus erythematosus: implications for the induction and maintenance of the autoimmune process

OBJECTIVE: Toll-like receptors (TLRs) are pattern-associated receptors in innate immunity that may be involved in the recognition of self antigens and the production of pathogenic autoantibodies. This study was undertaken to examine the expression and function of various TLRs in subpopulations of peripheral blood mononuclear cells (PBMCs) of patients with systemic lupus erythematosus (SLE). METHODS: The expression of TLRs in PBMCs from 50 SLE patients with active disease (SLE Disease Activity Index [SLEDAI] score >or=8; n = 26) or inactive disease (SLEDAI score <8; n = 24) and 20 healthy controls was studied by flow cytometry. TLR expression was assessed on various subpopulations of PBMCs (TLR-2 and TLR-4 by membrane staining; TLR-3 and TLR-9 by intracellular staining). TLR function was accessed by stimulating PBMCs with specific ligands. RESULTS: The proportion of B cells and monocytes expressing TLR-9 was higher among patients with active SLE (mean +/- SD 49.5 +/- 24.4% and 30.7 +/- 24.1%, respectively) than among patients with inactive disease (22.8 +/- 19.6% and 14.3 +/- 8.4%, respectively; P = 0.02 and P = 0.03). Among B cells, the proportion of plasma cells and memory B cells expressing TLR-9 was increased in patients with active SLE. Increased percentages of TLR-9-expressing B cells correlated with the presence of anti-double-stranded DNA antibodies (P = 0.007). Treatment with serum from patients with active disease increased the percentage of TLR-9-expressing plasma cells in serum from healthy controls. Enhanced induction of HLA-DR after TLR-9 stimulation was documented in B cells from patients with active disease. CONCLUSION: In patients with active SLE, the proportion of peripheral blood memory B cells and plasma cells expressing TLR-9 is increased. Endogenous nucleic acids released during apoptotic cell death may stimulate B cells via TLR-9 and contribute to SLE pathogenesis.     

QT-interval parameters are increased in systemic lupus erythematosus patients

Systemic lupus erythematosus (SLE) patients have increased cardiovascular morbidity and mortality. QT-interval parameters are presumed markers of cardiovascular risk and have not been previously evaluated in SLE. Standard 12-lead ECGs were obtained from 140 female SLE outpatients and 37 age and body mass index-matched controls. QT interval was measured in each lead and heart rate-corrected maximum QT-interval duration (QTcmax) and QT-interval dispersion (QTd) were calculated. Risk factors for cardiovascular disease and lupus clinical features, disease treatment, disease activity and damage index were recorded. SLE patients have increased QT-interval parameters when compared to controls (QTcmax: 427.91 +/- 31.53 ms(1/2) versus 410.05 +/- 15.45 ms(1/2), P < 0.001; QTd: 52.38 +/- 22.21 ms versus 37.12 +/- 12.88 ms, P < 0.001). These differences persisted after excluding those patients with arterial hypertension, diabetes and with ECG abnormalities (QTcmax: 419.90 +/- 28.78 ms(1/2) versus 409.15 +/- 15.85 ms(1/2), P = 0.041; QTd: 54.74 +/- 26.00 ms versus 37.96 +/- 13.05 ms, P = 0.001). Multivariate linear regression for factors associated with QTcmax selected the presence of electrocardiographic left ventricular hypertrophy (ECG-LVH) (P = 0.003), nonspecific ST-T-wave abnormalities (P = 0.022) and left atrial enlargement (P = 0.044). Multivariate associates with QTd were age (P = 0.018), ECG-LVH (P = 0.022) and ST-T abnormalities (P = 0.031). In conclusion, SLE patients have increased QT interval parameters when compared to controls. This prolongation may lead to an increased cardiovascular risk. This finding might be due to subclinical atherosclerotic cardiovascular disease.     

Relationship of serum paraoxonase 1 activity and paraoxonase 1 genotype to risk of systemic lupus erythematosus

OBJECTIVE: Low serum paraoxonase 1 (PON1) activity determined with paraoxon as substrate has been found to be associated with coronary artery disease. This study was undertaken to examine the relationship of PON1 activity and genotype to risk of systemic lupus erythematosus (SLE). METHODS: The impact of 7 PON1 single-nucleotide polymorphisms (SNPs) was analyzed in relation to PON1 activity, SLE risk, lupus nephritis, antiphospholipid antibody (aPL) positivity, and carotid vascular disease in 380 SLE patients (334 white, 46 black) and 497 controls (455 white, 42 black). RESULTS: Compared with findings in controls, PON1 activity with paraoxon substrate was reduced both in white lupus patients (mean +/- SEM 618.9 +/- 24.0 units/liter versus 719.6 +/- 24.6 units/liter; P = 0.007) and in black lupus patients (991.1 +/- 82.7 units/liter versus 1,164.3 +/- 101.4 units/liter; P = 0.2711). Low PON1 activity in SLE was not associated with the occurrence of aPL, carotid vascular disease, or the use of immunosuppressive drugs. In multiple regression analyses, the Q192R SNP was found to be independently associated with PON1 activity and explained 28% and 41% of the variation in PON1 activity in white patients and black patients, respectively. Stratification of the lupus sample by presence (n = 81) or absence (n = 247) of renal disease revealed significant associations with 3 promoter SNPs, with odds ratios of 3.82 (95% confidence interval [95% CI] 1.49-9.82, P = 0.005), 3.41 (95% CI 1.35-8.61, P = 0.009), and 2.17 (95% CI 1.01-4.68, P = 0.049). CONCLUSION: To our knowledge, this is the first study to assess the role of PON1 activity in SLE risk in a large biracial sample from the US. Our data indicate that low PON1 activity determined with paraoxon substrate is independently associated with SLE and that certain PON1 SNPs are associated with lupus nephritis.     

Reduced numbers of complement receptor type 1 on erythrocytes are associated with increased levels of anticardiolipin antibodies. Findings in patients with systemic lupus erythematosus and the antiphospholipid syndrome

In several diseases, including systemic lupus erythematosus (SLE) and autoimmune hemolytic anemias, the numbers of complement receptor type 1 (CR1) expressed on erythrocytes of patients are reduced. In patients with SLE, anticardiolipin antibodies (aCL) have been associated with positive results on direct antiglobulin tests. Because of these findings, we investigated whether the reduced expression of erythrocyte CR1 in 61 patients (53 with SLE and 8 with the antiphospholipid syndrome) might be associated with the presence of aCL. A negative correlation was observed between aCL levels and mean numbers of CR1 (rs = -0.43, P = 0.001), and a positive correlation was observed between aCL levels and the levels of erythrocyte C4d and C3d (rs = 0.33 and 0.41, P = 0.01 and 0.001, respectively), but no correlation of aCL levels with serum C4 levels was found. When the results were further analyzed according to the IgG or IgM class of aCL, levels of antibodies of both classes were negatively correlated with CR1 numbers, but only IgM aCL levels were correlated with erythrocyte C4d and C3d numbers. The levels of anti-double-stranded DNA antibodies showed no correlation with erythrocyte CR1, C4d, or C3d numbers but were negatively correlated with serum C4 levels (rs = -0.43, P = 0.002). These data suggest that aCL, or a closely related antibody specificity, may bind to erythrocytes and may be directly involved in the mechanism for reduction of erythrocyte CR1 expression in SLE patients.     

CD146在血管炎患者外周血白细胞表达的意义初探

目的探讨血管炎患者外周血白细胞CD146表达与临床活动性间的关系。方法流式细胞术检测39例活动期系统性血管炎患者[显微镜下多血管炎（MPA）13例,韦格纳肉芽肿（WG）9例,变应性肉芽肿性血管炎（CSS）2例,大动脉炎（TA）9例,白塞病（BD）4例,结节性多动脉炎（PAN）2例]及24例系统性红斑狼疮（SLE）患者外周血白细胞CD146表达,其中18例（MPA5例,WG4例,CSS2例,SLE4例,PAN2例,TA1例）患者经糖皮质激素和环磷酰胺治疗后于病情好转时再次检测。结果（1）与健康者相比,血管炎患者活动期中性粒细胞、淋巴细胞CD146表达增多,尤以中性粒细胞最多,差异均有统计学意义（P〈0．05）。（2）中性粒细胞CD146表达与淋巴细胞、单核细胞CD146表达相关（r值分别为0．66、0．853,P=0．000）,与病程、年龄、血沉、C反应蛋白、抗中性粒细胞胞浆抗体（ANCA）、PR3-ANCA、MPO-ANCA、血肌酐、伯明翰血管炎活动指数（BVAS）、系统性红斑狼疮疾病活动指数（SLEDAI）等无明显相关（r值分别为-0．108、-0．059、-0．073、-0．103、0．012、-0．5、-0．232、0．001、-0．08、0．089,P〉0．5）。（3）18例患者经治疗后好转期中性粒细胞、淋巴细胞CD146表达多数呈逐渐减少的趋势（P〈0．05）。结论CD 146在血管炎患者活动期外周血白细胞尤其是中性粒细胞中表达明显升高,随着糖皮质激素和免疫抑制剂治疗病情好转后呈下降或转阴趋势,其在血管炎发病机制中的意义有待深入研究。     

Prevalence of conventional and lupus-specific risk factors for cardiovascular disease in patients with systemic lupus erythematosus: A case-control study

OBJECTIVE: Patients with systemic lupus erythematosus (SLE) are significantly more likely to experience a myocardial infarction or a stroke than age-matched controls. We compared the prevalence of conventional and lupus-specific risk factors in patients with SLE just before a cardiovascular event and in matched controls with SLE but no cardiovascular disease (CVD). METHODS: Twenty-nine patients with SLE and CVD were enrolled. For each patient, 2 ethnically- and sex-matched controls were obtained, 1 matched for age and 1 for SLE duration. Data regarding risk factors were collected for the time immediately preceding the relevant cardiovascular event, or at an equivalent time for controls. RESULTS: Patients' median age at event was 49 years (interquartile range 43-54 years) and mean disease duration was 12.0 +/- 7.1 years. Patients with SLE and CVD were more likely than both age and duration controls to be treated for hypertension (P = 0.01 and P = 0.001, respectively) and to have elevated triglyceride levels (P = 0.05 and P = 0.01, respectively). Compared with duration controls, CVD patients were more likely to have lupus anticoagulant (P = 0.03), but less likely to be receiving treatment with hydroxychloroquine (P = 0.003). Compared with age controls, patients were more likely to be current smokers (P = 0.03), to have taken a mean dosage >7.5 mg/day of prednisolone (P = 0.04), and to have been treated with pulsed methylprednisolone (P = 0.03). In multivariable analysis, only hypertension treatment was an independent risk factor for CVD. CONCLUSION: We identified significantly increased prevalence of some conventional and lupus-specific risk factors in patients with SLE immediately before a CVD event compared with controls matched for age or disease duration.