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1.
Previously, we have shown that anti-DNA can bind to heparan sulphate (HS), a constituent of the glomerular basement membrane (GBM). We hypothesized that binding of anti-DNA to HS in the GBM plays a role in the onset of systemic lupus erythematosus (SLE) nephritis. To test this hypothesis we measured the anti-HS reactivity in cross-sectional and longitudinal studies of SLE patients with or without nephritis. In the transverse serum study single serum samples from 26 SLE patients were studied. We found no correlation between anti-HS reactivity and previously development of nephritis (anti-HS positive: seven out of 16 with history of nephritis, two out of 10 without nephritis). However, six of the seven anti-HS positive sera in the nephritis group were obtained within 1 month of the onset of nephritis, suggesting a temporal relationship between anti-HS reactivity and onset of nephritis. In the longitudinal serum study between six and 16 serum samples were studied from each of 10 SLE-patients. In five out of five episodes of nephritis we found anti-HS reactivity before the onset or exacerbation of the nephritis. In four non-renal manifestations anti-HS reactivity was found in only one episode; in none of the three patients who remained clinically stable did serum samples show anti-HS reactivity. Anti-HS reactivity was only found in sera positive for anti-DNA by Farr assay but the anti-HS titre was not a mere reflection of the reactivity measured in the Farr assay. This indicates that only a subpopulation of anti-DNA can bind to HS. We found a high correlation (r = 0.99) between anti-HS reactivities in plasma and serum and we conclude that anti-HS reactivity in serum samples from SLE patients is not due to in vitro complex formation during clotting. Although further prospective analysis is necessary, our data suggest that measurement of anti-HS reactivity in SLE patients might identify patients at risk for the development of nephritis. 相似文献
2.
In order to investigate the relationship between renal histopathology and the characteristics of circulating immune complexes (CICs) in patients with lupus nephritis (LN), we measured the sizes of CICs, DNA-bound immunoglobulins in patients with systemic lupus erythematosus (SLE) and different histopathological forms of nephritis. Sera were obtained from nine patients: four with diffuse proliferative LN (DPLN), four with membranous LN (MLN), and one with mesangial LN, who fulfilled the criteria of the American Rheumatism Association for SLE. The DNA-bound immunoglobulins were measured by ELISA, in which ELISA plates were coated with mouse monoclonal anti-DNA antibodies. The sizes of CICs were analysed by sucrose density gradient ultracentrifugation. Large (larger than 19S), intermediate (19-7S) and small (nearly 7S) sized DNA-bound immunoglobulins (high peaks of IgG and IgA, but low IgM peaks) were found in the patients with DPLN. By contrast, in patients with MLN, the sizes of ICs; DNA-bound IgG, IgA were in general slightly larger than 7S. In one patient with DPLN, at the onset, various sized DNA-bound IgG, IgA and IgM were found. After the methylprednisolone pulse therapy, CICs became smaller and gradually disappeared. We conclude that the characteristics of DNA-anti-DNA IgG, IgA complexes may determine the localization of ICs in the glomeruli and suggest that CICs play an important role in the pathogenesis of LN. 相似文献
3.
We previously reported that lysozyme electrostatically inhibits the fibronectin-mediated DNA binding to the glomerular basement membrane (GBM) and reduces in situ DNA-anti-DNA complex formation in the GBM in NZB/W F1 mice [1]. In this study, we further noticed significant increases in urinary excretion of anti-DNA antibodies and immune complexes (IC) in lysozyme-treated NZB/W F1 mice. Their clearance ratios of IgG anti-DNA antibody to whole IgG were markedly high compared with those of saline-treated animals. A large number of IgG and C3 positive granules were observed in the tubular cells of NZB/W F1 mice treated with lysozyme. On the contrary, nil or only small amounts of anti-DNA antibodies were detected in the urine of NZB/W F1 mice without lysozyme administration despite a large amount of proteinuria, suggesting entrapment of the antibodies in lupus glomeruli. Lysozyme neither inhibited the binding of anti-DNA antibodies to DNA or heparan sulphate nor did it displace anti-DNA antibodies and IC from the kidney homogenates of lupus mice. It thus appears that the inhibition of DNA binding to the GBM due to lysozyme reduced the entrapment of anti-DNA antibodies in the GBM, resulting in urinary excretion of the antibodies. 相似文献
4.
Cross-reactive antibodies against heparan sulphate (HS) have been suggested to play a role in initiating renal disease in SLE. Recently, we found that HS-reactivity is mediated by anti-DNA antibodies complexed with DNA and histones. To evaluate the clinical significance of anti-HS reactivity, we studied prospectively a cohort of 72 consecutive SLE patients, of whom 22 experienced 40 exacerbations. In 20 of these exacerbations renal symptoms were present. In these 20 exacerbations significantly higher anti-DNA (median 1:160) and anti-HS (median 1:30) titres were detected compared with exacerbations without renal manifestations (median 1:60 for anti-DNA and negative for anti-HS). There were no correlations with other symptoms of SLE. Anti-HS titres showed a significant correlation with anti-DNA antibody titres (rs = 0.57, P < 0.05). Anti-HS without anti-DNA reactivity was never detected. Some SLE patients showed a high anti-DNA titre without anti-HS reactivity, suggesting that not all anti-DNA antibodies are able to bind to histone/DNA complexes and thus to exhibit anti-HS reactivity. Our findings indicate that anti-HS reactivity is correlated with renal disease in SLE. 相似文献
5.
To investigate differences between cationic anti-dsDNA antibodies during active and inactive nephritis, low- and high-affinity IgG anti-dsDNA antibodies were prepared from sera of a lupus patient and compared for their binding affinity, spectrotype, and idiotype expression. The ratio of high-affinity to low-affinity anti-DNA antibodies and the relative avidity of the high-affinity anti-DNA antibodies decreased when active nephritis became inactive. Isoelectric focusing showed that cationic anti-dsDNA populations were present predominantly in the high-affinity fraction during active nephritis and in the low-affinity fraction during inactive nephritis. Idiotypic analysis by ELISA and Western blotting showed that the high-affinity cationic anti-DNA antibodies during active nephritis were idiotypically different from their low-affinity counterparts during inactive nephritis. The differences in binding affinity and idiotypy of the cationic anti-dsDNA antibodies suggest that certain serum IgG anti-dsDNA antibodies with both cationic charge and high affinity may be associated with active nephritis. 相似文献
6.
Histone can mediate the binding of both free DNA and DNA complexed to anti-DNA antibody to the glomerular capillary wall. We tested whether preformed histone–DNA–anti-DNA immune complexes (IC) could bind to the glomerular capillary wall. The immune complex, generated with anti-DNA antibody derived from an SLE patient and excess of 125I-DNA followed by digestion with DNase, was mixed with histones. The complex containing 4 μg DNA was injected via the aorta into the left kidney of rats. At 15 min, 1.3% of the histone–DNA–anti-DNA antibody complex bound (measured as 125I-DNA), when histone was omitted less than 0.1% of the DNA–anti-DNA antibody complex bound. By immunofluorescence human immunoglobulins and histones, representing the IC, could be observed in a capillary pattern; but no complement deposition was detected. Electron microscopy revealed discrete, electron dense deposits in a subendothelial, subepithelial and mesangial localization at 15 min. These results provide direct evidence that antibodies from serum of SLE patients can form soluble histone–DNA–anti-DNA immune complexes that bind to the glomerular capillary wall in vivo 相似文献
7.
Antibodies to dsDNA are characteristically present in serum from patients with systemic lupus erythematosus (SLE), and have been shown to have the capacity to react with various molecules bearing repeating negative charges. After a number of polymeric or monomeric molecules with differently charged groups and hydrophobic molecules had been coupled covalently as ligands on cellulose gel, the adsorption capacities of the ligands for anti-dsDNA antibodies were evaluated. It was found that gels coupled with polyanionic dextran sulphate (DXS) and polyacrylic acid (PA) and monoanionic sulphanilic acid (SA) absorbed anti-dsDNA antibodies effectively. DXS gel also adsorbed antibodies to ssDNA and heparan sulphate, antigens with repeating negatively charged moieties, while no ligand was able to adsorb anti-nRNP antibodies. The finding that DXS gels adsorbed anti-dsDNA antibody in proportion to their charge density, and that the interaction between anti-dsDNA and DXS gel is broken readily by an increase in ionic strength, indicated that the binding is ionic in nature. Moreover, virtually all F(ab')2 anti-dsDNA became adsorbed onto the DXS gels, suggesting that the binding occurred via specific antigen-binding sites on the antibody molecule. Binding of these polyanion-binding autoantibodies with anionic sites in the glomerular basement membrane may therefore cause the tissue damage observed in SLE. 相似文献
8.
This study compares recently devised methods for producing IgG anti-DNA MoAbs from patients with SLE and analyses the antibodies generated from one patient at different phases of disease. Lymphocytes from SLE patients were transformed with Epstein-Barr virus(EBV) and/or fused with a heteromyeloma cell line, CB-F7. Direct fusion with CB-F7 resulted in the highest proportion of IgG-secreting lines, whereas EBV transformation resulted in a high percentage of IgM-secreting lines. Using direct fusion, five IgM anti-DNA antibody-secreting hybridomas were generated using lymphocytes from a patient with relatively inactive SLE. Six months later when the disease was active, only IgG anti-DNA antibodies were produced. The antigen-binding patterns of the MoAbs were analysed. Only one of the IgM anti-DNA antibodies reacted with dsDNA by ELISA and none by Crithidia immunofluorescence, whereas two of the IgG antibodies reacted with dsDNA by ELISA and Crithidia but did not bind to ssDNA. Only the two IgG high affinity anti-dsDNA antibodies bound to histones, and this was enhanced by added DNA, whereas three IgM antibodies bound to cardiolipin. This study supports the notion that MoAbs derived from a patient with SLE represent those found in the serum of SLE patients at different stages of disease activity. The binding to histones by the two IgG anti-dsDNA antibodies supports the recently expressed view that antibodies binding DNA/histone may be important in the pathogenesis of SLE. 相似文献
9.
We searched for antiidiotypes directed against anti-DNA in sera of healthy family members of lupus patients. Controls were healthy individuals without a personal or family history of lupus. No significant differences were noted between the family members' and the control group's sera with respect to binding to DNA or to non-anti-DNA F(ab) 2 fragments. Family members' sera had higher binding to anti-DNA F(ab) 2 and to normal IgG F(ab) 2 fragments ( P<0.01). Sera of the family members had significantly higher binding to anti-DNA F(ab) 2 than to normal IgG F(ab) 2 fragments ( P<0.0036). Inhibition experiments have shown that the antiidiotype is directed against the framework determinants and not against the antigen binding sites of the idiotype. The anti-idiotypic antibodies were directed against cross-reactive anti-DNA idiotypes and were not restricted to the idiotypes of the lupus proband. Age, sex, and blood relationship to the lupus patient did not influence the presence of antiidiotypes in the family members. The possible role of environmental factors in the induction of antiidiotypes and the role of the latter in regulating anti-DNA antibodies are discussed. 相似文献
10.
Anti-DNA autoantibodies were thought to play a major role in the pathogenesis of lupus nephritis (LN). A recent study revealed that affinity-purified anti-DNA antibodies had a cross-reaction with human glomerular mesangial cells (HMC). However, whether the cross-reaction was antigen-antibody-mediated was unclear. The aim of the current study was to investigate the binding of anti-DNA antibodies to HMC membrane proteins and to characterize the target antigens. Affinity-purified IgG anti-DNA antibodies were purified by DNA-cellulose chromatography in sera from nine patients with biopsy-proven active lupus nephritis. In vitro cultured primary HMCs were disrupted by sonication and HMC membranes were obtained by differential centrifugation. The membranes of human umbilical vein endothelial cells (HUVEC), human proximal renal tubular epithelial cell line (HK2) and peripheral mononuclear cells (PMC) were obtained as controls. Binding of anti-DNA antibodies to the membrane proteins was investigated by Western blot analysis using soluble membrane proteins as antigens. Both HMC membrane and affinity-purified anti-DNA antibodies were treated with DNase I to exclude DNA bridging. All nine affinity-purified anti-DNA antibodies could blot the HMC membrane proteins, and there were at least three bands at 74 kDa, 63 kDa and 42 kDa that could be blotted. Among the nine IgG preparations, all nine (100%) could blot the 74 kDa band; eight (88.9%) could recognize 63 kDa and 42 kDa protein bands separately. After DNase treatment, the same bands could still be blotted by most affinity-purified anti-DNA antibodies. Affinity-purified anti-DNA antibodies could also blot similar bands on membrane proteins of other cells, but some bands were different. In conclusion, anti-DNA autoantibodies could cross-react directly with cell membrane proteins of human glomerular mesangial cells and might play an important role in the pathogenetic mechanism in lupus nephritis. 相似文献
11.
The discovery of serum biomarkers specific for paediatric lupus nephritis (pLN) will facilitate the non‐invasive diagnosis, follow‐up and more appropriate use of treatment. The aim of this study was to explore the role of serum high‐mobility group box 1 (HMGB1) protein, antibodies against nucleosomes (anti‐NCS), complement factor C1q (anti‐C1q) and glomerular basement membrane (anti‐GBM) in pLN. Serum samples of 42 patients with paediatric systemic lupus erythematosus (pSLE) (22 with pLN and 20 without renal involvement), 15 patients with other autoimmune nephritis (AN) and 26 healthy controls (HCs) were examined using enzyme‐linked immunosorbent assay (ELISA). The activity of both pSLE and pLN was assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) tool. The levels of all four biomarkers were significantly higher in pLN compared to AN and to HCs. The anti‐NCS, anti‐GBM and HMGB1 serum levels were significantly higher in pLN than in pSLE without renal involvement. The anti‐C1q and the HMGB1 serum levels were correlated positively with pSLE activity. The HMGB1 serum levels were also correlated positively with pLN activity. These findings suggest that serum anti‐NCS, anti‐GBM and HMGB1 may serve as biomarkers specific for the presence of nephritis in pSLE. HMGB1 emerged as a useful biomarker for the assessment of pLN and pSLE activity, whereas anti‐C1q only of pSLE activity. 相似文献
12.
Systemic lupus erythematosus (SLE) and lupus nephritis (LN) have strong concomitance with cardiovascular disease that cannot be explained fully by typical risk factors. We examined the possibility that serum or urine expression of adipokines may act as biomarkers for LN, as these proteins have been associated previously with cardiovascular disease as well as SLE. Antibody arrays were performed on serum and urine from lupus patients and matched controls using a cross‐sectional study design. From the initial array‐based screening data of 15 adipokines, adiponectin, leptin and resistin were selected for validation by enzyme‐linked immunosorbent assay (ELISA). Correlations were determined between adipokine expression levels and measures of disease activity or lupus nephritis. The expression of adiponectin and resistin was increased in both sera and urine from LN patients, while leptin was increased in LN patient sera, compared to matched controls. Serum resistin, but not urine resistin, was correlated with measures of renal dysfunction in LN. Serum resistin expression may be useful as a marker of renal dysfunction in patients with LN, although longitudinal studies are warranted. Further studies are necessary to determine if resistin has functional consequences in LN. 相似文献
13.
The glomerulonephritis in systemic lupus erythemalosus (SLE) is presumably triggered by ihe binding of circulating immune elements (autoantibodies and immune complexes) to the glomerulus; however, the nature of these elements is unclear. In order to detect and characterize such elements, we developed an ELISA using whole intact glomeruli as the substrate. With this assay, glomerular binding activity (GBA) was detected in the serum of MRL lpr, NZB × W, and B × SB mice, but not in non-autoimmune BALB/c mice. Less activity was present in the serum of C3H l pr, C57B1/6J Ipr and AKR lpr animals which develop signs of autoimmunity but only modest renal disease. The GBA in MRL lpr mice contained IgG (subclasses 1, 2a and 2b), but not IgG3. IgM. igA, orC3. GBA was not significantly decreased by preadsorption of MRL lpr serum by DNA-agarose (although anti-DNA antibodies were). Binding activity in serum, however, was diminished by DNAase treatment. Fractionation of MRL lpr serum over a molecular sizing column showed that GBA eluled in a broad peak. GBA bound to the glomerulus ex vivo in a tissue-specific fashion and was enriched in renal eluates relative to serum in vivo. In sum, the binding activity detected by this assay appeared to be a heterogeneous entity (possibly in part immune complexes containing DNA) which bound specifically to the glomerulus and which appeared to parallel the presence of renal disease. This novel assay system may help elucidate the pathogenesis of SLE nephritis and have utility as a disease marker. 相似文献
14.
C1 esterase inhibitor (C1INH) is an important regulatory protein of the classical pathway of complement. Mutations in the gene for this protein cause the autosomal dominant disorder hereditary angioedema (HAE). Approximately 85% of patients with HAE have a Type I defect, characterized by a diminished level of antigenic and functional C1INH. Patients with Type II defects have sufficient protein, but one allele produces dysfunctional protein. We have sequenced the DNA from HAE patients and have discovered four previously unreported mutations. The first mutation is a splice site error at nucleotide 8721, which changes the 3' acceptor splice site AG to GG at the end of intron 5 at nucleotide 8721-8722. The second mutation is a single base insertion in exon 3 between nucleotides 2467 and 2468. The third mutation is a missense error present in the eighth exon of the C1INH; at nucleotide 16867 (amino acid 470), a T to A mutation transforms a Met to a Lys. The fourth mutation closely resembles the third mutation in that it is a missense error occurring in exon 8 in the distal hinge region; a T16827C substitution changes the Phe at amino acid 457 to Leu. This report compiles a list of 97 distinct defects in the C1INH gene that cause hereditary angioedema. 相似文献
15.
目的探讨狼疮肾炎(LN)小鼠肾脏和正常小鼠肾脏蛋白质组的差异。方法应用双向凝胶电泳技术(two-dimensional gel electrophoresis,2-DE)分离肾组织总蛋白质,凝胶用银染显色,扫描仪获取凝胶图像并对其进行软件分析。结果同组实验重复3次,其中正常对照组3张图找到蛋白质点平均573±52个,匹配率为83%;LN组找到蛋白质点平均658±43个,匹配率为87%。经软件分析,LN组和对照组比较表达增加大于2倍的点有119个;降低大于0.5倍的点有140个。结论LN小鼠肾脏蛋白质表达发生了显著变化,这可能和LN的发生发展有着密切关系。 相似文献
16.
Augmentation of osteopontin (OPN) expression in renal tubuli is often observed in lupus nephritis. To investigate whether this might depend on histopathological type of glomerular lesions, comparative studies of the distribution and levels of OPN expression in kidneys were performed by in situ hybridization and real-time polymerase chain reaction in mouse lupus nephritis manifesting inflammatory (endocapillary proliferative) and deposit (wire loop) types of glomerular lesions. These glomerular lesions were developed in C.B-17/Inc-scid/scid mice by injection of IgG3 antibody producing hybridoma clones, 2B11.3 and 7B6.8, respectively, which are derived from an MRL/Mp-lpr/lpr (MRL/lpr) lupus mouse. Both clones significantly augmented OPN expression in renal tubuli, but a non-nephritogenic IgG3 clone, 1G3, derived from the same MRL/lpr mouse, did not. The OPN augmentation was prominent in the renal cortex and the inner stripe of the outer medulla. These results indicate that OPN augmentation in renal tubuli is not associated with a histopathological type of glomerular lesion in lupus nephritis, at least not with an inflammatory or a deposit type. 相似文献
17.
The TNF superfamily cytokine TWEAK induces mesangial cells, podocytes, and endothelial cells to secrete pro-inflammatory chemokines including MCP-1, IP-10 and RANTES, which are crucial in the pathogenesis of lupus nephritis (LN). As TWEAK regulates the secretion of these inflammatory mediators, we studied whether urinary TWEAK (uTWEAK) levels might be predictive and/or diagnostic in LN. In a cross-sectional study of a large, multi-center cohort of systemic lupus erythematosus (SLE) patients, uTWEAK levels were higher in patients with active as compared to never or non-active nephritis (median (IQR): 16.3 (9.9-23.0) versus 5.5 (2.3-16.8) pg/mg creatinine, p=0.001), and levels of uTWEAK correlated with the renal SLE disease activity index (rSLEDAI) score (r=0.405, p<0.001). uTWEAK levels were higher in patients undergoing a flare as compared to patients with chronic stable disease (11.1 (8.1-18.2) and 5.2 (2.3-15.3) pg/mg creatinine, respectively; p=0.036). Moreover, uTWEAK levels were significantly higher in patients undergoing a renal flare, as opposed to a non-renal flare (12.4 (9.1-18.2) and 5.2 (3.0-11.9) pg/mg creatinine, respectively; p=0.029). An accurate, non-invasive method to repeatedly assess kidney disease in lupus would be very helpful in managing these often challenging patients. Our study indicates that urinary TWEAK levels may be useful as a novel biomarker in LN. 相似文献
18.
Properdin is the only positive regulator of the complement system. In this study, we characterize the prevalence, functional consequences and disease associations of autoantibodies against properdin in a cohort of patients with autoimmune disease systemic lupus erythematosus (SLE) suffering from lupus nephritis (LN). We detected autoantibodies against properdin in plasma of 22·5% of the LN patients (16 of 71) by enzyme-linked immunosorbent assay (ELISA). The binding of these autoantibodies to properdin was dose-dependent and was validated by surface plasmon resonance. Higher levels of anti-properdin were related to high levels of anti-dsDNA and anti-nuclear antibodies and low concentrations of C3 and C4 in patients, and also with histological signs of LN activity and chronicity. The high negative predictive value (NPV) of anti-properdin and anti-dsDNA combination suggested that patients who are negative for both anti-properdin and anti-dsDNA will not have severe nephritis. Immunoglobulin G from anti-properdin-positive patients’ plasma increased the C3b deposition on late apoptotic cells by flow cytometry. Nevertheless, these IgGs did not modify substantially the binding of properdin to C3b, the C3 convertase C3bBb and the pro-convertase C3bB, evaluated by surface plasmon resonance. In conclusion, anti-properdin autoantibodies exist in LN patients. They have weak but relevant functional consequences, which could have pathological significance. 相似文献
19.
AbstractLupus nephritis is one of the most serious complications of systemic lupus erythematosus and manifests with considerable phenotypic and histological heterogeneity. In particular, diffuse proliferative lupus nephritis (DPLN) and membranous lupus nephritis (MLN) represent morphologic forms that are polar opposites. DPLN is associated with autoimmune responses dominated by Th1 immune response associated with high levels of interferon (IFN)-γ. In contrast, a Th2 cytokine response is associated with the pathogenesis of MLN. MRL/ lpr mice develop human LN-like immune complex-associated nephritis and provide a suitable histological model for human DPLN. Infection with Schistosoma mansoni skewed a Th2-type immune response induction and IL-10 in MRL/ lpr mice, drastically changing the pathophysiology of glomerulonephritis from DPLN to MLN accompanied by increased IgG1 and IgE in the sera. T cells in 32-week-old MRL/ lpr mice infected with S. mansoni expressed significantly more IL-4 and IL-10 than T cells of uninfected mice; T cells with IFN-γ were comparable between infected and uninfected MR/ lpr mice. Thus, the helminthic infection modified the cytokine microenvironment and altered the pathological phenotype of autoimmune nephritis. 相似文献
20.
Introduction: In the last few decades, identification of predictors of pregnancy outcome and appropriate pregnancy planning have significantly reduced the maternal and fetal risks in pregnant women with lupus nephritis. Areas covered: Successful pregnancies have been reported even in women with chronic renal disease and renal insufficiency. However, refractory hypertension and severe renal or cardiac chronic dysfunction are still considered contraindications to pregnancy. Pre-term delivery and fetal growth restriction may still occur in SLE patients more frequently than in healthy women, even in pregnancies regularly planned and monitored by a team of nephrologists and gynaecologists. Expert commentary: Stable disease remission is the most important factor for a successful pregnancy. In case of flare-ups of lupus, timely diagnosis and appropriate management may ensure a successful outcome in the majority of pregnant women. The negative role of anti-phospholipid antibodies and of chronic arterial hypertension may be countered with appropriate anticoagulation and anti-hypertensive therapy. Further studies are needed to better assess the possible impact of pregnancy on the long-term outcome of lupus nephritis. 相似文献
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