Diagnostic And Predictive Value In Lupus Nephritis By Measurement Of RAGE, MCP-1, And Fractalkine

IntroductionSystemic lupus erythematosus is an autoimmune disease, characterized by infringement of multiple systems, multiple organ dysfunction. Lupus nephritis is a common complication of systemic lupus erythematosus, and the major cause resulted in disabling and death in lupus patients.The pathological types of lupus nephritis related to the clinical manifestations. Treatment and clinical outcome differs among the different pathological types. The kidney biopsy is the'gold standard'to determine the pathological type of lupus nephritis. But the kidney biopsy is a kind of invasive inspection; many patients in our country still could not accept this examination.The markers of serum and urine are widely used in clinical, such as the anti-double stranded DNA, complement, erythrocyte sedimentation rate, but these markers often lack specificity and significance for the diagnosis and and prognosis of different pathological types of lupus nephritis. Therefore, noninvasive, more specific and sensitive indicators for the diagnosis of pathological types and predict the treatment effect of lupus nephritis are needed. In recent years, researchers have been dedicated to explore more sensitive and timely indicators for the diagnosis the lupus nephritis and predict the relapse. Such as NGAL, ICAM-1, VCAM-1, C1q, could detected in urine and serum.The aim of our study is to investigate whether level of RAGE, MCP-1, Fractalkine in urine and serum is a useful noninvasive tool for the pathological diagnosis and prognosis of treatment. Our topic is expected to provide new noninvasive diagnostic markers for lupus nephritis and to provide some clinical basis for future research.Part I:Diagnostic and Predictive Value in Lupus Nephritis by Measurement of RAGEObjective:To investigate the relationship between lupus nephritis and the level of RAGE in serum, explore the diagnostic and predictive value of the measurement of serum RAGE.Methods:We examined serum samples from lupus nephritis patients between June2004and June2011.197patients were enrolled, including82cases of proliferative lupus nephritis (including type Ⅲ and type IV,53cases of membranous (type V),43patients with mixed lupus nephritis(including type Ⅳ+Ⅴ, Ⅴ+Ⅲ), other types19cases (including typel, type Ⅱ, and patients were not classified for minor lesion); RAGE was measured in serum samples using a commercial human RAGE enzyme-linked immunosorbent assay(ELISA) kit (R&D Systems). All samples were tested in by a standardized ELISA technique. Statistical analysis was performed by using SPSS software package (Version16.0) and Medcalc11.5. Because of nonparametric distribution, comparisons of RAGE levels among different groups were performed by Mann Whitney U test and Wilcoxon Signed Ranks Test. A conventional receiver operating characteristic (ROC) curve was applied to determine the sensitivities and specificities for RAGE measurements for patients with proliferative and membranous lupus nephritis.Area under the curve were also calculated. Results were expressed in the text as mean±SEM unless otherwise stated. P<0.05was considered statistically significant.Result:The serum RAGE among the proliferative,membranous and lupus nephritis had significant difference (2020.738pg/ml vs1257.938pg/ml vs1638.081pg/ml, p=0.0053). ROC curve was constructed to determine the discriminatory power of RAGE levels for diagnosis of proliferative and membranous lupus nephritis.The area under ROC curve was0.708(95%CI:0.593-0.790, P=0.001). At a cut point of RAGE=1231.52pg/ml, the sensitivity was72%and the pecificity was62.3%. And in the40patients with refractory lupus nephritis, the serum RAGE level was lower than the therapy sensitive group (141.64±828.53pg/ml vs1700.42±1345.38pg/ml, p=0.0055). ROC curve was constructed to determine the discriminatory power of RAGE levels for predict of refractory and sensitive lupus nephritis. The area under ROC curve was0.643(95%CI:0.539-0.680, P=0.0012). At a cut point of RAGE=1852.1pg/ml, the sensitivity was89.7%and the pecificity was41%. There was no significant correlation between serum RAGE levels with SLE-DAI indexConclusion:The detection of RAGE in serum may be a new and noninvasive approach for assistant diagnosis of lupus nephritis's pathology, and help to predict the effects of the drug in clinical therapy. Part Ⅱ:Diagnostic and Predictive Value in Lupus Nephritis by Measurement of MCP-1Objective:To investigate the relationship between lupus nephritis and the level of MCP-1in serum and urine, explore the diagnostic and predictive value of by the measurement of serum and urine MCP-1.Methods:We examined serum samples from lupus nephritis patients between June2004and June2011.197patients were enrolled, including82cases of proliferative lupus nephritis (including type Ⅲ and type Ⅳ,53cases of membranous (type V),43patients with mixed lupus nephritis(including type IV+V, V+Ⅲ), other types19cases (including typeⅠ, type Ⅱ, and patients were not classified for minor lesion); MCP-1was measured in serum and urine samples using a commercial human MCP-1enzyme-linked immunosorbent assay(ELISA) kit (R&D Systems). All samples were tested in by a standardized ELISA technique. Statistical analysis was performed by using SPSS software package (Version16.0) and Medcalc11.5. Because of nonparametric distribution, comparisons of MCP-1levels among different groups were performed by Mann Whitney U test and Wilcoxon Signed Ranks Test. A conventional receiver operating characteristic (ROC) curve was applied to determine the sensitivities and specificities for MCP-1measurements for patients with proliferative and membranous lupus nephritis and MCP-1measurements for refractory and sensitive lupus nephritis.Area under the curve was also calculated. Results were expressed in the text as mean±SEM unless otherwise stated. P<0.05was considered statistically significant.Result:The serum and urine MCP-1among the proliferate,membranous and lupus nephritis had significant differenc (354.49±598.60pg/ml vs200.40±171.83pg/ml vs273.31±429.31pg/ml, p=0.02),,(1240.65±876.38pg/mmol creatinine vs544.47±430.63pg/mmol creatinine vs594.8±610.55pg/mmol creatinine, p=0.008). ROC curve was constructed to determine the discriminatory power of serum, urine MCP-1levels for diagnosis of proliferative and membranous lupus nephritis. The area under ROC curve of serum MCP-1was0.627(95%CI:0.539-0.710, P<0.001). At a cut point of serum MCP-1=154.97pg/ml, the sensitivity was62.0%and the specificity was66.0%. The area under ROC curve of urine MCP-1was0.746(95%CI:0.658-0.822, P<0.0001). At a cut point of urine MCP-1=640.23pg/mmol creatinine, the sensitivity was72.4%and the specificity was71.4%. And in the40patients with refractory lupus nephritis, the serum and urine RAGE level was lower than the therapy sensitive group (180.81±105.94pg/ml vs352.75±535.71pg/ml, p=0.036),(483.95.33±433.21pg/mmol creatinine vs943.47±791.69pg/mmol creatinine, P=0.0002).ROC curve was constructed to determine the discriminatory power of MCP-1levels for predict of refractory and sensitive lupus nephritis. The area under serum ROC curve was0.611(95%CI:0.539-0.680, P=0.0012). At a cut point of serum MCP-1=329.54pg/ml, the sensitivity was97.4%and the pecificity was32.5%. The area under urine ROC curve was0.693(95%CI:0.622-0.758, P=0.0002). At a cut point of serum MCP-1=974.46pg/ml, the sensitivity was89.7%and the pecificity was41%.Urine MCP-1was correlated with SLE-DAI (r=0.43, P<0.0001).There was no significant correlation between serum RAGE levels with SLE-DAI index.Conclusion:The detection of MCP-1in serum and urine may be a new and noninvasive approach for assistant diagnosis of lupus nephritis's pathology, and help to predict the effects of the drug in clinical therapy. refractory lupus nephritis;Part III:Diagnostic and Predictive Value in Lupus Nephritis by Measurement of Fractalkine.Objective:To investigate the relationship between lupus nephritis and the level of fractalkine in serum and urine, explore the diagnostic and predictive value of by measurement of serum and urine fractalkine.Methods:We examined serum samples from lupus nephritis patients between June2004and June2011.197patients were enrolled, including82cases of proliferative lupus nephritis (including type Ⅲ and type Ⅳ,53cases of membranous (type V),43patients with mixed lupus nephritis(including type IV+V, V+III), other types19cases (including typeⅠ, typeⅡ, and patients were not classified for minor lesion);Fractalkine was measured in serum and urine samples using a commercial human MCP-1enzyme-linked immunosorbent assay(ELISA) kit (R&D Systems). All samples were tested in by a standardized ELISA technique. Statistical analysis was performed by using SPSS software package (Version16.0) and Medcalc11.5. Because of nonparametric distribution, comparisons of fractalkine levels among different groups were performed by Mann Whitney U test and Wilcoxon Signed Ranks Test. A conventional receiver operating characteristic (ROC) curve was applied to determine the sensitivities and specificities for fractalkine measurements for patients with proliferative and membranous lupus nephritis and fractalkine measurements for refractory and sensitive lupus nephritis. Area under the curve was also calculated. Results were expressed in the text as mean±SEM unless otherwise stated. P<0.05was considered statistically significantResult:The urine fractlkine among the proliferative, membranous and lupus nephritis had significant difference (4.44±3.05ng/mmol creatinine vs2.37±1.88ng/mmol creatinine vs3.42±2.45ng/mmol creatinine, p<0.0001).The serum fractalkine among the proliferative membranous and lupus nephritis had no significant difference.(2.53±1.24ng/ml vs2.07±1.19ng/ml vs2.28±1.05ng/ml, P=0.87)ROC curve was constructed to determine the discriminatory power of s urine fractalkine levels for diagnosis of proliferative and membranous lupus nephritis. The area under ROC curve of urine fractalkine was0.740(95%CI:0.657-0.812, P<0.001). At a cut point of serum urine fractalkine=3.007ng/mmol creatinine, the sensitivity was66.7%and the specificity was77.5%.And in the40patients with refractory lupus nephritis, the serum and urine fractalkine level was similar to the therapy sensitive group (2.70±2.25ng/ml vs2.38±1.39ng/ml pg/ml, p=0.77),(3.88±2.33ng/mmol creatinine vs3.42±2.80ng/mmol creatinine, P=0.11). Serum and urine fractalkine was correlated with SLE-DAI (r=0.29, P<0.0001;r=0.43, P<0.0001,respectively)Conclusion:The detection of urine fractalkine may be a new and noninvasive approach for assistant diagnosis of lupus nephritis's pathology. But still could not help to predict the effects of the drug in clinical therapy. The value of serum fractalkine for assistant diagnosis of lupus nephritis's pathology and predict the effect of the drug therapy was still not clear. The serum and urine fractalkine level were all correlated with SLE-DAI.