The Relationship Between NLR,RPR And Disease Activity Together With Renal Damage In Childhood-onset Systemic Lupus Erythematosus

Objective The levels of neutrophil/lymphocyte(NLR)and red blood cell distribution width/platelet(RPR)in newly diagnosed patients with systemic lupus erythematosus(SLE)in children were analyzed to explore their clinical significance in assessment of disease activity together with renal damage.Methods A total of 70 children newly diagnosed with SLE from January 2012 to June 2018 in the First Affiliated Hospital of Zhengzhou University were studied.50 healthy children of the same age in the same period were used as controls.We divided the patients into 2 groups using the SLEDAI-2000.Group 1 included patients with SLEDAI score ≤9(mild disease activity group)and group 2 with SLEDAI >9(severe disease activity group).Children with SLE were divided into LN group and non-LN group according to whether accompanied by renal involvement.A subgroup was conducted by the renal pathological classification of LN.General clinical data,SLE disease activity index and laboratory data,including gender,age,blood routine,inflammatory indicators,and renal pathological data,were collected from all enrolled children,and NLR and RPR values were calculated.We used Mann-Whitney U test to compare the differences of NLR、RPR in different groups;Kruskal-Wallis was used to compare the differences of NLR、RPR among different renal pathological types.Spearman correlation coefficient was calculated to examine the association between NLR、RPR、SLEDAI-2000 and other index,Receiver-operating characteristic(ROC)curve analysis was then performed to determine the sensitivity and specificity of possible inflammatory markers in predicting SLE and lupus nephritis,to explore the relationship between the two indiactors and disease activity together with renal damage.Results 1.70 newly diagnoses SLE patients in children were included in this study,the ratio of male to female was 1:5.36,the range of age was 7～15 years old,average age: 11.1±2.0 years old;53 patients(75.7%)with LN were included,the ratio of male to female was 1:4.89,average age: 10.9±2.1 years old.The most common clinical manifestation was rash(60%)and fever(52.8%).Renal(75.7%)and blood system damage(57.1%)were more susceptible than other organs.Type Ⅳ were the most common pathological type,31 cases(58.5%)with Type Ⅳ,3 cases(5.7%)with type,4 cases(7.5%)with type Ⅱ,13cases(24.5%)with type Ⅲ,2cases(3.8%)with type Ⅴ,there were no type Ⅵ.2.NLR,RPR showed statistically significant increased values of SLE patients as compared to control group(P<0.001).3.The levels of NLR,RPR in the severe disease activity group were higher in the mild disease activity group(P=0.001).NLR,RPR were positively correlated with SLEDAI cores(r=0.373,0.377),ESR(r=0.285,0.279),CRP(r=0.249,0.233),were negative correlated with C3(r=-0.317,-0.351),C4(r=-0.262,-0.281)(P<0.05);The level of NLR was positively correlated with BUN,Scr(r=0.245,0.261,P<0.05),and negative correlated with ALB(r=-0.255,P<0.05),RPR has no correlated with these parameters(P>0.05).4.The levels of NLR,RPR,Scr and SLEDAI scores in LN group were higher than non-LN group,ALB was lower than non-LN group,the difference was statistically significant(P<0.05).NLR showed positive correlated with 24 h urinary protein(r=0.406,P=0.024),but it had no correlated with RPR(r=0.116,P>0.05).5.The levels of ALB,BUN,Scr in between different renal clinical classification showed differences(P<0.05).The level of BUN in patients with Type Ⅳ was higher than in patients with type Ⅰ+Ⅱ,24-hour urinary protein in patients with type Ⅲ,Ⅳ showed statistically significant increased values as compared to patients with type Ⅰ+Ⅱ.But NLR,RPR,Scr had no difference between these groups(P>0.05).6.The receiver-operating characteristic curve analysis showed that the area under of NLR,RPR in diagnosis highly active SLE was 0.740,0.725 respectively,and the critical value was 1.710,0.123;The sensitivities were 0.775,0.675;and the specificities were 0.700,0.767 respectively;the area under of NLR in predicting the diagnosis of lupus nephritis was 0.730,the critical value was 1.710,The sensitivities were 0.679,and the specificities were 0.765;the area under of RPR was 0.585,it had no value(P>0.05).Conclusions 1.NLR and RPR are correlated with the disease activity in newly diagnosed children with systemic lupus erythematosus,and they may be used as auxiliary indicators to assess the disease activity of SLE.2.NLR has a certain predictive value for predicting SLE renal damage,but it isn’t associated with the different classes of its histological staging.