Study On The Relationship Between Serum Ferritin Level And Disease Activity And Pathological Damage In Patients With Lupus Nephritis

Background and purposeSystemic lupus erythematous(SLE)is a chronic autoimmune disease with impaired immune tolerance,production of autoantibodies,and immunological damage to multiple organ systems.Renal involvement is common among patients with SLE,and lupus nephritis(LN)is a major risk factor for overall morbidity and mortality in SLE.The pathogenesis of LN is complicated,and there are great differences in disease course and treatment response of patients,which brings great challenges to the management of LN.It is one of the directions of scientific research to look for biomarkers that are convenient and helpful to the diagnosis and activity of the disease.Many studies at home and abroad have reported the relationship between serum ferritin and SLE disease activity,suggesting that serum ferritin is one of the valuable serological markers for the diagnosis of SLE.However,the relationship between serum ferritin and LN disease activity has not been reported in China.This study analyzed the differences of serum ferritin levels between LN group,SLE non-nephritis group and healthy control groups,active LN group and stable LN group,and different pathological types,the differences of clinical and pathological features between high-ferritin LN group and low-ferritin LN group,to explore the relationship between serum ferritin level and disease activity and pathological changes in lupus nephritis patients,and to provide new ideas for the diagnosis and treatment of LN.Materials and MethodsA total of 159 patients with LN who were admitted in the Department of Nephrology of the First Affiliated Hospital of Zhengzhou University from January 2018 to May 2019 were selected,at the same time,43 SLE patients without renal damage were selected from the Department of Rheumatic Immunology,as SLE non-nephritis group,and 63 healthy adults were recruited from the outpatient physical examination center,as the healthy control group.According to SLE disease activity index(SLEDAI)score,LN patients were divided into the active LN group and the stable LN group,and according to serum ferritin,they were divided into the low-ferritin LN group and the high-ferritin LN group.The data were statistically analyzed by SPSS22.0 statistical software,and the differences of serum ferritin levels among groups were compared,and the differences of general data,clinical and pathological indexes between the low-ferritin LN group and the high-ferritin LN group were compared.Spearman correlation analysis and multiple linear regression equation were used to analyze the relationship between serum ferritin level and disease activity and pathological features in patients with LN.Results1.Compared with the healthy control group,the levels of serum ferritin in SLE non-nephritis group and LN group were significantly higher(all P<0.05).The level of serum ferritin in LN group was significantly higher than that in SLE non-nephritis group(P<0.05).Compared with the stable LN group,the level of serum ferritin in the active LN group was significantly higher(P<0.05).2.The serum ferritin level of type IV LN was significantly higher than that of type V LN group and type IV+V LN group(all P<0.05),there was no significant difference in serum ferritin levels among other pathological types(all P>0.05).3.Compared with the low-ferritin LN group,SLEDAI,serum creatinine,serum uric acid,blood urea nitrogen,24-hour proteinuria,acute activity index(AI)and chronic activity index(CI)in the high-ferritin LN group were significantly higher(all P<0.05),while complement C3,complement C4,hemoglobin and albumin were significantly lower than that in the low-ferritin LN group(all P<0.05).However,there were no significant differences in age,disease course,C-reactive protein,ESR and anti-dsDNA between the two groups(all P>0.05),and there was no significant difference whether it is "full-housed" in renal tissue immunofluorescence examination between the two groups(all P>0.05).4.Serum ferritin was positively correlated with anti-dsDNA,SLEDAI,serum creatinine,serum uric acid,blood urea nitrogen,AI and CI(all P<0.05),but negatively correlated with complement C3,complement C4,albumin and hemoglobin(all P<0.05),while not correlated with C-reactive protein,ESR and 24-hour proteinuria(all P>0.05).5.Multiple linear regression analysis was performed with serum ferritin as dependent variable,gender,SLEDAI,anti-dsDNA antibody,complement C3,complement C4,serum creatinine,serum uric acid,blood urea nitrogen,hemoglobin,albumin,24-hour proteinuria,AI and CI as independent variables.The results showed that gender,SLEDAI,anti-dsDNA,hemoglobin,and AI were independent factors affecting serum ferritin(R2=0.553,F=12.928,P<0.05).ConclusionSerum ferritin can reflect the disease activity and renal pathological damage in lupus nephritis patients.