The Clinical Significance Of Lupus Nephritis With Antineutrophil Cytoplasmic Antibodies Seropositivity

Objective:To analyze the clinicopathologic characteristics and outcomes of LN patients with ANCA seropositivity,and investigate the clinical relationships between ANCA and LN patients.Methods:120 patients with biopsy-proven LN by the first time in our hospital were enrolled in our study from October 1st,2010 to September 30th,2019.Presence of serum ANCA was detected by indirect immunofluorescence as well as enzyme-linked immunosorbent assay.According to the ANCA test results,101patients which met the inclusion and exclusion criteria were divided into ANCA-positive group and ANCA-negative group.The general conditions,clinical manifestations,laboratory indexes,pathology data and induction therapies were analyzed retrospectively.We used independent t-test,Mann-Whitney U test,chi-square and Fisher’s exact test to describe and analyze the baseline information mentioned above.We used Kaplan-Meier survival curve to compare the cumulative renal survival rate between the two groups and used Cox regression model to analyse the risk factors for poor outcomes of LN patients.Results:1.101 LN patients were included totally,composed of 12 males and 89 females.Among these patients,30(29.70%)were seropositive for ANCA,mostly were p ANCA.The proportion of male in ANCA-positive group were significantly higher than that in ANCA-negative group(p=0.038).There were no significant differences in age,disease duration before renal biopsy,hypertension,infections and the use of steroids or immunosuppressants within the last half year of the admisson between the two groups(P>0.05).2.Compared with ANCA-negative group,ANCA-positive group had significantly higher incidences of oral ulcer and thrombocytopenia(P=0.011,0.004,respectively),and SLEDAI score was notably higher(P=0.021).No differences were found in malar rash,anemia and other clinical manifestations between the two groups(P>0.05).3.Compared with ANCA-negative group,the levels of serum albumin,e GFR and complement C3 in ANCA-positive group appeared much lower(P=0.010,0.028,0.004,respectively);the levels of serum creatinine and uric acid,the positive rate of anti-double stranded DNA antibodies and the incidence of leukocyturia in ANCA-positive group were significantly higher(P=0.022,0.011,?0.001,0.013,respectively).Peripheral blood leukocyte count,platelet count,hemoglobin,triglyceride,cholesterol,high density lipoprotein cholesterol,low density lipoprotein cholesterol,24 hours urine protein,hematuria and cyclinduria were not statistically significant between the two groups(P>0.05).There were no significant differences in the levels of complement C4 and Ig G and the positive rates of ANA,Anu A and other autoantibodies between the two groups(P>0.05).4.Class IV was the most frequent pathological class of LN patients(43.56%).The proportion of class IV in ANCA-positive group was significantly higher than that in ANCA-negative group(P=0.030),while there were no differences in the distributions of other LN classifications(P>0.05).ANCA-positive group had a notably higher AI score than ANCA-negative group(P=0.008),while there found no significant differences in CI score and TIL score between the two groups(P>0.05).Compared with ANCA-negative group,ANCA-positive group had significantly higher incidence of fibrinoid necrosis/karyorrhexis(P=0.002),however,no significant differences were found in endocapillary hypercellularity,hyaline trombi/wire-loop and other renal pathologies between the two groups(P>0.05).5.ANCA-positive group and ANCA-negative group had no significant differences in the therapies of induction period(P>0.05).During the follow-up of 6 months,there were no significant differences in the complete remission rate and partial remission rate between the two groups(P>0.05).There also found no significant differences in the end-point events of all-cause death,doubling of serum creatinine,development of ESRD or renal replacement therapy between the two groups(P>0.05).6.Kaplan-Meier survival curve showed that there was no significant difference in the cumulative renal survival rate between the two groups(Log-rank test:χ~2=0.548,P=0.459).7.Univariate Cox regression analysis suggested that hypertension,SLEDAI score,serum uric acid,serum creatinine,e GFR,24 hours urine protein,fibrinoid necrosis/karyorrhexis,crescents formation,AI score and CI score were associated with the prognosis of LN patients.Multivariate Cox regression analysis revealed that high CI score was the independent risk factor for poor outcomes of LN patients(HR=1.351,P=0.044).Conclusions:The positive rate of ANCA in LN patients was 29.70%,the majority of which were p ANCA.ANCA was associated with the disease activity and AI score in LN patients.ANCA-positive group had significantly higher incidences of oral ulcer,thrombocytopenia and leukocyturia,and had worse basic renal function at renal biopsy.The levels of serum albumin and complement C3 in ANCA-positive group appeared much lower while the level of serum uric acid and the positive rate of anti-double stranded DNA antibodies in ANCA-positive group were notably higher.The most frequent pathological class in ANCA-positive group was Class IV.ANCA-positive group had significantly higher incidence of fibrinoid necrosis/karyorrhexis.