Screening And Analysis Of Prognostic Factors In ANCA-associated Vasculitis

Part 1 Prognosis and risk factors of ANCA associated vasculitisBackgroundAnti-neutrophil cytoplasmic antibody(ANCA)-associated vasculitis(AAV)is characterized by inflammation and necrosis of blood vessel wall with high morbidity and mortality.Renal involvement is common and closely associated with prognosis.This improvement could possibly be due to greater awareness and earlier diagnosis of concurrent AAV and more prudent use of immunosuppression.With the development of research,the diagnosis and treatment of AAV has been widely concerned.Recently,the clinical early intervention can greatly improve the prognosis of AAV.However,the adverse effects caused by the long-term use of immunosuppressive agents occur gradually.To improve the long-term survival of patients with AAV is still a challenge.Therefore,early identification of prognostic factors or clinical symptoms of AAV is expected to promote early and optimal immunosuppressive therapy in patients with AAV.In 2002,the European team of vasculitis suggested that glomerular sclerosis and tubulointerstitial injury could effectively predict the prognosis of renal function in patients with AAV.After Berden proposed new AGN pathologic classification,more and more researchers have verified the clinical significance of this type in the standard to evaluat e the prognosis of patients.As we known,renal biopsy is not yet universal,particularly in many community hospitals.The evaluation of the prognosis depending on pathological information is not fully implemented.On the other hand,some patients with AAV have poor blood clotting function,or have a clear tendency to bleeding in the near future,and they can not take renal biopsy in the short term.Therefore,it is very important to pay attention to the biochemical indexes and clinical features which are closely related to the prognosis.The role of the complement system in AAV has received much attention.Several studies abroad have found that serum complement C3(sC3)is associated with poor prognosis in AAV.So far there is no similar report in China.In this study,a retrospective analysis of 54 patients with AAV have been performed from January 2011 to March 2016 in our hospital,aiming to explore the risk factors of poor prognosis and provide clinical basis for the optimization of AAV patients with ear ly treatment options.MethodsDemographic and laboratory parameters of 54 consecutive patients with AAV diagnosed in Department of Nephrology,Xinqiao Hospital between January 2011 and March 2016 were collected retrospectively.To identify the clinical baseline variables associated with poor prognosis,comparison have been performed respectively between patients with and without outcomes events,and between patients with and without remission.Multivariate Cox regression model was used to determine the independent predictors of poor prognosis.In addition,the clinicopathological feature and outcome of patients with low sC3 levels have been investigated.Results1?In comparison with these patients without outcomes events,the levels of SCr and 24h-proteinuria were significantly higher in patients with outcomes events(P=0.001,0.026,respectively),whereas platelet count,CRP,Alb,sC3 and e GFR were significantly lower(P=0.041,0.041,0.049,0.001,0.005,respectively).2?These patients who achieved remission tened to show higher levels of platelet count,CRP,ESR,and sC3(P=0.016,0.004,0.009,<0.001,respectively),and a lower level of 24h-proteinuria(P=0.021).3?Multivariate Cox regression model showed that high 24h-proteinuria(HR=1.315,P=0.034),high BVAS(HR=1.091,P=0.034)and low sC3(HR=3.476,P=0.019)were independent predictors of poor prognosis in patients with AAV.4?Low sC3 group showed a higher level of initial serum creatinine than the normal sC3 group(P=0.008).Significant lower levels of c-reactive protein and e GFR were seen in the former group,when compared with the latter group(P<0.001,0.012,respectively).5?The low sC3 group showed higher incidences of rapid progressive renal failure and renal replacement therapy at diagnosis than normal sC3 group(P=0.035,0.014,respectively).However,the low sC3 group showed lower incidence of remission than normal sC3 group(P<0.001).6?Kaplan–Meier analysis indicated the low sC3 group showed worse prognosis than normal sC3 group(log-rank=10.197,P=0.001).Conclusions1?High 24h-proteinuria,high BVAS and low sC3 level were independent predictors of poor prognosis in patients with AAV.2?AAV patients with low sC3 levels tend to have severe renal impairment with a rapid progression and poor prognosis.3?Early attention to sC3 levels may contribute to early effective treatment and improve prognosis.Part 2 The clinical significance of ANCA in IgA nephropathyBackgroundANCA plays an important role in the pathogenesis of AAV.Recently,ANCA has been paid much attention to.Many clinical observations have found that ANCA can exist in other diseases such as systemic lupus erythematosus,purpura nephritis and IgA nephropathy(IgAN),and may be involved in the occurrence and development of diseases.In our previous study,we found that ANCA is an independent risk factor for poor prognosis in lupus patients.More and more IgAN patients with ANCA positivity have been reported.Most of the researchers suggested that ANCA positive IgAN patients often coexist with AAV,which requires early initiation of immunosuppressive therapy to improve their prognosis.However,less attention has been paid to the clinical features of IgAN associated with ANCA in patients with AAV.As we know,AAV is a kind of autoimmune disease which can involve multiple organs.The clinical symptoms are complex.However,the extra-renal clinical manifestation of IgAN is very rare.Roth et al.indicated that not all ANCA have the pathogenicity.Based on this,our previous study found not all IgAN with ANCA positivity could show severe clinical and pathological damage.It implied that not all ANCA play a pathogenic role in IgAN.Therefore,it is important to determine whether the ANCA could show pathogenicity.At present,the routine clinical detection programs can not differentiate pathogenic ANCA from non pathogenic ANCA.Previous reports of ANCA positive in serum were mostly case study or case series study,and the clinical significance of ANCA in IgAN nephropathy was poorly studied in the IgAN.In this study,we analyzed the clinical characteristics and prognosis of ANCA positive IgAN patients(with or without crescent),aiming to promote reasonable treatment in clinical practice.MethodsA total 35 IgAN patients with ANCA positivity,from January 2011 to June 2016 in the Department of Nephrology,Xinqiao Hospital,were included as case group.Simultaneously,40 IgAN patients with ANCA negative were randomly selected as control group.The clinical and pathological feature of 35 IgAN patients with ANCA positive were analyzed,by comparing with 40 IgAN patients with ANCA negative.And than we stratified the former into two subgroups(with systemic involvement(n=14)and without systemic involvement(n=21),and further did a comparison of the the clinical and pathological feature between the subgroups.Results1?Only 10 cases(28.6%)of ANCA positive IgAN patients have the formation of crescentic and rapid progression of renal failure.2?No significant difference in renal function was seen between IgAN patients with and without ANCA positivity(P=0.360).3?Subgroup analysis showed that 40%ANCA positive IgAN patients showed systemic symptoms.4?Further stratified analysis of these ANCA-positive patients indicated that cases with systemic involvement showed lower levels of e GFR,Alb and HGB than these without systemic involvement.The higher levels of SCr and ESR,higher percentage of glomerulosclerosis and higher incidence of crescent formation and moderate-severe tubular atrophy can be seen in patients with systemic involvement,when compared with these without systemic involvement(P<0.0167).5?Kaplan–Meier analysis indicated that cumulative renal survival rate was lower in patients with systemic involvement than these without systemic involvement(P<0.0167).Conclusions1?Not all ANCA positive IgAN patients presented an overlap syndrome of IgAN and AAV.2?Systemic involvement needs to be evaluated seriously in clinical practice.3?Evaluation of systemic signs or symptoms using BVAS could be a practical approach to identification of pathogenic and non-pathogenic ANCA.Part 3 Screening of novel biomarkers for the activity and prognosis of ANCA associated vasculitisBackgroundAt present,the diagnosis of AAV mainly depends on tissue biopsy.Biopsy is a traumatic examination,and there is great difficulty in the implementation of disease follow-up,both at home and abroad.However,all biomarkers reported for AAV disease,activity,or prognosis have been limited in sensitivity and specificity.With the development of the study,many researchers begin to pay attention to the pathological mechanism and clinical significance of chemokines in AAV.Recently,studies have shown that the regulation of chemokine networks promotes granulocyte activation and recruitment to inflammatory regions,and different levels of immune imbalance in vivo may make the chemokine and its receptor expressed in different levels and roles.The balance between different chemokines often determines the activity and prognosis of the disease.Some researchers stress that the study of the pathological roles of chemokines in AAV cannot be done alone in the study of the levels of a single chemokine,and that systemic and systematic studies of the levels and activities of chemokines are needed.The traditional detection method of trend factor,such as enzyme linked immunosorbent assay(Enzyme Linked Immunosorbent Assay,ELISA),polymerase chain reaction(Polymerase Chain Reaction,PCR)have some obvious defects,such as each experiment can only detect a serum factor,the larger the amount,tedious,time-consuming.In the study,we used the liquid chip technology to detect and analyze the serum chemokines in AAV patients and healthy controls,aiming to seek patient assessment of new,more accurate,optimization of treatment,biological prognostic markers,on the other hand aiming to explore the mechanism of chemokine AAV in pathological mechanism,lay the theoretical foundation for the further development of new drugs for the treatment of AAV.MethodsChemokines of AAV patients and healthy controls determined using high specificity,high throughput Luminex serum less liquid phase chip technology.And we further analysis of the relationship between clinical indexes and some chemokines,including prognosis.Results1?AAV patients showed higher levels of MPIF-1,BRAK,CXCL16,HCC-4,CCL28,YKL40,GCP-2,I-TAC,MIG,BCA-1,I-309,SCF,CTACK,MIP-1 and IP-10 than healthy controls(P<0.05).2?Correlation analysis of difference factors and clinical indicators,the results showed that there were significant correlations between CXCL16,HCC-4,CTACK,MIG and MIP-1d and AAV in patients with serum creatinine(P<0.05);there is a significant correlation between CXCL16,IP-10,MIG and YKL40 with BVAS score(P<0.05);there were significant the correlation between CXCL16,GCP-2,HCC-4,I-TAC,MIG,SCF and YKL40 and TNF-levels(P<0.05);there is a significant correlation between GCP-2 and serum C3 levels(P<0.05).3 ? Kaplan-Meier survival analysis showed that these patients with high CXCL16(83.3% vs.27.8%,P=0.001),CTACK(72.2% vs.38.9%,P=0.047),MIP-1d(77.8% vs.33.3%,P=0.008),YKL40(72.2% vs.38.9%,P= 0.047)showed significantly lower renal survival than these with low levels.No significant differences were seen in other factors(P>0.05).Conclusions1? The serum levels of MPIF-1,CXCL16,HCC-4,YKL40,GCP-2,I-TAC,MIG,BCA-1,SCF,CTACK,MIP-1d and IP-10 in AAV were significantly increased,which could lay the foundation for further study of the pathogenesis of AAV.2?CXCL16,CTACK,MIP-1d and YKL40 are expected to be the new serological markers to judge the prognosis of AAV.