Retrospective Analysis Of The Clinical Characteristics And Pulmonary Images In 320 Cases Of ANCA Associated Vasculitis

Background and objective ANCA associated vasculitis(AAV)is a common pulmonary vasculitis.This article was aim to improve our knowledge of the different characteristics in both clinical diagnosis subtypes and ANCA-based subgroups.Methods All patients with primary AAV in our hospital from January 2003 to December 2015 were retrospectively reviewed.We compared their clinical characteristics,pulmonary radiological changes and pulmonary function changes between both clinical diagnosis subtypes and ANCA-based subgroups.Results(1)320 patients with primary AAV were included in this article,248 cases microscopic polyangiitis(MPA),55 cases granulomatosis with polyangittis(GPA),6 cases eosinophilic granulomatosis with polyangiitis(EGPA)and 11 cases unclassified AAV(U-AAV);211 cases with MPO-ANCA positive(MPO subgroup),52 cases with PR3-ANCA positive(PR3 subgroup),8 cases with dual positive and 49 cases with ANCA-negative.(2)Renal and pulmonary symptoms were the most common first symptoms in the primary AAV,while the proportions in each subgroup were different.GPA patients presented more frequently ear,nose and throat(ENT)symptoms(P<0.001),cough(P<0.001),expectoration(P=0.007),hemoptysis(P=0.003),mucosal and optical symptoms(P=0.001),but less renal(P<0.001)and constitutional manifestation(P=0.035)than MPA.And PR3 subgroup had a higher incidence of ENT symptoms(P<0.001),cough(P=0.010),hemoptysis(P=0.003),dyspnea(P=0.024)and mucosal and optical symptoms(p=0.028)but less frequent renal(P=0.026)and constitutional manifestation(P=0.003)than MPO subgroup.Smoking patients presented less renal impairment(P=0.012)but more skin involvement(P=0.035),and GPA smokers had a higher incidence of dyspnea(P=0.012).(3)Pulmonary radiological changes were various in all 313 patients with pulmonary X-ray or CT scan examination.Among the 241 cases with CT scan,the incidence of pulmonary nodules was higher in GPA than MPA(P=0.016),also higher in PR3 subgroup than MPO subgroups(P=0.034).Pulmonary interstitial manifestations appeared more frequently in MPA(P=0.034)than GPA,also more in MPO’s than PR3’s(P=0.040).(4)Pulmonary function test had been measured in 116 patients.66 cases(56.9%)presented pulmonary ventilation dysfunction,including 13 cases(11.2%)with obstructive,27 cases(23.3%)with restrictive,and 26 cases(22.4%)with mixed ventilation dysfunction.There is no difference in the proportion of ventilation dysfunction in both clinical diagnosis subtypes and ANCA-based subgroups.69 cases completed pulmonary diffusion test,in which 63 cases(91.3%)had pulmonary diffusion dysfunction,and 44 cases(63.8%)with reduction of DLCO/VA%.Among the patients with diffusion dysfunction,the reduction of DLCO% and DLCO/VA% were more severe in MPO subgroup than PR3 subgroup,but no difference existed in the clinical diagnosis subtypes,and the pulmonary diffusion dysfunction was not correlation with pulmonary radiological interstitial changes.(5)The concentration of PR3-ANCA was linear correlation with the titer of C-ANCA in patients with PR3-ANCA positive,but not with C-ANCA positive;the concentration of MPO-ANCA was linear correlation with the titer of P-ANCA in patients with MPO-ANCA positive or with P-ANCA positive(P<0.05).ESR elevated more significantly when the titer of C-ANCA was more than 1:160 or P-ANCA more than 1:80.(6)Patients who need plasma exchange or renal replacement therapy had higher incidence of in-hospital malignant prognosis,but there was no difference in both clinical diagnosis subtypes and ANCA-based subgroups.Conclusions Different clinical characteristics have been found in both clinical diagnosis-based subtypes and ANCA-based subgroups.Pulmonary nodule was more frequently presented in PR3 and GPA,while pulmonary interstitial manifestation was more commonly occurred in MPA and PR3.Abnormal pulmonary ventilation and diffusion function was found in AAV patients,in which the abnormal diffusion function rate is high,and the decline of DLCO/VA and DLCO more severe in MPO-ANCA positive than PR3-ANCA positive.The decline of diffusion capacity could not accompany with radiological pulmonary fibrosis,which suggested the pulmonary diffusion test would be a valuable complement to the pulmonary radiological examination,to which we should pay more attention.