An Exploratory Study Of Autoantibodies In Sputum And Serum Of Patients With Eosinophilic Granulomatosis With Polyangiitis(EGPA)

Objective: 1.The comparisons of clinical indexes and autoantibodies in serum and sputum between localized EGPA and systemic EGPA;2.The comparisons of autoantibodies in serum and sputum between EGPA in exacerbation and EGPA in remission;3.To explore the correlation among autoantibodies from serum and sputum in EGPA;4.To explore the correlation between clinical indexes and autoantibodies from serum and sputum in EGPA.Methods: 14 systemic EGPA patients and 21 localized EGPA in remission,12 systemic EGPA patients and 18 localized EGPA in exacerbation were recruited.We collected clinical indexes of EGPA patients and made comparison of clinical indexes from localized EGPA and systemic EGPA patients.Sputum and serum from 21 localized EGPA and 14 systemic EGPA patients in remission,and 18 localized EGPA and 12 systemic EGPA patients in exacerbation were collected.We established Luminex which could interact autoantibodies with bead-antigen complex to detect the immunoglobulin G(Ig G)antibodies of ten autoantibodies in serum and sputum from localized EGPA and systemic EGPA patients,including Sm,Anti-ribosomal P antibody(P0),Ro-52,SSB/La,Scl-70,Jo-1,small nuclear ribonucleoprotein(Sn RNP),thyroid peroxidase(TPO),Proteinase 3(PR-3)and Myeloperoxidase(MPO).The comparisons of autoantibodies in serum and sputum between localized EGPA and systemic EGPA patients were carried out.Besides,we made the comparisons of autoantibodies in serum and sputum between EGPA in exacerbation and EGPA in remission.The associations among autoantibodies in serum and sputum from EGPA patients were explored.Finally,we also explore the correlation between clinical indexes and autoantibodies in serum and sputum from EGPA patients.Results: 1.Compared with systemic EGPA in remission,the percentage of induced sputum lymphocyte from localized EGPA in remission was greater [0.50(0.5,1.63)vs.2.00(1.13,2.50)%,p=0.009].Compared with systemic EGPA in exacerbation,the percentage of blood monocyte from localized EGPA in exacerbation was greater [6.12±1.95 vs.8.24±1.94%,p= 0.006].There was no difference in other clinical indexes between systemic EGPA and localized EGPA.2.There was no difference about 10 autoantibodies levels in serum between systemic EGPA and localized EGPA in remission or exacerbation.There was no difference about 10 autoantibodies levels in serum between systemic EGPA in remission and systemic EGPA in exacerbation,or between localized EGPA in remission and localized EGPA in exacerbation.3.Compared with systemic EGPA in exacerbation,Sm [381.5(208.5,790.0)vs.842.5(386.3,2935.4),p=0.022],La [148.0(107.3,250.5)vs.374.0(207.8,777.5),p=0.010],PO[292.0(191.5,737.8)vs.900.3(474.0,1695.0),p=0.028] in sputum from localized EGPA in exacerbation were significantly higher.Compared with systemic EGPA in remission,Sm [250.5(196.3,449.4)vs.527.0(299.8,867.3),p=0.014],Sn RNP [738.7±257.0 vs.1407.9±833.0,p=0.012],PO[270.7(126.8,323.0)vs.558.0(323.5,803.5),p=0.004],Jo-1[396.9±288.7 vs.706.9±378.4,p=0.030],TPO [269.3(206.3,394.6)vs.551.0(418.5,903.8),p=0.014],Scl-70 [357.0(300.4,504.8)vs.636.0(464.3,843.8),p=0.012] in sputum from localized EGPA in remission were significantly higher.Compared with localized EGPA in remission,PO [1103.3±801.5 vs.561.1±267.7,p=0.012] in sputum from localized EGPA in exacerbation were significantly higher.Compared with systemic EGPA in remission,Sn RNP [1022.4 ±402.1 vs.738.7±257.0,p=0.049] in sputum from systemic EGPA in exacerbation were significantly higher. 4.In sputum or serum of systemic EGPA and localized EGPA in remission or exacerbation,the associations between autoantibodies were strong,but the associations of autoantibodies between sputum and serum were weak.5.Sputum Eos% was positively associated with TPO antibody in sputum from systemic EGPA in exacerbation.The MPO antibody in sputum from localized EGPA patients in remission was positively related with blood Eos%,sputum Eos%,sputum Eos% and sputum Lym% whereas negatively with sputum Neu%.Conclusion: 1.The PO and Sm antibody in sputum maybe important biomarkers which could distinguish localized EGPA from systemic EGPA.The PO antibody in sputum could reveal disease activity.2.There was possibly a relatively independent autoantibody reaction in lung and blood in EGPA patients.3.There were obvious associations between clinical indexes and autoantibodies in sputum and serum of EGPA patients.