[Role of anti c-mpl antibody in systemic lupus erythematosus with thrombocytopenia].

Objective:To determine whether anti-thrompoietin receptor(TPO-R,c-mpl) antibody contributes to thrombocytopenia in systemic lupus erytematosus(SLE) and explore the pathogenic role of this antibody.Methods: Sera from 24 SLE patients with thrombocytopenia,27 SLE patients having normal platelet counts with a history of thrombocytopenia,18 SLE patients with neither thrombocytopenia nor post thrombocytopenia and 18 healthy controls were collected.Anti c-mpl antibodies were detected by an indirected ELISA assay.The serum TPO levels were measured by an ELISA assay.Clinical findings,autoantibody profiles,and SLEDAI were evaluated.Results: Serum anti c-mpl antibodies were detected in 18.8% of the SLE patientis.The frequency of this antibody in SLE with thrombocytopenia,SLE with a history of thrombocytopenia and SLE without thrombocytopenia were of no difference(P=0.600).In the patients with anti c-mpl antibodies,their platelet counts were decreased(P=0.025) and serum TPO levels elevated(P=0.038) than those in the patients without,while there were no differences between the two groups in C3,C4,ESR,CRP level,the frequency of ANA,dsDNA,ANCA and SLEDAI.Conclusion: Anti c-mpl antibody contributes to SLE-associated thrombocytopenia by functionally blocking an interaction between thrombopoietin and c-mpl,which might inhibit TPO-dependent megakaryocyte proliferation and differentiation.