A case of eosinophilic granulomatosis with polyangiitis complicated with a similar condition to IgG4 related lung disease

• Main Authors: Li Zhou, Fen Cao, Songqing Fan, Ping Chen, Shuizi Ding, Guiqian Liu, Ruoyun Ouyang
• Format: Article
• Language: English
• Published: BMC 2019-08-01
• Series: BMC Pulmonary Medicine
• Subjects: EGPA; IgG4-RD; Elevated serum IgG4; IgG4 positive plasma cell; Pathology of lung tissue
• Online Access: http://link.springer.com/article/10.1186/s12890-019-0917-4

Abstract Background Atypical manifestations, such as elevated serum immunoglobulin-G4 (IgG4) and extra-pulmonary IgG4 positive plasmacyte infiltration, have been described in patients with eosinophilic granulomatosis with polyangiitis (EGPA), such complicated situation might not be readily differentiated from IgG4-related disease. Case presentation Here, we report an interesting and rare case of EGPA in a 41 year-old male with negative anti-neutrophil cytoplasmic antibodies (ANCAs), which showed abundant pulmonary IgG4-positive plasma cells infiltration and markedly elevated serum IgG4 levels without extra-pulmonary lesions of IgG4-related disease. The clinical characteristics hesitated us whether the diagnosis as EGPA overlapping with IgG4-related lung disease should be concluded because of the absence of storiform fibrosis and obliterative phlebitis with lymphoplasmacytic infiltration. The patient’s systemic symptoms, pulmonary lesions, blood eosinophils count / percentage, and serum IgG4 levels were significantly improved with immunosuppressive therapy. Conclusions We consider that the overlapping pathogenesis exists in the disease course of EGPA and IgG4-related disease, which may lead to interaction during the course of the diseases. And the utilization of diagnostic criteria for IgG4-related lung disease with the careful differentiation is needed in such cases.