Research progress of clinical and Thoracic Imaging characteristics of IgG4-Related chest Disease

NI Yifei; WANG Jianping; LIU Min

doi:10.3969/j.issn.1006-5725.2024.21.007

Abstract：IgG4-related disease(IgG4-RD)is a chronic fibroinflammatory disorder with systemic involve-ment,predominantly affecting middle-aged and elderly males.Although the precise etiology and pathogenesis of the disease remain incompletely understood,its hallmark histopathological features include dense lymphoplasmacytic infiltration with IgG4-positive plasma cells,storiform fibrosis,obliterative phlebitis,and often increased numbers of eosinophils.While more than half of patients with IgG4-RD exhibit elevated serum IgG4 concentrations,this finding lacks specificity as it can also be observed in other conditions;furthermore,a subset of patients may present with normal serum IgG4 levels.Therefore,serum IgG4 elevation is not considered a definitive diagnostic criterion for this condition.The disease is characterized by its broad organ involvement frequently affecting the lymph nodes,salivary glands,lungs among others.The clinical and radiological manifestations of IgG4-RD exhibit a wide range of diver-sity,varying according to the specific organ involved.However,it generally demonstrates a favorable response to corticosteroid therapy while displaying a high propensity for relapse.Thoracic involvement in IgG4-RD presents an array of imaging findings encompassing abnormalities in the lungs,lymph nodes,pleura,chest wall,mediastinum,as well as large vessels such as the aorta and coronary arteries.Accurately differentiating IgG4-RD from malignancies,inflammatory conditions,and other autoimmune diseases poses a significant diagnostic challenge specifically for radi-ologists.This review aims to provide comprehensive insights into the pathophysiology,clinical characteristics,and thoracic imaging features of IgG4-RD with the ultimate goal of facilitating precise diagnosis and thorough evaluation of thoracic involvement.