IgG4 immunohistochemistry in granulomatosis with polyangiitis / 中国耳鼻咽喉头颈外科

ABSTRACT

OBJECTIVE To obser ve t he histopathological features and immunohistochemical expression of IgG4 in nasal granulomatosis with polyangiitis(GPA) and to study the relationship between GPA and IgG4-related disease(IgG4-RD). METHODS A total of 12 nasal GPA patients were collected from the Department of Pathology, Beijing TongRen Hospital during January 2012 to December 2016. EnVision immunohistochemical technique was used to detect the expressions of CD38, CD138, IgG and IgG4. RESULTS Nine cases were found pulmonary abnormalities. Elevated titer of anti-neutrophil cytoplasmic antibody was presented in 8 cases in this study. On histopathologic evaluation, 8 of 12 cases were graded as pathologic score 3, one as score 2, and the remaining 3 as score 1. Eight cases showed increased number of IgG4+ cells higher than 10/HPF, 2 of which showed the ratio of IgG4+/IgG cells were more than 40％. CONCLUSION IgG4+ cells can be increased in biopsies of nasal GPA. Since the morphologic and clinical manifestations of GPA and IgG4-RD may overlap, it could be a significant diagnostic pitfall in the differential diagnosis of these two entities. The diagnosis of GPA should combine clinical manifestations, imaging findings, serological examinations and pathological features.