Definite IgG4-related disease had no overlap with eosinophilic granulomatosis with polyangiitis in Korean patients: a pilot study in one centre

Coexistence of IgG4-related disease and ANCA-associated vasculitis: case report and review of the literature

IgG4-related disease (IgG4-RD) is a fibroinflammatory condition that is characterized by storiform fibrosis, infiltration of IgG4-positive lymphocytes, obliterative phlebitis, and high IgG4 levels. Since IgG4-RD affects a wide variety of organs, a differential diagnosis must include multiple conditions. IgG4-RD is also believed to coexist with certain diseases. In recent years, case reports and case series describing the co-occurrence of IgG4-RD and ANCA-associated vasculitis (AAV) have been published. We intended to evaluate patients with IgG4-RD and AAV overlap in the literature using a case similar to one that was diagnosed and monitored in our department. We searched the databases of Web of Science, Scopus, and Google Scholar as well as PubMed with the keywords ANCA, IgG4, IgG4-RD, granulomatosis with polyangiitis, Wegener's granulomatosis, microscopic polyangiitis, Eosinophilic granulomatosis with polyangiitis, and Churg-Strauss syndrome. Cases and Case series addressing the coexistence of IgG4-RD and AAV have been selected. Comprehensive diagnostic criteria are used to diagnose IgG4-RD. The Chapel Hill Consensus Conference nomenclature criteria were used for the inclusion of AAV. Out of a total of 910 publications, 20 articles, including 65 cases, were found to be eligible. Forty-seven cases with IgG4-RD were evaluated as definitive (71.2%), 10 cases as probable (15.1%), and 9 cases as possible IgG4-RD (13.6%). 26 patients were diagnosed with GPA, 1 patient with localized GPA, 23 patients with MPA, and 4 patients with EGPA. The aorta, lacrimal tissue, pancreas, and retroperitoneum are the sites of IgG4-RD rather than AAV. AAV and IgG4-RD might coexist in the same patient. IgG4-RD is mainly associated with GPA.

A case of eosinophilic granulomatosis with polyangiitis showing multiple white lichen lesions on the airway mucosa

A 70-year-old man, treated for asthma for 2 years and chronic sinusitis for several months, presented with fever, numbness in the lower limbs, heaviness in the head, gross hematuria, and black stools. He also had eosinophilia, elevated serum IgG4 levels, high levels of myeloperoxidase-anti-neutrophil cytoplasmic antibodies (MPO-ANCA), and pulmonary infiltrative shadows. Bronchoscopy revealed multiple white flattened lesions (white moss) on the airway mucosa, suggesting mycobacterial infection or malignancy. A biopsy from tracheal mucosa revealed airway inflammation with marked eosinophil infiltration. The patient was diagnosed with eosinophilic granulomatosis with polyangiitis (EGPA) and treated with steroids, and all findings improved. However, a year and a half after the initiation of treatment, eosinophils and IgE gradually increased; subjective symptoms, such as asthma symptoms and numbness in the lower limbs, worsened; and ANCA, which had been negative, turned positive. Therefore, we suspected disease relapse and anti-IL-5 antibody (mepolizumab) treatment was initiated. Thereafter, ANCA turned negative again, eosinophils and IgE normalized, and subjective symptoms decreased. The presence of airway mucosal lesions in EGPA is relatively rare, and we report this case as a valuable case owing to the interesting bronchoscopic findings that are worth comprehending as a respiratory physician.