Immunoglobulin G4-related disease: A narrative review

Abstract

Immunoglobulin G4-related disease (IgG4-RD) is a rare and new but increasingly recognized immune-mediated fibroinflammatory condition known to affect multiple organs. The diagnostic approach is challenging, as there is no single investigation to confirm the diagnosis, which requires the integration of clinical, biochemical, and radiographic manifestations with classic histopathologic features to establish the diagnosis. The histology of IgG4-RD is determined by a dense lymphoplasmacytic infiltrate, storiform fibrosis, and obliterative phlebitis in the presence of an increased level of IgG4 in most patients. The first line of treatment is systemic glucocorticoids, but adverse effects of the drug, suboptimal response, and disease recurrences on reduction or termination of therapy highlight the need for an alternative therapy such as rituximab, which appears to be a promising alternate agent in the treatment of IgG4-RD; however, its efficacy needs to be evaluated in large clinically controlled trials.