IgG4-related disease: Evidence from six recent cohorts.

IgG4-related disease (IgG4-RD) is a rare autoimmune fibrosing disorder. In this review we aim to describe and compare the characteristics of the six largest IgG4-RD cohorts, since the new 2012 consensus diagnostic criteria were released. These observational studies were published between 2012 and 2015. Patients were included using the comprehensive diagnostic criteria or the 2012 consensus criteria. Results were reviewed and summarized. Most patients were middle aged men. Fibro-inflammatory masses developed in virtually all organs except the brain, with an unexplained preference for salivary glands, lymph nodes and pancreas. Corticosteroids were the treatment of choice but up to 40% of patients relapsed within the first year. Standardized response assessment tools, biomarkers and the validation of new treatments are still in development. In conclusion, the features of IgG4-RD are similar across the globe. At the moment, corticosteroids are the only validated treatment but rituximab seems to be promising.