IgG4-gerelateerde ziekte: huidige stand van zaken = IgG4-related disease: current situation

IgG4-related disease (IgG4-RD) is a systemic fibro-inflammatory disease that can involve almost every part of the body. The pathophysiological mechanism remains unclear. Fibrosis of the affected tissue is the hallmark of the disease. Measurement of serum IgG4 levels may be useful in the diagnostics of IgG4-RD, but histology remains the golden standard. Awareness of IgG4-RD is pivotal to avoid misdiagnosis and delay in the treatment. Untreated disease can lead to irreversible damage of the affected tissue due to fibrosis or even AA amyloidosis. Corticosteroids are the preferred first-line treatment. In case of relapse, immunosuppressive drugs such as methotrexate and azathioprine can be used. There is increasing evidence for the efficacy of rituximab in the treatment of IgG4-RD and this should be initiated in refractory diseases or in cases of severe clinical presentation.