IgG4 is a rare autoimmune disease with excessive IgG4 immunoglobulins that can affect multiple organs yielding plasma cell deposition (inflammation) and fibrosis.There has been great progress in treatment. Traditionally, glucocorticoids were used and if ineffective, then an oral immunesuppressive (ex: Azathioprine, MMF) and, if needed, rituximab. Many patients can improve sufficiently on this regimen.

For the last several years, conversations about JAK inhibitors have often started and ended with safety. The shadow cast by ORAL Surveillance has made clinicians more cautious and regulators more restrictive. Yet in practice, many of us continue to reach for upadacitinib when we face challenges in treatment, from rheumatoid arthritis to axial spondyloarthritis.