gms | German Medical Science

Background: In this report, we present the case of a patient with retroperitoneal fibrosis and aortitis due to an immunoglobulin G4-related disease (IgG4-RD). IgG4-RD is a rare, immune-mediated systemic disorder that may affect multiple organs. It is characterized by an increased serum concentration of immunoglobulin G4 (IgG4) and unique histopathologic findings associated with tissue destruction. Most authors suggest glucocorticoid treatment as first-line therapy of IgG4-RD. Further optimal steroid-sparing medication for IgG4-RD treatment has not been established.

Over the years, our patient was treated with mycophenolat mofetil, methotrexate, infliximab, etanercept, azathioprine and several steroid-pulse therapies. Despite of this wide immunosuppressive treatment regular fluor-18-fluorodeoxyglucose positron emission computed tomography (F-18-FDG-PET/CT) scans revealed refractory aortitis of the dilated ascending aorta starting at the aortic root while the abdominal manifestation showed only low inflammatory activity in the clinical course. Since a growing number of reports support the efficacy of B cell depletion with rituximab (RTX) in patients with IgG4-RD, we started medication with RTX. After nine months of treatment a follow-up F-18-FDG-PET/CT scan still showed unaffected aortitis with a persistent high fluorodeoxyglucose (FDG) uptake. Since the aortitis was refractory to previous immunosuppressive drugs including TNF-alpha inhibitors, corticosteroids and RTX, we decided to start medication with tocilizumab (TCZ). This seemed feasible, since several studies indicated that TCZ may be a useful therapy option in patients with inflammatory aortitis and in patients with large vessel vasculitis featuring a positive response upon treatment with TCZ. Six months after the last cycle of RTX, we initiated weekly subcutaneous treatment with 162 mg TCZ. The most recent F-18-FDG-PET/CT scan after six month of treatment revealed a significant decrease in FDG uptake at both the thoracic and abdominal aorta following TCZ therapy.

Conclusion: To avoid complications such as aneurysm or dissection, effective treatment of refractory IgG4-related aortitis is necessary. In our case, TCZ was an effective therapy option rendering TCZ a useful medication for patients with IgG4-related aortitis.