The treatment outcomes in IgG4-related disease.

INTRODUCTION: IgG4-related disease (IgG4-RD) is an emerging systemic inflammatory disease involving nearly all organs eventually leading to fibrosis. Prompt and adequate treatment to prevent irreversible organ damage is therefore pivotal. To evaluate the treatment outcomes, we studied a well-defined cohort of patients with IgG4-RD. METHOD: 32 patients with histologically confirmed IgG4-RD diagnosed between 1999 and April 2017 were included and reviewed for demographic and clinical characteristics. The response to treatment with glucocorticoids, disease modifying antirheumatic drugs, rituximab and other therapeutic interventions were evaluated. RESULTS: Glucocorticoids as well as rituximab appeared successful therapeutic drugs leading to clinical remission (complete or partial remission) in all patients. Recurrences, however, were frequently seen (62% versus 100%, respectively). Diseases modifying antirheumatic drugs (DMARDs), including azathioprine, methotrexate and mycophenolate mofetil were effective in less than half of the cases. A minority of patients was treated with alternative treatments including hydroxychloroquine, thalidomide and infliximab which all appeared effective. Surgical intervention and radiotherapy in local disease seemed to induce clinical remission and were associated with low recurrence rates. CONCLUSION: Glucocorticoids and rituximab induce substantial responses as well as primary surgical intervention and radiotherapy, while the efficacy of DMARDs is limited. Based on the few data available, hydroxychloroquine, infliximab and thalidomide may be promising treatment options for second or third line strategies.

Soluble Interleukin-2 Receptor: A Potential Marker for Monitoring Disease Activity in IgG4-Related Disease.

BACKGROUND: IgG4-related disease (IgG4-RD) is a fibroinflammatory condition. T-cells play a crucial role in the pathogenesis, and therefore, serum soluble interleukin-2 receptor (sIL-2R) may be a potential biomarker. METHOD: We studied the levels of sIL-2R in 26 histologically proven IgG4-RD patients with available serum sIL-2R and compared them to those in newly diagnosed and untreated sarcoidosis patients (n = 78) and controls (n = 101) and the serum sIL-2R levels in patients after treatment of IgG4-RD (n = 15). The disease activity was measured using the IgG4-Related Disease Responder Index (IgG4-RD RI). RESULTS: Median serum sIL-2R in IgG4-RD patients was 4667 pg/ml compared to 1515 pg/ml in controls (P < 0.001) and 6050 pg/ml in sarcoidosis patients (P = 0.004 compared to IgG4-RD). All IgG4-RD patients had elevated serum sIL-2R levels compared to the reference value of <2500 pg/ml in controls and 85% elevated serum IgG4; however, these did not correlate with each other. Both serum sIL-2R and IgG4 levels declined significantly after treatment (P = 0.001 and P = 0.01, resp.). Before treatment, serum sIL-2R level and IgG4-RD RI did not correlate with each other. However, the decrease in serum sIL-2R upon treatment did correlate significantly (P = 0.04) with the decrease in disease activity assessed by IgG-RD RI. CONCLUSION: Serum sIL-2R is elevated in IgG4-RD reflecting the inflammatory process with enhanced T-cell activation. Furthermore, serum sIL-2R might serve as a potential marker of response to treatment in IgG4-RD.