Background IgG4-related disease is a rare entity consisting of inflammation and fibrosis that has been described in many locations. Diagnosis may be challenging and concrete diagnostic criteria have been established recently.

Objectives To describe the therapeutic experience and the evolution of a series of patients diagnosed with IgG4-related disease (IgG4-RD) in Spain.

Methods A retrospective multicentric study was performed. A clinical protocol and a joint database were created to constitute the IgG4-related Disease Spanish Register. Patients were enrolled from 14 different centers. Pathologic studies were conducted according to Deshpande et al.¹ diagnostic criteria (histologically highly suggestive or probable IgG4-RD). Patients with insufficient histopathological evidence of IgG4-RD were excluded.

Results Thirty-five patients were included in the study, 27 of whom (77.1%) were male. Median age at diagnosis was 55 years (IQR 29 years). Eighteen patients (51.4%) presented IgG4-RD with more than one organ affected. There were no differences regarding the treatments received between localized and multi-organic IgG4-RD subjects. Corticosteroids were administered in 30 (85.7%) patients. The median maximum dose was 60 mg/day (IQR 30 mg/day) during 1 month (IQR 0.25 months). Corticosteroid tapering lasted 7.5 months (IQR 8.5 months), although 7 patients kept a low maintenance daily dosage of 5 mg/day (IQR 5 mg/day). In 17 (48.5%) cases, immunosupressors were added due to corticosteroid resistance (sustained disease activity, progression of clinical symptoms or flares when downscaling steroids): mofetil mycophenolate/mycophenolic acid in 6 patients (17.1%), azathioprine in 7 (20%) and cyclophosphamide, azathioprine plus methotrexate, and azathioprine plus cyclophophamide in 1 (2.9%) patient each. Biologic treatment with rituximab was given to 2 (5.7%) patients. Six (17.1%) subjects underwent radical surgery. Median follow up was 22.01 months (IQR 35.79 months). Eleven (31.4%) patients presented a complete response (complete regression of the fibrotic mass/masses) and 22 (62.9%) presented a partial response (<50% of regression). Corticosteroids alone were more frequently given in the complete response group. No patients were refractory to all treatments, and 12 (34.3%) presented recurrences. One patient was asymptomatic and did not require any treatment, and one patient did not have avalable treatment records. During follow-up, one subject (2.9%) died in a car accident, two (6.1%) developed a monoclonal gammopathy of unknown significance and one (3%) developed a prostate cancer.

Conclusions IgG4 related disease is a rare entity in our country. The most common treatment regime was corticosteroids, initially at high doses, followed by a slow descent of doses, with or without immunosupressors. Rituximab was the only biological drug used. Surgery may be needed occasionally. A partial disappearance of the fibrotic component with resolution of systemic symptoms was the most frequent evolution after treatment. No deceases related to IgG4-RD were reported. More collaborative studies are required in order to assess the treatment response and the evolution of IgG4-RD.

References

1. Deshpande V, Zen Y, Chan JK, et al. Consensus statement on the pathology of IgG4-related disease. Mod Pathol. 2013;26(8):1150-1.

Disclosure of Interest : None declared

DOI 10.1136/annrheumdis-2014-eular.2664