18A140

A retrospective cohort study of IgG-4 Related Disease in Irish patients

Author(s)

Aadil Al Ghafri1, Aurelie Fabre2, Eamonn Molloy1

Department(s)/Institutions

1Rheumatology Department, St. Vincent’s University Hospital, Dublin 2Pathology Department, St. Vincent’s University Hospital, Dublin

Introduction

Immunoglobulin (Ig) G4-related disease (IgG4RD) is a novel clinical entity characterized by elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4-positive plasma cells.

Aims/Background

To describe the clinical presentations, laboratory features, imaging manifestations, histopathologic characteristics and treatments in a cohort of 38 patients with IgG4RD.

Method

A retrospective study was performed at St. Vincent’s University Hospital. Clinical, laboratory, imaging and histopathologic data was retrieved from electronic records. All data were assessed using SPSS 24.0.

Results

Median age was 59 years with M:F ratio= 2.2:1. 24 (63.2%) patients were between 25-65 years), 14 (36.8%) were >65 years. 23 (60.5%) patients fulfilled the Comprehensive Diagnostic Criteria for IgG4RD as ‘definite’, whereas 5 (13.2%) patients fulfilled ‘probable’ diagnoses and 10 (26.3%) patients fall in ‘possible’ category. GI manifestations (followed by pancreatic) were the most frequent clinical presentation. 23 (60.5%) patients presented with single organ involvement;pancreas was the most frequently involved organ (17/38, (44.7%)). 55.3% had a serum IgG4 level above 135mg/dL. Lymphoplasmacytic infiltration was the commonest histopathologic pattern reported in 29 (76.3%) specimens. 25 (65.8%) patients had received steroid therapy and 19 (50.0%) had a good response. 11 (28.9%) patients received immunomodulatory agents including Rituximab (n=4), Azathioprine (n=7), and Mycophenolate mofetil (n=4). Overall, 28 (73.7%) patients had complete remission with treatment.

Conclusions

IgG4RD is a rare entity in Ireland and an inadequately understood condition overall. Further research is required to better understand the pathophysiology, clinical course and optimal treatment for IgG4RD.