P43 Immunoglobulin G4-related disease in a 10 year-old girl with multisystem involvement
Authors: Cinar Ovgu Kul , Khaosut Parichat , Sebire Neil , Eleftheriou Despina , Al-Obaidi Muthana 
Published: October 2019

Abstract

Background
IgG4-related disease (IgG4RD) is an immune-mediated fibroinflammatory condition characterized by the infiltration of IgG4-carrying plasma cells and storiform fibrosis in most of the tissues. The condition is reported to cause multisystem involvement, however salivary gland is the most commonly affected organ with IgG4-related sialadenitis. Raised IgG4 concentrations in the serum and prominent infiltration by plasmacytes expressing IgG4 in the lacrimal and salivary glands have been confirmed.

Methods
We conducted a retrospective case review of a 10 year-old girl who was diagnosed with IgG4-RD at Great Ormond Street Hospital for Children in 2017. Patient’s clinical, laboratory and imaging data was extracted from our database and literature search was done to find out different manifestations of the IgG4-RD in Children.

Results
10 year-old-girl with lacrimal and salivary gland swelling, sicca symptoms and fatigue. Ultrasound scan neck revealed multiple small lymph nodes and enlargement of both submandibular glands (Picture1) Salivary glands also appeared bulky and heterogenous with multiple small hypoechoic focci. Appearances likely to represent sialoadenitis and there was no evidence of malignancy or lymphoma. USS abdomen normal.
Full blood count, routine biochemistry and urine microscopy normal. Autoantibodies came back negative (ANA: Negative, ANCA: Negative, Anti-Ro and Anti-La: Negative, RF:Negative, Thyroid autoantibodies:Negative) IgG level elevated (in repeated samples). IgA, IgM and IgE levels normal. IgG subgroups revealed significantly elevated IgG4 levels (21.49 Normal range: 0-1.1) IgG1, IgG2 and Ig G3 levels elevated as well. Lymphocyte subsets were normal.
The biopsy of salivary gland: Chronic inflammation with IgG4 staining, suggestive of IgG4 related disorder.
Lung function test showed decreased DLCO at 76 %, FEV1 at 82% and FVC at 89% suggestive of interstitial lung involvement. CT Thorax: Multiple abnormalities including moderate lymphadenopathy, renal parenchymal lesions and interstitial lung abnormality. MRI Abdomen: T2 hypointense renal foci, suggestive of infiltration as part of the IgG4 related disease.
Diagnosed with IgG4 related disease. Treatment started with intravenous methylprednisolone followed by Anti-CD20 (Rituximab) therapy and a weaning plan for steroids. Mycophenolate mofetil commenced for the maintenance therapy. Patient has shown good response with clinical and lung function improvement.

Conclusion
IgG4-RD is a rare condition which can cause multisystem involvement with the infiltration of IgG4-bearing plasma cells in the tissues. We wanted to emphasize that this condition could also be seen in the paediatric population. We also wanted to highlight that after further investigations multisystem involvement can be discovered.
Steroids are mainstay of the treatment with Anti-CD20 medication (Rituximab) and steroid sparing agents such as mycophenolate mofetil could be the choice for maintenance therapy. However, further studies need to be done in paediatric age group.

Conflicts of Interest
The authors declare no conflicts of interest.