AB1002 IMMUNOGLOBULIN G4 RELATED DISEASE IN A 10 YEAR-OLD GIRL WITH MULTISYSTEM INVOLVEMENT
Authors: Ovgu Kul Cınar, Muthana Al-Obaidi, Neil Sebire, Parichat Khaosut, Despina Eleftheriou
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> 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 <h3>Objectives</h3> IgG4-RD has mostly been decribed in adult population and therefore generally not well-known among paediatricians. To the best of our knowledge, this patient is one of the rare paediatric cases in literature diagnosed with IgG4-RD. We intended to emphasize that IgG4RD should be kept in mind for differential diagnosis of the patients presenting with enlarged parotid, lacrimal and submandibular glands and sicca symptoms. <h3>Methods</h3> We extracted patient's clinical, laboratory and imaging data from our database and reviewed literature to reveal different manifestations of the IgG4RD. <h3>Results</h3> 10 year-old-girl presented with lacrimal and salivary gland swelling, sicca symptoms and fatigue. Ultrasound scan (USS) neck revealed multiple small lymph nodes and enlargement of both submandibular glands. Salivary glands also appeared bulky and heterogenous with multiple small hypoechoic focci. Appearances were likely to represent sialoadenitis and there was no convincing evidence of malignancy or lymphoma. USS abdomen showed no abnormality. Full blood count, routine biochemistry and urine microscopy were normal. Autoantibodies came back as negative (ANA:Negative, ANCA: negative, Anti-Ro and Anti-La: negative, RF:negative, thyroid autoantibodies:negative). Anti-Cardiolipin IgG was weakly positive on the first visit, however repeated analyses were negative. IgG level was elevated in repeated samples. IgA, IgM and IgE levels remained normal. IgG subgroups were performed which revealed significantly elevated IgG4 levels (21.49 Normal range: 0-1.1) IgG1, IgG2 and IgG3 levels were slightly elevated. The biopsy of salivary gland showed chronic inflammation with IgG4 staining and was suggestive of IgG4 related disorder. The patient was diagnosed with IgG4 related disease and treatment was started with intravenous methylprednisolone followed by Anti-CD20 (Rituximab) therapy and a weaning plan for steroids was given. Mycophenolate mofetil was commenced for the maintenance therapy. Patient has been in remission on maintenance therapy. <h3>Conclusion</h3> IgG4RD 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. Steroids are the cornerstone of the treatment, however Anti-CD20 medication (Rituximab) and steroid sparing agents such as mycophenolate mofetil could be the choice for maintenance therapy. <h3>References</h3> [1] IgG4 related Disease: A disease Entity Developed in the 21st Century.Mimori T. Mod Rheumatol. 2019 Jan 24:1-2 [2] Major salivary gland enlargement in IgG4 related disease is associated with multiorgan involvement and higher basal disease activity. Martín-Nares E, ángeles A, Hernandez-Molina G. Mod Rheumatol. 2019 Jan 24:1-15 <h3>Disclosure of Interests</h3> None declared