Retinal choroidal microvascular occlusion as a possible initial manifestation of IgG4-related disease: a case report

Abstract

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is an immune-mediated fibroinflammatory disease that affects almost all body organs. Although ocular manifestations such as lacrimal gland inflammation, orbital myositis, scleritis, and uveitis have been reported, there are currently no reports of ocular vascular involvement. Herein, we report a rare case of clinically suspected IgG4-RD presenting with acute occlusion of retinal choroidal microvessels. A 39-year-old male complaining of blurred vision in his right eye had a large area of white retinal lesions with unclear boundaries surrounding retinal blood vessels. Spectral-domain optical coherence tomography revealed typical paracentral acute middle maculopathy (PAMM) features. Fundus fluorescein angiography and indocyanine green angiography revealed two clearly defined high fluorescence areas. His platelets, erythrocyte sedimentation rate, C-reactive protein, serum IgG4 and D-dimer levels were significantly elevated. An enhanced computed tomography scan of the entire abdomen revealed inflammatory lesions in the pancreas and kidneys. A multidisciplinary team of ophthalmologists, rheumatologists, radiologists, neurologists, and general surgeons was convened. According to the 2019 American College of Rheumatology and the European League Against Rheumatism (ACR/EULAR) IgG4-RD classification criteria, our patient had a cumulative score of 27 as shown: serum IgG4 levels 4.045 g/L + 6, renal cortex thickening + 10. enhancement and weakening of pancreas, blurred tail edge of pancreas, dilation of pancreatic duct + 11. The patient was diagnosed with possible IgG4 RD with retinal and choroidal microvasculature involvement. The inflammation in the eyes, pancreas, and kidneys of the patient improved significantly after systemic immunosuppressive therapy with prednisolone and azathioprine. To our knowledge, this is the first reported case of clinically suspected IgG4-RD with retinal choroidal microvessels involvement in the absence of histopathological confirmation, broadening the known spectrum of ocular manifestations of IgG4‑related disease. A comprehensive multidisciplinary evaluation is recommended for joint diagnosis and treatment in patients with atypical manifestations of IgG4-RD. Ophthalmologists and internists should consider IgG4-RD in the differential diagnosis of unexplained retinal vascular occlusions, particularly in patients with systemic inflammatory markers or organ involvement.