Presumed Choroidopathy of IgG4-Related Disease Discovered During 16-Year Follow-Up of a Patient With Polycystic Kidney Disease.

Immunoglobulin G4 (IgG4)-related disease is characterized by infiltration with IgG4-producing plasma cells in different organs and the elevation of serum IgG4. We present a patient with polycystic kidney disease in long-term follow-up who developed bilateral lacrimal gland enlargement and presumed IgG4-related choroidopathy at different time points. A 45-year-old woman developed bilateral upper eyelid swelling. Head MRI showed bilateral lacrimal gland enlargement, and the resection on both sides revealed foci of infiltration with lymphocytes and plasma cells in bilateral lacrimal glands. The IgG4-immunostaining did not satisfy the diagnostic criteria. She had been taking oral valsartan 40 mg daily for hypertension with polycystic kidney disease. The patient was well until the age of 49 years, when she noticed yellowish vision in the right eye compared to the left eye. The right eye showed multiple yellowish spotty lesions in the deep retina to choroid with a mildly hyperemic optic disc, while the left eye showed the normal fundus. No inflammation was noted in the anterior segments of both eyes. Fundus angiography demonstrated early-phase no-filling with late-phase leakage by fluorescein dye and both early-phase and late-phase no-filling by indocyanine green dye, leading to the diagnosis of acute posterior multifocal placoid pigment epitheliopathy (APMPPE). She began to have oral prednisolone tapered from 30 mg daily and discontinued in a year. At the age of 52 years, she switched to candesartan 8 mg daily and began to have tolvaptan (a selective competitive vasopressin receptor 2 (V) antagonist) 90 mg daily for polycystic kidney disease with liver cysts. At that time, the lesions in the right eye had mild degeneration. The patient was followed once a year ophthalmologically to maintain good vision. At 57 years, serum IgG4, which was measured for the first time on suspicion of IgG4-related disease, was elevated to 269.6 mg/dL. In the following four years to the latest visit at 61 years, she kept stable but high levels of serum IgG4 around 300 mg/dL. Serum IgG4 measurement is helpful to make a clinical diagnosis and, hence, a clinical decision since the spectrum of IgG4-related disease remains obscure.