Abstract
Purpose: :
Investigate the etiology of acute exudative polymorphous vitelliform maculopathy (AEPVM) in a patient with metastatic melanoma by testing for autoimmune mechanisms. AEPVM is a rare disease of unknown etiology characterized by serous retinal detachments and subretinal accumulation of hyper-autofluorescent yellowish material in the posterior pole.
Methods: :
Serum was obtained from a 50-year-old man with AEPVM and metastatic unknown primary melanoma during active disease (acute stage) and three years later when subretinal fluid had resolved and the melanoma was in remission (convalescent stage). Western immunoblots using both serum samples against human donor retinal extract and cultured primary human retinal pigment epithelium (RPE) cell extract were performed looking for anti-retinal and anti-RPE antibodies. Serum samples from five unaffected subjects were tested as controls. Protein identification was performed using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) tandem mass spectrometry, and then confirmed by blotting against purified protein.
Results: :
Western blotting of the patient’s serum against human retinal and RPE extract demonstrated several anti-retinal antibodies, as well as anti-RPE antibodies against a 26 kD protein that was identified using mass spectrometry, and confirmed with purified protein testing, as peroxiredoxin 3. The serum reactivity against peroxiredoxin 3 was greatly decreased in the convalescent stage compared with the acute stage serum. Five separate serum samples from subjects without AEPVM had no autoantibodies against this protein. Literature review revealed several patients with melanoma and clinical findings similar to our patient.
Conclusions: :
Paraneoplastic autoimmune reaction against RPE may be a cause of acute exudative polymorphous vitelliform maculopathy. Assays for RPE autoantibodies may be useful in exploring the pathogenesis of other presumed RPE-related diseases.
Keywords: retinal pigment epithelium • autoimmune disease • macula/fovea