Susac Syndrome Treated with Subcutaneous Immunoglobulin

Abstract

Background: Susac syndrome is a rare disease characterized by the triad of encephalopathy, branch retinal artery occlusion, and sensorineural hearing loss mainly affecting young women. The finding of antibodies against the endothelium in the sera of these patients has supported the hypothesis of an autoimmune endotheliopathy of the brain, inner ear and retina. Because of the rarity of the disease, treatment is based on the knowledge of case reports and small case series. Medical therapy consists of glucocorticoids, immunosuppressants, acetyl salicylic acid, and immunomodulatory agents such as intravenous immunoglobulin. Methods: We present the case histories of 2 young women with Susac syndrome presenting with several episodes of encephalopathy, branch retinal artery occlusions, and hearing loss that were treated with different immunosuppressive drugs, glucocorticoids and intravenous immunoglobulin. In the course of the disease, the treatment was successfully switched to subcutaneous immunoglobulin without any further relapse in both patients. Conclusion: We conclude that the application of subcutaneous immunoglobulin is easy to learn, helps to reduce in-hospital costs and enables a more flexible everyday life. The treatment with subcutaneous immunoglobulin helps to reduce immunosuppressants and appears to prevent relapses.

CD8+ T cell-mediated endotheliopathy is a targetable mechanism of neuro-inflammation in Susac syndrome

“…Furthermore, few CD20 + B cells and no plasma cells are present in CNS biopsies of SuS patients 9 . However, the clear response of SuS to immunosuppressive and immunomodulatory drugs 13–15 strongly supports the hypothesis that SuS is immune mediated and scant perivascular T lymphocytes have been demonstrated histopathologically 9 .…”

“…An (auto)immune process leading to the disruption and occlusion of microvessels in the affected organs has been postulated 11 . Elevated serum levels of anti-EC antibodies (AECA) are found in approximately 25% of SuS patients 12,13 , suggestive of a pathogenic scenario involving an antibody-mediated attack against ECs. However, this hypothesis has been challenged, since AECA are only detected in a subset of patients and are not associated with disease severity 12 .…”

Diagnostic criteria for Susac syndrome

“…In the acute episode, treatment comprises high-dose corticosteroids. To avoid further disease attacks or progression, a continuous immunosuppressive therapy is currently recommended 1 4 15 16. Response to immune treatment was not chosen for the criteria as an 'ex juvantibus' prove of the diagnosis.…”

Susac syndrome (Retino-cochleo-cerebral vasculitis), the ophthalmologist in the role of the whistleblower

“…To reduce corticosteroids immunosuppressive agents like mycophenolate mofetil, azathioprine or cyclosporine, should be added early [22,25]. Other possible treatment options are plasma exchange or the application of subcutaneous immunoglobulins (sc IgG) [26]. Treatment with monoclonal antibodies (Rituximab) or tumor necrosis factor (TNF) inhibitor Infliximab have been described [27,28].…”