Autoantibodies to glutamate receptor GluRε2 in a patient with limbic encephalitis associated with relapsing polychondritis

Abstract

Limbic encephalitis is a rare central nervous system (CNS) manifestation of relapsing polychondritis (RP). Vasculitis is assumed to be the cause of CNS involvement in RP. Several studies, however, have described CNS involvement in RP with no evidence of vasculitis but with a more nonspecific inflammatory picture. We report a patient with limbic encephalitis associated with RP who presented with anti-glutamate receptor (GluR) ε2 (NR2B) autoantibodies in his cerebrospinal fluid and sera. Brain MRI showed a high signal intensity lesion in the medial temporal lobe and progressive atrophy without multifocal abnormality on fluid-attenuated inversion recovery scanning. Our patient's results raise the interesting possibility that anti-GluRε2 (NR2B) antibodies function in the development of limbic encephalitis in certain patients with RP.

Introduction

Relapsing polychondritis (RP) is a disorder of unknown etiology manifesting as episodic and progressive inflammation of cartilaginous structures throughout the body that include the ears, joints, nose, eyes, respiratory tract, cardiovascular system and skin [1]. The etiology and pathogenesis of RP are unknown, but autoantibodies to type II collagen restricted to cartilage have been detected in the sera of 30–50% of patients studied [2]. Rarely, the central nervous system (CNS) is involved in RP with clinical manifestations of headache [3], [4], [5], meningitis [5], encephalitis [3], [6], [7], [8], cerebral infarction [9], hemiplegia [3], ataxia [10], [11], seizures [3], [5], [7], confusion [3], [8], [10], [11], [12], psychosis [3], [5], [10], [12] or dementia [4], [6], [7], [8], [9], [11]. We report a patient with limbic encephalitis associated with RP who presented with anti-glutamate receptor (GluR) ε2 (NR2B) antibodies.