KLHL11 antibody-associated autoimmune encephalomyelitis in a middle-aged female patient: a case report and literature review.

ABSTRACT

HEADINGS Kelch-like protein 11antibody is a recently identified biomarker for paraneoplastic neurological syndromes associated with germ-cell tumors that was first described as an onconeural antibody causing autoimmune encephalitis associated with seminoma in 2019. Ataxia is the most prevalent presenting symptom, with other neurological symptoms including vertigo, double vision, hearing loss, tinnitus and dysarthria. Magnetic resonance imaging scans reveal that the lesions are mostly located in the cerebellum and brainstem, particularly in the pontine region, and may also exhibit cerebellar atrophy. AIM OF THE STUDY In this study, we report the clinical features of Kelch-like protein 11 antibody-associated paraneoplastic neurological syndrome. MATERIALS AND METHODS: We present a middle-aged female patient who presented with vertigo, cognitive decline, ataxia and limb weakness. A cell-based assay (CBA) showed positive IgG Kelch-like protein 11 in both her serum and CSF, as well as positive oligoclonal bands in her CSF. She was diagnosed with KLHL11 antibody-associated autoimmune encephalomyelitis and received high-dose intravenous methylprednisolone pulse therapy. RESULT AND CONCLUSIONS: Clinical outcomes suggest that patients with Kelch-like protein 11 antibody mostly have poor prognoses, excepting our case. We propose that early and appropriate treatments are critical for timely diagnosis and rapid improvement.