Clinical Features and Prognosis in Chinese Patients With Dipeptidyl–Peptidase–Like Protein 6 Antibody–Associated Encephalitis

Abstract

Objectives:Anti-dipeptidyl–peptidase–like protein 6 (anti-DPPX) encephalitis an extremely rare type of immune-mediated encephalitis. This study aimed to analyze the electroclinical characteristics and prognosis of anti-DPPX encephalitis.Methods:Five patients (all male) with anti-DPPX encephalitis in East China from January 2016 to October 2021 was retrospective analyzed. Electroclinical features and outcomes were reviewed.Results:All five patients were male. The media age at disease onset was 32 years old with a range of 14–56 years. The main symptoms included psychiatric disturbances (2/5), amnesia (4/5), confusion (3/5), and seizures (3/5). Migrating myoclonus were identified in patient 4 with positive DPPX and contactin-associated protein-like 2 antibodies in blood. All of the patients had positive DPPX antibodies in serum. Only one of them had positive antibody in the cerebrospinal fluid. EEG showed diffuse slowing in two patients, but no epileptiform discharges were observed. Eighty percent (4/5) of the patients showed normal brain magnetic resonance imaging. After immunotherapy, improvement of neuropsychiatric symptoms from all of the patients was observed. Over a mean follow-up of 30.8 weeks, all of the patients had marked improvement in the modified Rankin Scale. To date, no tumors were not observed in any patients.Conclusions:Anti-DPPX encephalitis mainly presents as neuropsychiatric symptoms. Cooperation of DPPX antibodies and CASPR2 antibodies might have contributed to the migration of myoclonus in the patient 4. Prompt immunotherapy often results in improvement.

The effect of double filtration plasmapheresis and corticosteroids on patients with anti‐dipeptidyl‐peptidase‐like protein 6 encephalitis

“…Tumors are relatively rare in anti‐DPPX encephalitis [2, 3, 5, 6], but the disease might be associated with tumors such as B‐cell neoplasms and gastrointestinal lymphomas [22]. All five patients in our study underwent detection of tumor‐associated markers, including in serum, and three additionally underwent a 18F‐FDG‐PET/MRI scan, but no neoplasms were found.…”

“…The study included five patients with anti-DPPX encephalitis admitted to the Department of Neurology between December 2020 and August 2022. The diagnostic criteria for anti-DPPX encephalitis followed those previously described in Table 1 [5]. All patients tested positive for anti-DPPX antibody in serum and/or cerebrospinal fluid (CSF) and received treatment with DFPP.…”

“…Initial signs often include agitation, confusion, myoclonus, tremors, and seizures, as described by Anna Boronat and her team in 2013 [1]. Subsequently, additional clinical symptoms have since been reported, including gastrointestinal disturbances and atypical neurological symptoms like sensory disturbance, autonomic nervous dysfunction, and mental and psychological disorders [2–9].…”

“…like sensory disturbance, autonomic nervous dysfunction, and mental and psychological disorders [2][3][4][5][6][7][8][9].…”

Expanding the clinical spectrum of anti-DPPX encephalitis: a multicenter retrospective study

“…Anti-DPPX antibodies were found to co-exist with anti-AQP4 ( Bien et al, 2020 ), anti-CAPSR2 ( Miao et al, 2021 ), anti-GFAP ( Xiao et al, 2022 ), and anti-CRMP5 antibodies ( Wan et al, 2023 ). Others include thyroid-related antibodies, lupus anticoagulant (LA), antinuclear antibody, and anti-cardiolipin IgM ( Miao et al, 2021 ; Tsai et al, 2021 ).…”