Lambert-Eaton Myasthenic Syndrome Caused by Atezolizumab in a Patient with Small-cell Lung Cancer

Abstract Background Paraneoplastic neurological syndromes (PNS) are rare disorders affecting any part of the central, peripheral or autonomic nervous system that occur in association with cancer. Among cancer patients, less than 1% overall develop PNS. Anti- SOX1 antibodies positive paraneoplastic neurological disorders are rare and most often associated with small cell lung cancer (SCLC). Case presentation Herein, we report a case of a 61-year-old male presented with an unusual anti- SOX1 positive PNS. Electrodiagnostic study showed notable low amplitude motor potentials and high amplitude motor potentials of the right tibialis anterior suggesting the presence of Lambert–Eaton myasthenic syndrome (LEMS). Typical MRI and PET-CT found a hyperintense lesion with contrast enhancement in the thorax in front of 5-6 centrum of vertebrae, and thoracoscopic biopsy revealed pathological findings for SCLC. Because the diagnosis was made in time, the patient is currently receiving chemotherapy and radiotherapy for the cancer at Chinese PLA General Hospital, and the clinical symptoms improved obviously. Conclusions The comprehensive screening of onconeural antibodies in PNS-suspicious cases combined with early diagnosis and treatment of tumor are important for achieving a good outcome.

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Identification of LOC338963 and AP3B2 as Potential Biomarkers for Lambert-Eaton Myasthenic Syndrome

10.21203/rs.3.rs-332560/v1 ◽

2021 ◽

Author(s):

Fei Yang ◽

Feng Jing ◽

Yang Li ◽

Shanshan Kong ◽

Shimin Zhang ◽

...

Keyword(s):

Lung Cancer ◽

Small Cell Lung Cancer ◽

Cell Lung Cancer ◽

Expression Profiles ◽

Small Cell ◽

Differentially Expressed ◽

Healthy Controls ◽

Small Cell Lung ◽

Qrt Pcr ◽

Myasthenic Syndrome

Abstract Background: Lambert-Eaton myasthenic syndrome (LEMS) is a rare neuromuscular junction disorder associated with muscle weakness and small-cell lung cancer. Here, we used microarray analysis to identify long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) that might serve as biomarkers for LEMS.Methods: Plasma lncRNA and mRNA expression profiles of three patients with paraneoplastic LEMS and three healthy controls were analyzed using Arraystar Human lncRNA Microarray v4.0. Differentially expressed lncRNAs and adjacent mRNAs were analyzed jointly, and candidates were verified in individual samples by quantitative real-time polymerase chain reaction (qRT-PCR). The identified lncRNAs and mRNAs were evaluated in nine patients with paraneoplastic LEMS, eight patients with non-tumor LEMS, and four patients with small cell lung cancer (SCLC). Results: A total of 320 lncRNAs were differentially expressed in patients with paraneoplastic LEMS compared to healthy controls (fold change >1.5, P < 0.05), and nine were further evaluated. One of the identified lncRNAS, LOC338963 (NR_031439), is known to regulated the expression of the mRNA AP3B2, and both were upregulated more than 2-fold in patients with paraneoplastic LEMS compared to healthy controls. Furthermore, qRT-PCR analysis revealed significant upregulation of LOC338963 (NR_031439) and AP3B2 expression in patients with paraneoplastic LEMS compared to those with either non-tumor LEMS (2.37- and 5.06-fold, respectively) or SCLC (4.36- and 14.97-fold, respectively).Conclusions: Plasma LOC338963 (NR_031439) and AP3B2 were found to be upregulated in LEMS and might be used as diagnostic biomarkers for this disease.

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