PMID- 36403297 OWN - NLM STAT- MEDLINE DCOM- 20221130 LR - 20230322 IS - 1878-5883 (Electronic) IS - 0022-510X (Linking) VI - 443 DP - 2022 Dec 15 TI - Motor end-plate analysis to diagnose immune-mediated myasthenia gravis in seronegative patients. PG - 120494 LID - S0022-510X(22)00356-2 [pii] LID - 10.1016/j.jns.2022.120494 [doi] AB - This study aimed to evaluate the diagnostic usefulness of motor end-plate (MEP) analysis along with clustered acetylcholine receptor (AChR) antibody (Ab) assays in patients with myasthenia-like symptoms but negative routine AChR and muscle-specific kinase (MuSK) Ab tests. MEP analysis of muscle biopsies of the biceps brachii was performed in 20 patients to try to differentiate between those with or without immune-mediated myasthenia gravis (MG). Using a quantitative method, complement C3 deposition and AChR densities in MEPs were examined. Independently, cell-based assays were used to detect serum clustered-AChR Abs. Only five of 20 patients had complement deposition at MEPs; four of these patients had reduced AChR densities similar to those in patients with typical AChR Ab positive MG, and distinct from those in the remaining 15 patients. Two of the four serum samples from these patients had clustered-AChR Abs. All complement-positive patients were considered as having immune-mediated MG and improved with appropriate treatments; although one patient presented with MG 3 years later, the remaining patients had other diagnoses during over 10 years of follow-up. These results suggest the usefulness of MEP analysis of muscle biopsies in diagnosing immune-mediated MG in seronegative patients with myasthenia-like symptoms but, due to the invasiveness of the muscle biopsy procedure, clustered AChR Abs should, if possible, be tested first. CI - Copyright (c) 2022 Elsevier B.V. All rights reserved. FAU - Nagaoka, Atsushi AU - Nagaoka A AD - Department of Clinical Neuroscience, Unit of Clinical Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki City, Japan. Electronic address: a-naga@nagasaki-u.ac.jp. FAU - Tsujino, Akira AU - Tsujino A AD - Department of Clinical Neuroscience, Unit of Clinical Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki City, Japan. Electronic address: akrtjn@nagasaki-u.ac.jp. FAU - Shiraishi, Hirokazu AU - Shiraishi H AD - Department of Neurology and Strokology, Nagasaki University Hospital, Nagasaki City, Japan. FAU - Kanamoto, Tadashi AU - Kanamoto T AD - Department of Neurology and Strokology, Nagasaki University Hospital, Nagasaki City, Japan. FAU - Shima, Tomoaki AU - Shima T AD - Department of Neurology and Strokology, Nagasaki University Hospital, Nagasaki City, Japan. Electronic address: tomoakishima0915@nagasaki-u.ac.jp. FAU - Yoshimura, Shunsuke AU - Yoshimura S AD - Department of Neurology and Strokology, Nagasaki University Hospital, Nagasaki City, Japan. Electronic address: shun-yoshimura@nagasaki-u.ac.jp. FAU - Miyazaki, Teiichiro AU - Miyazaki T AD - Department of Neurology and Strokology, Nagasaki University Hospital, Nagasaki City, Japan. Electronic address: tmiyazaki@nagasaki-u.ac.jp. FAU - Tateishi, Yohei AU - Tateishi Y AD - Department of Neurology and Strokology, Nagasaki University Hospital, Nagasaki City, Japan. Electronic address: ytate@nagasaki-u.ac.jp. FAU - Tsujihata, Mitsuhiro AU - Tsujihata M AD - Nagasaki Kita Hospital, Nagasaki City, Japan. Electronic address: kita_m_tsuji@mx22.tiki.ne.jp. FAU - Motomura, Masakatsu AU - Motomura M AD - Medical Electronic Course, Nagasaki Institute of Applied Science, Nagasaki City, Japan. Electronic address: MOTOMURA_Masakatsu@NiAS.ac.jp. FAU - Maxwell, Susan AU - Maxwell S AD - Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK. Electronic address: susan.maxwell@ndcn.ox.ac.uk. FAU - Higuchi, Osamu AU - Higuchi O AD - Department of Neurology, Nagasaki Kawatana Medical Center, Nagasaki, Japan. Electronic address: osmhgc_nkmc@nagasaki-u.ac.jp. FAU - Beeson, David AU - Beeson D AD - Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK. Electronic address: David.beeson@ndcn.ox.ac.uk. FAU - Vincent, Angela AU - Vincent A AD - Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK. Electronic address: angela.vincent@ndcn.ox.ac.uk. LA - eng GR - MR/M006824/1/MRC_/Medical Research Council/United Kingdom PT - Journal Article DEP - 20221114 PL - Netherlands TA - J Neurol Sci JT - Journal of the neurological sciences JID - 0375403 RN - 0 (Autoantibodies) SB - IM CIN - J Neurol Sci. 2023 Feb 15;445:120542. PMID: 36621038 MH - Humans MH - *Motor Endplate MH - *Myasthenia Gravis/diagnosis MH - Autoantibodies MH - Biopsy MH - Research Design OTO - NOTNLM OT - Clustered AChR antibody OT - Complement OT - Motor end-plate OT - Myasthenia gravis OT - Seronegative COIS- Declaration of Competing Interest None. EDAT- 2022/11/21 06:00 MHDA- 2022/12/01 06:00 CRDT- 2022/11/20 18:05 PHST- 2022/06/14 00:00 [received] PHST- 2022/11/08 00:00 [revised] PHST- 2022/11/10 00:00 [accepted] PHST- 2022/11/21 06:00 [pubmed] PHST- 2022/12/01 06:00 [medline] PHST- 2022/11/20 18:05 [entrez] AID - S0022-510X(22)00356-2 [pii] AID - 10.1016/j.jns.2022.120494 [doi] PST - ppublish SO - J Neurol Sci. 2022 Dec 15;443:120494. doi: 10.1016/j.jns.2022.120494. Epub 2022 Nov 14.