{"doi":"10.1111/ene.16435","title":"Concordance between radioimmunoassay and fixed cell‐based assay in subjects without myasthenia gravis: optimizing the diagnostic approach","abstract":"BACKGROUND AND PURPOSE: Acetylcholine receptor antibody (AChR-Ab) detection is crucial in myasthenia gravis (MG) diagnosis and, currently, the radioimmunoassay (RIA) is the gold standard. However, RIA may detect AChR-Ab against nonpathogenic intracellular epitopes. In this study, we performed fixed cell-based assay (F-CBA) in RIA-AChR-Ab positive subjects without MG symptoms, to assess whether F-CBA could show a higher specificity compared to RIA in detecting pathogenic Abs. METHODS: We reviewed medical records of patients referred to our MG outpatient clinic because of RIA-AChR-Ab detection. MG diagnosis was based on clinical examination, electrophysiology and Ab detection. AChR-Abs were tested by RIA in the whole cohort. Serum samples from RIA-positive asymptomatic subjects were retested by F-CBA. RESULTS: Of 605 subjects who tested RIA-AChR-Ab positive, MG diagnosis was confirmed in 599. Six subjects were RIA-AChR-Ab positive although they had never had MG symptoms; in four of these subjects AChR-Abs were not detected by F-CBA, whereas the remaining two (both non-MG thymoma cases) were positive also by F-CBA. CONCLUSIONS: RIA false positivity for AChR-Ab is very rare. Previous literature has demonstrated that F-CBA has higher sensitivity than RIA for MG, especially in ocular cases. Our preliminary results show that, in rare instances, F-CBA may be more specific than RIA for MG diagnosis.","journal":"European Journal of Neurology","year":2024,"id":440936,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":9,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9611,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1252896,"name":"Sofia Helena Valente de Lemos‐Marini","orcid":"0000-0002-8289-5703","position":1,"is_corresponding":false},{"id":864425,"name":"Cinzia Carrozza","orcid":"0000-0003-1045-0470","position":2,"is_corresponding":false},{"id":1252897,"name":"Eleonora Sabatelli","orcid":"0000-0001-8604-7544","position":3,"is_corresponding":false},{"id":865237,"name":"Giovanni Mascagna","orcid":null,"position":4,"is_corresponding":false},{"id":1253383,"name":"Martina Marini","orcid":null,"position":5,"is_corresponding":false},{"id":1252898,"name":"Jacopo Morroni","orcid":"0000-0002-3564-3976","position":6,"is_corresponding":false},{"id":1128717,"name":"Amelia Evoli","orcid":"0000-0002-4644-2299","position":7,"is_corresponding":false},{"id":1252899,"name":"Raffaele Iorio","orcid":"0000-0002-6270-0956","position":8,"is_corresponding":false},{"id":1230294,"name":"Silvia Falso","orcid":"0000-0002-6264-5299","position":0,"is_corresponding":true}],"reference_count":16,"raw_metadata":null,"created_at":"2026-07-19T02:01:01.842286Z","pmid":"39118440","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}