{"doi":"10.1002/acr.25697","title":"Performance Characteristics of Anti–Collagen <scp>II</scp> Antibodies in Relapsing Polychondritis and Related Diseases: Prospective Analysis, Systematic Review, and Meta‐Analysis","abstract":"Objective Relapsing polychondritis (RP) is a rare disease defined by recurrent cartilaginous inflammation. Anti–collagen II (Col2) antibodies have been proposed as a diagnostic biomarker for RP, but their performance characteristics are not well defined. Methods In an observational cohort, anti‐Col2 antibody levels were measured in patients with RP compared to other inflammatory diseases that mimic RP. In parallel, a systematic review and meta‐analysis was performed to assess anti‐Col2 antibody prevalence across a broad spectrum of diseases. Individual study risk ratios (RRs) and pooled disease category RRs, study bias, and interstudy heterogeneity were assessed. Results In the observational cohort, anti‐Col2 antibody prevalence did not differ between RP and comparators. The performance characteristics of anti‐Col2 to diagnose RP were poor (sensitivity = 18%; specificity = 72%). Anti‐Col2 antibody titers did not correlate with disease activity in RP ( r = 0.08, P = 0.44). In the systematic review, 71 of 2,443 reviewed articles were included. Anti‐Col2 antibodies were not associated with RP across five pooled studies (RR: 2.09; 95% confidence interval [CI]: 0.05–81.80; P = 0.69). Anti‐Col2 antibodies were significantly associated with a composite group of inflammatory diseases with cartilaginous involvement (RR: 2.99; 95% CI: 1.29–6.91; P = 0.01). Studies using healthy controls reported increased effect sizes compared to studies that used disease controls (β‐estimate = 1.14, I 2 = 17.08%; P = 0.0004). Conclusion Anti‐Col2 antibodies are neither sensitive nor specific for RP, are detected in the minority of patients with RP, and are detected at similar prevalences across a spectrum of inflammatory diseases with cartilage inflammation. Use of these antibodies to diagnose or monitor RP is not advisable.","journal":"Arthritis Care & Research","year":2025,"id":581208,"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":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9588,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":218219,"name":"Marcela A. Ferrada","orcid":"0000-0003-3256-3273","position":1,"is_corresponding":false},{"id":549878,"name":"Alice Fike","orcid":"0000-0003-2597-1981","position":2,"is_corresponding":false},{"id":691094,"name":"Kaitlin A. Quinn","orcid":"0000-0002-5794-194X","position":3,"is_corresponding":false},{"id":424037,"name":"Benjamin A. Turturice","orcid":"0000-0001-9382-4612","position":4,"is_corresponding":false},{"id":1492875,"name":"Casey Stein","orcid":null,"position":5,"is_corresponding":false},{"id":5958,"name":"Peter C. Grayson","orcid":"0000-0002-8269-9438","position":6,"is_corresponding":false},{"id":1373929,"name":"Karyssa Stonick","orcid":null,"position":0,"is_corresponding":true}],"reference_count":79,"raw_metadata":null,"created_at":"2026-07-19T02:58:47.357782Z","pmid":"41235806","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":[]}