{"doi":"10.14814/phy2.15814","title":"Decreased plasma cartilage acidic protein 1 in COVID‐19","abstract":"Cartilage acidic protein-1 (CRTAC1) is produced by several cell types, including Type 2 alveolar epithelial (T2AE) cells that are targeted by SARS-CoV2. Plasma CRTAC1 is known based on proteomic surveys to be low in patients with severe COVID-19. Using an ELISA, we found that patients treated for COVID-19 in an ICU almost uniformly had plasma concentrations of CRTAC1 below those of healthy controls. Magnitude of decrease in CRTAC1 distinguished COVID-19 from other causes of acute respiratory decompensation and correlated with established metrics of COVID-19 severity. CRTAC1 concentrations below those of controls were found in some patients a year after hospitalization with COVID-19, long COVID after less severe COVID-19, or chronic obstructive pulmonary disease. Decreases in CRTAC1 in severe COVID-19 correlated (r = 0.37, p = 0.0001) with decreases in CFP (properdin), which interacts with CRTAC1. Thus, decreases of CRTAC1 associated with severe COVID-19 may result from loss of production by T2AE cells or co-depletion with CFP. Determination of significance of and reasons behind decreased CRTAC1 concentration in a subset of patients with long COVID will require analysis of roles of preexisting lung disease, impact of prior acute COVID-19, age, and other confounding variables in a larger number of patients.","journal":"Physiological Reports","year":2023,"id":378971,"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":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.959,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":109554,"name":"Joseph Balnis","orcid":"0000-0003-0894-2839","position":1,"is_corresponding":false},{"id":109558,"name":"Laura K. Muehlbauer","orcid":"0000-0001-8878-9154","position":2,"is_corresponding":false},{"id":894809,"name":"Yury V. Bukhman","orcid":"0000-0002-8111-7651","position":3,"is_corresponding":false},{"id":652700,"name":"Matthew S. Stefely","orcid":null,"position":4,"is_corresponding":false},{"id":109551,"name":"Katherine A. Overmyer","orcid":"0000-0002-1929-1229","position":5,"is_corresponding":false},{"id":1143113,"name":"Rachel Vancavage","orcid":"0009-0004-1445-5986","position":6,"is_corresponding":false},{"id":109563,"name":"Anupama Tiwari","orcid":"0000-0003-1569-5354","position":7,"is_corresponding":false},{"id":1143114,"name":"Anish Adhikari","orcid":"0000-0002-0156-8728","position":8,"is_corresponding":false},{"id":317797,"name":"Paul J. Feustel","orcid":"0000-0002-6963-4349","position":9,"is_corresponding":false},{"id":109572,"name":"Bradford S. Schwartz","orcid":null,"position":10,"is_corresponding":false},{"id":71208,"name":"Joshua J. Coon","orcid":"0000-0002-0004-8253","position":11,"is_corresponding":false},{"id":3794,"name":"Ron Stewart","orcid":"0000-0002-9041-1828","position":12,"is_corresponding":false},{"id":109576,"name":"Ariel Jaitovich","orcid":null,"position":13,"is_corresponding":false},{"id":109575,"name":"Deane F. Mosher","orcid":"0000-0002-1233-1005","position":14,"is_corresponding":false},{"id":371771,"name":"Mats W. Johansson","orcid":"0000-0001-5699-978X","position":0,"is_corresponding":true}],"reference_count":50,"raw_metadata":null,"created_at":"2026-07-19T01:16:48.594070Z","pmid":"37667413","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":[]}