{"doi":"10.3389/fimmu.2022.815833","title":"Activation of Complement Components on Circulating Blood Monocytes From COVID-19 Patients","abstract":"The coronavirus disease-2019 (COVID-19) caused by the SARS-CoV-2 virus may vary from asymptomatic to severe infection with multi-organ failure and death. Increased levels of circulating complement biomarkers have been implicated in COVID-19-related hyperinflammation and coagulopathy. We characterized systemic complement activation at a cellular level in 49-patients with COVID-19. We found increases of the classical complement sentinel C1q and the downstream C3 component on circulating blood monocytes from COVID-19 patients when compared to healthy controls (HCs). Interestingly, the cell surface-bound complement inhibitor CD55 was also upregulated in COVID-19 patient monocytes in comparison with HC cells. Monocyte membrane-bound C1q, C3 and CD55 levels were associated with plasma inflammatory markers such as CRP and serum amyloid A during acute infection. Membrane-bounds C1q and C3 remained elevated even after a short recovery period. These results highlight systemic monocyte-associated complement activation over a broad range of COVID-19 disease severities, with a compensatory upregulation of CD55. Further evaluation of complement and its interaction with myeloid cells at the membrane level could improve understanding of its role in COVID-19 pathogenesis.","journal":"Frontiers in Immunology","year":2022,"id":268677,"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":21,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9657,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2022-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":529097,"name":"Joseph M. Rocco","orcid":"0000-0003-4307-4934","position":1,"is_corresponding":false},{"id":342096,"name":"Elizabeth Laidlaw","orcid":"0000-0001-8241-6859","position":2,"is_corresponding":false},{"id":399561,"name":"Adam Rupert","orcid":"0000-0002-3778-9856","position":3,"is_corresponding":false},{"id":727841,"name":"Frances Galindo","orcid":null,"position":4,"is_corresponding":false},{"id":830644,"name":"Anela Kellogg","orcid":null,"position":5,"is_corresponding":false},{"id":444050,"name":"Princy Kumar","orcid":"0000-0002-5994-2727","position":6,"is_corresponding":false},{"id":830134,"name":"Rita Poon","orcid":"0000-0002-7362-7678","position":7,"is_corresponding":false},{"id":554215,"name":"Glenn Wortmann","orcid":"0000-0002-7801-8871","position":8,"is_corresponding":false},{"id":332535,"name":"Andrea Lisco","orcid":"0000-0002-1475-356X","position":9,"is_corresponding":false},{"id":431963,"name":"Maura Manion","orcid":"0000-0003-0991-0011","position":10,"is_corresponding":false},{"id":241760,"name":"Irini Sereti","orcid":"0000-0002-0076-0224","position":11,"is_corresponding":false},{"id":469516,"name":"Silvia Lucena Lage","orcid":"0000-0001-8519-8164","position":0,"is_corresponding":true}],"reference_count":49,"raw_metadata":null,"created_at":"2026-07-19T00:27:14.088663Z","pmid":"35250994","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":[]}