Indicator Explainer
Complement C3
Complement C3 (1663 aa, ~187 kDa) is encoded by the human C3 gene. This protein plays a role in complement-mediated immunity.
This page explains what the indicator is and how results are interpreted in general terms. Reference ranges depend on the laboratory, the method, and your own situation — no single “normal value” applies to everyone. This page is health information, not a diagnosis. For symptoms, treatment, or urgent concerns, contact a healthcare professional.
When it is tested
Source: National Cancer Institute, NCI Thesaurus 26.09d, C21527. NCI definition, reproduced without modification under CC BY 4.0. Source identity and definition checked automatically on 2026-10-18. No individual clinical interpretation or human reviewer is asserted.
Reading results
Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.
Also Known As
Related Tests
Tests that measure or involve this indicator.
References
- NCI Thesaurus 26.09d — Complement C3 (C21527)
- Source: National Cancer Institute, NCI Thesaurus 26.09d, C21527. NCI definition, reproduced without modification under CC BY 4.0.
- Complement C3 in the silica nanoparticles protein corona promotes macrophage M1 polarization and subacute pulmonary fibrotic remodeling. — Environ Pollut, 2026-10-03 (PMID 42829097; literature)
- Corrigendum to "Kidney injury and colocalization of complement C3, IgA, and IgG in glomerular immune-complex deposits of patients with IgA nephropathy or IgA vasculitis with nephritis." Kidney International 2025;108:1158-1169. — Kidney Int, 2026-10-01 (PMID 42760012; literature)
- The relationship between autoantibody and complement levels in the sera of patients with systemic lupus erythematosus. — Clin Immunol, 2026-09-25 (PMID 42790660; literature)
- Host C3 complement restricts bovine coronavirus infection in vitro via virus-induced IL-1β signaling. — Vet Immunol Immunopathol, 2026-09-12 (PMID 42735537; literature)
- Low serum complement C3 levels are associated with all-cause mortality in Chinese centenarians: a prospective cohort study. — Front Immunol, 2026-09-09 (PMID 42780620; literature)
- Complement C5 defines 2 chronic spontaneous urticaria endotypes with distinct autoantibody profiles and omalizumab responses: The INCA study. — Ann Allergy Asthma Immunol, 2026-09-02 (PMID 42685900; literature)
- Systemic complement C3 reduction in infertile women with endometrial dysbiosis: preliminary observations. — Reprod Fertil Dev, 2026-10-01 (PMID 42863816; literature)
- Complement C3 is associated with cancer-induced frailty: genetic and clinical evidence. — Front Nutr, 2026-09-30 (PMID 42876568; literature)
- Complement resistance of seabird-associated Borrelia garinii. — Ticks Tick Borne Dis, 2026-10-17 (PMID 42892284; literature)
- Complement C3a plays a role in diabetic cardiomyopathy mainly via C3aR-ERK-PANoptosis pathway. — Int Immunopharmacol, 2026-10-17 (PMID 42892107; literature)
- Convergent Immunopathology in Influenza-Associated Encephalopathy: CD3+ CD4+ T Cell Depletion, IL-6-Mediated Inflammation, and Complement C3 Dysregulation. — Diagnostics (Basel), 2026-10-10 (PMID 42938130; literature)