Indicator Explainer
Complement C5
Complement C5 (1676 aa, ~188 kDa) is encoded by the human C5 gene. This protein is involved 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, C21539. NCI definition, reproduced without modification under CC BY 4.0. Source identity and definition checked automatically on 2026-10-20. 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 C5 (C21539)
- Source: National Cancer Institute, NCI Thesaurus 26.09d, C21539. NCI definition, reproduced without modification under CC BY 4.0.
- Complement C5 inhibitor as a rescue therapy for acute NMOSD attacks: a multicenter retrospective cohort study in China. — Front Immunol, 2026-09-15 (PMID 42812414; literature)
- How Severe is Severe Enough? Organ Failure Rather Than Anemia Severity as a Potential Threshold for Complement Inhibition in Pediatric Paroxysmal Cold Hemoglobinuria: A Case Report. — Case Rep Pediatr, 2026-09-03 (PMID 42694628; literature)
- Independent prognostic value of semaphorin-4D, interleukin-1β and complement activation in newly diagnosed multiple myeloma patients. — Haematologica, 2026-09-03 (PMID 42687818; 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)
- A complement C5-targeted GalNAc-conjugated siRNA with sustained efficacy in a non-human primate model of IgA nephropathy. — Mol Ther, 2026-08-13 (PMID 42596551; literature)