Indicator Explainer
IgG
An immunoglobulin isotype (subclass) that characterizes secondary immune responses. This isotype is further broken down into several smaller subclasses (IgG1, IgG2a, IgG2b, IgG3 in the mouse; IgG1-4 in the human), and each subclass is differentially synthesized and secreted into the serum upon differential immune stimuli.
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, C568. 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 — IgG (C568)
- Source: National Cancer Institute, NCI Thesaurus 26.09d, C568. NCI definition, reproduced without modification under CC BY 4.0.
- Detection of MOG-IgG and MOG-IgA in Maternal Breast Milk and Infant Blood in MOGAD: A Case Report. — Neurol Neuroimmunol Neuroinflamm, 2026-10-09 (PMID 42854177; literature)
- Expression and Purification of Staphylococcal Enterotoxin B and Detection of SEB-Specific IgG Antibodies in Allergic Children. — Am J Rhinol Allergy, 2026-10-09 (PMID 42852902; literature)
- Cerebral Attack With Cortical-Leptomeningeal Involvement and Seizures in AQP4-IgG-Positive Neuromyelitis Optica Spectrum Disorder. — Intern Med, 2026-10-15 (PMID 42875206; literature)
- Pretransplantation Risk Stratification for BK Polyomavirus DNAemia After Kidney Transplantation: Impact of Donor Viruria, Anti-BKPyV IgG Antibodies, and Viral Subtype. — Transpl Infect Dis, 2026-10-22 (PMID 42910455; literature)
- Vaccination in Pregnancy with the Bivalent Respiratory Syncytial Virus Vaccine Elicits Significant Specific IgA, IgG, and Secretory Antibody Titers in Human Milk. — Breastfeed Med, 2026-10-21 (PMID 42908311; literature)