IgG Subclasses
Department of Immunology
Notes
- There are four IgG subclasses, the levels of which vary with age.
- Mainly used for the diagnosis of IgG4-related disease. Of limited use in the investigation of patients with suspected immune deficiency.
- Test performed by Immunology, North Bristol NHS Trust.
Sample Requirements
Clotted blood. (No patient preparation or special handling required)
Adult
5ml Gold-top SST tube or 3.5ml Rust-top gel tube (Trust users only)
Paediatric
1ml Serum Sample
Turnaround Times
1 week
Time Limit for Add-ons
3 days
Reference Ranges
| IgG1 | IgG2 | IgG3 | IgG4 | |||||
|---|---|---|---|---|---|---|---|---|
| Age | Low | High | Low | High | Low | High | Low | High |
| 0-2 years | 1.94 | 8.42 | 0.3 | 3 | 0.18 | 0.85 | 0.01 | 0.78 |
| 2-4 years | 3.15 | 9.45 | 0.36 | 2.25 | 0.17 | 0.68 | 0.01 | 0.54 |
| 4-6 years | 3.06 | 9.45 | 0.61 | 3.45 | 0.10 | 1.2 | 0.01 | 1.2 |
| 6-8 years | 2.88 | 9.18 | 0.44 | 3.76 | 0.16 | 0.85 | 0.01 | 0.99 |
| 8-10 years | 4.23 | 10.2 | 0.72 | 4.3 | 0.13 | 0.85 | 0.02 | 0.93 |
| 10-12 years | 4.23 | 10.6 | 0.76 | 3.55 | 0.17 | 1.73 | 0.02 | 1.15 |
| 12-14 years | 3.42 | 11.5 | 1 | 4.55 | 0.28 | 1.25 | 0.04 | 1.36 |
| 14-18 years | 3.15 | 8.55 | 0.64 | 4.95 | 0.23 | 1.96 | 0.04 | 1.57 |
| Adult | 3.82 | 9.29 | 2.4 | 7 | 0.22 | 1.76 | 0.04 | 0.86 |
Source of Reference Ranges for Subclasses: NBT Website (The Binding Site (TBS))
Information:
Updated: September 2025