UNDER REVIEW AND EDITING: VALUES NOT CONFIRMED
A reference range is a set of values used by a health professional to interpret a set of medical test results. The range is usually defined as the set of values 95% of the normal population falls within.
The reference range will vary, depending on the age, sex and race of a population, and even the instruments the laboratory uses to perform the tests. Furthermore, by definition, 5% of the normal population will fall outside the reference range.
| Category | Test | Low | High | Unit | Comments |
| Acute phase protein markers of Inflammation | Erythrocyte sedimentation rate (ESR) | 0 | (Age, +10 if female)/2 | mm/hr | |
| C-reactive protein (CRP) | 0 | 6 | mg/L | ||
| Autoantibodies | Antinuclear antibodies (ANA) | ||||
| Extractable nuclear antigen (ENA) | |||||
| Rheumatoid factor (RF) | 0 | 20 | IU/mL | High levels not specific for Rheumatoid Arthritis alone. | |
| Serology | Antistreptolysin O titre (ASOT) – preschoolers | n/a | 100 | units/mL | |
| Antistreptolysin O titre (ASOT) – others | n/a | 200 | units/mL |