Low C4 levels can occur in hereditary and acquired angioneurotic oedema.
|Adults||10 – 40 mg/dL||0.1 – 0.4 g/L|
Each laboratory should check if the reference ranges are transferable to its own patient population and determine own reference ranges if necessary. For diagnostic purposes, the results should always be assessed with the patient’s medical history, clinical examinations and other findings.
- Acute phase reaction
- Complement comsumption due to infection or auto immune reaction