From the Research
The normal values of C3 and C4 complement proteins in a 7-year-old boy are approximately 0.90-1.80 g/L for C3 and 0.10-0.40 g/L for C4, as supported by the most recent and relevant study 1. These values may vary slightly between different laboratories due to differences in testing methods.
- Complement proteins are important components of the immune system that help fight infections and clear immune complexes.
- C3 is the most abundant complement protein in serum and plays a central role in all three complement activation pathways.
- C4 is involved in the classical and lectin pathways of complement activation. Low levels of these proteins may indicate complement consumption due to immune complex diseases, autoimmune disorders like lupus, or certain kidney diseases.
- Persistently low levels warrant further investigation, while elevated levels may occur during inflammation or infection. When interpreting these values, it's essential to consider the clinical context and other laboratory findings, as noted in various studies 2, 3, 4, 5. However, the study by 1 provides the most relevant information for determining normal C3 and C4 levels in children.