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Complement CH50

Published: July 27, 2026Updated: August 25, 2026

Complement CH50 measures the total hemolytic activity of the complement system, reflecting the overall function of the classical complement pathway.

Quick summary

CH50 assesses the functional activity of the classical complement pathway.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
U/mL
Clinical utility
diagnostic
Result kind
quantitative
FDA-cleared
Diamed CH50, Hemolytic Assays CH50
interpretation: {"text":"May indicate complement deficiency or consumption, often seen in autoimmune diseases like systemic lupus erythematosus (SLE).","label":"Low CH50"}; {"text":"Suggests an acute phase response or chronic inflammatory condition, such as rheumatoid arthritis or infection.","label":"High CH50"}

Complement CH50 is a blood test that evaluates the functional activity of the classical complement pathway, which is a part of the immune system's defense mechanism.

The test measures the ability of the patient's serum to lyse sheep red blood cells coated with antibodies, providing a global assessment of the complement system's function.

Abnormal CH50 levels can indicate deficiencies or overactivity of the complement system, which may be associated with various inflammatory and autoimmune conditions.

Frequently asked questions

What is a normal CH50 range?
The normal range for CH50 is typically between 60–144 U/mL.
Why is CH50 testing important?
CH50 testing is important for diagnosing and monitoring conditions related to complement deficiencies or overactivity, such as autoimmune diseases and infections.
  1. 1
    Complement CH50 TestSource
  2. 2
    Complement SystemSource

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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

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If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy