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Updated: Aug 14, 2026
06:17
Depletion of Specific Cell Populations by Complement Depletion
Published on: February 5, 2010
Complementing the patient: a complement component deficiency in a patient with recurrent infections and
David Sinclair1, Graeme Wilde, Samantha Bex
1Department of Clinical Biochemistry, Queen Alexandra Hospital, Portsmouth, UK. david.sinclair@porthosp.nhs.uk
Clinical Laboratory
|November 16, 2005
Summary
A rare C2 complement deficiency caused severe infections in a child. Testing complement function is crucial for diagnosing immune deficiencies in patients with recurrent pyogenic infections.
Area of Science:
- Immunology
- Pediatrics
- Nephrology
Background:
- Recurrent pyogenic infections can indicate underlying immune system dysfunction.
- The complement system plays a vital role in innate immunity and pathogen clearance.
- Classical complement pathway activation is essential for effective immune responses.
Observation:
- A 7-year-old girl presented with empyema and glomerulonephritis.
- Her "immunological" defect was identified as a deficiency in the complement component C2.
- This C2 deficiency impaired her ability to activate the classical complement pathway.
Findings:
- The patient's C2 deficiency was the sole identified "immunological" defect.
- The deficiency directly explained her susceptibility to severe infections.
- Impaired classical complement pathway activation was confirmed.
Implications:
- Complement component deficiencies should be considered in unexplained severe or recurrent infections.
- Comprehensive immune deficiency workups must include assessment of complement system function.
- Early diagnosis of complement deficiencies can guide timely management and prevent severe sequelae.
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