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Updated: Aug 14, 2026

Depletion of Specific Cell Populations by Complement Depletion
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
PubMed

Insights

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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