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Hereditary, complete deficiency of complement factor H associated with recurrent meningococcal disease
H E Nielsen1, K C Christensen, C Koch
1Complement Laboratory, Statens Seruminstitut, Copenhagen, Denmark.
Scandinavian Journal of Immunology
|December 1, 1989
Summary
A rare deficiency in complement factor H (beta-1H globulin) in a 15-year-old girl led to spontaneous complement activation and meningococcal disease. Erythrocyte CR1 compensated for factor H in C3 degradation, preventing erythrocyte lesions.
Area of Science:
- Immunology
- Biochemistry
Background:
- Complement factor H (beta-1H globulin) is crucial for regulating the alternative complement pathway.
- Deficiency in factor H can lead to uncontrolled complement activation and increased susceptibility to infections.
Observation:
- A 15-year-old female presented with undetectable plasma factor H levels and a history of two meningococcal disease episodes.
- Despite factor H deficiency, she remained otherwise healthy, with reduced levels of alternative pathway components (factor B, properdin, C3, C5-C9).
Findings:
- Spontaneous in vivo activation of the alternative complement pathway was observed due to factor H deficiency.
- Elevated plasma C3dg levels suggested erythrocyte CR1 compensated for factor H in C3 degradation.
- In vitro studies showed increased spontaneous erythrocyte hemolysis in citrate plasma, but not serum.
Implications:
- This case highlights the critical role of factor H in preventing spontaneous complement activation and associated infections.
- Erythrocyte CR1's compensatory role in C3 degradation offers insights into complement regulation mechanisms.
- Understanding factor H deficiency is vital for managing recurrent infections and complement-mediated disorders.