Two related cases of primary complement deficiencies
A Farhoudi1, Nasrin Bazargan, Zabra Pourpak
1Immunology, Asthma and Allergy Research Institute; Children Hospital Medical Center; Tehran University of Medical Sciences, Tehran, Iran.
Insights
Two related patients with rare primary complement deficiencies, C3 deficiency and hereditary angioedema, highlight a potential genetic link between these immune disorders.
Area of Science:
- Immunology
- Genetics
Background:
- Primary complement deficiencies are rare immune system disorders.
- Two related patients presented with distinct complement deficiencies: C3 deficiency and hereditary angioedema.
Purpose of the Study:
- To report two related cases of primary complement deficiencies.
- To investigate a potential genetic relationship between C3 deficiency and hereditary angioedema.
Main Methods:
- Case report of two related patients.
- Immunological testing including serum C3, C1INH, and C4 levels.
- Exclusion of other causes for angioedema.
Main Results:
- Patient 1: 41-year-old male with C3 deficiency, recurrent pneumococcal meningitis, and glomerulonephritis.
- Patient 2: 40-year-old female with low C1INH and C4 levels, experiencing recurrent angioedema, diagnosed with hereditary angioedema.
- Both patients had normal results in other immunological tests.
Conclusions:
- The findings suggest a possible genetic relationship between C3 deficiency and hereditary angioedema in related individuals.
- Early diagnosis and management are crucial for patients with primary complement deficiencies.
Abstract:
Primary complement deficiencies are rare and two related patients are reported here. The first patient is a 41- year- old man with eighteen episodes of pneumococcal meningitis and other purulent infections. The serum C3 level was checked at three separate times, showing that this was a primary C3 deficient case; other immunological tests were however normal. This patient now takes prophylactic antibiotics and the meningitis has not recurred, but he does have glomerulonephritis. The second case is a 40 - year-old woman with repeated episodes of orofacial and laryngeal edema and dyspnea. The serum C1INH levels were 4.3 to 7 mgldL which were very low compared with normal healthy subjects (C1INH was 40-50 mg/dL in ten normal controls) and C4 was lower than normal but other immunological tests were normal. Other causes of angioederna such as lymphoproliferative disorders were excluded. She had hereditary angioedema without a family background. The condition may be due to genetic mutation. The angioedema was controlled with Danazol and Stanasol. As our patients are related, this may suggest a genetic relationship between these two disorders.
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