[Hereditary complement C5 deficiency: study of 3 Tunisian adult cases and literature review]
Yusr Zerzri1, Maryam Kallel-Sellami, Rim Abdelmalek
1Laboratoire d'immunologie, Hôpital Rabta, Tunis, Tunisie.
Insights
Hereditary C5 complement deficiency (C5D) is linked to increased risk of meningococcal meningitis. This study highlights C5D is not rare in Tunisia and often presents with meningitis, showing variable C5 levels.
Area of Science:
- Immunology
- Genetics
- Clinical Medicine
Background:
- The complement system is crucial for innate and adaptive immunity.
- Hereditary deficiencies in the terminal complement pathway (C5-C9) elevate the risk of severe infections, particularly meningococcal meningitis.
Observation:
- This study assessed three Tunisian adults with hereditary C5 deficiency (C5D).
- Two patients underwent familial studies.
- Clinical and biochemical features were evaluated.
Findings:
- All three patients presented with septic meningitis, confirmed as meningococcal in one case.
- Serum C5 levels ranged from 0 to 0.4%, with normal levels for other complement components (C1q, C3, C4, properdin, C6, C8, C9).
- One patient had 50% C7 levels; familial studies showed no other cases.
Implications:
- C5D may be more prevalent in Tunisia than previously thought.
- Meningitis is a common complication of C5D, with varying severity.
- Biological characterization of C5D involves variable plasma C5 levels.
Background:
The complement system is one of the main effectors of both innate and adaptive immunity. Hereditary complement deficiency, mainly those of the terminal pathway (C5-C9), is at increased risk for septic meningitides particularly meningococcal ones.
Aim:
to assess clinical and biochemical features of 3 Tunisian adults with C5 hereditary complement deficiency (C5D), with a familial study performed for two of them.
Methods:
Functional activity of the classical and the alternative pathway of complement (CH50 and AP50 respectively) were measured according to standards haemolytic procedures. Serum concentration of complement components were determined by nephelemetry and ELISA. C5D was diagnosed when CH50, AP50 and C5 antigenic level were highly decreased.
Results:
Our patients were 2 men and one woman. All these patients presented clinical symptoms of septic meningitides. Meningococcal orign was confirmed in one case. C5 level varies between 0 and 0.4%. Levels of other complement components: Clq, C3, C4, properdine, C6, C8 and C9 were normal. Antigenic C7 level was 50% in the female patient. Familial study revealed no similar hereditary complement deficiency in relatives.
Conclusion:
Only 27 cases with C5D were reported in the literature. The description of 3 cases in our series demonstrates that: * C5D is not rare in Tunisia, ** C5D is clinically commonly complicated by meningitides with unconstant severity, *** C5D is biologically caracterised by a variable level of the plasmatic C5 component.
More Related Videos
Related Concept Videos
01:23Cystic Fibrosis: Pathogenesis
CF is primarily caused by a genetic mutation in a chromosome 7 gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The most common gene mutation leading to CF is the ΔF508 mutation, but...
00:49Complementation Tests
Organisms heterozygous for different mutations are crossed pairwise in all combinations. If present on different genes, the mutations can complement each other by providing the missing...
01:43Incomplete Dominance
01:21Huntington Disease l: Introduction
02:20Cohesins
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of homologous...
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy