title: Possible disease-modifying factors: the mannan-binding lectin pathway and infections in hereditary angioedema of children and adults.
abstract: BACKGROUND
  Hereditary angioedema (HAE) is caused by mutations in the C1inh gene, leading to dysfunction of the C1-esterase inhibitor (C1-INH). C1-INH interacts with MASP-1 and MASP-2 proteases, participating in the mannan-binding lectin (MBL) pathway of complement activation. The aim of the study was to investigate the contribution of possible changes in MBL/MASP-2 complex activity and Helicobacter pylori, hepatitis B virus (HBV), and hepatitis C virus (HCV) infections to the severity and frequency of clinical symptoms of HAE.
  
  
  METHODS
  The study was performed in 65 patients with HAE and 113 healthy persons. The parameters measured were C1-INH, C4, MBL concentration and MBL/MASP-2 complex activity, and serological markers of H. pylori, HBV, and HCV infection. Scores for the frequency and severity of HAE symptoms were determined.
  
  
  RESULTS
  HAE scores were significantly higher in patients whose C1-INH activity did not exceed 10% than in patients with activity of 10-52% (p=0.016). No significant differences were found in the median levels of MBL concentration and MBL/MASP-2 complex activity between patients and the control group. There was a slight association between contact with H. pylori in patients and HAE symptom score (p=0.052, not significant). Adult patients showed a 2.6-times higher frequency of anti-HBc than the general population. HBV DNA was negative in anti-HBc(+) patients.
  
  
  CONCLUSIONS
  These results suggest that the MBL complement activation pathway itself does not contribute to the frequency of angioedema attacks. Infections with H. pylori and HBV may slightly influence the disease score (not significant).
authors.affiliation: Laboratory of Immunobiology of Infections, Center of Medical Biology, Polish Academy of Sciences, Łódź, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Cedzyński
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Madaliński
authors.forename: Hanna
authors.initials: H
authors.lastname: Gregorek
authors.forename: Anna S
authors.initials: AS
authors.lastname: Swierzko
authors.forename: Ewa
authors.initials: E
authors.lastname: Nowicka
authors.forename: Krystyna
authors.initials: K
authors.lastname: Obtułowicz
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Dzierzanowska-Fangrat
authors.forename: Urszula
authors.initials: U
authors.lastname: Wojda
authors.forename: Daniel
authors.initials: D
authors.lastname: Rabczenko
authors.forename: Masaya
authors.initials: M
authors.lastname: Kawakami
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D054179:Angioedemas, Hereditary / Q000150:complications / Q000276:immunology* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D003167:Complement Activation; D050718:Complement C1 Inhibitor Protein / Q000276:immunology / Q000378:metabolism; D003171:Complement Pathway, Classical / Q000276:immunology; D037582:Complement Pathway, Mannose-Binding Lectin / Q000276:immunology*; D005260:Female; D016481:Helicobacter Infections / Q000097:blood / Q000150:complications / Q000276:immunology*; D006509:Hepatitis B / Q000097:blood / Q000150:complications / Q000276:immunology*; D006526:Hepatitis C / Q000097:blood / Q000150:complications / Q000276:immunology*; D006801:Humans; D008297:Male; D037601:Mannose-Binding Lectin / Q000276:immunology / Q000378:metabolism*; D050606:Mannose-Binding Protein-Associated Serine Proteases / Q000276:immunology / Q000378:metabolism*; D008875:Middle Aged; D012720:Severity of Illness Index
chemical_list: D050718:Complement C1 Inhibitor Protein; D037601:Mannose-Binding Lectin; C105296:MASP2 protein, human; D050606:Mannose-Binding Protein-Associated Serine Proteases