title: Thyroid hormones and complement parameters in hereditary angioedema with C1-inhibitor deficiency.
abstract: Thyroid hormones control and up-regulate the synthesis of many plasma proteins.
  
  
  
  To explore possible associations between thyroid hormone and complement levels in patients with hereditary angioedema resulting from the deficiency of the C1-inhibitor (C1-INH-HAE).
  
  
  
  In this case-control study, serum thyrotropin, free triiodothyronine (FT3), and free thyroxine (FT4) levels, anti-thyroid peroxidase and antithyroglobulin antibody titers, and C1-INH concentrations were measured in 117 euthyroid patients with C1-INH-HAE and compared with their clinical properties. The control group comprised 150 healthy, age- and sex-matched, euthyroid individuals.
  
  
  
  The thyrotropin and antithyroglobulin levels were similar between the patients and the controls. Significantly lower FT3 (P < .001) and FT4 (P = .002) levels, as well as higher anti-thyroid peroxidase titers (P < .001), were seen in the patients with C1-INH-HAE. The proportion of patients with reduced C1-INH activity was greater among those with below-median FT4 levels than among those with above-median values (P = .02). Patients who experienced more edematous attacks per year had lower FT4 levels (within the normal range) than those afflicted by fewer episodes (P = .01). The FT3 and FT4 levels were significantly higher in patients undergoing long-term danazol therapy than in those who did not receive this drug (P = .01 and P = .02, respectively). The proportion of patients with FT4 levels in the below-median range was higher in the subset with increased d-dimer concentration (P = .009).
  
  
  
  Minor variations of the thyroid hormone levels (within the reference range) can influence the function of C1-INH in C1-INH-HAE. Our findings suggest a role for the endocrine system in the pathophysiology of C1-INH-HAE.
authors.affiliation: 3rd Department of Internal Medicine, Semmelweis University, Budapest, Hungary; Department of Pulmonology, Semmelweis University, Budapest, Hungary.
authors.forename: Ibolya
authors.initials: I
authors.lastname: Czaller
authors.affiliation: 3rd Department of Internal Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Dorottya
authors.initials: D
authors.lastname: Csuka
authors.affiliation: 3rd Department of Internal Medicine, Semmelweis University, Budapest, Hungary; Urology Department, Medical Center, Hungarian Defence Forces, Budapest, Hungary.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Zotter
authors.affiliation: 3rd Department of Internal Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Nóra
authors.initials: N
authors.lastname: Veszeli
authors.affiliation: Department of Nuclear Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Edit
authors.initials: E
authors.lastname: Takács
authors.affiliation: Department of Laboratory Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Éva
authors.initials: É
authors.lastname: Imreh
authors.affiliation: 3rd Department of Internal Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Lilian
authors.initials: L
authors.lastname: Varga
authors.affiliation: 3rd Department of Internal Medicine, Semmelweis University, Budapest, Hungary. Electronic address: farkas.henriette@med.semmelweis-univ.hu.
authors.forename: Henriette
authors.initials: H
authors.lastname: Farkas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood; D015415:Biomarkers; D016022:Case-Control Studies; D050718:Complement C1 Inhibitor Protein; D003181:Complement C4 / Q000378:metabolism; D003165:Complement System Proteins; D003613:Danazol / Q000627:therapeutic use; D018450:Disease Progression; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products; D005340:Fibrinogen; D056829:Hereditary Angioedema Types I and II / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D013963:Thyroid Hormones / Q000097:blood*; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D050718:Complement C1 Inhibitor Protein; D003181:Complement C4; D005338:Fibrin Fibrinogen Degradation Products; D013963:Thyroid Hormones; C006606:anti-thyroglobulin; C036309:fibrin fragment D; D005340:Fibrinogen; D003165:Complement System Proteins; D003613:Danazol