title: Complement factor I deficiency associated with recurrent meningitis coinciding with menstruation.
abstract: BACKGROUND
  Complement (C) factor I deficiency is a rare immunodeficiency state frequently associated with recurrent pyogenic infections in early infancy. This deficiency causes a permanent uncontrolled activation of the alternative pathway resulting in massive consumption of C3.
  
  
  METHODS
  A 23-year-old woman with monthly recurrent meningitis episodes, mostly in the perimenstrual period, since August 1999. Previously, at age 16 years, she had meningococcal sepsis, also coinciding with menstruation.
  
  
  OBJECTIVE
  To study the patient and her family to elucidate the molecular defects in the pedigree and to evaluate her clinical evolution.
  
  
  RESULTS
  We describe clinical, immunological, and treatment follow-up during this period. First, we characterized the existence of a total complement factor I deficiency defined by undetectable levels by enzyme immunosorbent assay. This total deficiency was also found in her sister. Her parents and brother had approximately half of the normal levels. In addition, the patient had very low levels of C3; factor B; and an important reduction of factor H, properdin, C5, C7, and C8 complement components. Additional studies in the patient's sera evidenced high levels of immune complexes containing C1q and immunoglobulin (Ig) G, as well as C3b/factor H, C3b/properdin, C3b/IgG, and properdin/IgG complexes. Treatment with prophylactic antibiotics, antiestrogen medication, plasma infusions, or intravenous immunoglobulin has been unsuccessful in avoiding consecutive meningitis episodes.
  
  
  CONCLUSIONS
  For the first time to our knowledge, these data present an unusual relationship between meningitis episodes and menstruation in factor I immunodeficiency.
authors.affiliation: Immunology Unit, Hospital Universitario, La Paz, Paseo de la Castellana, 261, 28046 Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: González-Rubio
authors.forename: A
authors.initials: A
authors.lastname: Ferreira-Cerdán
authors.forename: I M
authors.initials: IM
authors.lastname: Ponce
authors.forename: J
authors.initials: J
authors.lastname: Arpa
authors.forename: G
authors.initials: G
authors.lastname: Fontán
authors.forename: M
authors.initials: M
authors.lastname: López-Trascasa
mesh_terms: D000293:Adolescent; D000328:Adult; D000936:Antigen-Antibody Complex / Q000097:blood; D002648:Child; D017244:Complement Factor I / Q000172:deficiency* / Q000235:genetics* / Q000276:immunology; D003165:Complement System Proteins / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008581:Meningitis / Q000209:etiology* / Q000276:immunology; D008598:Menstruation; D010375:Pedigree; D012008:Recurrence
chemical_list: D000936:Antigen-Antibody Complex; D003165:Complement System Proteins; D017244:Complement Factor I