title: Recurrent infections in partial complement factor I deficiency: evaluation of three generations of a Brazilian family.
abstract: We report here on the evaluation of a factor I-deficient Brazilian family (three generations, 39 members) with strong consanguinity. The complete factor I-deficient patients (n = 3) presented recurrent respiratory infections, skin infections and meningitis; one of them died after sepsis. They presented an impaired total haemolytic activity (CH50), low C3, low factor H and undetectable C3dg/C3d. Partial factor I deficiency was detected in 16 family members (normal low cut-off value was 25 microg/ml). Respiratory infections were the most common clinical occurrence among partial factor I-deficient relatives. Two of them were submitted to nephrectomy following recurrent urinary tract infections. An additional two heterozygous relatives presented with arthritis and rheumatic fever. Apparently, patients with partial factor I deficiency are also at higher risk for recurrent infections. Vaccination against capsulated bacteria and the eventual use of prophylactic antibiotics should be considered individually in this patient group.
authors.affiliation: Laboratory of Clinical and Experimental Allergy-Immunology, Department of Dermatology, University of São Paulo Medical School, SP, Brazil.
authors.forename: A S
authors.initials: AS
authors.lastname: Grumach
authors.forename: M F
authors.initials: MF
authors.lastname: Leitão
authors.forename: V G
authors.initials: VG
authors.lastname: Arruk
authors.forename: M
authors.initials: M
authors.lastname: Kirschfink
authors.forename: A
authors.initials: A
authors.lastname: Condino-Neto
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001424:Bacterial Infections / Q000235:genetics / Q000276:immunology*; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D017244:Complement Factor I / Q000032:analysis / Q000172:deficiency* / Q000276:immunology; D005192:Family Health; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics / Q000276:immunology; D008297:Male; D008581:Meningitis / Q000276:immunology; D010375:Pedigree; D012008:Recurrence; D012141:Respiratory Tract Infections / Q000235:genetics / Q000276:immunology; D012874:Skin Diseases, Infectious / Q000235:genetics / Q000276:immunology
chemical_list: D017244:Complement Factor I