title: PI SZ phenotype in chronic obstructive pulmonary disease.
abstract: BACKGROUND
  A study was undertaken to clarify whether the PI SZ phenotype of the protease inhibitor system predisposes to chronic obstructive pulmonary disease (COPD).
  
  
  METHODS
  The prevalence of PI Z and PI SZ deficient phenotypes was investigated in a population of 702 patients with COPD followed up at the Chest Unit of a tertiary hospital and in 15400 newborn infants from the same geographical area. Individuals with deficiency were detected by screening of dried blood spots on filter paper using a comparative electro-immunodiffusion technique for alpha 1-antitrypsin and transferrin. The serum phenotype was confirmed by means of isoelectrofocusing on polyacrylamide gel.
  
  
  RESULTS
  Of the 702 blood samples from patients with COPD, six PI Z subjects (0.85%) and one PI SZ (0.14%) were detected. Of the 15400 samples from neonates, the number of PI Z subjects was eight (0.052%) and that of PI SZ was 24 (0.156%). The difference between the two groups was significant for PI Z but not for PI SZ.
  
  
  CONCLUSIONS
  The data do not indicate an increased risk for development of COPD associated with the PI SZ phenotype but confirm the predisposition of PI Z individuals for the development of COPD.
authors.affiliation: Department of Paediatrics, University Hospital of Valdecilia, Santander, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Alvarez-Granda
authors.forename: M J
authors.initials: MJ
authors.lastname: Cabero-Perez
authors.forename: A
authors.initials: A
authors.lastname: Bustamante-Ruiz
authors.forename: D
authors.initials: D
authors.lastname: Gonzalez-Lamuño
authors.forename: M
authors.initials: M
authors.lastname: Delgado-Rodriguez
authors.forename: M
authors.initials: M
authors.lastname: García-Fuentes
mesh_terms: D000328:Adult; D000368:Aged; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008173:Lung Diseases, Obstructive / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D014168:Transferrin / Q000032:analysis; D000515:alpha 1-Antitrypsin / Q000032:analysis; D019896:alpha 1-Antitrypsin Deficiency
chemical_list: D014168:Transferrin; D000515:alpha 1-Antitrypsin