Serum levels of α1-antitrypsin predict phenotypic expression of the α1-antitrypsin gene

Research output: Contribution to journalArticle

23 Scopus citations


We conducted a retrospective analysis to determine if both α 1-antitrypsin serum level and phenotype need be studied when evaluating children for α1-AT deficiency. We collected data from patients less than 19 years old who had both serum α1-AT level and phenotype determined over a 9-year period (January 1992-December 2000). Eighty-eight patients were identified and 15 had the PiZZ phenotype. The serum α1-AT level was below normal (normal 85-215 mg/dl) in all 15 PiZZ patients. Seventy-two of 73 non-PiZZ patients had normal or above normal serum levels. The sensitivity of the serum α1-AT level was 100%, and the specificity was 99%. The serum α1-AT level had a positive predictive value of 94% and a negative predictive value of 100%. We conclude that serum α1-AT levels are highly predictive of the PiZZ phenotype. Determination of the serum α1-AT level alone should be the initial test when evaluating for α1-AT deficiency.

Original languageEnglish (US)
Pages (from-to)1793-1796
Number of pages4
JournalDigestive diseases and sciences
Issue number9
StatePublished - Sep 1 2003


  • α -antitrypsin
  • Cholestasis
  • Liver diseases
  • Neonatal jaundice
  • Pediatrics

ASJC Scopus subject areas

  • Gastroenterology

Fingerprint Dive into the research topics of 'Serum levels of α<sub>1</sub>-antitrypsin predict phenotypic expression of the α<sub>1</sub>-antitrypsin gene'. Together they form a unique fingerprint.

  • Cite this