Paediatrics: Alpha1-antitrypsin deficiency

2021-03-04 12:00 AM

Alpha1-antitrypsin is a serum protease inhibitor responsible for controlling inflammatory cascades.

Alpha1-antitrypsin deficiency

Alpha1-antitrypsin is a serum protease inhibitor responsible for controlling inflammatory cascades.

  • It is the commonest genetic cause of liver disease in children, with autosomal dominant inheritance. Prevalence is 1:2000 to 1:7000.
  • Genetic variants are identified by enzyme electrophoretic mobility as medium (M), slow (S), or very slow (Z). S is associated with 760% Alpha1-antitrypsin level of normal; Z 715%. The normal genotype is designated PiMM. Only PiZZ individuals are at risk of liver disease.

Presentation

  • Cholestasis in infancy may progress to liver failure.
  • Cirrhosis can occur from late childhood to adulthood. Chronic liver disease affects 25% of patients in late adulthood.
  • Pulmonary emphysema is the commonest presentation in adulthood.

Diagnosis

  • Serum A1-antitrypsin level d.
  • Phenotyping by enzyme isoelectric focusing (see Alpha1-antitrypsin deficiency).

Treatment

  • Supportive treatment of liver complications.
  • Strongly advise against smoking.
  • Liver transplant for end-stage liver failure.