iatroX Rounds #38
The clues
- 1
A 42-year-old male smoker presents with a six-month history of worsening shortness of breath on exertion and a chronic cough.
- 2
He notes that his exercise tolerance has declined much faster than his peers who also smoke, and he has no history of childhood asthma or atopy.
- 3
His father died in his late 40s from an unspecified chronic lung condition despite having never smoked.
- 4
On examination, he has a hyperexpanded chest with reduced breath sounds; he also has mild jaundice with a bilirubin of 38 µmol/L and spider naevi on his chest.
- 5
Chest X-ray shows hyperinflated lung fields with significant flattening of the diaphragms, with the lucency and bullous changes most prominent at the lung bases.
- 6
Liver histology reveals characteristic PAS-positive, diastase-resistant globules within the hepatocytes, and genetic analysis confirms a homozygous PiZZ genotype.
Alpha-1 antitrypsin deficiency is an autosomal codominant genetic disorder where the lack of a specific protease inhibitor leads to uninhibited neutrophil elastase activity. This results in tissue destruction, typically manifesting as early-onset panacinar emphysema and chronic liver disease, including cirrhosis and hepatocellular carcinoma.
- Early-onset emphysema, often occurring in the fourth or fifth decade, especially in smokers
- Panacinar emphysema that characteristically affects the lung bases rather than the apices
- Associated liver involvement ranging from neonatal cholestasis to adult-onset cirrhosis
- Low serum levels of the protein and presence of the PiZZ genotype
more Respiratory rounds
for education and entertainment. not medical advice.