Saturday, 30 October 2010

MRCP revision battle 37.5: alpha-1 antitrypsin deficiency

alpha-1 antitrypsin is a serine protease inhibitor produced in the liver.

In the lung it prevents neutrophil elastase from breaking down the alveolar wall.
It is inactivated by cigarette smoke.

Genetic varients of alpha-1 antitrypsin exist and are labelled based on their electrophoresis mobility, with M (medium), S (slow) and Z (very slow).  MM is 'normal' while 'ZZ' has the worst prognosis with panlobular emphysema.

Patients with an alpha-1 antitrypsin defiency are likely to develop COPD early (even without smoking) and liver cirrhosis is common.

Now for a very straightforward battle - cystic fibrosis