Alpha-1-antitrypsin deficiency

What is alpha-1-antitrypsin deficiency (A1AT)?

A1AT is a protein made by the liver that normally circulates in the blood. It protects the organs against the aggression of enzymes that are released by certain cells during inflammation (an infection, for example).

In this disease, A1AT remains in the liver and does not provide any protection. Enzymes are no longer neutralized and attack mainly the lungs by gradually destroying them.
This leads to emphysema (presence of air bubbles in lung tissue).

How is it transmitted?

A1AT deficiency is a genetic disease. It is due to a gene mutation that controls the production of A1AT.
It is transmitted in an autosomal recessive manner, i.e. the gene responsible for the disease is recessive.
In order for the disease to manifest itself, a child must have inherited two defective (recessive) genes, one from each parent.
If the parents are not sick, they are considered to be “carriers” of this recessive gene.

What are the symptoms?

In the lungs, they often appear in adulthood and are aggravated by tobacco: shortness of breath, coughing, wheezing while breathing and pulmonary infections.
In the liver, an A1AT deficiency causes inflammation (hepatitis), which can lead to cirrhosis. Sometimes jaundice can occur at birth or later.
Symptoms can vary. Some patients remain asymptomatic.

How is it diagnosed?

In general, a simple blood test is enough to diagnose this disease by measuring the amount of A1AT in the blood.
Other tests can be done to more accurately describe the type of deficiency and to evaluate the condition of the liver: an ultrasound scan of the abdomen, other blood tests and a liver biopsy.

What are the treatments?

To treat pulmonary symptoms occurring in adulthood, bronchodilators and corticosteroids are used.
It is strongly recommended that the child is never exposed to smoke.
It is also recommended that the patient is vaccinated against bacteria and viruses that can damage the lungs and liver (influenza, pneumococcus, hepatitis A and B).
In very severe forms of A1AT deficiency, we may resort to a liver or lung transplantation.