00:00 / 00:00
Apnea of prematurity
Acute respiratory distress syndrome
Pulmonary changes at high altitude and altitude sickness
Congenital pulmonary airway malformation
Superior vena cava syndrome
Meconium aspiration syndrome
Neonatal respiratory distress syndrome
Sudden infant death syndrome
Transient tachypnea of the newborn
Alpha 1-antitrypsin deficiency
Idiopathic pulmonary fibrosis
Restrictive lung diseases
Retropharyngeal and peritonsillar abscesses
Upper respiratory tract infection
Apnea, hypoventilation and pulmonary hypertension: Pathology review
Cystic fibrosis: Pathology review
Deep vein thrombosis and pulmonary embolism: Pathology review
Lung cancer and mesothelioma: Pathology review
Obstructive lung diseases: Pathology review
Pleural effusion, pneumothorax, hemothorax and atelectasis: Pathology review
Pneumonia: Pathology review
Respiratory distress syndrome: Pathology review
Restrictive lung diseases: Pathology review
Tuberculosis: Pathology review
0 / 8 complete
0 / 4 complete
Alpha-1 Antitrypsin Deficiency - Sharing your story
Alpha-1 antitrypsin deficiency is a genetic disorder in which a protein called alpha-1 antitrypsin is defective or absent, and it causes lung and liver disease.
Trypsins are a type of protease, which is an enzyme that can break down other proteins.
So this antitrypsin protein is a protease inhibitor, and inactivates trypsins, thereby preventing protein breakdown.
The “alpha-1” is just a holdover from when the protein was discovered – a letter and number combination given before its role was known.
Now, in the lungs, if we zoom in on a tiny alveolus—where gas exchange happens—if there’s some sort of infection or other cause of inflammation, immune cells like neutrophils arrive on the scene.
Neutrophils make an enzyme called neutrophil elastase, a protease capable of breaking down elastin, which is an extracellular matrix protein that gives elasticity and strength to lung tissues.
So while these little guys can help fight off infection by breaking down proteins of the bacteria, it can also go on to break down that precious elastin.
Fortunately, the liver makes alpha-1 antitrypsin which gets released into the blood and sent to the lungs, where it inhibits neutrophil elastase just like it inhibits trypsin, inactivating it before it can break down the protein elastin.
Without alpha-1 antitrypsin, the opposite happens - neutrophil elastase goes unchecked, and it damages the walls of the alveoli, and without that elastin, the alveoli loses its elasticity and structural integrity.
Zooming out a bit and looking at the acinus, which is a bunch of alveoli, it just turns into one big cavity. This destruction and enlargement of the air spaces is called emphysema.
It turns out that emphysema can develop in a couple different ways, and alpha-1 antitrypsin deficiency causes pan-acinar emphysema, meaning the whole acinus is affected, and it also tends to affect the lungs’ lower lobes the most.
Another effect of unchecked inflammation in alpha-1 antitrypsin deficiency is chronic bronchitis, resulting from increased mucus production and narrowing of the airways.
Latest on COVID-19
Nurse Practitioner (NP)
Physician Assistant (PA)
Create custom content
Raise the Line Podcast
Copyright © 2024 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Cookies are used by this site.
Terms and Conditions
USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.