[Alpha 1-protease inhibitor deficiency. Diagnosis, follow-up and therapy options]

Indications for active case searches and intravenous alpha-1 antitrypsin treatment for patients with alpha-1 antitrypsin deficiency chronic pulmonary obstructive disease: an update

The effect of hereditary alpha-1 antitrypsin (AAT) deficiency can manifest clinically in the form of chronic obstructive pulmonary disease (COPD). AAT deficiency (AATD) is defined as a serum concentration lower than 35% of the expected mean value or 50 mg/dl (determined by nephelometry). It is associated in over 95% of cases with Pi*ZZ genotypes, and much less frequently with other genotypes resulting from combinations of Z, S, rare and null alleles. A systematic qualitative review was made of 107 articles, focusing mainly on an active search for AATD in COPD patients and intravenous (iv) treatment with AAT. On the basis of this review, the consultant committee of the Spanish Registry of Patients with AATD recommends that all COPD patients be screened for AATD with the determination of AAT serum concentrations, and when these are low, the evaluation must be completed with phenotyping and, on occasions, genotyping. Patients with severe AATD COPD should receive the pharmacological and non-pharmacological treatment recommended in the COPD guidelines. There is enough evidence from large observational studies and randomized placebo-controlled clinical trials to show that the administration of iv AAT reduces mortality and slows the progression of emphysema, hence its indication in selected cases that meet the inclusion criteria stipulated in international guidelines. The administration of periodic infusions of AAT is the only specific treatment for delaying the progression of emphysema associated with AATD.

Alpha-1 antitrypsin deficiency: pathogenesis, clinical presentation, diagnosis, and treatment

Alpha-1 antitrypsin deficiency is an inherited disease affecting the lung and liver. The typical pulmonary manifestation is chronic obstructive pulmonary disease and emphysema. Severe chronic obstructive pulmonary disease may occur in young adulthood, and terminal respiratory insufficiency causes premature death in many patients. In the liver, alpha-1 antitrypsin deficiency may manifest as benign neonatal hepatitis syndrome; a small percentage of adults develop liver fibrosis, with progression to cirrhosis and hepatocellular carcinoma. The alpha-1 antitrypsin molecule is a serine protease inhibitor that is predominantly produced in the liver. Its most important physiologic functions are the protection of pulmonary tissue from aggressive proteolytic enzymes and regulation of pulmonary immune processes. Diagnosis of alpha-1 antitrypsin deficiency can be established by measurement of the serum alpha-1 antitrypsin concentration or by genetic analysis. Treatment is similar to the usual treatment for patients with chronic obstructive pulmonary disease. A further option is substitution therapy with human alpha-1 antitrypsin. The targets of treatment are the prevention of the accelerated decline of pulmonary function, reduction of lung infections, and improvements in exercise capacity.