Emphysema due to<unk>  Computed tomography of the lung showing emphysema and bullae in the lower lobes of a subject with type ZZ<unk> . There is also increased lung density in areas with compression of lung tissue by the bullae. The gold standard of diagnosis for<unk>  consists of blood tests to determine the phenotype of the AAT protein or genotype analysis of DNA. Liver biopsy is the gold standard for determining the extent of hepatic fibrosis and assessing for the presence of cirrhosis.<unk><unk>  remains undiagnosed in many patients. Patients are usually labeled as having COPD without an underlying cause. It is estimated that about<unk> % of all COPD patients actually have an<unk><unk> . Testing is recommended in those with COPD, unexplained liver disease, unexplained bronchiectasis, granulomatosis with polyangiitis or necrotizing panniculitis. American guidelines recommend that all people with COPD are tested, whereas British guidelines recommend this only in people who develop COPD at a young age with a limited smoking history or with a family history. The initial test performed is serum<unk> level. A low level of<unk> confirms the diagnosis and further assessment with<unk> protein phenotyping and<unk> genotyping should be carried out subsequently. As protein electrophoresis does not completely distinguish between<unk> and other minor proteins at the<unk> -1 position (agarose gel),<unk>  can be more directly and specifically measured using a nephelometric or immunoturbidimetric method. Thus, protein electrophoresis is useful for screening and identifying individuals likely to have a<unk> .<unk> is further analyzed by isoelectric focusing (IEF) in the pH range 4.5-5.5, where the protein migrates in a gel according to its isoelectric point or charge in a pH gradient. Normal<unk> is termed M, as it migrates toward the center of such an IEF gel. Other variants are less functional and are termed A-L and N-Z, dependent on whether they run proximal or distal to the M band. The presence of deviant bands on IEF can signify the presence of<unk> . Since the number of identified mutations has exceeded the number of letters in the<unk> bet, subscripts have been added to most recent discoveries in this area, as in the Pittsburgh mutation described above. As every person has two copies of the<unk> gene, a heterozygote with two different copies of the gene may have two different bands showing on electrofocusing, although a heterozygote with one null mutant that abolishes expression of the gene will only show one band. In blood test results, the IEF results are notated as, e.g., PiMM, where Pi stands for protease inhibitor and "MM" is the banding pattern of that person. Other detection methods include use of enzyme-linked-immuno-sorbent-assays in vitro and radial immunodiffusion.<unk> -1<unk>  levels in the blood depend on the genotype. Some mutant forms fail to fold properly and are, thus, targeted for destruction in the proteasome, whereas others have a tendency to polymerize, thereafter being retained in the endoplasmic reticulum. The serum levels of some of the common genotypes are: * PiMM:<unk> 00% (normal) * PiMS: 80% of normal serum level of<unk> * PiSS: 60% of normal serum level of<unk> * PiMZ: 60% of normal serum level of<unk> * PiSZ: 40% of normal serum level of<unk> * PiZZ:<unk> 0–15% (severe<unk>
Alpha-1 antitrypsin deficiency
Asthma
CHILD syndrome
Reactive airway disease
Mineral dust airway disease
Cystic fibrosis
Yokkaichi asthma
Upper airway resistance syndrome