Simple cost effective allele identification within your laboratory
Alpha-1 Antitrypsin (A1AT) is a 52 kDa single chain glycoprotein with a normal concentration of 150-350mg/dL in human serum. This rises during immune response and inflammation, as A1AT is an acute phase protein. A1AT is part of the serpin protein superfamily, and is able to inhibit a wide range of proteases. It is secreted by hepatocytes and circulates in the blood, mainly as a protective inhibitor against proteases released by granulytic white blood cells in immune response. Specifically, it acts against neutrophilic elastase, which is produced by neutrophils and if not inhibited will break down connective elastin wherever it is found.
In an individual with a deficiency in this there is not enough A1AT circulating in the blood protecting the body’s organs from this neutrophilic elastase, and in particular in the lungs which leaves the lungs vulnerable to be attacked by the proteases and the lung tissue damaged. The damaged lung tissue can then lead onto lung disease which can be precipitated by environmental factors.
Helena Biosciences has a highly sensitive and accurate IEF kit used to diagnose any A1AT deficiency by recognizing and separating the main genetic variants involved in any deficiency.
A number of disease states are associated with a lack of A1AT, including lung disease, liver disease and more rarely, skin disease. If A1AT is deficient in the blood or rendered inefficient by mutation then the neutrophil elastase present in the blood is left relatively unregulated. This is then able to break down elastin in the connective tissue, most importantly in the lungs. This can lead to chronic obstructive pulmonary disease (COPD), which encompasses emphysema and bronchitis. Smoking can also cause this by oxidising methionine 358 on A1AT, which alters the reactive centre of the protein making it unable to bind elastase.
A1AT deficiency is a genetic disorder. There are several forms and degrees of deficiency; the form and degree depend on whether the sufferer has one or two copies of the defective allele.
The major variants of A1AT are M (normal) or PiMM (where Pi stands for Protease Inhibitor, and MM is the banding pattern of the patient), F, S and Z, all of which focus between pH 4.5 and 4.7. The Z allele is the main clinically significant variant, and causes the largest reduction in levels of A1AT, with ZZ and ZS phenotypes being strongly associated with liver and lung disease.
Detection of A1AT variants outside of the ‘normal’ M alleles within the human body is not necessarily indicative of possible health concerns or significant alterations in the normal physiological levels of A1AT.
Helena Biosciences offers an A1AT kit that provides separation of genetic variants of A1AT on the basis of isoelectric focusing (IEF) on agarose gel. IEF utilises isoelectric points or pI as the basis for separation of A1AT variants. Alterations to amino acid sequences give each A1AT variant a different pI, the pH in which their net charge is zero. A1AT IEF gels have a pH gradient 4.2-4.9.
When serum samples are applied to the agarose gel under an electrical field they migrate to their isoelectric point, allowing separation of common variants. The 4 clinically significant variants, (M, F, S, Z) are identified on the Helena Biosciences gel kit.