Alpha1-antichymotrypsin Concentrations Research Articles

Assay of complexed alpha 1-antichymotrypsin in plasma

We introduce an assay to measure complexed alpha 1-antichymotrypsin in human plasma. The assay works on the principle that the target proteinase cathepsin G has a very high affinity to the surface of microtiter plates, even if these surfaces are blocked with albumin and Tween 20. alpha 1-Antichymotrypsin, when complexed to cathepsin G, is thus immobilized and can be detected with specific antibodies. The mean (SD) concentration of alpha 1-antichymotrypsin in 50 healthy individuals was 1.73 (0.58) nmol/L. The detection limit was 0.84 nmol/L. The results of the assay are linear to at least 14 nmol/L. We propose to use this assay for diseases in which increased turnover of alpha 1-antichymotrypsin or cathepsin G can be expected to clarify further the function of this enzyme-inhibitor system.

A case of partial deficiency of alpha 1-antichymotrypsin.

A 20-year-old woman, admitted to a neurological ward with a diagnosis of benign intracranial hypertension, was found on specific protein electroimmunoassay to have a consistently decreased concentration of alpha 1-antichymotrypsin in her plasma. Serum from her father showed the same result. Further investigation of her family demonstrated that this partial deficiency was transmitted in an autosomal dominant fashion and was not associated with any obvious specific clinical abnormalities.

Serum protein fractions from children of differing nutritional status analysed by polyacrylamide gel electrophoresis and electroimmunoassay.

1. The nutritional status of children showing no clinical signs of malnutrition, from the University School of Khon Kaen, Khon Kaen province, north-east Thailand and from two villages nearby, was tested. The children were grouped according to their body-weight expressed as a percentage of expected weight-for-height (Harvard standards (Stuart & Stevenson, 1959), as given by Jelliffe (1966)). 2. The differing prealbumin concentrations indicated that nutritional status differed between the groups. 3. The urinary urea: creatinine ratio was significantly lower in the village children compared with the children from Khon Kaen, indicative of the higher dietary protein intake of the latter. 4. alpha1-Acid glycoprotein and the first 'post-albumin peak' (obtained by polyacrylamide gel electrophoresis of serum and containing mainly mainly Gc-globulin, alpha1-antichymotrypsin and alpha1-B-glycoprotein) were found to be significantly higher in the village children compared with children from Khon Kaen. 5. The three main proteins of the first 'post-albumin peak' from polyacrylamide gel electrophoresis of serum were tested separately using the electroimmunoassay method. There was no significant difference in Gc-globulin between the children from Khon Kaen and the village children. The concentration of alpha1-B-glycoprotein from those Khon Kaen children whose body-weight was more than 95% expected weight-for-height was significantly lower compared with that of village children, alpha1-Antichymotrypsin concentration was significantly higher in serum from Khon Kaen children than in serum from village children.