These results suggest a possible alteration in the carbohydrate moiety of alpha 2-macroglobulin in cystic fibrosis, presumably due to a defective posttranslational process.
The mean alpha 2-macroglobulin concentrations were investigated and it was shown that PiMZ phenotypes had a higher concentration, 2.67 +/- 0.27 g/l (newborns) and 2.74 +/- 0.32 g/l (Down's syndrome), in comparison with PiMS, PiSS, and PiMM.
The mean alpha 2-macroglobulin concentrations were investigated and it was shown that PiMZ phenotypes had a higher concentration, 2.67 +/- 0.27 g/l (newborns) and 2.74 +/- 0.32 g/l (Down's syndrome), in comparison with PiMS, PiSS, and PiMM.
These studies demonstrated that: (a) alpha 1-antitrypsin is the major antielastase of the normal human lower respiratory tract; (b) alpha 2-macroglobulin, a large serum antielastase, and the bronchial mucous inhibitor, an antielastase of the central airways, do not contribute to the antielastase protection of the human alveolar structures; (c) individuals with PiZ alpha 1-antitrypsin deficiency have little or no alpha 1-antitrypsin in their lower respiratory tract and have no alternative antiprotease protection against neutrophil elastase; and (d) the lack of antiprotease protection of the lower respiratory tract of PiZ individuals is a chronic process, suggesting their vulnerability to neutrophil elastase is always present.
The highest alpha 2-macroglobulin concentrations were found in the PI Q0 patients (5 with emphysema, 2 with no lung disease), and these patients had almost no circulating alpha 1-antitrypsin.
Raised concentrations of serum alpha 2-macroglobulin were not due to emphysema: 86 patients with emphysema, of PI type M, and the normal control subjects had similar average concentrations of alpha 2-macroglobulin.
alpha 2-Macroglobulin (alpha 2M) is a major plasma protease inhibitor that has been studied because of its suggested role in the pathology of cystic fibrosis (CF).
CF heterozygotes shared the decrease of alpha 1-lipoprotein with the patients while exhibiting small but significant depressions of alpha 2-macroglobulin and IgG.
Fever was continuously recorded and 24 h after induction acute phase reactant (APR) response was measured as indicated by the rise of alpha-macrofetoprotein (alpha M FP, alpha 2 macroglobulin of the rat).Controls received 0.9% saline i.c.v.
A heritable elevation in alpha 2-macroglobulin (alpha 2M) was identified in a 9-year-old girl with a severe bleeding tendency and activated partial thromboplastin time (APTT) prolonged to 49.1 sec (normal 27-38) as well as recalcification time prolonged to 438 sec (less than 180).