Mucoproteina versus alfa-1-glicoproteína ácida: O que quantificar?

Abstract

The alpha-1 -acid glycoprotein (AGP, orosomucoid) serum measurement is useful in the diagnosis and management of acute processes of multiple causes. This protein can also be estimated by measuring the mucoprotein (Muco) that reflects the serum glycoproteins with high levels of sugars, in which than AGP is the principal component. The analytical performance between Muco and AGP was analyzed and a linear regression equation was proposed in this study. Samples from 540 patients between the ages of 10 and 79 years, averaged 34.6, being most of then women (71.3%), were analyzed simultaneously for Muco (Winzler manual procedure with in house reagents) and AGP (immunoturbidimetry Roche, automated in Gobas mira). The regression equation considering Muco as a dependent variable showed: Muco (mg/dL Tyrosine) = 0.031 × GPA (mg/dL) + 0.8 (r = 0.91), and fixing the intercept to zero showed Muco = 0.039 × GPA (r = 0.98). In the imprecision studies (inter-run, coefficient of variation) 23.4% and 5.2% were found for Muco and AGP, respectively. Conclusion: the determination of serum mucoprotein is a highly imprecise assay that must be substituted by alpha-1-acid glycoprotein measurement. When necessary, we recommend the estimate of mucoprotein values, measuring AGP, with assays with same performances as we did in this paper, and using the regression equation AGP (mg/dL) × 0.039 = Muco (mg/dL in Tyrosine).