Examination of the molecular diversity of alpha(1) antitrypsin in urine: Deficit of an alpha(1) globulin fraction on cellulose acetate membrane electrophoresis.

摘要

In the clinical field of nephrology, a noninvasive approach employing the analysis of electrophoretic patterns in urinary protein has been established. In this study a total of 52 urine samples with IgA nephropathy (IgAN), anti-neutrophil cytoplasmic antigen-associated crescentic glomerulonephritis (GN), and other types of GN were analyzed. Patients with high alpha(1) globulin (alpha(1)G) fractions, which contained alpha(1)AT in cellulose acetate membrane electrophoresis (CAE), tended to have alpha(1) antitrypsin (alpha(1)AT) of normal molecular weight (57 kDa and 49 kDa), while patients with a deficit alpha(1)G fraction tended to have alpha(1)AT of low molecular weight (<49 kDa) (P<0.01). The alpha(1)G fraction was significantly higher in patients with IgAN, and there were significantly more patients with normal molecular weight alpha(1)AT compared to patients with other diseases (P<0.01). The isoelectric point of alpha(1)AT with lower-weight molecules was more on the alkali side compared to higher-weight molecules in two-dimensional electrophoresis. Detecting changes in alpha(1)G fractions in CAE may support the differential diagnosis of IgAN from other types of GN. J. Clin. Lab. Anal. 19:16-21, 2005. (c) 2005 Wiley-Liss, Inc.