Reversed-phase high-performance liquid chromatography for analysis of urinary proteins: diagnostic significance of alpha 1-acid glycoprotein.

In order to analyze urinary proteins from patients with various renal diseases, a reversed-phase high-performance liquid chromatography with IPG PACK ODS column packed with polyporous glass was employed. The peak areas of alpha 1-acid glycoprotein (alpha 1-AGP), beta 2-microglobulin (beta 2-MG) and albumin were measured by a chromato-integrator. The alpha 1-AGP/albumin ratio was regarded as the marker of glomerular damage, while the beta 2-MG/albumin ratio indicated tubular dysfunction. As a result, the alpha 1-AGP/albumin ratio in the urine from patients with either various glomerulonephritis (GN) or idiopathic nephrotic syndrome was significantly higher than that from either patients with postural proteinuria or healthy children. However, the beta 2-MG/albumin ratio in the urine from patients with GN was the same level as controls. The beta 2-MG/albumin ratio was elevated only in urine from patients with tubular dysfunctions. These data suggest that the urinary alpha 1-AGP/albumin ratio could be a beneficial indicator in locating patients with GN from among children with asymptomatic proteinuria.