Human alpha 1-microglobulin and its relationship to renal function.
To evaluate the clinical usefulness in terms of estimation for glomerular filtration rate (GFR), we determined the levels of alpha 1-microglobulin (alpha 1m) in the serum and urine of patients with various renal diseases and compared with those of beta 2-microglobulin (beta 2m) and creatinine. Serum and urinary alpha 1m levels were measured by using single-radial immunodiffusion method. 24-hour creatinine clearance (Ccr) was used as a indicator of GFR. There was a significant positive correlation between serum alpha 1m and creatinine levels (r = 0.75, p less than 0.001). Serum alpha 1m, beta 2m and creatinine inversely correlated and logarithmically correlated to Ccr as shown in the following equations: log alpha 1m = 2.30 - 0.42 X log Ccr (r = -0.74); log beta 2m = 2.06 - 0.91 X log Ccr (r = -0.92); log creatinine = 1.57 - 0.78 X log Ccr (r = -0.94). Both correlation coefficient and regression coefficient for alpha 1m were rather poor compared to those for beta 2m and creatinine. However, alpha 1m levels started to increase over normal range when Ccr fell below 80 liters/day, while beta 2m and creatinine remained within normal ranges. The daily urinary excretion of alpha 1m was increased in the patients whose Ccr was within normal limits compared to that of healthy control subjects (15.2 +/- 3.2 mg/day, n = 19, vs. 5.7 +/- 0.7, n = 7, p less than 0.001). Fractional clearance of alpha 1m increased proportionally to the decrease of Ccr. These data suggest that combined measurements of alpha 1m in the serum and urine seem to be useful to estimate GFR, especially to detect the mild reduction of CFR.
Kusano
E
E
Suzuki
M
M
Asano
Y
Y
Itoh
Y
Y
Takagi
K
K
Kawai
T
T
D000293:Adolescent; D000328:Adult; D000368:Aged; D000510:Alpha-Globulins / Q000378:metabolism* / Q000652:urine; D003404:Creatinine / Q000097:blood / Q000652:urine; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D001613:beta 2-Microglobulin / Q000378:metabolism / Q000652:urine
D000510:Alpha-Globulins; C016001:alpha-1-microglobulin; D001613:beta 2-Microglobulin; D003404:Creatinine