In order to assess the significance of .β
2-microglobulin (.β
2-mg) in glomerlar disease, a total of 52 measurements of para-aminohippurate and sodium thiosulfate cleance (C
PAH and C
thio) in 42 patients (22 men and 20 women) with various renal diseases was performed. At the same time, the serum levels and the urinary excretion levels of .β
2-mg were measured. The results were as follows: 1) On double-logarithmic graph, the correlation “r” between C
thio and serum β
2-mg [β
2-mg(s)] was 0.90. The regression line of log C
thio on log .β
2-mg(s) was: log C
thio=-0.85 log .β
2-mg(s)+2.09, with the standard error of estimate of 0.129. 2) The regression slope of log C
thio on log β
2-mg(s) was lower than that of log C
thio on log cr(s)[cr(s): serum creatinine] (p<0.05). The standard error of estimate of log C
thio for log β
2-mg(s) (Se=0.129) was significantly less than that of log C
thio for log cr(s) (Se=0.192)(p<0.01). When production of .β
2-mg was held constant, β
2-mg(s) was supreior to the predicted GFR for cr(s). 3) When serum β
2-mg levels were 4.1 μg/ml or less, increased β
2-mg clearance (>500 μl/min) in patients with glomerular disease was significantly related to fatty degeneration and/or atrophy of proximal tubular cells in the nephron maintaining some filtration functions (<0.01).
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