血液透析患者における血中および尿中β2-microglobulin

抄録

Serum and urinary β₂-microglobulin (β₂m) were measured by radioimmunoassay in 35 hemodialyzed patients and 22 control subjects (13 chronic glomerulonephritis and 9 healthy persons). 1) There was a significant correlation between serum β₂m (Sβ₂m) and creatinine clearance (Ccr) in hemodialyzed patients (r=-0.538) and in control subjects (r=-0.754) 2) Urinary excretion of β₂m (Uβ₂m) did not correlate to Ccr in hemodialyzed patients (r=0.174) but correlated in control subjects (r=-0.533). 3) In hemodialyzed patients an increased urinary excretion of β₂m per nephron (Uβ₂m⋅V/GFR) and an increase of glomerular filtration of β₂m per nephron (Sβ₂m⋅0.9⋅GFR/GFR) were found in comparison with control subjects. There was no correlation between urinary excretion of β₂m per nephron and glomerular filtration of β₂m per nephron in hemodialyzed patients (r=0.262) but was significant correlation in control subjects (r=0.713). (V; volume of urine) 4) Tubular reabsorption rate of β₂m did not correlate to golmerular filtration of β₂m per nephron in hemodialyzed patients (r=0.083) but correlated in control subjects (r=0.632). 5) Tubular reabsorption rate of β₂m correlated to urinary excretion of β₂m per nephron in hemodialyzed patients (r=-0.807) and in control subjects (r=-0.828). These facts suggest that in hemodialyzed patients main contributing factors of an increased excre-tion of β₂m are an excess of tubular load of β₂m and a decrease of tubular reabsorption capacity of β₂m and in control subjects an increased excretion of β₂m is mainly caused by an excess of tubular load of β₂m.