Proteinuria and excretion of ribonuclease in patients with chronic granulocytic leukaemia.

Elevated RNase activity which occurs in serum and urine of CGL patients parallels the urinary protein excretion. Acid RNase and alkaline RNase activities in urine of CGL patients, as well as acid and alkaline RNase clearance values correlated with the urinary protein concentration. Mean urinary protein level in CGL patients was approximately twice as high as that in controls. The molecular mass of CGL urinary proteins ranged from 12,000 to 80,000 proving the LMWP type of proteinuria. No particular protein contributed to the elevation of LMWPs in CGL urine. Among numerous protein fractions, albumin, acid alpha 1 glycoprotein, prealbumin RNase and in a few cases LZM were observed. The results of this study suggest that the increase of RNase activity in serum and urine reflects a more general phenomenon of increase in excretion of the entire set of LMWPs.