[The low molecular weight proteins ribonuclease, beta 2 microglobulin and lysozyme in the serum and urine of patients with chronic kidney diseases].

The diagnostical relevance of the low-molecular proteins ribonuclease, beta 2-microglobulin and lysozyme in serum and urine to detect a reduced glomerular filtration rate was examined in 52 patients with chronic renal diseases. The radioisotope clearance using 99mTc-DTPA was the base reference; the reference values of the low-molecular proteins were estimated in a control group. Ribonuclease was increased above the upper borderline value, if the glomerular filtration rate was lower than 1.24 ml s-1. Creatinine, beta 2-microglobulin and lysozyme remain yet in part in the normal range. The estimation of the ribonuclease in serum is suitable to detect an impaired glomerular filtration rate if the creatinine value is still not increased. Thereby, the diagnostics in renal diseases may be improved in the creatinine-blind area.