[New methods in the laboratory diagnosis of chronic glomerulonephritis and chronic pyelonephritis]

Two new laboratory diagnostic tests for chronic glomerulonephritis and pyelonephritis have been developed. The first one is based on electrophoretic mobility of urinary lysozyme under certain conditions, such as the use of 12% polyacrylamide gel with pH of 4.3 and acid electrode buffer with pH of 4.0. After electrophoresis was discontinued, lysozyme position was determined by lysis of Micrococcus lysodeikticus, used as test agents and added to the gel as a suspension prior to polymerization. Urinary lysozyme was found to be in the anode area of the gel in 95% of patients with chronic pyelonephritis, and in its cathode area in 92% of patients with chronic glomerulonephritis. There was no lysozyme in the urine of normal subjects. The other laboratory technique, the ethanol test, is based on comparative assessment of the degree of urinary opacification after ethanol is added in conditions of neutral reaction (following the addition of physiologic saline) and marked alkaline reaction (following the addition of sodium hydroxide solution). The ratio of optic density of the alkaline specimen to that of the neutral specimen was above 1 in patients with chronic glomerulonephritis, and below 1 in patients with chronic pyelonephritis and normal subjects. Examination of biochemical mechanisms of the proposed tests has demonstrated that the pattern of proteinuria is the most important factor affecting the results.