Survival of urinary leucocytes.

The survival of white cells under 15 mu in diameter (95% polymorphonuclear leucocytes), obtained from the urine of patients with urinary tract infections, was examined in vitro under different conditions of osmolarity, pH, and temperature of incubation. The rate at which urinary white cells disintegrate was found to be accelerated by raising the pH, decreasing the osmolarity, and by increasing the temperature at which suspensions were kept. The most rapid disappearance of white cells occurred in hypotonic alkaline suspension at 37 degrees C. There was little change in cell suspensions kept in acid (pH 3.0) or in hypertonic (1,200 mOsmoles/1.) conditions over a period of 24 hours. The findings indicate that in interpreting the significance of the number of leucocytes in urine it is necessary to take into account the condition of the urine and the time and temperature at which it has been kept before examination.