Chemotactic factors as cause of polyleukocyte urine in urinary tract infection: chemotactic activity of urinary protein fraction.

The possible cause of the excessive increase in the number of polymorphonuclear leukocytes in the urine of patients suffering from urinary tract infections was investigated in regard to the chemotactic factor(s) for the leukocyte. We separated urinary protein fractions of 2 controls and 10 patients with urinary tract infections by gel filtration on a Sephadex G-50 column, and tested chemotactic activity in vitro by using Boyden's apparatus and in vivo by injecting the protein fractions into guinea pig skins. Chemotactic activity was found in the urinary protein fractions of 6 patients. The fractions of these 6 patients showed typical infiltration of polymorphonuclear leukocytes in the local tissue of guinea pigs. A high correlation was found between the activity and the leukocyte increase, although there was no relation between the type of infecting bacteria and chemotactic activity. The data suggest that the marked increase in the number of urinary leukocytes is attributable to the chemotactic factor(s) in the urine.