The host response to urinary tract infection

This article concerns the molecular mechanisms of host response activation and the defense effector functions that maintain tissue integrity. Experimental models show that specific toll receptor dependant response pathways determine the severity of acute urinary tract infection, and that the inactivation of the corresponding host response genes may result in asymptomatic bacteriuria. Also shown is that the quality of the innate host defense determines the severity of acute pyelonephritis and the progression to chronic disease, because IL-8 receptor mutations disrupt neutrophil function and trafficking, and cause the entire syndrome of acute pyelonephritis and renal scarring. Finally, it is demonstrated that patients prone to urinary tract infection carry distinct mutations in the innate host response genes. The implications for diagnosis and therapy are discussed.