The importance of urinary tract infection for the development of renal insufficiency.

Course and severity of urinary tract infections are determined by the efficacy of the host's defensive mechanisms on the one hand, and by the pathogenicity and virulence of the infective microorganisms on the other Uropathogenic microorganisms can develop a number of specific properties (0- and K-antigens, adhesins, hemolysins, serum resistance mechanisms, aerobactins etc.) enabling them to colonize the urogenital tract and to overcome the epithelial boundary layer of the urinary tract and the kidneys. infection develops as a result of colonization, adhesion, internalization, and invasion. Due to an activation of the complement cascade, the release of cytokines, growth factors, and adhesion molecules as well as of the recruitment of granulocytes, macrophages, and lymphocyte subpopulations, immunoregulatory processes may be initiated. Predisposing factors for the manifestation of an infection are deformities, and obstructions of the urinary tract (insufficiency of the urethral valve, disturbed micturition, strictures, compressions, reflux, Formation of urinary calculi), impairment of local defence mechanisms due to metabolic disorders (diabetes mellitus, hyperuricemia, nephrocalcinosis), or humoral and/or cellular immunodeficiency (disturbed local antibody production, sIgA deficiency), immunosuppressive therapeutic procedures, and existing disturbances of renal function. In general, urinary tract infections do wt necessarily result in renal insufficiency. But, In case of preexisting damage of the renal parenchyma, an infection may dramatically influence the course of the disease and the progress of renal insufficiency.