[Relevance of urinary enzyme determination for the diagnosis and follow-up of kidney injuries and secondary kidney damage--results of a prospective study].

In a prospective study we examined and confirmed the suitability of urinary enzyme determinations for the diagnosis and control of kidney injuries. Overall, 186 patients were included in the study. 68 patients had blunt lumbar, thoracic and abdominal traumata. Renal operations (n = 14), in particular nephropexy, served as clinical model. Moreover, analyses were performed in 15 polytraumatized patients, 20 patients with fractures of the extremities, 10 patients with thermic injuries, 10 operations on the intervertebral disks, 35 abdominal operations, 1 extirpation of brain tumour, 2 meniscectomies and 11 patients with renal diseases without surgical intervention. We determined the catalytic activities of alanine aminopeptidase (AAP), gamma glutamyltransferase (GGT) and alkaline phosphatase (AP) in the gel-filtered spontaneous urine. The urinary enzyme activities were related to the symptoms, laboratory findings and other parameters. With high sensitivity and without depending on the occurrence and duration of a haematuria the urine enzymes reacted to a traumatic damage to the renal parenchyma by an increased efflux of enzymes. The amount of information from intravenous urography was small. However, there was considerable agreement between nuclear medical findings (isotope nephrography and renal sequence scintigraphy) and enzymuria registered. The methods of investigation complement each other and should be employed in combination. A wide use of urinary enzyme diagnosis to identify mild and moderate renal injuries can be recommended.