Association between Urinary Zinc and Neopterin Excretion: A Manifestation of the Acute Phase Response in the Kidney?

Summary An elevation in urinary neopterin excretion is established to be a sensitive index of immune system activation in various disorders. In many of these conditions, a simultaneous increase in urine zinc output is observed, but this phenomenon remains largely unexplained. In previous studies in patients with different diseases, a significant correlation between urine zinc and neopterin was demonstrated. This suggests that the immune system may be involved in inducing an augmentation in urine zinc loss. As both zinc and neopterin are now known to influence oxidative processes, and lipid peroxidation has been demonstrated 10 play an important role in renal pathology, a protective role of the increase in urine zinc and neopterin, which might represent a manifestation of the acute phase reaction in the kidney, is discussed.

Serum and urine zinc response in head-injured patients

✓ A prospective longitudinal evaluation of serum zinc concentrations was performed in 26 head-trauma patients, and 24-hour urine zinc excretion was determined in 15 of these subjects. Patients had markedly depressed admission serum zinc concentrations (mean ± standard error of the mean: 40.2 ± 3.2 µg/dl; normal values: 70 to 120 µg/dl), which gradually increased during the 16-day study period. All subjects demonstrated increased urinary zinc losses throughout the study period. Urinary zinc excretion was greater in patients with more severe head injuries. Indeed, patients with more severe head trauma had mean peak urinary zinc losses of greater than 7000 µg/day (normal less than 500 (µg/day). The implications of this altered zinc metabolism for protein metabolism, wound healing, and immune function, and the specific role of zinc in brain function and recovery from injury are discussed.