Urine of Patients with Acute Kidney Transplant Rejection Show High Normetanephrine and Decreased 2-Hydroxyestrogens Concentrations

BackgroundA shift from anti- to proinflammatory steroid hormones has been observed in chronic inflammation. We tested the hypothesis that this shift occurs also in kidney transplant rejection together with a rise of urinary catecholamine degradation product concentrations as a consequence of locally produced cytokines, thus further promoting rejection.MethodsWe examined 8 patients with an early rejection episode in the protocol biopsy ∼2 weeks, 9 with biopsy-proven rejection at 2–3 months, and 18 without rejection, both at 2 weeks and 3 months after transplantation. Metanephrine, normetanephrine, and 2- and 16-hydroxyestrogens concentrations were measured by EIA.ResultsThe median urinary concentrations of normetanephrine, but not metanephrine, were significantly higher in acute kidney transplant rejection in the first 2 weeks after transplantation (P < .05). During acute kidney transplant rejection at 2–3 months, but not in the first 2 weeks, after transplantation, 2-, but not 16-hydroxyestrogens, concentrations were significantly decreased (P < .05).ConclusionsWe demonstrated that the downstream product of noradrenaline conversion normetanephrine was elevated in kidney transplant rejection in the first weeks after transplantation. This change may promote rejection together with an important proinflammatory and mitogenic steroid hormone shift, which becomes increasingly relevant over time.