Factors associated to hypermanganesemia in patients receiving home parenteral nutrition

BACKGROUND: Home parenteral nutrition (HPN) patients often present hypermanganesamia. AIM: To examine which factors may be associated to hypermanganesemia in HPN patients. METHODS: Plasma manganese (Mn), liver function tests, C-reactive protein concentrations, erythrocyte sedimentation rate (ESR), tumor necrosis factor-alpha (TNF- alpha), interleukin-6, soluble receptors of interleukin-2, and blood neopterin concentrations were determined in 21 HPN patients and 10 healthy controls. Brain magnetic resonance imaging (MRI) and careful neurologic clinical examination were performed in 11 patients. RESULTS: Mn concentration was higher in HPN patients than controls (1.96+/-1.1 vs 0.81+/- 0.4 microg/L;P<0.001) and positively correlated to the amount of parenteral nutrition (PN) supply, transaminases and alkaline phosphatase (r=0.53, P<0.0001) concentrations, as well as to ESR (r=0.61, P<0.0001), TNF- alpha and blood neopterin. The amount of calories provided by PN was positively correlated to inflammatory markers and liver parameters. All patients investigated by MRI showed hyperintense basal ganglia on T1-weighted images suggesting brain Mn deposition. Only one had slight clinical extrapyramidal symptoms. CONCLUSION: In HPN patients, sustained inflammation may facilitate hypermanganesemia through 1. cholestatic liver disease and thereby decreased Mn biliary excretion, 2. high nutritional requirements (responsible for increased Mn supply), and/or 3. modified Mn metabolism or body distribution. Neurologic complications appeared marginal whereas Mn brain deposition seems frequent.