Object: Anemia and leukopenia caused by copper deficiency are well-documented consequences of long-term total parenteral nutrition. We measured the serum copper levels of bed-ridden patients receiving enteral feeding, and evaluated optical and ultrastructural features of bone marrow before and after copper supplementation.
Patients and methods: Serum samples were obtained from 15 bed-ridden elderly patients receiving tube feeding (TF) and 10 age-matched bed-ridden patients who took food orally (CO), and the copper ceruloplasmin concentration of each sample was measured. Bone marrow samples were obtained from patients who exhibited copper deficiency and leukopenia and/or anemia before and after the copper supplementation, for use in light and electron microscopic analysis.
Results: The tube-fed patients had significantly lower mean serum copper and ceruloplasmin concentrations than the control patients. Seven of the 15 tube-fed patients had reduced serum copper concentrations and leukopenia. Six of those 7 patients also had anemia. Copper sulfate was administered to those 7 patients by enteral tube; their copper concentration, anemia and leukopenia improved within 1 month after they were administered copper sulfate. In the bone marrow examination before copper supplementation, light microscopy showed cytoplasmic vacuolization in both myeloid and erythroid precursors, and electron microscopy showed electron-dense deposits in mitochondria and cytoplasm of erythroid and myeloid cells. After copper supplementation, these pathological changes disappeared.
Conclusions: Bicytopenia is likely to occur in tube-fed patients with copper deficiency. Copper deficiency appears to be associated with cytoplasmic vacuolization and electron-dense deposits in mitochondria in erythroid and myeloid cells.