Isolated neutropenia caused by copper deficiency due to jejunal feeding and excessive zinc intake: A case report

BACKGROUND: Percutaneous endoscopic gastrostomy with jejunal extension (PEG-J) is often used to treat patients with neurological impairment and difficulty in swallowing. However, these patients often develop copper deficiency. This report describes a case of isolated neutropenia, which is a rare manifestation of copper deficiency. CASE SUMMARY: Our patient was a 19-year-old boy with neurological impairment and gastroesophageal reflux. He received PEG-J feeding, including an enteral supplement containing copper and zinc. However, as his serum zinc level was low (53 μg/dL) at the age of 19 years and 2 mo, we changed to a zinc-rich supplement containing 22 mg/d of zinc and 1.0 mg/d of copper. The supplement comprised a mixture of isocal 1.0 junior (5 packs/d), Tezon [2 packs (250 mL)/d], and cocoa powder. Seven months later, he had neutropenia (606/mm(3)) with a serum copper level of 16 μg/dL. There were no other manifestations of copper deficiency, including anemia. Copper deficiency and neutropenia both improved following the administration of cocoa powder and Tezon. CONCLUSION: In patients receiving long-term PEG-J feeds, white blood cell counts, hemoglobin, and serum levels of copper and zinc should be regularly monitored.