S4119 Pancytopenia Due to Copper and Zinc Deficiency Following Roux-en-Y Gastric Bypass (RYGB): Importance of Nutritional Monitoring and Adherence to Supplementation: A Case Report

Introduction: Bariatric surgery is effective for the treatment of severe obesity. Roux-en-Y gastric bypass (RYGB) and gastric banding are the procedures with the best outcomes and highest success rates, including significant and sustained weight loss, diabetes remission, obstructive sleep apnea and cardiovascular risk reduction. However, because of malabsorption, they can lead to micronutrient deficiencies, with prevalence varying depending on the specific micronutrient involved and surgical procedure. Case Description: A 55-year-old woman with hypothyroidism and prior RYGB performed 10 years before, presented with a 2-year history of chronic diarrhea and abdominal pain. Three weeks before presentation, a 10% body weight loss and dyspnea appeared. Physical exam revealed cachexia, edema, and paresthesias. Workup showed macrocytic anemia, leukopenia, mixed liver enzymes elevation, and exocrine pancreatic insufficiency (fecal elastase: 40 µg/g). Endoscopic biopsies revealed chronic gastritis, moderate chronic ileitis, intraepithelial lymphocytosis (no atrophy or malignancy), and mild chronic colitis. Bone marrow biopsy showed mildly hypercellular marrow with dysplastic features and fibrosis. Serum copper and zinc levels confirmed severe deficiencies (copper: 23 µg/dL; ceruloplasmin: 7 mg/dL; zinc: 45 µg/dL). Treatment with intravenous cuprous histidine and zinc sulfate led to clinical and hematologic improvement. This case highlights trace element deficiencies as an underrecognized complication post-RYGB, contributing to gastrointestinal and hematologic manifestations. Discussion: Copper and zinc deficiencies are underrecognized and can mimic hematologic, gastrointestinal, and neurologic disorders. Copper is vital for iron metabolism, erythropoiesis, and neurological function; deficiency may lead to anemia, leukopenia, and neuropathy. Zinc supports porphyrin synthesis and erythropoiesis. Their combined deficiency, as seen in this patient post-RYGB, can present with pancytopenia, diarrhea, and neuropathy. RYGB alters nutrient absorption, especially in the duodenum and proximal jejunum. Despite supplementation guidelines, adherence remains low due to socioeconomic barriers and complex regimens. Standard multivitamins often lack adequate trace elements. Long-term follow-up, personalized supplementation, and monitoring of high-risk patients with gastrointestinal symptoms are essential. This case highlights the need for greater awareness of late-onset trace element deficiencies post-bariatric surgery.