A 37-year-old man comes to the emergency department due to blood-tinged vomiting and abdominal discomfort. Six months ago, he lost his job as an investment banker and began drinking large amounts of whiskey on a daily basis. He has since been hospitalized several times with alcohol intoxication. His temperature is 36.7 C (98 F), blood pressure is 110/70 mm Hg, pulse is 84/min, and respirations are 18/min. Physical examination shows a firm, enlarged liver. Peripheral blood smear results show neutrophils with 6-8 nuclear lobes. Which of the following is the most likely explanation for this patient's abnormal hematologic findings?

Question

A 37-year-old man comes to the emergency department due to blood-tinged vomiting and abdominal discomfort.  Six months ago, he lost his job as an investment banker and began drinking large amounts of whiskey on a daily basis.  He has since been hospitalized several times with alcohol intoxication.  His temperature is 36.7 C (98 F), blood pressure is 110/70 mm Hg, pulse is 84/min, and respirations are 18/min.  Physical examination shows a firm, enlarged liver.  Peripheral blood smear results show neutrophils with 6-8 nuclear lobes.  Which of the following is the most likely explanation for this patient's abnormal hematologic findings?

Quizplus · Accepted Answer

Alcohol use disorder is one of the most common causes of folate deficiency anemia due to poor dietary intake and impaired folate absorption, utilization, and enterohepatic recycling. A normal individual with a folate-deficient diet can maintain normal red blood cell (RBC) production for months due to folate recycling, whereas a patient who consumes large amounts of alcohol will experience anemia within a few weeks. A reduced form of folic acid, tetrahydrofolic acid, is necessary for the synthesis of amino acids, thymidine, and purines. Impaired nucleotide synthesis leads to defective DNA production in blood cell precursors, resulting in abnormal cell division and megaloblastic hyperplasia of the bone marrow. The peripheral blood smear shows pancytopenia and hypersegmented neutrophils containing nuclei with >5 lobes. RBC abnormalities include ovalocytosis and macrocytosis, with a mean corpuscular volume (MCV) >100 µm³. (Choice A) Lipid abnormalities such as extreme hypertriglyceridemia can cause acute pancreatitis. (Choice B) Chronic blood loss causes iron deficiency anemia, which is not characterized by hypersegmented neutrophils. (Choice C) Chronic alcohol use can deplete vitamin B₁₂ levels; however, depletion would take place over a period of years, not weeks (in contrast to folate deficiency). In addition, this patient does not have any of the classic neurologic symptoms that accompany B₁₂ deficiency (eg, subacute combined degeneration). (Choice E) Elevated MCV can be present in hypothyroidism, but hypersegmented neutrophils would not be expected. (Choice F) Myelodysplasia is a premalignant condition that manifests with pancytopenia, impaired blood cell differentiation, and clonal expansion of mutated hematopoietic cells in the bone marrow. Elevated MCV can be present, but hypersegmented neutrophils are not commonly seen. Educational objective: Folic acid deficiency anemia commonly occurs in alcoholism. It is a megaloblastic anemia that can develop within weeks. Peripheral blood smear shows macrocytosis, ovalocytosis, and neutrophils with hypersegmented nuclei.

A 37-Year-Old Man Comes to the Emergency Department Due to Blood-Tinged