A 29-year-old woman with a 4-year history of Crohn disease presents to clinic for follow-up evaluation. She reports persistent loose stools (4-5 per day) and intermittent crampy abdominal pain despite adherence to mesalamine. Vital signs are stable. Laboratory findings: hemoglobin 8.2 g/dL, hematocrit 26%, MCV 68 fL, ferritin 8 ng/mL, serum iron 35 μg/dL (normal 60-170), TIBC 520 μg/dL (normal 250-425). Reticulocyte count is 1.8% (normal 0.5-2.5%). Fecal calprotectin is elevated at 850 μg/g. Recent colonoscopy showed patchy inflammation with skip lesions and shallow ulcerations but no active gross bleeding. She denies hematochezia. Which of the following best explains her anemia?
- A)Vitamin B12 deficiency from impaired terminal ileal absorption
- B)Iron deficiency from chronic occult blood loss and mucosal diseaseGABARITO
- C)Folate deficiency from sulfasalazine-induced malabsorption
- D)Anemia of chronic inflammation without significant iron depletion
- E)Hemolytic anemia secondary to autoimmune phenomenon associated with IBD
Explicação
The lab pattern of microcytic anemia (MCV 68), low ferritin, low serum iron, and elevated TIBC indicates iron deficiency. Although the patient denies gross hematochezia and fecal occult blood testing was negative, chronic Crohn disease causes anemia primarily ... Ver explicação completa e trilha adaptativa →