HY USMLE Q #1103 – Biochem / Immuno

A 21-year-old man comes to the physician for a health maintenance examination. Hemoglobin is 11 g/dL. MCV is 112 fL. He eats a diverse diet including meat, fish, dairy, fruit, and vegetables. Which of the following is most likely to be seen in this patient?

  Type II hypersensitivity; ↓ Jejunal absorption; ↑ Homocysteine; ↑ Methylmalonic acid
  Type II hypersensitivity; ↓ Jejunal absorption; ↑ Homocysteine; ↔ Methylmalonic acid
  Type II hypersensitivity; ↓ Jejunal absorption; ↔ Homocysteine; ↑ Methylmalonic acid
  Type II hypersensitivity; ↓ ileal absorption; ↑ Homocysteine; ↑ Methylmalonic acid
  Type II hypersensitivity; ↓ ileal absorption; ↑ Homocysteine; ↔ Methylmalonic acid
  Type II hypersensitivity; ↓ ileal absorption; ↔ Homocysteine; ↑ Methylmalonic acid
  Type III hypersensitivity; ↓ Jejunal absorption; ↑ Homocysteine; ↑ Methylmalonic acid
  Type III hypersensitivity; ↓ Jejunal absorption; ↑ Homocysteine; ↔ Methylmalonic acid
  Type III hypersensitivity; ↓ Jejunal absorption; ↔ Homocysteine; ↑ Methylmalonic acid
  Type III hypersensitivity; ↓ ileal absorption; ↑ Homocysteine; ↑ Methylmalonic acid
  Type III hypersensitivity; ↓ ileal absorption; ↑ Homocysteine; ↔ Methylmalonic acid
  Type III hypersensitivity; ↓ ileal absorption; ↔ Homocysteine; ↑ Methylmalonic acid