A 35-year-old Caucasian male with aplastic anemia undergoes bone marrow transplantation. The donor is an HLA-matched sibling. Two weeks after the procedure, he develops a maculopapular pruritic rash that is predominantly found on his face, hands, and feet. He also complains of diarrhea. The stool is positive for occult blood. Liver function tests are abnormal. Which of the following is the most likely pathophysiologic mechanism of this patient's condition?

Question

A 35-year-old Caucasian male with aplastic anemia undergoes bone marrow transplantation.  The donor is an HLA-matched sibling.  Two weeks after the procedure, he develops a maculopapular pruritic rash that is predominantly found on his face, hands, and feet.  He also complains of diarrhea.  The stool is positive for occult blood.  Liver function tests are abnormal.  Which of the following is the most likely pathophysiologic mechanism of this patient's condition?

Quizplus · Accepted Answer

The clinical scenario described is typical for acute graft-versus-host disease (GVHD), which is common after bone marrow transplantation. Up to 50% of patients with bone marrow transplantation from matched siblings develop the disease. The target organs for GVHD are the skin (maculopapular rash involving palms, soles, and face that may generalize is typical), intestine (blood-positive diarrhea), and liver (abnormal liver function tests and jaundice). The basic pathophysiologic mechanism involved is recognition of host major and minor HLA-antigens by donor T-cells and consequent cell-mediated immune response. (Choice B) The donor B-lymphocytes have less importance in the development of GVHD. (Choices C and E) Activation of the host T lymphocytes mediates the rejection of the graft, thereby resulting in the depression of myelopoiesis. Failure to generate blood cells manifests as severe neutropenia for several consecutive days and increased risk of infection. Graft rejection may occur in up to 20% of high-risk patients. (Choice D) Virus-induced lymphocyte proliferation due to Epstein-Barr virus is the mechanism responsible for the development of immunoblastic lymphoma in patients who underwent bone marrow transplantation. Educational Objective: GVHD is caused by recognition of host major and minor HLA-antigens by donor T-cells and consequent cell-mediated immune response. The organs that are typically affected include the skin, intestine, and liver.

A 35-Year-Old Caucasian Male with Aplastic Anemia Undergoes Bone Marrow