In a graft-versus-host disease (GVHD) scenario following allogeneic bone marrow transplantation, the primary effector mechanism of acute GVHD is mediated by:

• A Donor NK cells lysing host hematopoietic cells
• B Host B-cells producing antibodies against donor HLA
• C Complement-mediated lysis of host endothelial cells
• D Donor T-cells recognizing host MHC alloantigens ✓

Explanation

Acute GVHD results from donor T-lymphocytes recognizing host MHC alloantigens (direct allorecognition) and mounting a cytotoxic immune response against host tissues, particularly gut, liver, and skin. NK cells contribute to graft-versus-leukemia effect. Host B-cell antibodies characterize hyperacute rejection. Complement-mediated mechanisms dominate hyperacute rejection of solid organs.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.