A 36-year-old woman with end stage renal disease secondary to polycystic kidney disease undergoes renal transplantation. On the tenth postoperative day she complains of general malaise, appears mildly ill, and has decreased urine output. What is the most likely pathologic mechanism underlying this patient’s current illness?
Donor T-lymphocytes reacting against recipient major histocompatibility complexes (MHCs)
Immune complex deposition within renal artery walls
Immune complex deposition within renal glomerular subendothelium
Preformed anti-donor antibodies reacting against donor antigens
Recipient cytotoxic T-lymphocytes reacting against donor major histocompatibility complexes (MHCs)
Correct answer
Recipient cytotoxic T-lymphocytes reacting against donor major histocompatibility complexes (MHCs)
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correct answer: E
Given the recent renal transplant, time course, and evidence of organ failure this patient appears to be suffering from acute transplant rejection. The most likely mechanism in acute rejection involves recipient cytotoxic T-lymphocytes reacting against donor MHCs (Choice E). Immunosuppressive medications such as cyclosporine aim to attenuate these reactions.
Donor T-lymphocytes reacting against recipient major histocompatibility complexes (MHCs) (Choice A) is the mechanism underlying graft-versus-host disease (GVHD). GVHD is typically seen in recipients of bone marrow, not solid organs, due to its high load of functional donor immune cells that may perceive recipient tissues as foreign due to MHC incompatibility. Because the recipient is immunocompromised, the donor cells cannot be destroyed or inactivated.
Immune complex deposition within renal artery walls (Choice B) is the pathologic mechanism in polyarteritis nodosa. Although polyarteritis nodosa typically involves renal and visceral vessels, the process would be more chronic than seen in this situation; moreover, renal failure would be an unusual sequela. Typical signs and symptoms include fever, weight loss, malaise, abdominal pain, melena, headache, myalgia, hypertension, neurologic dysfunction, and cutaneous eruptions.
Immune complex deposition within renal glomerular subendothelium (Choice C) is the mechanism of renal failure in systemic lupus erythematosis (SLE). Though SLE may result in renal failure, the process would be more chronic than seen in this situation.
Moreover, additional stigmata of SLE would be expected, such as rash, photosensitivity, mucositis, neurologic dysfunction, pleuritis, pericarditis, hematologic dysfunction, or arthritis.
Preformed anti-donor antibodies reacting against donor antigens (Choice D) is the mechanism underlying hyperacute transplant rejection. The reaction typically occurs within minutes to hours of organ implantation. Immunosuppressive medications offer little towards reversing or attenuating these reactions.