A 72 year-old female came to your office complaining of fever, fatigue, lower abdominal pain, and decreased urine output. Her past medical history is significant for dialysis dependent end-stage renal disease for 12 years and a renal transplantation 9 months ago. Your physical examination is significant for pain on the right lower abdomen. In consultation with her nephrologist, you ordered some laboratory studies and a renal transplant biopsy. As you await the test results, she reports she is concerned about transplant rejection. Regarding transplant rejection, which of the following is a correct statement?
