Human Health and Diseases Question 56
56. Transplantation of tissues/organs fails often due to non-acceptance by the patient’s body. Which type of immune-response is responsible for such rejections?
[2017]
(a) Cell - mediated immune response
(b) Hormonal immune response
(c) Physiological immune response
(d) Autoimmune response
Show Answer
Answer : a
Hints & Solutions
(a) Cell mediated immune response causes non-acceptance or rejection of graft or transplanted tissues/organs. Transplant rejection is caused primarily by a cell-mediated immune response to HLA antigens expressed on donor antigenpresenting cells (APCs) transferred along with the transplanted organ. Recognition of donor HLA antigens on the cells of the graft induces vigorous $T$ cell proliferation in the recipient. $B$ cells and anti-HLA antibodies have recently been shown to play an important role in both acute and chronic allograft rejection. The presence of CD20+ B cells and plasma cells infiltrating allograft has been found to correlate with irreversible acute rejection episodes.
