Question

Explain the primary set, secondary set and final lysis of graft rejection. Clinically, how is graft rejection prevented?

Answer 1

Sensitised T-cells, macrophages and plasma cells are involved in the primary set rejection. In the secondary set rejection, B-cells are involved. In the cell-mediated rejection, interleukins take part. The final lysis of the graft is achieved by lymphotoxins or TNF (Tumour necrosis factors) or proteolytic enzymes.

In clinical fields, graft rejection is prevented by:

1. Blood groups estimation (ABO and Rh) in the host.

2. Testing the presence of cytotoxic antibodies in the host serum.

3. Cross-matching of tissues (Host Vs graft) prior to transplantation.

4. Giving immunosuppressive drugs like cyclosporin and steroids etc to the host.

5. Total lymphoid tissue irradiation.