17. Transplantation Immunology

Question 1

What are the patient’s cells incubated with in the microcytotoxicity test? How are positive cells detected?

Answer 1

1. Wells in plate contain antibodies to individaul HLA antigens.
2. If typing for HLA-A,-B, -C = add mononuclear cells
   If typing for HLA-DR = add purified B cells
3. then add reagent complement and viability stain.

Positive cells will have lysed and taken up the dye so they will appear colored.

Question 2

What serologic test is performed to prevent hyperacute rejection? What is incubated in this test?

Answer 2

Cross-match test

1. serum from recipient and peripheral blood mononuclear cells from donor with complement are incubated in microtiter plates.
2. Then viability stain is added before reading results.

Question 3

The cell proliferation that occurs in the mixed lymphocyte culture is in response to which HLA antigen(s)?

Answer 3

Recipient lymphocytes proliferate in response to HLA-D Ags on potential donor lymphocytes if they are different HLA-D Ags than the recipients

Question 4

Why are anti-proliferative agents like azathioprine used in immunosuppression for transplant patients?

Answer 4

• block DNA synthesis and therefore, lymphocyte proliferation

Question 5

How do corticosteroids like prednisone suppress the immune response?

Answer 5

• block cytokine production by T cells and macrophages

- anti-inflammatory effects