Immunosuppressants

Question 1

Cyclosporin

Answer 1

CNI
Inhibits IL-2 generation thereby decreases clonal proliferation of T cells

Binds: Cyclophilin
Target: Calcineurin

Safe in pregnancy

Question 2

Tacrolimus

Answer 2

CNI
Tsacrolimus forms complexes with cytoplasmic immunophilin FKBP‑12, which blocks the action of calcineurin in activated T cells.

This prevents production of interleukin‑2 and other cytokines, which normally stimulate T cell proliferation and differentiation.

Binds: FKBP-12
Target: Calcineurin

Question 3

Calcineurin inhibitors

Answer 3

Cyclosporin

Tacrolimus

Question 4

Mycophenolate

Answer 4

Prodrug for mycophenolic acid

Reversible inhibitor of inositol monophosphate dehydrogenase (IMPDH) in purine biosynthesis

G1 arrest

Selective for the de novo pathway
Critical to lymphocyte proliferation and activation

Use in CsA Toxicity

Target: IMPDH

Teratogenic

Question 5

Azathioprine

Answer 5

Metabolised into the active compound mercaptopurine, a purine analogue that inhibits DNA synthesis

Safe in pregnancy

Question 6

Prednisolone

Answer 6

Suppresses cell-mediated immunity

Inhibits genes that code for cytokines: IL1-2-3-4-5-6-8, TNF-gamma

IL2 is the most important of these –> reduces T cell proliferation

Question 7

Basiliximab

Answer 7

Anti-IL2 (CD25)
Binds and blocks IL-2 receptor alpha chain on activated T cells -> depletes them -> inhibits IL-2 induced T cell activation

Lower rates of rejection in quadruple therapy

Question 8

ATG

Answer 8

Polyclonal anti-lymphocyte globulin

Blocks T cell membrane proteins (CD2, CD3, CD45)