0515 - Immunosuppresion by Medication

Question 1

What are the various strategies of immunosuppression?

Answer 1

Elimination of lymphocytes

Inhibition of lymphocyte proliferation

Inhibition of lymphocyte activation

Modulation of lymphocyte function

Blockade of effector responses.

But any component of the immune system could be targeted.

Question 2

How can you achieve elimination of lymphocytes? What are the problems with this?

Answer 2

Can occur via total lymphoid irradiation, thoracic duct drainage, cytotoxic therapy, or targeted sera or monoclonal antibodies.

Problems - not all lymphocytes are equally susceptible, considerable side-effects.

Question 3

How do glucocorticoids have anti-inflammatory activity?

Answer 3

Binds to glucocorticoid receptor protein, and moves into the nucleus, where it binds to DNA (glucocorticoid response element) with a broad anti-inflammatory action.

Genomic effects - disrupt T-cell activation, inhibit cytokines from T-cells and macrophages, interrupt NF-KB signalling, and modulate transcription of cytokines.

Question 4

What are some major complications of immunosuppression?

Answer 4

Infection:

• T-cell deficiency (herpes, fungal - cryptococcus, pneumocystis, mycobacterial).
• B-cell deficiency (encapsulated bacteria, exotoxins)
• Neutropenia - (Gram-negative bacteria, fungaemia)

Malignancy:

•Non-Hodgkin’s Lymphoma, skin, viral infection, reduced immune surveillance, and activity of immunosuppressing drugs.