**6. Clinically relevant immunosuppressive agents**

Immunosuppressive agents are drugs that inhibit or block the activity of the immune system to prevent the rejection of transplanted organs and tissues.

These drugs are not without side effects and risks. Because the majority of immunosuppressive agents act non-selectively, the immune system is less able to resist infections and the spread of malignant cells. There are also other side effects, which include hypertension, dyslipidemia, hyperglycemia, peptic ulcers, and liver or kidney injury. Immunosuppressive drugs also interact with other medicines, affecting their metabolism and action. Actual or suspected immunosuppressive agents can be evaluated in terms of their effects on lymphocyte subpopulations in tissues using immunohistochemistry [16, 17].

Immunosuppressive drugs can be classified into the following groups:
