eign protein so the person doesn’t reject the transplanted organ. Some of these
drugs include azathioprine (Imuran), cyclosporine (Sandimmune), muromonab-
DC3 (Orthoclone OKT3), mycophenolate mofetil (Cell Cept), and tacrolimus
(FK506 Prograf).
Some of the side effects of these drugs include nausea and vomiting and an
increased risk of tumor growth. Significant leukopenia and thrombocytopenia
may occur. These drugs are expensive and must be continued for the life of
the patient.
Summary
The immune system provides a natural defense against pathogens and against
abnormal cells that might lead to cancer. This system differentiates between self-
cells and non-self cells by protein on the surface of the cell. Abnormal self-cells
are considered non-self cells. Microorganisms are antigens and considered non-
self cells and cause the immune system to generate antibodies that neutralize and
destroy the antigen.
There are three processes to produce immunity: inflammation,antibody-
mediated immunity (humoral immunity), and cell-mediated immunity (CMI).
Human immunodeficiency (HIV) is a retrovirus that destroys the immune sys-
tem. When the retrovirus becomes active, the patient exhibits acquired immun-
odeficiency syndrome (AIDS).
Highly Active Antiretroviral Therapy (HAART) is the use of antiretroviral
medications designed to slow or inhibit reverse transcriptase and protease
enzymes which replicate HIV. The patient must adhere to HAART therapy or the
virus becomes resistant and the antiretroviral agents lose their therapeutic effect.
There are four classes of medication approved by the FDA for treatment of HIV:
NNRTI, NRTI, PI, and Fusion Inhibitors.
A vaccine contains a small amount of a pathogen that is enough to stimu-
late the production of antibodies, but not sufficient for the patient to acquire
the disease. Once antibodies for a specific pathogen are generated, the immune
system can quickly regenerate the antibodies when the pathogen invades the
body again.
In the next chapter we look at medications that are used to treat gastrointesti-
nal and digestive diseases.
CHAPTER 17 Immunologic Agents^325