What are characteristic findings of immune dysfunction
Cellular and Immunological Complexities By Jeannie Randall Essential Questions
• What are the normal functions of the immune system? • What are characteristic findings of immune dysfunction, including hypersensitivity
reactions, cancer, and AIDS? • What are supportive nursing interventions for patients suffering from immune
dysfunction? • What resources should patients be linked to as they transition to recovery?
Introduction
• The immune system is the body’s safeguard against pathogenic microorganisms. A healthy immune system allows the body to fight off invading microorganisms and prevent infection. Immune pathology occurs when the immune system stops functioning properly. Pathologies of the immune system may be caused by internal hypersensitivity reactions, microbial invasion of the immune system, or cellular mutations caused by cancerous cells. Nursing response to immune system disorders involves physical, spiritual, and psychosocial support to improve patient outcomes. This chapter will discuss normal and abnormal immune functions, nursing interventions, and patient education. Patient resources and linkage to care to promote restoration of health will also be explored.
Pathophysiology
Normal Function
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Innate defenses of the immune system may be physical barriers, such as the skin and mucus membranes. Innate chemical barriers of the immune system include lysozymes found in bodily secretions and hydrochloric acid found in the stomach. Other innate defenses are antimicrobial cells, including phagocytes, lymphocytes, and the complement complex. The complement system (see Figure 4.1) enhances the activity of antibodies and phagocytes. The complement system is comprised of small, inactive proteins that circulate in the blood. When stimulated by infection, enzymatic action cleaves these proteins, which causes a release of cytokine and starts a cascade of immunologic events. The result is the stimulation of phagocytes that engulf the invading microbes, an inflammatory response that attracts more phagocytes to the affected area, and the activation of the membrane attack complex (MAC), which ultimately kills the infected cell (Janeway, Travers, Walport, & Shlomchik, 2001). Figure 4.1
Complement Complex
Note. Adapted from Immunobiology: The Immune System in Health and Disease (5th ed.), by C. A. Janeway, Jr., P. Travers, M. Walport, & M. J. Shlomchik. New York, NY: Garland Science, 2001.
The inflammatory response is triggered upon invasion of pathogenic microorganisms. Inflammation occurs locally upon injury to tissue and includes activity of leukocytes, platelets, monocytes, basophils, and macrophages. This response is part of the immune system and may be innate or acquired. Acquired immune response involves humoral response of the B lymphocytes or cell mediated response of T lymphocytes (U.S. National Library of Medicine, 2018b) (see Figure 4.2). Figure 4.2
Cell Mediated Response
Abnormal Findings When the immune systems do not function correctly, disease ensues. Different abnormal responses include hypersensitive response of the immune system and autoimmune responses (Merck, 2018). Nurses must be prepared to manage patient care holistically in response to disease and immune dysfunction. Immune dysfunction may present as hypersensitivity, anaphylactic shock, or some cancers.
Hypersensitivity
• An exaggerated immune response that occurs on second and following exposures to an antigen is known as hypersensitivity. Hypersensitivity leads to inflammation and eradication of healthy tissue. This is also known as an allergic reaction. Allergic reactions can be immediate or delayed. Hypersensitivity reactions are the result of complex immune responses involving degranulation of mast cells, which activates the release of histamine. Most hypersensitivity reactions are mild. Mild allergic reactions may present with itching, hives, watery eyes, rash, scratchy throat, and rhinitis (U.S. National Library of Medicine, 2018a). Nurses must be aware of the signs and symptoms of anaphylactic shock, a life-threatening allergic reaction requiring immediate response. Common antigens that are associated with anaphylactic shock include certain foods, such as peanuts, tree nuts, dairy, eggs, and shellfish; environmental allergens, including mold, pollen, venom from insect stings; and certain medications. Symptoms may include flushing, nausea, vomiting, fever, rash, hives, angioedema, feelings of impending doom, bronchospasm, back pain, and circulatory collapse (U.S. National Library of Medicine, 2018a).
Nursing Considerations
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• In the clinical setting, nurses must be aware of signs, symptoms, and appropriate response should a patient exhibit anaphylactic shock. If a nurse suspects an anaphylactic reaction, immediate
steps must be taken. First, stop administration of any medications and alert the primary physician. Assess the patient’s vital signs, oximetry, and breath sounds. Prepare for emergency response, including administration of oxygen, IV fluids, and resuscitative medications: epinephrine IM or SQ, albuterol inhalant, corticosteroids, and antihistamines. It is common for facilities to have specific protocols in place with standing orders for intervention in the event of anaphylaxis. Nurses should familiarize themselves with their organization’s protocols. Patients with known allergies producing anaphylactic response are advised to carry an epi-pen. Nurses may be involved in patient education involving the use and storage of the epi-pen.
Cancer Cancer arises when an unhealthy cell that should normally die and be replaced by new, healthy cells undergoes genetic changes causing the unhealthy cell to divide and multiply. As the unhealthy cells divide and multiply, they start to form masses of tissue known as tumors. Malignant tumors can spread to other parts of the body, including the blood and lymphatic systems, causing new cancers throughout the body. Nursing support of cancer patients is multifaceted and involves medical, psychosocial, and spiritual management. Surgery is often categorical treatment for cancers that are contained within a specific body compartment. Surgery may also be performed for relief of symptoms when a tumor is causing pressure or pain (National Cancer Institute, n.d.) Surgery may be performed prophylactically for certain high-risk diseases, such as some breast cancers. Surgery may also be used to grade tumors. Tumors are graded as a 1-2-3-4, based on their rate of growth and level of abnormality. The higher the grade, the more abnormal and rapidly growing the tumor is (National Cancer Institute, 2013). A small, incisional biopsy to collect tissue for microscopic examination can yield information as to the level of aggressiveness, or grade of a tumor. An excisional biopsy may be used to remove the entire tumor if the tumor is small or discovered to be benign.
It is not possible to accurately determine whether one will develop cancer. There are certain risk factors that increase the likelihood of the development of cancer. Genetic predisposition and age are risk factors that cannot be controlled. Other risk factors include alcohol and tobacco use, sun exposure, chemical exposure to known carcinogens, infection, obesity, diet, hormone use, and immunosuppression (National Cancer Institute, 2015).
