Immune System Function, Assessment, and Therapeutic Measures PDF

4068_Ch18_323-338 15/11/14 1:30 PM Page 324 18 Immune System Function, Assessment, and Therapeutic Measures KEY TERMS...

4068_Ch18_323-338 15/11/14 1:30 PM Page 324 18 Immune System Function, Assessment, and Therapeutic Measures KEY TERMS SHARON M. NOWAK AND active immunity (AK-tiv im-YOO-nih-tee) JANICE L. BRADFORD anaphylactic (AN-uh-fih-LAK-tik) antibody (AN-tih-baw-dee) antigen (AN-tih-jen) LEARNING OUTCOMES autoimmune (AW-toe-ih-mewn) cell-mediated immunity (SELL mee-dee-ay-ted 1. Identify the type of immunity that is obtained with a ih-MYOO-nih-tee) vaccine. humoral immunity (HYOO-mur-uhl ih-MYOO-nih-tee) 2. Describe the two mechanisms of immunity. lymphocyte (LIM-fuh-site) neutrophil (NEW-troh-fil) 3. Discuss the function of each class of immunoglobulin and passive immunity (PASS-iv ih-MYOO-nih-tee) how each behaves in a particular immune response. white blood cells (WYTE BLUHD SELLS) 4. Describe how aging affects the immune system. 5. Explain subjective data that are collected when caring for a patient with a disorder of the immune system. 6. Explain the objective data that are collected when caring for a patient with a disorder of the immune system. 7. Describe nursing care provided for patients undergoing di- agnostic tests for the immune system. 8. Discuss common therapeutic measures used for disorders of the immune system. 324 4068_Ch18_323-338 15/11/14 1:30 PM Page 325 Chapter 18 Immune System Function, Assessment, and Therapeutic Measures 325 NORMAL IMMUNE SYSTEM ANATOMY AND PHYSIOLOGY Cervical nodes Tonsil Thymus Immunity is defined as the ability to destro y pathogens or gland other foreign material and to pre vent further cases of infec- Left Right tious disease. Immunity is typically the body’ s response to lymphatic subclavian vein foreign microorganisms such as bacteria, viruses, and fungi. duct Thoracic However, immune responses can be directed to ward other Right duct cells or substances that are identif ied by the body, correctly subclavian Axillary nodes or incorrectly, as foreign. Malignant cells are considered for- vein eign and are usually destro yed by the immune system after mutation but before they become malignant. Unfortunately, Skin- Spleen Cisterna transplanted organs are usually perceived as foreign and are associated chyli lymphoid therefore rejected. Occasionally, the immune system mistak- tissue enly reacts to self ( autoimmune disease) or to a substance Genital that should be tolerated (allergic reaction). associated The immune system consists of lymphoid organs and tis- lymphoid tissue Inguinal sues, lymphocytes and other white blood cells (WBCs), and nodes many chemicals that activate our own cells for the destruction of foreign antigens (Fig. 18.1). The lymphatic system in- cludes lymph, lymphatic vessels that help return tissue fluid to the circulatory system; lymph nodes, nodules, and the Bone marrow spleen, where macrophages phagocytize (engulf and destroy) pathogens and B and T cells carry out immune functions; and red bone marrow and the thymus (which functions primarily in childhood and atrophies with age). Lymph flows from ves- sels through lymph nodes where pathogens are percolated out and destroyed. Lymph nodes are especially concentrated in the cervical, axillary, and inguinal areas. L ymph nodules, lacking encapsulation, are found under the surface of mucous membranes (e.g., tonsils). Antigens Antigens are chemical markers that identify cells or mole- cules. Human cells ha ve their own antigens—thousands of markers that identify the cell as “self. ” These are the major histocompatibility complex antigens, also called human FIGURE 18.1 Immune system organs, lymph vessels, and major leukocyte antigens, which are genetically determined. Major lymph nodes. histocompatibility complex antigens are tolerated by the body’s immune system, whereas foreign antigens will be Both T cells and B cells arise in the red bone marrow. T cells destroyed in one of several ways. then migrate to the thymus, where the thymic hormones bring Lymphocytes about their maturation. From the thymus, T cells migrate to the There are three types of lymphocytes: natural killer (NK) cells, lymph nodes and nodules and to the spleen. B cells mature in thymus-derived lymphocytes (T cells), and bone marro w– the bone marrow and migrate directly to lymphatic tissue.When derived lymphocytes (B cells), each with different functions. activated during an immune response, T cells perform direct attack, whereas B cells dif ferentiate into plasma cells that Natural Killer Cells release antibodies for an indirect approach. NK cells are found throughout the body and are nonspecific in action, destroying a variety of foreign cells including al- Antibodies tered self-cells. After binding with an abnormal cell, NK cells Antibodies are also called immunoglobulins (Ig) or gamma glob- release either perforins or granzymes, which cause cytolysis. ulins and are glycoproteins produced by plasma cells in response Cell fragments are then phagocytized by WBCs. to foreign antigens. Antibodies do not themselves destroy foreign antigens but rather become attached to such antigens to label T Cells and B Cells The lymphocytes called T cells and B cells are in volved in WORD BUILDING specific immune responses; that is, each cell is programmed lymphocyte: lympho—lymph + kytos—cell to respond to one kind of foreign antigen. antigen: anti—against + gennan—to produce 4068_Ch18_323-338 15/11/14 1:30 PM Page 326 326 UNIT FOUR Understanding the Immune System them for destruction. Each antibody is specific for only one anti- assist; and memory Ts, which retain kno wledge of the gen, and B cells (that become plasma cells) are capable of pro- pathogen in the e vent of future encounters with the same ducing millions of different antibodies. There are five classes of (Fig. 18.3). human antibodies, designated by letter names: IgG, IgA, IgM, IgD, and IgE (Fig. 18.2). Their functions are summarized in Humoral Immunity Table 18.1. Humoral immunity is also called antibody-mediated immu- nity and involves antibody production. It is effective against Mechanisms of Immunity extracellular pathogens, which are usually bacteria b ut can The two mechanisms of immunity are cell-mediated immu- also be viral or fungal infections (Fig. 18.4). nity, which involves T cells, and humoral immunity, which Although B cells are stationary, the antibodies produced involves mainly B cells b ut is assisted by T cells. Although by plasma cells circulate throughout the body and the mechanisms are different, invasion by a pathogen often bond to the antigen, forming an antigen–antibody triggers both. complex. This immobilizes the bacteria; also, the antigen is now labeled for phagoc ytosis by macrophages or Cell-Mediated Immunity neutrophils. The antigen–antibody complex also activates This mechanism of immunity is ef fective against intracel- the complement cascade. lular pathogens (such as viruses or fungi), malignant cells, and grafts of foreign tissue. A T-cell response results WORD BUILDING in cytotoxic Ts, which attack altered cells; helper Ts, which neutrophil: neutro—neuter + philein—to love FIGURE 18.2 Antibodies. (A) Structure of the five classes of antibodies. (B) Antibody activity. Adapted from Scanlon, V., & Sanders, T. (2015). Essentials of anatomy and physiology (7th ed.). Philadelphia: F.A. Davis. TABLE 18.1 CLASSES OF ANTIBODIES Immunoglobulin (Ig) Location Function IgG Blood, extracellular fluid, Crosses the placenta to provide passive immunity in lymph newborns Provides long-term immunity after a vaccination or illness recovery IgA External secretions (e.g., Provides passive immunity for breastfed infants tears, saliva) Found in secretions of all mucous membranes IgM Blood, lymph Produced first during an infection (IgG production follows) IgD B cells Antigen-specific receptors on B lymphocytes IgE Mast cells or basophils Important in allergic reactions Mast cells release histamine Source: Scanlon, V., & Sanders, T. (2015). Understanding human structure and function (7th ed.). Philadelphia: F.A. Davis. 4068_Ch18_323-338 15/11/14 1:30 PM Page 327 Chapter 18 Immune System Function, Assessment, and Therapeutic Measures 327 Antigen (pathogen) 1 The immune process begins when a phagocyte (such as a macrophage, reticular cell, or B cell) ingests an antigen. 1 Phagocyte 2 The phagocyte, called an antigen- presenting cell (APC), displays fragments of the antigen on its surface—a process called Antigen antigen presentation—which alerts the immune system to the presence of a foreign 2 T cell antigen. When a T cell spots the foreign antigen, it binds to it. 3 This activates (or sensitizes) the T cell, which begins dividing repeatedly to form clones: identical T cells already sensitized to APC the antigen. Some of these T cells become 3 effector cells (such as cytotoxic T cells and helper T cells), which will carry out the attack, while others become memory T cells. Cytotoxic T cell Helper T cell Memory T cell 4 The cytotoxic T cell binds to the surface of the antigen and delivers a toxic dose of chemicals that will kill it. 4 Neutrophil 5 Helper T cells support the attack by secreting the chemical interleukin, which attracts neutrophils, natural killer cells, and 5 macrophages. It also stimulates the production of T and B cells. Helper T cell FIGURE 18.3 Cellular immunity. From Thompson, G. S. (2013). Understanding anatomy and physiology. Philadelphia: F.A. Davis, p. 321. Complement is a group of more than 30 plasma proteins coated with antibodies are phagocytized by macrophages. In- that circulate in the blood until acti vated by either the pres- terferon, another defense against viruses, is a chemical pro- ence of foreign bacteria or by an antigen–antibody complex. duced by cells infected with viruses. Although it does not The activation of complement results in the formation of a help the infected cell, interferon protects surrounding cells protein cascade that lyses (causes disintegration of) the cell. by enabling them to resist viral replication. Other complement proteins bind to foreign antigens and serve Antibodies are also in volved in aller gic responses, in as further labels to attract macrophages. which the immune system responds to foreign b ut harmless antigens (an allergen), such as plant pollen. IgE antibodies bond to mast cells, which break down and release histamine ANTIBODY RESPONSES and other chemicals that contrib ute to inflammation. Ana- phylactic shock is an aller gic reaction, but massive in re- The first exposure to a foreign antigen stimulates antibody sponse. It is characterized by loss of plasma from capillaries production, but the antibodies are produced too slowly to pre- (an effect of histamine) and a sudden drop in the intravascular vent the disease. However, with time, the person accumulates blood volume and blood pressure. antibodies and memory cells specific for that pathogen. On a second exposure to the antigen, the memory cells begin rapid production of large amounts of antibody, often enough to pre- TYPES OF IMMUNITY vent a second occurrence of the illness (Fig. 18.5).This is the basis for the protection given by vaccines. A vaccine contains Two categories of immunity are passive immunity and active an antigen that is not pathogenic. The vaccine stimulates the immunity. In passive immunity, antibodies are not produced formation of antibodies and memory cells. by the person but are obtained from another source. One form Antibodies may also neutralize viruses; that is, they attach to a virus and render it unable to enter a cell (see Fig. 18.2). WORD BUILDING Viruses cannot reproduce outside of li ving cells, and those anaphylactic: ana—up + phylaxis—protection 4068_Ch18_323-338 15/11/14 1:30 PM Page 328 328 UNIT FOUR Understanding the Immune System 1 The surface of a B cell contains thousands of receptors for a specific antigen. When the antigen specific to that receptor comes 1 Antigen along, it binds to the B cell. B cell 2 The B cell then engulfs the antigen, digests it, and displays some of the antigen’s fragments on its surface. A helper B cell 2 Helper T cell T cell binds to the presented antigen and secretes interleukins, which activate the B cell. Interleukins 3 The B cell begins to rapidly reproduce, creating a clone, or family, of identical B cells that are programmed against the same 3 antigen. 4 Some of these cloned B cells become effector B cells or memory B cells; most, though, become plasma cells. 4 Memory 5 The plasma cells secrete large numbers of antibodies. Antibodies stop the antigens through a number of different means. 5 cell FIGURE 18.4 Humoral immunity. From Thompson, G. S. (2013). Understanding anatomy and physiology. Philadelphia: F.A. Davis, p. 322. of naturally acquired passive immunity includes placental transmission of antibodies from mother to fetus and transmis- sion of antibodies in breast milk. Artificially acquired passive immunity involves injection of preformed antibodies; this may Gerontological Issues help prevent disease after exposure to a pathogen such as the hepatitis B virus. P assive immunity is al ways temporary, in Significant changes occur in the immune system of the that antibodies from another source eventually break down. older adult. These changes are kno wn as immune Active immunity means that the person produces his or senescence, which refers to a decline in immune her own antibodies. An example of naturally acquired active system function. Some specif ic changes include the immunity occurs when a person reco vers from an infection following: and then has antibodies and memory cells specif ic for that Thymus gland decreases in size, increases production pathogen. Artificially acquired active immunity occurs as the of immature T cells, and has a subsequent decline in result of a vaccine that stimulates production of antibodies response to antigens. and memory cells. The duration of active immunity depends Antibody response to foreign organisms decreases. on the particular disease or vaccine; some confer lifelong im- Immunizations to support the immune responses of munity, but others do not. older adults include the following: Influenza vaccine (plus H1N1 flu vaccine if recom- Aging and the Immune System mended) yearly mid-October to mid-November, The efficiency of the immune system decreases with age before influenza season (Fig. 18.6). As such, older adults are more susceptible to in- Pneumococcal vaccine once when age 65 fections and autoimmune disorders (see “Gerontological Is- Herpes zoster vaccine once when age 60 sues”). The incidence of cancer is also higher; malignant cells Tetanus, diphtheria, and pertussis booster every that might once have been quickly destroyed by the immune 10 years. system live and proliferate. 4068_Ch18_323-338 15/11/14 1:30 PM Page 329 Chapter 18 Immune System Function, Assessment, and Therapeutic Measures 329 Primary and secondary antibody responses IgG First Second exposure exposure to to antigen antigen IgG Antibody level IgM IgM 10 days 20 days some months some years 10 days 20 days Time after exposure FIGURE 18.5 Antibody responses to a first and then subsequent exposure to a pathogen. From Scanlon, V., & Sanders, T. (2015). Essentials of anatomy and physiology (7th ed.). Philadelphia: F.A. Davis. History The Aging Demographic Data Immune System The patient’s gender and ethnicity are important to note be- cause some diseases tend to be associated with a particular gender or ethnicity. For instance, systemic lupus erythemato- sus (SLE; see Chapter 19), an autoimmune disorder , affects women up to nine times more than men (Ferenkeh-Koroma, Less Increased Malignant 2012). In addition, Hispanic, Nati ve American, Asian, and efficient perception cells not African American women develop SLE two to three times immune of body's responses tissue as destroyed more often than Caucasian women. as quickly foreign Health History Assessment of the patient’ s past and present medical Increased conditions should also include a f amily history. Many infections Increased Increased atopic (allergic) disorders, such as aller gic rhinitis and autoimmune cancer especially disorders incidence asthma (see Chapter 31), and autoimmune disorders, such secondary infections as ankylosing spondylitis (see Chapter 19), are thought to be either familial or have a genetic predisposition in certain FIGURE 18.6 This concept map shows the effects the aging ethnic or cultural groups (“Cultural Considerations”). process has on the immune system. For example, 4 new genes have been identified that are strongly associated with SLE, and 10 others are possible risk factors. Patients’ surgical history may give clues about their pre- NURSING ASSESSMENT OF THE vious health or current condition. For example, with thymus IMMUNE SYSTEM gland removal (thymectomy), T-cell production may be al- tered, which af fects the cell-mediated immune response. Disorders of the immune system can af fect every system in If the spleen w as removed (splenectomy), lymphocyte and the body, so it is important to collect head-to-toe data as well plasma cell production may be altered, which af fects the as a patient history (Table 18.2). humoral immune response. 4068_Ch18_323-338 15/11/14 1:30 PM Page 330 330 UNIT FOUR Understanding the Immune System TABLE 18.2 SUBJECTIVE DATA COLLECTION FOR THE IMMUNE SYSTEM Questions to Ask During the Category Health History Rationale/Significance Demographic Data What is your age? The immune system decreases in functional effec- tiveness as one ages, and a number of immune disorders tend to afflict individuals of particular age ranges. Where were you born? What is This information can aid in determining ethnic and your ethnic or cultural back- cultural background influences. Some immune ground? disorders tend to afflict individuals of particular cultural/ethnic groups more than others. Where have you lived? This information can aid in determining ethnic and Where do you currently reside? cultural background as well as possible environ- mental influences. History Do you have allergies to any medica- This information may lead to a direct cause of cur- tions? Latex? Foods? Insects? En- rent symptoms and provides information regard- vironmental allergens? If yes, have ing the status of the patient’s immune system. you had a recent exposure to any Medication side effects are commonly inaccu- of these? Describe the reaction. rately considered allergies by patients. Is anyone in your family allergic to If family members (especially immediate) have se- medications? Latex? Foods? In- vere reactions to substances, the patient may be sects? Environmental allergens? predisposed to immune reactions to the same antigen or in general. What medications are you currently Some medications can mask symptoms or taking? immune responses, others can suppress immune responses. What illnesses or conditions are May provide clues to patient’s current condition or you currently being treated for? symptoms. Have you been treated for? What surgeries have you had? Have any immune organs been removed, therefore reducing immune function? May also provide indications about overall health. Have you ever had a blood Antibodies to various antigen markers on the transfusion? If so, why? blood cells may have been formed. May also provide indications regarding overall health. What is your occupation? Have you Many chemicals can produce local reactions, usu- been exposed to hazardous ally skin reactions or systemic immune reactions, chemicals, fumes, or radiation? and some can lead to bone marrow suppression in which all cell production is reduced. Do you engage in any form of risky Risky behavior, such as intravenous drug use or un- behavior? protected sex with multiple partners, increases a patient’s chances of contracting the human im- munodeficiency virus (HIV), which leads to a reduction in the immune system function. Describe your overall stress level Stress is known to suppress the immune system and life stressors. and, over prolonged periods, can lead to a vari- ety of illnesses. What do you do to cope with Not all coping behaviors and mechanisms are stress? healthy; therefore, it is important to assess what the patient’s coping behaviors are to see if the patient needs education. What sort of support systems do Support systems can buffer the day-to-day stress you have? as well as during crisis. 4068_Ch18_323-338 15/11/14 1:30 PM Page 331 Chapter 18 Immune System Function, Assessment, and Therapeutic Measures 331 Cultural Considerations The Navajo people have a high incidence of severe combined immunodeficiency syndrome (SCIDS), an immunodefi- ciency syndrome unrelated to acquired immunodeficiency syndrome (AIDS). SCIDS is a failure of the antibody re- sponse and cell-mediated immunity. Infants who survive are initially sent to tertiary care facilities. They must receive gamma globulin on a regular basis until a bone marrow transplant can be performed. Thus far, studies indicate that SCIDS is unique to the Navajo population. For current medications, include prescription drugs, Useful data for associated symptoms. Immunosuppres- over-the-counter drugs, and herbal preparations. Corticos- sion? Family history? Allergies? teroids and immunosuppressants decrease the immune re- Perception of the patient of the problem. What do you sponse, and some anti-infectives and antineoplastics depress think is wrong? the bone marrow. This results in decreased production of Common signs and symptoms present with immune dis - the cells made in the bone marrow. Bone marrow depression orders include fe ver, fatigue, joint pain, sw ollen glands, of WBCs can alter cell-mediated and humoral immune re- weight loss, and rash. sponses. The herbal preparation licorice, which is some- times used for its anti-inflammatory and expectorant effects, Physical Examination when taken with corticosteroids, increases the effects of the Physical data collection begins by observing the patient’s gen- corticosteroids. eral appearance, color, posture, gait, f acial expression, skin, A patient’s lifestyle may influence immune system func- and nailbeds (Table 18.3). Any cyanosis or erythema (redness) tion and should be assessed. Kno wing a patient’s dietary is noted. Rashes should be examined for size, shape, location, habits and supplemental vitamins gi ves insight into the po- texture, drainage, and pruritus (itching). Visual and hearing tential reserve of the patient’s immune system for fighting in- changes can be associated with an immune disorder. fection. Anaphylactic reactions can be caused by exposure to Adventitious lung sounds, such as wheezing, may indicate latex, which may be found in gloves and other medical prod- asthma or an allergic response. Crackles are often associated ucts that health care w orkers and their patients touch. Be with upper respiratory infection. Lymph nodes should be in- aware of this potentially life-threatening reaction, and know spected and then gently palpated (by the adv anced practi- the agency’s latex allergy protocol. Patients who are allergic tioner; see Fig. 18.1). Normally, lymph nodes are not palpable to latex should wear medical identif ication jewelry or have in the adult. If enlar ged, note the following characteristics: other readily available identification and carry an epinephrine location, size, shape, tenderness, temperature, consistenc y, auto-injector (EpiPen). mobility, symmetry, pulsation, and if red streaks, redness, or The patient’s life stressors, coping beha viors, and sup- edema are present. port systems should be e xplored. Stress (environmental, physical, and psychological) can depress immune system function. Coping beha viors are essential to k eep stress within manageable limits to maintain optimum immune LEARNING TIP function. Support systems play an important role in coping A normally functioning immune system is required with stress and should be encouraged and nurtured by to trigger an inflammatory response and produc- nurses. tion of the signs of inflammation or infection: Current Problem fever, redness, pain, swelling, and warmth. If the immune system is suppressed or functioning ab- Use the WHAT’S UP? format to collect data about the cur- normally, this normal inflammatory response may rent immune system problem. For immune disorders, ask the not occur. Thus, the patient may have only a low- patient the following questions: grade fever with none of the other signs of inflam- Where is it? What part of the body is affected? mation or infection (redness, pain, swelling, and How does it feel? Painful? Itching? warmth). Aggravating and alleviating factors? Recognize patients with suppressed immune Timing: Was there exposure to a pathogen? Did you have systems so that low-grade fevers are reported a previous infection? Does it occur only in certain set- to the physician for prompt treatment. This may tings? Did you have chemotherapy or radiation therapy? be the only sign of a life-threatening infection How long have symptoms persisted? that develops because of the suppressed immune Severity. Does it affect activities of daily living (ADLs)? system. Work? Roles? 4068_Ch18_323-338 15/11/14 1:30 PM Page 332 332 UNIT FOUR Understanding the Immune System TABLE 18.3 OBJECTIVE DATA COLLECTION FOR THE IMMUNE SYSTEM Category Physical Examination Findings Possible Abnormal Findings/Causes Neurologic Alertness and orientation Confusion or lethargy are common in later stages of systemic lupus erythematosus (SLE) and ac- quired immunodeficiency syndrome (AIDS). Skin Warm, dry, smooth, supple, even Rash, urticaria, pruritus, pustules with many forms coloring, nonpruritic of allergic reactions. “Butterfly rash” (red rash over bridge of nose and cheek bones) occurs in less than 50% of patients with SLE. Painless purple lesions with Kaposi’s sarcoma, as- sociated with HIV and AIDS. Pink mucous membranes Pale edematous mucous membranes along with rhinorrhea and “allergic shiners” (dark circles under the eyes) occur with allergic rhinitis. Pale conjunctiva is associated with anemia. Periorbital edema can indicate hypothyroidism. Nail attached to nailbed Onycholysis (nail detaches from nailbed) occurs with Hashimoto’s thyroiditis. Heart Sounds Clear S1 and S2 Pericardial friction rub may be heard with rheuma- toid arthritis or SLE because of inflammation of the connective tissue surrounding the heart (pericardium). Lung Sounds Clear throughout Pleural effusion with tachypnea and diminished sounds in lungs can be seen in SLE or rheuma- toid arthritis; pleural friction rub can occur. Crackles with a dry cough may be indicative of Pneumocystis jiroveci pneumonia (PCP). Lymph Nodes Nonpalpable and nontender Enlarged lymph nodes that are painless, firm, and fixed are associated with cancerous lesions, whereas painful enlarged lymph nodes are asso- ciated with inflammation and infection. Gastrointestinal Appropriate appetite without nau- Anorexia, nausea, and vomiting associated with sea or vomiting immune disorders. Regular pattern of brown, soft, Diarrhea or diarrhea alternating with constipation formed stools is common with irritable bowel syndrome (IBS). Renal An average of 30 mL per hour of Urine output of less than 30 mL/hour, the presence clear, yellow/amber urine with- of protein in urine, and edema occur with SLE out presence of protein or pain or serum sickness. Transfusion reactions can cause hematuria, flank pain, or oliguria. Glomerulonephritis may cause hematuria, flank pain, or oliguria. Musculoskeletal Painless and nonswollen joints with Swollen, painful joints and limited joint range of full range of motion motion occur in rheumatoid arthritis. Overall strength, endurance and Decreased strength and coordination occur in coordination appropriate for age patients with multiple sclerosis. and physical fitness Patients with myasthenia gravis lose strength and endurance with repetitive movements. 4068_Ch18_323-338 15/11/14 1:30 PM Page 333 Chapter 18 Immune System Function, Assessment, and Therapeutic Measures 333 Gene Testing CRITICAL THINKING With human genome mapping data, scientists are able to test Mrs. Sims for numerous diseases, predisposition to diseases, and en- zyme deficiencies that can alter immune response. Mrs. Sims is scheduled for a lymph node biopsy and is seen in preadmission testing before sur gery. As the nurse prepares to draw blood specimens, he learns that THERAPEUTIC MEASURES FOR THE Mrs. Sims is allergic to latex. IMMUNE SYSTEM 1. How can the nurse promote patient-centered care Allergies during this lab draw? With allergies, medical identification jewelry or other readily 2. Why is this patient allergy information important? available identification is essential. Allergies must be verified 3. What should the nurse do next? before giving any medications or foods. All allergies, including 4. What precautions should the nurse use for drawing those to food, must be tak en very seriously (see “Evidence- the blood specimen? Based Practice”). Suggested answers are at the end of the chapter. EVIDENCE-BASED PRACTICE If enlarged, the spleen may be palpable (by an adv anced Clinical Question practitioner) in the left upper quadrant of the abdomen with If a patient is allergic to shellfish, is the person disorders in which there is an o verproduction or excessive allergic to iodine and therefore unable to tolerate destruction of red blood cells (RBCs). iodine in products such as Betadine, Povidone Renal impairment from an immune disorder causes a being used on the skin? change in urinary output, flank pain, edema, weight gain, or Evidence elevated renal function studies. True hypersensitivity reactions to seafood, in- A general neurologic assessment of muscle strength and cluding shellfish, arise from the group of antigens coordination, changes, or abnormalities is made. Changes called tropomyosins, which are proteins needed may be an indication of an immune-based disorder such as for muscle contraction. These reactions are not multiple sclerosis or myasthenia gravis. caused by iodine in the seafood (Harrison, 2013). Implications for Nursing Practice DIAGNOSTIC TESTS FOR THE Although nurses need to continue to ask pa- IMMUNE SYSTEM tients about their allergies, there is no need to exchange the povidone-iodine solution found in Presenting signs and symptoms and the patient’s history deter- procedural kits for a non-iodine-based bacterici- mine which tests and procedures may be ordered. Table 18.4 dal cleanser in patients with seafood allergies. describes the most common blood tests for patients with aller- REFERENCES gic, autoimmune, or immune disorders. Table 18.5 presents Harrison, P. (2013, March 19). Shellfish allergy doesn’t pre- common noninvasive and invasive procedures for immune dis- dict reaction to imaging agents. Medscape Medical News. orders. Chest X-ray, magnetic resonance imaging (MRI), and Retrieved on November 15, 2013, from www.medscape.com computed tomography (CT) scans might also be useful. /viewarticle/781031 TABLE 18.4 DIAGNOSTIC LABORATORY TESTS FOR IMMUNE SYSTEM Test Definition/Normal Value Significance of Abnormal Findings RBC Count Number of RBCs per 1 mm of Decreased in all forms of anemia, such as blood pernicious anemia that develops from the Adult male: 4.7–6.1 × 1012/L autoimmune form of gastritis or idiopathic Adult female: 4.2–5.4 × 1012/L autoimmune hemolytic anemia. Differential Each of these tests (MCV, MCH, Can help determine the cause of anemia. MCHC, RDW) provides infor- Pernicious anemia can develop because of mation about RBC size, shape, the autoimmune form of gastritis. color, and intracellular structure. Continued 4068_Ch18_323-338 15/11/14 1:30 PM Page 334 334 UNIT FOUR Understanding the Immune System TABLE 18.4 DIAGNOSTIC LABORATORY TESTS FOR IMMUNE SYSTEM—cont’d Test Definition/Normal Value Significance of Abnormal Findings Normal: MCV 80–95 mm3 MCH 27–31 pg MCHC 32–36 g/dL RDW 11.0%–14.5% WBC Count Number of WBCs per 1 mm of Increased with immunosuppression and infection. blood Adult: 5–10 × 109/L Differential Percentage of type of WBCs in 1 Eosinophils elevate with type I hypersensitivity re- mm of blood. Or the actual num- actions such as allergic rhinitis or anaphylaxis. bers of specific types of WBCs if an absolute count is performed. Normal: % Absolute/mm3 Neutrophils 55–70 2500–8000 Lymphocytes 20–40 1000–4000 Monocytes 2–8 100–700 Eosinophils 1–4 50–500 Basophils 0.5–1.0 25–100 Erythrocyte A nonspecific test for generalized False negative may result if steroids or NSAIDs Sedimentation inflammation. Measures the are being used when test is performed. Rate (ESR) RBC descent (in millimeters) in test tube after being in normal saline solution for 1 hr (Westergren method). Male: Up to 15 mm/hr Female: Up to 20 mm/hr Rheumatoid An abnormal protein found in Increased in rheumatoid arthritis, SLE, leukemia, Factor serum when IgM reacts with an tuberculosis, older age, scleroderma, infectious (RF or RA) abnormal IgG; found in 80% of mononucleosis. patients with rheumatoid arthritis and other autoimmune disorders. Normal: Negative Antinuclear Measures autoantibodies that attack Most commonly present in SLE (>95% sensitiv- Antibody the cell’s nucleus. ity), leukemia, scleroderma, rheumatoid arthri- (ANA) Normal: Negative tis, and myasthenia gravis; many medications Anti-dsDNA Normal: 200 international units/mL Complement Specific serum proteins that help Deficiencies of specific complement proteins are mediate inflammation. Measures seen in SLE. the amount of each of the compo- nents in the complement system. Normal: Total 75–160 units/mL C3 0.55–1.20 g/L C4 0.2–0.5 g/L 4068_Ch18_323-338 15/11/14 1:30 PM Page 335 Chapter 18 Immune System Function, Assessment, and Therapeutic Measures 335 TABLE 18.4 DIAGNOSTIC LABORATORY TESTS FOR IMMUNE SYSTEM—cont’d Test Definition/Normal Value Significance of Abnormal Findings C-Reactive An abnormal protein found in Increased in rheumatoid arthritis, cancer, SLE. Protein (CRP) plasma during acute inflamma- Suppressed by aspirin and steroids. tory processes; more sensitive than sedimentation rate. Normal: