Body Defenses, Immunity, and Vaccines Chapter 17 Body Defenses, Immunity, and Vaccines

Functions of the Lymphatic System Return cellular waste products and excess fluid from the tissues to the circulatory system. Absorbs fats and fat-soluble vitamins from the digestive system and transport them to the cells. Serves as an important part of the immune system. Lacteals?

Structures of Lymphatic System Lymph fluid and vessels Lymph nodes Tonsils and adenoids Spleen Bone marrow Lymphocytes Thymus Immune system

Major structures and their primary functions Lymph fluid and vessels – return cellular waste and tissue fluid to the circulatory system. Lymph Vessels Lymph capillaries Right lymphatic duct and thoracic duct Lacteals Thymus – produces T lymphocytes for the immune system.

Lymph nodes Bean-shaped structures- site for lymphocyte production. produce lymphocytes and filter harmful substances from lymph. Major lymph node sites: Cervical lymph nodes Axillary lymph nodes Inguinal lymph nodes Tonsils and adenoids – protect the entry into the respiratory system. Adenoids or nasopharyngeal tonsils. Palatine tonsils Lingual tonsils

Vermiform appendix and Peyer’s patch – protect against the entry of invaders through the digestive system. Spleen – filters foreign materials from the blood. Stores red blood cells, and maintains the appropriate balance between cells and plasma in the body. Forms lymphocytes and monocytes, which are specialized WBCs with roles in the immune system. Hemolytic - destroys old worn out blood cells, acts as a blood reservoir, and stores platelets.

Functions of the Immune System Defends the body against harmful substances such as pathogenic microorganism, allergens, toxins, and malignant cells. It involves structures from many body systems.

Peyer’s patch

Common Diagnostic Tests ANA Total complement, C3 & C4 CRP CD4 T-Cells * ELISA ESR HLA-DW4 LE Prep PCR RBC * RF Total White Blood Cell count w/ differential * Western Blot

ANA Anti-Nuclear Antibody Fasting for 8 hours prior Antinuclear antibodies are produced and act against the body’s own DNA Causes tissue damage Specific for SLE Simple blood draw Antinuclear antibodies are produced and act against the body's own DNA and nuclear material that causes tissue damage as autoimmune disorders. This test is a fluorescent procedure that assists in differentiating among various connective tissue diseases. Antinuclear antibody testing is not diagnostic of all of the variety of diseases. However, if positive results do occur, the anti-DNA test is performed specifically to diagnose SLE

Total Complement, C3 & C4 Total complement refers to a group of 20 proteins in the blood Complement is important in the inflammatory process Main mediator in antigen-antibody reactions In SLE, large amounts of immune complexes are formed Just another simple blood test The total complement refers to a group of 20 proteins in the blood involved in a complex cascade system. Complement is important in the inflammatory process and is the main mediator in the antigen-antibody reactions of the cell-mediated immune response. The results associated with complement activation are cell lysis, release of mediators, vessel dilation, smooth muscle contraction, and increased vascular permeability. Complement activation consists of two major pathways: the classic and alternative pathways. The activation of the classic pathway requires antigen and complement-fixing antibody. The alternative pathway is important in the control of microbial infection and does not have an absolute requirement of an antibody. In systemic lupus erythematosus (SLE), large amounts of immune complexes are formed. These complexes activate complement and complement activation contributes to further inflammation. Complement levels decrease with SLE due to the consumption of enzymes from constant inflammation.

CRP C-Reactive Protein Fasting for 8 hours Red top tube (blood test) CRP is an abnormal protein that occurs in inflammatory disorders Progressive increases correlate with increases of inflammatory injury CRP may be used to follow therapeutic response medications C-reactive protein is a globulin that in the presence of calcium ions precipitates the C substance of pneumococcal cells. CRP is an abnormal protein that appears in the blood in the acute stages of various inflammatory disorders but is undetectable in the blood of healthy individuals. Progressive increases correlate with increases of inflammatory injury. CRP may be used to follow therapeutic response medications

CD4 T-Cells A simple count of the number of CD4 cells present in a typical CBC

ELISA Detects the antibodies that result from exposure to HIV. Antigens may be detected as early as two weeks post exposure, and may remain for 2-4 months. Antibodies can take up to 1 year to detect. If ELISA positive, a repeat ELISA is done, with follow up by a Western Blot and Indirect Fluorescent Antibody (IFA) This test requires signed informed consent prior to draw. HIV is the virus that causes AIDS. The virus infects the T-helper lymphocytes and affects the abiltiy to produce antibodies, which decreases the immune response. The lack of confirmation of HIV with negative WB and IFA testing does not preclude infection, and therfore, repeat testing in 3-6 months is suggested.

ESR Erythrocyte sedimentation rate (ESR), a.k.a. Sed. Rate Measures the rate of fall of RBC suspended in plasma Results reported in millimeters per hour. Elevated levels are found in RA, AMI, gout, Lupus, Hodgkin’s disease & multiple myeloma The Erythrocyte Sedimentation Rate (ESR) is a non-specific test that alerts physicians to the possible presence of disease or abnormality in the body. The ESR is determined by measuring, in millimeters per hour, the distance red cells have fallen after separating from the plasma in a vertical sed-rate pipette.

ESR Vertical sed-rate pipettes Elevated levels are found with conditions that have increased plasma fibrinogen, increased RBC size, increased plasma viscosity, or increased gamma globulins. Diagnoses polymyalgia rheumatica and temporal arteritis ESR can be helpful for tracking diseases (“sickness index”) Vertical sed-rate pipettes http://www.lt-burnik.si/LTB/wpe11.jpg

HLA-DW4 Human Leukocyte Antigens (HLA) are classified into five series, designated A, B, C, D and D related. Each series contains 10-20 distinct antigens. Used to determine tissue transplant compatibility The HLA combinations vary according to certain races and populations. The most common B antigens in American whites are B7, B8, and B12. In American blacks, the B series are Bw17, Bw35 and a specificity characterized as IAG. This test detects HLAs on the surface membranes of leukocytes, platelets, and tissue cells. Each site of location is called a locus and each locus has four subloci, each containing one gene. Each sublocus (gene) has multiple alleles, or a pool of several genes. The major subloci are designated A, B, C, D, and DR or D related. The HLA system has been closely identified with tissue transplant compatibility and is used in bone marrow and renal transplantation. Also certain HLAs have been found to occur with increased frequency in various diseases. The B27 antigen is associated with RA and variants. The incidence of HLA-B27 in ankylosing spondylitis is 90%-95% in whites. The D8 antigen is associated with MG and Celiac Disease.

LE Lupus erythematosus cell test Assists in diagnosing lupus ~75% of patients who have SLE will have LE cells in their blood stream LE cells are a result of immunological activity against nucleoproteins. It is only positive in about 50% of clients and has a high false positive rate

Pcr Plasma Creatinine Approximately 98% of creatine is contained in muscle, and about 1.7% is converted to creatinine. Skeletal muscle necrosis or atrophy causes a significant increase in serum creatine. Elevated levels are found with trauma, muscular dystrophy, poliomyelitis, amyotrophic lateral sclerosis, myasthenia gravis, starvation, hyperthyroidism, and diabetic acidosis.

RF Rheumatoid Factor An IgM antibody directed against a fragment of the IgG molecule Useful as a test for autoimmune disorders and particularly in the diagnosis of rheumatoid arthritis. Aids in early diagnosis of RA for potential treatment measures and inhibiting the progression of the disease.

Western Blot Determines the presence of antibodies for human T-cell lymphotrophic virus type III AIDS virus (one of the several strains of the HIV virus) Fast, sensitive and exacting test for identifying the presence of antibodies to HIV But, a negative result does not prove the client has the disease, nor does a positive result prove the client will develop it!!