Chapter 7: The Blood, Lymphatic, and Immune Systems

discrimination

Choice, The ability to distinguish self antigens from foreign antigens The ability to distinguish self antigens from foreign antigens

Which medication is taken orally to prevent clots from forming?

Coumadin

anemia

Decreased number of red blood cells

Which characteristic of the immune system enables it to recognize self versus non-self molecules?

Discrimination

which characteristic of the immune system enables it to recognize self versus non-self molecules?

Discrimination

Disseminated intravascular coagulation (DIC)

Disseminated intravascular coagulation (DIC) occurs when a severe bacterial infection activates the clotting mechanism simultaneously throughout the cardiovascular system. Small clots form and obstruct blood flow into tissues and organs, particularly the kidney, leading to renal failure

Select the correct statements regarding diagnostic procedures for blood disorders.

Enlarged or smaller than normal RBCs can indicate different types of anemia. Prothrombin (PT) time and prothromboplastin (PTT) time provide information on how quickly the blood clots. A CBC can help to diagnose the cause of weakness, fatigue, or excess bruising.

Immunosuppressant drugs inhibit or prevent activity of the immune system and are used to prevent the rejection of transplanted organs and tissues, treat autoimmune diseases, and help control long-term allergic asthma. There are four main types of immunosuppressant drugs:

Glucocorticoids, which suppress cell-mediated immunity and protect through T-cells and macrophages, and by stimulating cells to secrete cytokines. Cytostatics, which inhibit cell division. Cyclophosphamide (Cytoxan), a nitrogen mustard alkylating agent, is probably the most potent immunosuppressant. Methotrexate, an antimetabolite, interferes with the synthesis of nucleic acids and is used in the treatment of autoimmune diseases. Azathioprine (Imuran) is the main immunosuppressive cytotoxic substance and is used to control transplant rejection reactions. Antibodies can be used as quick immunosuppressive therapy and are described above in sections on monoclonal antibodies and immunoglobulins. Calcineurin is a phosphatase that stimulates the growth and differentiation of T-cells. Calcineurin inhibitors such as ciclosporin (Sandimmune), tacrolimus (Prograf), and sirolimus (Rapamune) are used in the prevention and treatment of transplant rejection reactions.

Abbreviations

Hct-hematocrit RBC-red blood cell WBC-white blood cell Hb or Hgb-hemoglobin PA-pernicious anemia SOB-short(ness) of breath DIFF-differential white blood cell count ig-immunoglobulin PMNL-polymorphonuclear leukocyte EBV-Epstein-Barr virus DIC-disseminated intravascular coagulation ITP-idiopathic thrombocytopenic purpura vWD-von Willebrand disease vWF-von Willebrand factor Ab-antibody ABO-blood group system Rh-Rhesus HDN-hemolytic disease of the newborn RhoGAM-Rhesus immune globulin CBC-complete blood count ITP-idiopathic thrombocytic purpura MCV-mean corpuscular volume PT-prothrombin time PTT-partial thromboplastin time TPA-tissue plasminogen activator AIDS- acquired immunodeficiency syndrome HIV- human immunodeficiency virus CA-MRSA-community-associated methicillin-resistant Staphylococcus aureus CDC-Centers for Disease Control and Prevention CRE-carbapenem-resistant Enterobacteriaceae MRSA-methicillin-resistant Staphylococcus aureus SARS-severe acute respiratory syndrome WNV-West Nile virus

Which condition is NOT treated by performing a bone marrow transplant?

Heart attack

Which substance gives erythrocytes their color?

Hemoglobin

Disorders of Coagulation (Coagulopathies)

Hemophilia, in its classical form (hemophilia A), is a disease males inherit from their mothers. It results from a deficiency of the coagulation factor named factor VIII. Von Willebrand disease (vWD)—the most common hereditary bleeding disorder—is a protein deficiency of the factor VIII complex (vWF) that is different from the factor deficiency involved in hemophilia

______ dose is monitored by activated partial thromboplastin time.

Heparin

Disorders of the Lymphatic System

Hodgkin lymphoma, or Hodgkin disease (Figure 7.18): The cancer spreads in an orderly manner to adjoining lymph nodes. This enables the disease to be staged depending on how far it has spread; and Non-Hodgkin lymphomas: These occur much more frequently than Hodgkin lymphoma. They include some 30 different disease entities in 10 different subtypes.

Human immunoglobulins are given by injection to confer passive (temporary) immunity that provides immediate protection lasting several weeks. There are two types:

Human normal immunoglobulin (HNIG) made from the plasma of about 1,000 unselected donors to provide antibodies against hepatitis A, rubella, measles, and other viruses found in the general population. Hyperimmune specific immunoglobulins are made from selected donors and provide antibodies individually against hepatitis B, varicella zoster, rabies, tetanus, and cytomegalovirus.

Which of the following statements are true regarding immunity?

Humoral immunity is an indirect attack using immunoglobulins to identify antigen. T cells, B cells, and macrophages are involved in cellular immunity. Plasma cells, which are mature B lymphocytes, produce immunoglobulins. Cellular and humoral immunity can both be deployed against the same antigen.

lymphadenitis

Infections in the lymph nodes cause them to be swollen and tender to the touch, a condition

Which immune system cells ingest foreign debris and pathogens?

Macrophages, which develop from monocytes

Functions of Blood

Maintains your body's homeostasis Transports nutrients, vitamins, and minerals from your digestive system and storage areas to your organs and cells. Examples of nutrients are glucose and amino acids Transports waste products from your cells and tissues to your liver and kidney for excretion. These waste products include creatinine, urea, bilirubin, and lactic acid Transports hormones, like insulin and thyroxine (see Chapter 12), from your endocrine glands to target cells. Transports gases, like oxygen and carbon dioxide (see Chapter 8), to and from your lungs and cells. Protects against foreign substances, including microorganisms and toxins. Cells and chemicals in your blood are an important part of your immune system's protective properties. Forms clots. Clots provide protection against blood loss. Clotting is the first step in tissue repair and restoration of normal function.

Identify the three main characteristics of the immune system that enable it to function as a defense system in the body.

Memory Discrimination Specificity

The types of immunotherapy include

Monoclonal antibodies, made in the laboratory, can attach to cancer cells to flag them so that macrophages in the body's immune system can recognize and destroy them. Two pathways inside cells that cancers use to evade the immune system have been identified and named PD-1/PD-L1 and CTLA-4. These pathways can be blocked with antibodies called immune checkpoint inhibitors to allow the body's immune system to respond to the cancer. Immune checkpoint inhibitors ipilimumab (Yervoy), nivolumab (Opdivo), and pembrolizumab (Keytruda) have been shown to improve overall patient survival in advanced melanoma. Interferons are a nonspecific immunotherapy mostly given at the same time as other cancer treatments such as chemotherapy or radiation therapy. An interferon called interferon alpha made in a laboratory is the most common type of interferon used in cancer treatment. Interleukins are also a nonspecific immunotherapy used to treat kidney and skin cancers, including melanoma.

Agranulocytes

Monocytes (Figure 7.7) are the largest blood cells and are normally 3% to 8% of the total WBC count. Monocytes leave the bloodstream and become macrophages that ingest bacteria, dead neutrophils, and dead cells in the tissues. Lymphocytes (Figure 7.8) are the smallest white blood cells and comprise 25% to 35% of the total WBC count. Lymphocytes are produced in red bone marrow and migrate through the bloodstream to lymphatic tissues—lymph nodes, tonsils, spleen, and thymus—where they multiply. There are two main types of lymphocytes: B cells differentiate into plasma cells, which are stimulated by bacteria or toxins to produce antibodies or immunoglobulins (Ig). T cells attach directly to foreign antigen-bearing cells like bacteria, which they kill with toxins they secrete. In a laboratory report, a differential white blood cell count (DIFF) lists the percentages of the different leukocytes in a blood sample

Granulocytes

Neutrophils (Figure 7.4), also called polymorphonuclear leukocytes (PMNLs), are normally 55% to 65% of the total WBC count. These cells ingest bacteria, fungi, and some viruses. In neutropenia, the number of neutrophils is decreased. In neutrophilia, the number is increased. Eosinophils (Figure 7.5) are normally 2% to 4% of the total WBC count. They leave the bloodstream to enter tissue that is undergoing an allergic response. In allergic reactions, the number and percentage of eosinophils increase. Basophils (Figure 7.6) are normally less than 1% of the total WBC count. Basophils migrate to damaged tissues to release histamine (which increases blood flow) and heparin (which prevents blood clotting).

Which ABO blood type is the universal donor?

O

______ of blood is/are smeared on a slide for a blood smear.

One drop

Which of the following are infectious pathogens?

Parasites Fungi Viruses

colloid

Percentage of red blood cells in the blood

anemic (adj)

Pertaining to or suffering from anemia

The functions of the spleen are to:

Phagocytose (consume) bacteria and other foreign materials. Initiate an immune response when antigens are found in the blood. Phagocytose old, defective erythrocytes and platelets. Serve as a reservoir for erythrocytes and platelets.

Pinworms

Pinworms are the most common parasite in America. Pinworm eggs are introduced into the body through the mouth and hatch in the intestine. The young worms migrate to the anus, where the female deposits her eggs. These eggs can be transferred unknowingly by the fingers from the anus or from infected bedding, to the mouth of the same child or to another child.

Purpura

Purpura is bleeding into the skin from small arterioles that produces a larger individual lesion than the tiny red spots or petechiae from capillary bleeds (Figure 7.10a and b). Bruises (or hematomas) are leaks of blood from all types of blood vessels.

Identify the two ways in which the blood provides protection to the body.

Recognition and destruction of microorganisms by immune cells Clotting to prevent blood loss from damaged vessels

To prevent HDN, an Rh-negative mother giving birth to an Rh-positive baby should be given ______ after delivery

RhoGAM

To prevent HDN, an Rh-negative mother giving birth to an Rh-positive baby should be given ______ after delivery.

RhoGAM

serum

Serum is a clear, yellowish fluid that contains all the blood proteins not used in clotting and all the electrolytes, antibodies, antigens, and hormones that are carried in blood. When blood clots, and the solid clot is removed, serum remains. Serum is identical to plasma except for the absence of clotting proteins.

allergist

Specialist in hypersensitivity reactions

Three characteristics distinguish immunity from the first two lines of defense of physical and cellular mechanisms:

Specificity: The immune response is directed against a specific pathogen. Immunity to one pathogen does not grant immunity to others. Specificity has one disadvantage; if a virus or a bacterium changes a component of its genetic code, it then becomes a new organism to the immune system. This mutation occurs, for example, with bacteria in response to antibiotics and in HIV's response to anti-HIV drugs (development of resistance). Memory: When exposure to the same pathogen occurs again, the immune system recognizes the pathogen and has its responses ready to act quickly. Discrimination: The immune system learns to recognize agents (antigens) that represent "self" and agents (antigens) that are "nonself" (foreign). Most of this recognition is developed prior to birth. A variety of disorders occur when this discrimination breaks down. They are known as autoimmune disorders.

Thousands of different bacteria can cause infections. Bacteria are single-celled microorganisms that reproduce by dividing. Frequently seen bacteria include:

Staphylococcus ("staph"), which can be harmless when present on the skin's surface but causes infections in wounds or other normally sterile places, like in a joint or the peritoneum; Streptococcus ("strep"), which is a cause of sore throats; Pneumococcus, which is a cause of pneumonia; and Coliform bacteria that normally live in the GI tract but cause infections elsewhere, such as the urinary tract.

______ is a drug that can dissolve clots after they have formed.

Streptokinase

specificity

The immune system recognizes specific antigens, marks them, and mounts an attack

Which of the following is the largest lymphatic organ?

The spleen

hematology.

The study of the blood and its disorders—the red and white blood cells within the blood, their proportions, and overall cell health

types of white blood cells

The types of white blood cells (WBCs) can be categorized as granulocytes or agranulocytes. Granulocytes contain a granular cytoplasm, made up of granules, which are sites for enzyme and chemical production. Agranulocytes do not contain cytoplasmic granules.

Which statement is correct about the structure of erythrocytes?

Their shape promotes more rapid diffusion of gases.

Thrombocytopenia

Thrombocytopenia is a deficiency of platelets.

Thrombus

Thrombus formation (thrombosis) is a clot that forms attached to a diseased or damaged area on the walls of blood vessels or the heart. If part of the thrombus breaks loose and moves through the circulation, it is called an embolus.

The functions of the RBCs are to:

Transport oxygen (O2), in combination with hemoglobin, throughout the body, from the lungs to the cells; Transport carbon dioxide (CO2) from the tissue cells to the lungs for excretion; and Transport nitric oxide (NO), a gas produced by the lining cells of blood vessels that signals smooth muscle to relax, throughout the body.

Which of the following transfusions are mismatched and could cause agglutination to occur?

Type O recipient receiving type A blood

memory

Upon a second exposure to a pathogen encountered in the past, the immune response is more rapid Upon a second exposure to a pathogen encountered in the past, the immune response is more rapid

Hemostasis is achieved through a three-step process:

Vascular spasm, an immediate but temporary constriction of the injured blood vessels. Platelet plug formation, an accumulation of platelets that bind themselves together and adhere to surrounding tissues. The binding and adhesion of platelets are mediated through von Willebrand factor (vWF), a protein produced by the cells lining the blood vessels. Blood coagulation is the process of going through prothrombin and thrombin to the formation of a blood clot that traps blood cells, platelets, and tissue fluid in a network of fibrin After a blood clot forms, platelets adhere to strands of fibrin and contract to pull the fibers and the edges of the broken blood vessel together. Fibroblasts invade the clot to produce a fibrous connective tissue that seals the blood vessel.

A test included in a CBC in which the number of each type of WBC is given is called a(n) ______.

WBC differential.

lymphadenectomy

When lymph nodes are removed

Plasma

a clear, yellowish liquid that is 91% water—makes up the remaining 55% of the blood sample in the tube. Plasma is a colloid, a liquid that contains floating particles, most of which are plasma proteins

the spleen

a highly vascular and spongy organ, is the largest lymphatic organ. It is located in the left upper quadrant of the abdomen, below the diaphragm and lateral to the kidney

Transplant rejection is an ______.

alloimmune disorder

Splenomegaly

an enlarged spleen, is not a disease in itself but the result of an underlying disorder. But when the spleen enlarges, it traps and stores an excessive number of blood cells and platelets (hypersplenism), reducing the number of blood cells and platelets in the bloodstream. Occasionally, a splenectomy is necessary.

Humoral defense of the body is an immune system function mediated by ______.

antibodies

In the blood, ______ are present in plasma.

antibodies

In the blood, ______ are found on the surface of red blood cells.

antigens

The treatment for ______ is to remove the toxin, drug, or radiation source that is causing the inability of the bone marrow to produce red blood cells.

aplastic anemia

Immunology technicians

are certified laboratory technicians with a special interest in immunology who generally work alongside medical researchers.

Transfusion technicians

are certified technicians who deal with all phases of blood transfusions.

Epidemiologists

are medical scientists involved in the study of epidemic diseases and how they are transmitted and controlled.

Parasites

are organisms that live on or in another organism and steal nourishment from their host. In many rural areas of the world, parasites are endemic. Malaria is caused by a parasite that is transmitted from person to person by a single mosquito bite

Immunologists and allergists

are physicians who specialize in immune system disorders, such as allergies, asthma, and immunodeficiency and autoimmune diseases.

Hematologists

are physicians who specialize in the diagnosis, treatment, and prevention of blood and bone marrow diseases.

Adenoids

are similar tissues on the posterior wall of the upper pharynx or nasopharynx

The tonsils

are two masses of lymphatic tissue located at the entrance to the upper part of the throat (the oropharynx) that entrap inhaled and ingested pathogens.

Phlebotomists

assist physicians by drawing patient blood samples for laboratory testing.

Abnormal reactions to one's own tissues are ______.

autoimmune disorders

Match each lymphatic system term with the location in the body to which it refers

axillary- armpit cervical- neck Inguinal- groin

Monoclonal antibodies

can attach to cancer cells to flag them for a macrophage

The two types of immunity are ______.

cellular immunity humoral immunity

Granules are the site for ______ and enzyme production.

chemical

Blood is a special type of ______ tissue composed of cells contained in a liquid matrix.

connective

Normally, maternal and fetal blood ______.

do not mix during pregnancy

Cancerous lymph nodes are usually ______.

enlarged, firm, and painless

Nasal smears check the amount of ______ in the nose.

eosinophils

Another name for hemolytic disease of the newborn (HDN) is ______.

erythroblastosis fetalis

The spleen is a reservoir for _____.

erythrocytes platelets

The blood functions in the transport of nutrients, waste products, hormones, and ______.

gases

The protein component of hemoglobin is called ______.

globin

The root in the term agglutination means ______.

glue

Leukocytes (WBCs) can be divided into two groups based on the presence or absence of specific granules in the cytoplasm. Those two groups are ______.

granulocytes and agranulocytes

Allergic reaction symptoms such as mucus hypersecretion, congestion, watery eyes, and urticaria are triggered by the release of ______ from immune system cells.

histamine

Types of physicians who specialize in immune system disorders are _____.

immunologists allergists

Tonsillitis,

inflammation of the tonsils and adenoids, occurs mostly in infancy and childhood. The infection can be viral or bacterial, usually streptococcal. It produces enlarged, tender lymph nodes under the jaw. The infection can be recurrent, and a tonsillectomy is sometimes performed (see Chapter 8). If the adenoids also show recurrent infection, an adenoidectomy can be performed, often at the same time as the tonsillectomy.

Ruptured spleen

is a common complication from car accidents or other trauma when the abdomen and rib cage are damaged. Intra-abdominal bleeding from the ruptured spleen can be extensive, with a dramatic fall in blood pressure. It is considered a surgical emergency requiring a splenectomy.

Lymphoma

is a malignant growth (neoplasm) of the lymphatic organs, usually the lymph nodes. Associated symptoms can be fever, night sweats, fatigue, and weight loss.

Lymphedema

is localized, brawny (does not easily pit on finger pressure), minimally pitting fluid retention caused by a compromised lymphatic system, often after surgery or radiation therapy. It can also be primary, where the cause is unknown.

Match the terms lymphadenitis, lymphadenopathy, and lymphadenectomy with its meaning.

lymphadenitis matches Choice, Swollen lymph nodes that are tender to the touch Swollen lymph nodes that are tender to the touch lymphadenopathy matches Choice, Any condition of enlarged lymph nodes Any condition of enlarged lymph nodes lymphadenectomy matches Choice, Surgical removal of lymph nodes Surgical removal of lymph nodes

Cellular defense of the body against pathogens is mediated by ______, which directly attack the foreign invaders.

lymphocytes

skin tests

measures the level of IgE antibodies in response to allergens injected under the skin

blood test

measures the levels of IgE antibodies to specific allergens in the blood

Interferon alpha

most common type of interferon used in cancer treatment

A person who is Rh-______ lacks the Rh antigen on their RBCs.

negative

Interleukens

nonspecific immunotherapy used to treat kidney and skin cancers

idiopathic thrombocytic purpura (ITP)

occurs when the immune system destroys the body's platelets. An acute, self-limiting form of the disease occurs in children; a chronic form affects adults.

Human immunoglobulins confer ______ immunity.

passive

Medical or clinical laboratory technicians

perform routine testing procedures on body fluids, blood, and other tissues using microscopes, computers, and other laboratory equipment.

B lymphocytes become ______ cells that secrete antibodies upon exposure to an antigen.

plasma

The cells that are most directly involved in hemostasis are ______.

platelets

The spleen is a reservoir for _____.

platelets erythrocytes

Platelets (also called thrombocytes)

play a key role in hemostasis. They are minute fragments of large bone marrow cells and consist of a small amount of granular cytoplasm surrounded by a plasma membrane. They have no nucleus.

If an Rh negative person is transfused with Rh positive blood they will ______.

produce antibodies against the Rh antigen

Which is NOT a function of the spleen?

produce red blood cells

The most numerous cells in the blood are the ______.

red blood cells (RBCs)

Normal flora are microorganisms ______.

that live in or on our bodies and do not harm us

Hemostasis,

the control of bleeding, is a vital issue in maintaining homeostasis, the state of the body's equilibrium. Uncontrolled bleeding can offset the body's balance by decreasing blood volume and lowering blood pressure.

Which of the following is the largest lymphatic organ?

the spleen

Another term for platelets is ______.

thrombocytes

The "T" in the term T cell or T lymphocyte stands for ______, the organ where these cells mature

thymsu

Which of the following statements are true regarding maternal and fetal Rh compatibility?

A first pregnancy in which an Rh-negative mother carries an Rh-negative fetus is usually not problematic. A second pregnancy of an Rh-negative female carrying an Rh-positive fetus could result in HDN in the baby. Maternal and fetal blood do not normally mix during pregnancy. Exposure of fetal blood to maternal blood can occur during delivery or miscarriage.

Disorders of White Blood Cells

A normal cubic millimeter (mm3) of blood contains 5,000 to 10,000 white blood cells. In leukocytosis, the total WBC count exceeds 10,000 per cubic millimeter. Other conditions that increase the WBC count beyond the normal range include: Allergic reactions, which increase the number of eosinophils; Typhoid fever, malaria, and tuberculosis, which increase the number of monocytes; and Whooping cough and infectious mononucleosis, which increase the number of lymphocytes.

The two most important blood groups, based on antigens on the surface of red blood cells, are the ______.

ABO and Rh groups

Match the functions of blood with its description.

transporting wastes matches Choice, Moving creatinine and urea from the cells to the kidneys for excretion. Moving creatinine and urea from the cells to the kidneys for excretion. transporting hormones matches Choice, Moving insulin from the pancreas to the tissues that require it. Moving insulin from the pancreas to the tissues that require it. clotting matches Choice, Preventing blood loss and initiating vessel repair. Preventing blood loss and initiating vessel repair. transporting nutrients matches Choice, Moving glucose absorbed from the intestines to the tissues that need it. Moving glucose absorbed from the intestines to the tissues that need it.

challenge test

very small amounts of allergens are administered by mouth or by inhalation

hemoglobin (Hb)

which gives the cells and blood their red color. Hb is composed of the iron-containing pigment heme bound to a protein called globin. The rest of the red blood cell consists of the cell membrane, water, electrolytes, and enzymes. Mature RBCs do not have a nucleus.

lymphadenopathy

All lymph node enlargements are collectively

Which of the following best describes the shape of an erythrocyte?

Biconcave disc

Deconstruct the term agglutination.

Blank 1: ag Blank 2: glutin Blank 3: ation

Disorders of Red Blood Cells

Anemia is a red blood cell condition where the number of RBCs or amount of hemoglobin contained in each RBC is reduced. Both of these conditions reduce the blood's oxygen-carrying capacity, producing shortness of breath (SOB) and fatigue. The different types of anemia include: Iron-deficiency anemia is the diagnosis for Ms. Sosin (Case Report 7.1). The cause was chronic bleeding from her gastrointestinal tract due to the aspirin and other painkillers she was taking. Her stools were positive for occult blood. Other causes of iron-deficiency anemia can be heavy menstrual bleeds or a diet deficient in iron. Pernicious anemia (PA) is due to vitamin B12 deficiency. It is caused by a shortage of intrinsic factor, which is normally secreted by cells in the stomach lining (see Chapter 9) and binds with B12. This complex is absorbed into the bloodstream. Without B12, hemoglobin cannot form. The number of red cells decreases, hemoglobin concentration decreases, and the size of the red cells increases. Sickle cell anemia is a genetic disorder found most commonly in African Americans. Here, the production of abnormal hemoglobin causes the RBCs to form a rigid sickle shape (Figure 7.3). The abnormal cells agglutinate (clump together) and block small capillaries. This creates intense pain in the hypoxic tissues (a sickle cell crisis) and can lead to stroke, kidney failure, and heart failure. Sickle cell trait is a minor form of this disease and rarely has any symptoms.

Anticoagulants used to reduce or prevent blood clotting include:

Aspirin, which reduces platelet adherence and is used in small 81 mg doses to reduce the incidence of heart attack. Heparin, which prevents prothrombin and fibrin formation and is given parenterally; its dose is monitored by activated partial thromboplastin time (aPTT). Warfarin (Coumadin), which inhibits the synthesis of prothrombin and others to act as an anticoagulant. It is given by mouth and its dose is monitored by prothrombin times (PTs), which are reported as an International Normalized Ratio (INR). Dabigatran etexilate (Pradaxa) and rivaroxaban (Xarelto), which inhibit the synthesis of thrombin and are given by mouth to reduce the risk of embolism and stroke in patients with nonvalvular atrial fibrillation (see Chapter 10). Idarucizumab (Praxbind injection) is available for patients using Pradaxa when reversal of its anticoagulant effects is needed for emergency surgery, for urgent procedures, or in life-threatening or uncontrolled bleeding. Streptokinase, derived from hemolytic streptococci, which dissolves the fibrin in blood clots. Given intravenously within 3 to 4 hours of a heart attack, it is often effective in dissolving a clot that has caused the heart attack. Recombinant Factor VIII, developed through recombinant DNA technology, is the main medication used to treat hemophilia A. It is given intravenously through a vein in the arm or a port in the chest. Desmopressin acetate (DDAVP) is a synthetic version of vasopressin that helps stop bleeding in patients with mild hemophilia. Pernicious anemia is treated initially with injections of vitamin B12, and then the vitamin B12 can be given through a nasal gel. Eltrombopag (Promacta) is available for pediatric patients with idiopathic thrombocytopenic purpura (ITP) who have not responded to corticosteroids, immunoglobulins, or splenectomy. Most leukemias in both adults and children are treated with chemotherapy, often with added radiation therapy and a stem cell transplant.