White Blood Cell Disorders Flashcards
Normal, Low, High WBC count
Normal = 5-10k
low < 5k = leuopenia
high > 10k = leukocytosis
Neutropenia
Decreased circulating neutrophils. Caused by
1) Drug toxicity = chemo damages stem cells and especially neutrophils. Give GM-CSF or G-CSF to boost granulocyte/neutrophils and prevent infection
2) Sever infection (gram negative sepsis) = neutrophils exit circulation and go into tissues to fight infection
Lymphopenia
Decreased circulating lyphocytes Causes:
1) Immunodeficiency = HIV or DiGeorge Syndrome = no thymus to make lymphocytes
2) High Cortisol state = exogenous corticosteroids or cushing syndrome. They causes apoptosis of lymphocytes
3) Autoimmune destruction = SLE
4) Whole body irradiation = lymphocytes are especially sensitive to radiation
Neutrophilic Leukocytosis
Increased circulating Neutrophils. Causes:
1) Bacterial infection or tissue necrosis = release of marginated pool (hanging out in tissues or latched on vessels) and bone marrow. Get immature forms (left shift). These immature cells lack Fc receptors so less likely to recognize Ig which acts as opsonin for phagocytosis , These immature neutrophils are often called “CD 16 nuetrophils”
2) High cortisol state = impairs leukocyte adhesion, so marginated pools enter circulation
Monocytosis
Increased circulating monocytes. Seen in chornic inflammatory states (autimmune or infections) and malignancy
Eosinophilia
Increased circulating eosinophils. Seen allergic reactions (Type I hypersensitivity), parasitic infections, and HODGKINS LYMPHOMA (release IL5 which is a eosinophil chemotaxic factor)
Basophilia
Increased basophils in circulation. Seen in CML
Lympocytic Leukocytosis
Increased circulating lymphocytes. Caused by
1) viral infections = t lymphocytes undergo hyperplasia in response to virally infected cells
2) Bordella pertussis = bacteria is strange in that it produces lymphocytosis-promoting factor, which blocks circulating lymphocytes from leaving the blood to enter the lymph node
Infectious Mononucleosis
EBV infection that results in lymphocytic leukocytosis comprised of CD8+ T cells.
Transmitted by saliva
Infects 1)oropharynx = pharyngitis 2) liver = hepatitis with hepatomegally and elevated liver enzymes 3)B cells
CD8+ T cell response leads to 1)generalized lymphadenopathy due to T cell hyperplasia in lymph node PARACORTEX 2) splenomegaly due to T cell hyperplasia in periarterial lymphatic sheath (PALS) 3)HIGH WBC with atypical lymphocytes (reactive CD8+ T cells)
Monospot Test
Detects IgM antibodies that cross react with horse or sheep RBCs. Positive after 1 week of infection. Definitive diagnosis is serologic testing for EBV viral capsid antigen. Negative monospot test indicates test done too early or CMV
Complciations of Infectious Mononucleosis
Increased risk for splenic rupture (avoid sports for 1 year)
Rash if exposed to ampicilin
Dormnacy of virus in B Cells leads to icnreased risk for recurrence and B Cell Lymphoma especially in immunodeficiency (HIV)
Acute Leukemia
Neoplastic proliferation of blasts (>20% blasts in bone marrow). Blasts “crowd out” normal hematopoiesis resulting in “acute” anemia (fatigue), thrombocytopenia (bleeding), and neutropenia (infection). Subdivided into ALL (TdT+) or AML (MPO+/auer rods)
Acute Lymphoblastic Leukemia (ALL)
Neoplastic accumulation of lymphoblasts in the bone marrow.
TdT+ (a DNA polymerase). Is absent in Mature lymphoblasts and myeloid blasts
Most commonly seen in children, see in Down Syndrome patients AFTER age of 5
B-ALL
Most common type of ALL
TdT+, and express CD10,19,and 20
Excellent response to to chemo but need to prophylactically treat scrotum and CNS since drugs cant cross their barriers
t(12;21) = children. great prognosis
t(9;22) = philadephia + ALL (remember philadelphia is normally seen in CML) and occurs in adults and carries poor prognosis
T-ALL
TdT+, express CD2-8. NOT CD10.
presents in Teenagers as Thymic mass (mediastinal mass)
Called acute lymphoblastic lymphOMA since malignant cells form a mass and do not go through blood like leukemia)
Acute Myeloid Leukemia
Neoplastic proliferation of immature myeloid cells (>20%) in bone marrow. Myeloperoixidase (MPO)+ (can form crystal aggreagates seen in blood smear as Auer Rods.
Usually see in older afults
Acute Promyelocytic Leukemia (APL)
characterized by t(15;17) that involves translocation of retinoic acid receptor (RAR) on Cr 17 to 15, RAR disruption blocks matureation and promyelocytes (blasts) accumulate)
These abnormal promyelocytes contain primary granules (auer rods) that increase risk for DIC
Treat with All-Trans Retinoic Acis (ATRA_ that binds altered ARA receptor and force blastst to mature (and therefore eventually die)
Acute Monocytic Leukemia
Proliferation of monoblasts (usually lack MPO).
INFILTRATES GUMS
Acute Megakaryoblastic Leukemia
Proliferation of megakaryoblasts (lack MPO)
Associated with Down Syndrome BEFORE age of 5
Risk factors for AML
Pre-existing dysplasias/myelodysplastic syndromes
Exposure to alkylating agents or radiotherapy
Down syndrome ( Acute Megakaryoblastic Leukemia)
Myelodysplastic Syndromes
Usually present with cytopenias, hypercellular bone marrow, and abnormal maturation cells but blasts are less than 20%.
Die from bleeding or infection but can progress to Acute leukemia
Leukemias in Down Syndrome
AML (especially acute megakaryoblasts) BEFORE age 5.
ALL AFTER age of 5.
CD10,19,20
CD2-8
B-ALL
T-ALL
Chronic Leukemia
Neoplastic proliferation of meture cicurlating lymphocytes.
High WBC count
insidious onset seen in older adults
Chronic Lymphocytic Leukemia (CLL)
Neoplastic proliferation of naive B cells that coexpress CD5 and CD 20.
Increased lymphocytes and smudge cells are seen on blood smear.
Involvement of lymph nodes leads to generalized lymphadenopathy and is called small lyphocytic lymphoma
Complications include
1) hypogammaglobulinemia - infection is most common cause of death
2) Autoimmune hemolytic anemia
3) Transformation to diffuse B cell lymphoma (Richter transfomration) marked by enlarging lymph node or spleen.