Lab Diagnostics Exam 4 - HEMATOLOGY

hematopoiesis

all cell lines originate from a pluripotent stem cell that is capable of maturing into many cell lines

myeloid stem cells

multi-colony stimulating factors (multi-CSF) to stimulate differentiation to:

- erythroblasts > erythrocytes

- megakaryocytes > platelets

- myeloblasts > neutrophils, eosinophils, basophils

- monoblasts > monocytes

lymphoid stem cells

differentiation into

- natural killer cells

- B-lymphocytes: antigen driven to form B-cells > plasma cells

- T-lymphocytes: antigen driven to form T-cells

leukocytes

aka "white blood cells;" indicator of infection and/or inflammation

diapedesis

aka "squeezing;" passage of blood cells (especially white blood cells) through intact capillary walls and into the surrounding tissue

leukocytosis

elevated leukocyte count generally associated with bacterial or viral infections

granulocytes

a group of leukocytes containing granules in their cytoplasm (i.e., neutrophils, eosinophils, basophils)

agranulocytes

a group of leukocytes without granules in their nuclei (i.e., lymphocytes, monocytes)

classification of WBC functionality

- myelocytic (granulocytes)

- monocytic

- lymphocytic

"never let monkeys eat bananas"

neutrophils (60%), lymphocytes (30%), monocytes (5%), eosinophils (4%), basophils (1%)

staining of neutrophils

pink (or neutral) granules

staining of eosinophils

red granules

staining of basophils

dark-blue granules

are cells functional in the maturation pool?

no; myelocyte > metamyelocyte > band neutrophil > segmented neutrophils

cardiovascular pool (CVP)

2 sub-compartments

- marginal pool

- circulating pool

marginal pool (MP2)

made up of cells that adhere to the epithelial lining of the vessels (cells can enter or leave circulation)

circulating pool (CP)

- contains the cells which are actively circulating in the bloodstream

- main function is to locate, ingest, and kill bacteria and other foreign invaders

when does the shift from the MP2 to the CP occur?

stress, trauma, or catecholamine release resulting in transient leukocytosis that can last from 4-6 hours

neutrophil

- nuclei segmented (lobes)

- primary defense for bacterial infections

- phagocytic with an active metabolism

what are the major cellular constituent of pus?

neutrophils

neutropenia

decreased number of neutrophils

causes of neutropenia

- decreased production of WBC

- increased neutrophil destruction

- drugs (penicillin)

pseudoneutropenia

a decrease in the neutrophil count associated with cells shifting from the circulatory pool to the marginated pool

neutrophilia

increased numbers of neutrophils

causes of neutrophilia

- acute infection (mostly bacterial)

- acute inflammation

- drugs (steroids, lithium)

pseudoneutrophilia

elevation of the neutrophil count that is the result of cells shifting from the marginated pool to the circulatory pool

the "left shift"

an increase in the number of immature neutrophils in the CP in response to a severe acute bacterial infection

where are many banded neutrophils present?

bone marrow

eosinophils

- bilobed nucleus

- drawn to sites of hypersensitivity reactions by mast cells

- play a role in parasitic infections

- produce histaminase

histaminase

an enzyme that breaks down histamines released by basophils in an effort to reduce inflammation

eosinophilia

increased number of eosinophils

causes of eosinophilia

- allergy (asthma, hay fever, urticaria)

- parasitic infections (tissue-invasive parasites such as trichinosis, visceral larva migrans, or filariasis)

- pernicious anemia

eosinopenia

decreased number of eosinophils

basophils

- least common of the WBCs

- can increase in response to same conditions that cause eosinophils to respond

- migrate into the peripheral tissue and become fixed (mast cells)

heparin

acts as an anticoagulant

histamine

induces vasodilation and increased capillary permeability to promote exudation of fluid into the tissues

SRS-A

slow-reacting substances of anaphylaxis

when you see tissue inflammation, think

basophils

causes of basophilia

- myeloproliferative disorders

- hypersensitivity reactions

- myxedema

- tuberculosis

- diabetes

primary role of monocytic line

phagocytosis; becoming "activated" when direct contact with microorganisms occurs

monocytes

- single, large nucleus with a "horseshoe" appearance

- cytoplasm is densely packed giving the cell a "frosted glass" appearance

monocytosis

increased number of monocytes

causes of monocytosis

- tuberculosis

- IBD

- chronic neutropenia

- sarcoidosis

main function of lymphocytic line

antigen recognition and immune response

2 phases of lymphocyte maturation

- antigen independent

- antigen dependent

antigen independent maturation

occurs in the bone marrow first where the lymphoblast gives rise to either pre-T or pre-B cells

maturation of natural killer cells

pre-T cells that move directly into the CP, bypassing the thymus

antigen dependent maturation

- T-cells migrate into lymphoid tissue

- B-cells migrate to germinal centers

what are the smallest WBCs?

lymphocytes

most common cause of lymphocytosis

viral infection (such as CMV or EBV)

causes of lymphopenia

- immunodeficiency (AIDS, chemo, transplant)

- acute bacterial infection

- increased steroids in circulation

which virus is associated with "atypical" or "reactive" lymphocytes?

an Epstein-Barr virus infectious mononucelosis

3 major divisions of a CBC used to evaluate illnesses

- WBC (infection and/or inflammation)

- RBC (weakness, shortness of breath, fatigue)

- platelets (easy bleeding, clotting disorders)

total white cell count

total number of all leukocytes in a sample

elevated levels of WBC

>11,000

leukemia

increased production of abnormal leukocytes and leukocyte precursors in the bone marrow and in the circulation

acute myelogenous leukemia (AML) on CBC

- hyperleukocytosis (>100,000) with markedly elevated levels of circulating blast cells

- pancytopenia (decreased number of the other WBC, RBC, and platelets)

acute myelogenous leukemia (AML) on blood smear

- increased number of immature cells with many myeloblasts and promyelocytes

- severe decrease in thrombocytes

- auer rods

acute lymphocytic leukemia (ALL)

most common form of leukemia in children

acute lymphocytic leukemia (ALL) on CBC

pancytopenia

acute lymphocytic leukemia (ALL) on blood smear

decreased number of platelets and RBC

terminal deoxynucleotidyl transferase stain (TdT)

if positive, aids in the diagnosis of ALL in children

chronic myelogenous leukemia (CML) on CBC

leukocytosis with a median WBC count of 150,000

chronic myelogenous leukemia (CML) on bone biopsy

- hypercellular with a left shift

- PCR used to identify BCR-ABL gene (aka Philadelphia gene)

chronic lymphocytic leukemia (CLL) on CBC

isolated leukocytosis with a WBC >20,000

lymph cells involved in chronic lymphocytic leukemia (CLL)

- B-cell CD19

- T-cell CD5

chronic lymphocytic leukemia (CLL) on peripheral blood smear and bone biopsy

- increase in mature but small lymphocytes

- smear aka "smudge" cells

Hodgkin's lymphoma on lymph node biopsy

Reed-Sternberg cells

what virus is present in half the cases of Hodgkin's lymphoma?

EBV

non-Hodgkin's lymphoma

90% of cases are from B-cells

non-Hodgkin's lymphoma on lymph node biopsy

invasion of prolymphocytic-like cells

plasma cell myeloma

previously called "multiple myeloma;" produces an abundance of monoclonal paraprotein (M protein)

Bence-Jones protein

also referred to "M-proteins," "myeloma proteins," "paraproteins," and "free immunoglobulin light chains"

production of Bence-Jones protein

component of immunoglobulin produced in excess by B cell-derived clonal cell populations

diagnostic testing for PCM (multiple myeloma)

- serum protein electrophoresis

- CBC

- serum protein

- urine and serum Bence-Jones proteins

- serum free kappa to lambda ratio

- bone marrow biopsy

toxic vacuolization

round, clear spaces within granulocyte cytoplasm; seen in patients with severe bacterial infections

toxic granualization

presence associated with bacterial infections, drug poisoning, and burns

auer rods

slender, rod-shaped bodies within the cytoplasm, only seen in blasts

Dohle bodies

round-oval pale grayish-blue inclusions that are found in the periphery of the cytoplasm of neutrophils, accompanies toxic granulation

smudge cells

reflects the fragility of lymphocytes

erythrocytes

- red blood cells

- stimulated by erythropoietin from the kidneys

polycythemia

increased RBC count

hemoglobin

oxygen carrying capacity

hematocrit

represents the percentage of cells per fluid volume

the "rule of three"

RBC count x 3 = hemoglobin x 3 = hematocrit

mean corpuscular volume (MCV)

a gauge of cell size

normocytic

80-100

microcytic

<80

macrocyctic

>100

mean corpuscular hemoglobin concentration (MCHC)

average concentration of hemoglobin per erythrocyte

normochromic

30-35

hypochromic

- <30

- deficiency of Hgb in the red blood cells

mean corpuscular hemoglobin (MCH)

average weight of hemoglobin per erythrocyte

normal MCH

27-32

anemia

condition in which the blood is deficient in RBCs, in Hgb, or in total volume

erythropoietin

glycoprotein hormone that stimulates the production of RBC by bone marrow

anisocytosis

variation in RBC size

poikilocytosis

variation in RBC chape

polychromasia

- increased number of abnormal colored RBC

- indicative of increased reticulocytes in the peripheral circulation

reticulocytes

- immature erythrocytes that are produced from erythroblasts

- constitutes about 1-1.5% of RBC volume