HemOnc Flashcards
term for process of blood cell production in
- adult bone marrow
- liver/spleen of fetus (mainly liver)
hematopoiesis
differentiation of hematopoietic stem cells
(hematopoiesis process)
- stem cell pool: proginitor cells ->
- bone marrow pool ->
- peripheral blood:
- granulocytes
- megakaryocyes -> trhomboytes
- erythrocytes
primary residence of hematopoietic stem cells
bone marrow (myeloid tissue)
- red vs. yellow
- adult active bone marrow:
- pelvic bones
- vertebrae
- cranium and mandible
- stermun and ribs
- humerus and femur
these control differentiation of hematopoietic progenitor cells
and the stem cells found in these
niches
- osteoblastic niche
- mesenchymal stem cells (MSC)
- differentiate into osteoblasts, adipocytes, chondrocytes (chartilage)
- mesenchymal stem cells (MSC)
- vascular niche
- hematopoietic stem cells (HSC)
- progenitors of all hematologic cells
- hematopoietic stem cells (HSC)
terms for unlimited vs. more limited differentiation hematopoietic cells
and what controls differentiation
- pluripotent cells - unlimited differentiation potential
- multipotent cells - more limited, but differentiate into many types
- colony-stimulating factors (CSFS) or hematopoietic growth factors
- stimulate progenitor cells to mature
- synthetic CSFS can be used to increase neutrophils
development of RBCs
erythropoiesis
- erythroblasts (normoblasts) derive erythrocytes
- stimulated by erythropoietin (EPO)
- produced by peritubular cells in the kidneys
- response to tissue hypoxia
reticulocyte count
(what is it)
- part of any enemia workup
- immature erythrocytes
- index of erythropoietic activity
- indicates if new RBCs are being producted
- # of circulating RBCs is constant if healthy
- in each step hemoglobin increases and nucleus decreases
term for formation of WBCs
leukopoiesis
leukopoiesis stimulated by 2 types of chemical messengers
from red bone marrow and matre WBCs
- interleukins (numbered IL-3, IL-5, etc)
- colony-stimulating factors / CSFS (named for WBC type they stimulate)
- all WBCs (leukocytes) come from hemocytoblasts (progenitor of WBCs) that branches into 2 pathways:
- Lymphoid stem cells - produce B and T lymphocytes
-
Myeloid stem cells - produce all other elements
- eosinophils, basophils, neutrophils, monocytes
function of neutrophil
phagocytize bacteria (first responder)
function of eosinophil
kill parasitic worms
complex role in allergy/asthma
function of basophil
release histamine and other inflammatory mediators
contain heparin (anticoagulant)
function of lymphocyte
immune response via antibodies or direct attack
term for formation of platelets
thrombopoiesis
hematopoietic stem cell -> megakaryocyte -> platelet fragments
indications for peripheral blood smear
- verification of automated results
- potential immediate diagnosis
- can narrow differential diagnostic list
terms for erythrocyte alterations
too many, too few, abnomal components
- polycythemias - too many
- anemia - too few
4 causes of anemia
- impaired erythrocyte production
- lowered hemoglobin synthesis
- DNA synthesis
- stem cell
- bone marrow infiltration
- pure red cell aplasia
- acute/chronic blood loss
- increased erythrocyte destruction
- intrinsic (within RBC) vs. extrinsic (outside RBC)
- combination of the above
anemia classifications
- etiologic factor (cause)
- size
- -cytic
- macrocytic (large), microcytic (small), normocytic (normal)
- hemoglobin content
- -chromic
- normochromic (normal amount), hypochromic (decreased)
- appearance
- anisocytosis - RBCs present in various sizes
- poikilocytosis - RBCs present in various shapes
different microcytic anemias
- iron deficiency
- thalassemia major
- thalassemia minor
important H&H measurements
- hemaglobin (g/dL)
- hematocrit (% of RBC in whole blood)
- red blood cell count (x10^6 /uL of blood)
- mean cell volume - MCV (fL)
- reticulocyte count (no/uL of blood)
anemia symptoms
- often none
- fatigue, dyspnea, palpations, pallor
- decreased exercise tolerance
- HG <7.5: CO, stroke volume, HR increase
- severe Sxs:
- cardiac- dizziness, HA, syncope, tinnitis, vertigo, MI
- irritable, decreased sleep and concentration
- cold sensitivity, yellowing skin/eyes
- GI: indigestion, anorexia, nausea
- abnormal menstruation, amenorrhea/increased bleeding
- impotence, loss of libido
- enlarged spleen
assessing anemia
(what to determine)
- is it decreased RBC production
- reticulocytes inappropriately low
- MCV, MCHC are informative
- bone marrow exam often required for Dx
- usually acquired
- increased RBC destruction (hemolysis)
- reticulocyte count increased
- RBC morphology on blood smear informative
- no bone marrow exam
- usually inherited
- blood loss
- must be ruled out
anemia workup
- CBC
- MCV: micro vs. macro
- reticulocyte count: distinguish decr. production vs. hemolysis
- elevation = hemolysis
- reduction = failure to produce
- peripheral blood smear
- esp. in enexplained anemia - pathologist will examine
- bone marrow examination
- quantitiy/quality of RBC precursors: defect in production
- hypoplasia or ineffective erythropoiesis
- cellularity: ratio of myeloid to erythroid precursors
- increased by inclusion of leukocytes, infection, leukemoid reaction, neoplastic myeloid cells
- presence of cellular infiltrates: leukemia, lymphoma, multiple myeloma
- quantitiy/quality of RBC precursors: defect in production
anemia d/t blood loss
- acute loss
- sxs secondary to hypovolemia and hypoxia
- vital signs reflect CV compensation
- assess postural orthostatic signs:
- supine to sitting: hypovolemia (loss >1000ml)
- pulse increase of 25%+
- systolic BP fall of 20+
- supine to sitting: hypovolemia (loss >1000ml)
- loss >1500ml leads to cardiovascular collapse
- leukocytosis (left shift) on labs
- tx
- transfusion of PRBCs, monitor and volume replacement
- control bleeding
- emergent coagulation profile
- chronic loss
- usually lesions in GI tract or uterus
- stool specimens and rectal exam
- manifests like iron deficiency anemia
- usually lesions in GI tract or uterus
3 major anemia classifications
(according to size or MCV of RBCs)
- microcytosis
- iron deficiency
- thalassemias
- amemia of chronic disease
- sideroblastic (acquired: drugs, congenital)
- atypical, abnormal nucleated erythroblasts w/ granules of iron accumulated in perinuclear mitochondria
- macrocytosis
- RBC aplasia
- alcoholism
- aplastic anemia
- myelodysplastic syndromes
- megaloblasic anemias
- hemolytic anemias
- extrinsic- antibody, microangiopathic, toxins, malaria
- intrinsic- RBC membrane defect, hemoglobinopathies
- normocytosis
- anemia of chronic disease
- acute hemorrhage
- hemoglobinopathies
- primary bone marrow failure
- aplasia
- myelophthisis
- secondary to chronic disease
anemia characterized by small RBCs with reduced hemoglobin
microcytic-hypochromic anemia
causes of microcytic-hypochromic anemia
- disorders of iron metabolism
- disorders of porphyrin and heme synthesis
- disorders of globin synthesis
the microcytic-hypochromic anemias
(improper HGB making cell smaller / MCV <80fl)
TICS
- T - thalessemias
- hemoglobin electrophoresis to quantify HGB A2 and F
- I - iron deficiency
- TIBC (total Fe binding), serum ferritin, transferrin (% Fe saturation)
- C - chronic disease/inflammatory
- inflammation can be detected w/ CRP or ESR
- 30% microcytic, 70% normocytic
- kidney damage MCC - can’t excrete EPO
- S - sideroblastic
significant reduction in size of circulating RBCs
w/ insufficient amounts of Fe
iron-deficiency microcytic-hypochromic anemia
function of monocytes
phagocytosis in tissues
