Hematology and Oncology - First Aid Flashcards
Blood Cells:
- carry O2 to tissues and CO2 to lungs
- anucleate and lack organelles
- biconcave with large surface area-to-volume ratio for rapid gas exchange
- life span of 120 days
- source of energy is glucose (90% used in glycolysis, 10% used in HMP shunt)
- membranes contain Cl−/HCO3− antiporter, which allow export of HCO3− and transport CO2 from the periphery to the lungs for elimination
Erythrocytes
Erythrocytes:
- polycythemia
- ↑ Hct
Erythrocytosis
Erythrocytes:
varying sizes
Anisocytosis
Erythrocytes:
varying shapes
Poikilocytosis
Erythrocytes:
- immature RBC
- reflects erythroid proliferation
Reticulocyte
Erythrocytes:
Bluish color (polychromasia) on Wright-Giemsa stain of reticulocytes represents \_\_\_\_\_.
residual ribosomal RNA
Blood Cells:
- involved in 1° hemostasis
- small cytoplasmic fragments derived from megakaryocytes
- life span of 8–10 days
- when activated by endothelial injury, aggregate with other _____ and interact with fibrinogen to form platelet plug
- contain dense granules (ADP, Ca2+) and α granules (vWF, fibrinogen, fibronectin)
- approximately 1⁄3 is stored in the spleen
Thrombocytes (Platelets)
Thrombocytopenia or ↓ platelet function results in _____.
petechiae
Thrombocytes (Platelets):
vWF Receptor
GpIb
Thrombocytes (Platelets):
Fibrinogen Receptor
GpIIb/IIIa
Thrombopoietin stimulates _____.
megakaryocyte proliferation
Leukocytes are divided into granulocytes (neutrophils, eosinophils, basophils, mast cells) and mononuclear cells (monocytes, lymphocytes). WBC differential counts from highest to lowest are _____.
Neutrophils Like Making Everything Better.
- Neutrophils (~ 60%)
- Lymphocytes (~ 30%)
- Monocytes (~ 6%)
- Eosinophils (~ 3%)
- Basophils (~ 1%)
Leukocytes:
Granulocytes
- Neutrophils
- Eosinophils
- Basophils
- Mast Cells
Leukocytes:
Mononuclear Cells
- Monocytes
- Lymphocytes
Blood Cells:
- acute inflammatory response cells
- numbers ↑ in bacterial infections
- phagocytic
- multilobed nucleus
- specific granules contain leukocyte alkaline phosphatase (LAP), collagenase, lysozyme, and lactoferrin
- azurophilic granules (lysosomes) contain proteinases, acid phosphatase, myeloperoxidase, and β-glucuronidase
- hypersegmented _____ (nucleus has 6+ lobes) are seen in vitamin B12/ folate deficiency
- ↑ band cells (immature _____) reflect states of ↑ myeloid proliferation (bacterial infections, CML)
Neutrophils
Important Neutrophil Chemotactic Agents
- C5a
- IL-8
- LTB4
- Kallikrein
- Platelet-Activating Factor
Blood Cells:
- found in blood
- differentiate into macrophages in tissues
- large, kidney-shaped nucleus
- extensive “frosted glass” cytoplasm
Monocytes
Blood Cells:
- phagocytose bacteria, cellular debris, and senescent RBCs
- long life in tissues
- differentiate from circulating blood monocytes
- activated by γ-interferon
- can function as antigen-presenting cell via MHC II
- name differs in each tissue type (eg. Kupffer cells in liver, histiocytes in connective tissue, Langerhans cells in skin, osteoclasts in bone, microglial cells in brain)
- important component of granuloma formation (eg. TB, sarcoidosis)
- Lipid A from bacterial LPS binds CD14 on _____ to initiate septic shock
Macrophages
Macrophages:
liver
Kupffer Cells
Macrophages:
connective tissue
Histiocytes
Macrophages:
skin
Langerhans Cells
Macrophages:
bone
Osteoclasts
Macrophages:
brain
Microglial Cells
Blood Cells:
- defend against helminthic infections (major basic protein)
- bilobate nucleus
- packed with large eosinophilic granules of uniform size
- highly phagocytic for antigen-antibody complexes
- produce histaminase, major basic protein (MBP, a helminthotoxin), _____ peroxidase, _____ cationic protein, and _____-derived neurotoxin
Eosinophils
Causes of Eosinophilia
PACCMAN:
- Parasites
- Asthma
- Churg-Strauss Syndrome
- Chronic Adrenal Insufficiency
- Myeloproliferative Disorders
- Allergic Processes
- Neoplasia (eg. Hodgkin Lymphoma)
Blood Cells:
- mediate allergic reaction
- densely basophilic granules contain heparin (anticoagulant) and histamine (vasodilator)
- leukotrienes synthesized and released on demand
- stains readily with basic stains
Basophils
Blood Cells:
- mediate allergic reaction in local tissues
- contain basophilic granules and originate from the same precursor as basophils but are not the same cell type
- can bind the Fc portion of IgE to membrane
- activated by tissue trauma, C3a and C5a, surface IgE crosslinking by antigen (IgE receptor aggregation) → degranulation → release of histamine, heparin, tryptase, and eosinophil chemotactic factors
- type I hypersensitivity reactions
- cromolyn sodium prevents degranulation (used for asthma prophylaxis)
Mast Cells
Blood Cells:
- highly phagocytic antigen-presenting cells (APCs)
- function as link between innate and adaptive immune systems
- express MHC class II and Fc receptors on surface
- called Langerhans cell in the skin
Dendritic Cells
Blood Cells:
- refer to B cells, T cells, and NK cells
- B cells and T cells mediate adaptive immunity
- NK cells are part of the innate immune response
- round, densely staining nucleus with small amount of pale cytoplasm
Lymphocytes
Blood Cells:
- part of humoral immune response
- originate from stem cells in bone marrow and matures in marrow
- migrate to peripheral lymphoid tissue (follicles of lymph nodes, white pulp of spleen, unencapsulated lymphoid tissue)
- when antigen is encountered, _____ differentiate into plasma cells (which produce antibodies) and memory cells
- can function as an APC
B Cells
B = Bone marrow
Blood Cells:
- mediate cellular immune response
- originate from stem cells in the bone marrow, but mature in the thymus
- differentiate into cytotoxic _____ (express CD8, recognize MHC I), helper _____ (express CD4, recognize MHC II), and regulatory _____
- CD28 (costimulatory signal) necessary for activation
- most circulating lymphocytes (80%)
- CD4+ helper _____ are the primary target of HIV
T Cells
T = Thymus
Rule of 8:
- MHC II × CD4 = 8
- MHC I × CD8 = 8
Blood Cells:
- produce large amounts of antibody specific to a particular antigen
- “clock-face” chromatin distribution and eccentric nucleus, abundant RER, and well-developed Golgi apparatus
- found in bone marrow and normally do not circulate in peripheral blood
- multiple myeloma is a _____ cancer
Plasma Cells
Fetal Erythropoiesis
Young Liver Synthesizes Blood.
- Yolk sac (3–8 weeks)
- Liver (6 weeks–birth)
- Spleen (10–28 weeks)
- Bone marrow (18 weeks to adult)
Hemoglobin Development
Embryonic Globins: ζ and ε
fetal → adult hemoglobin:
Alpha Always; Gamma Goes, Becomes Beta
- Fetal Hemoglobin (HbF) = α2γ2
- Adult Hemoglobin (HbA1) = α2β2
HbF has higher affinity for O2 due to less avid binding of 2,3-BPG, allowing HbF to extract O2 from maternal hemoglobin (HbA1 and HbA2) across the placenta. HbA2 (α2δ2) is a form of adult hemoglobin present in small amounts.
Blood Groups
Hemolytic disease of the newborn is also known as _____.
Erythroblastosis Fetalis
Rh HDN:
Interaction
- Rh ⊝ mothers
- Rh ⊕ fetus
Rh HDN:
Mechanism
- First Pregnancy:
- mother exposed to fetal blood (often during delivery) → formation of maternal anti-D IgG
- Subsequent Pregnancies:
- anti-D IgG crosses the placenta → HDN in the fetus
Rh HDN:
Presentation
- jaundice shortly after birth
- kernicterus
- hydrops fetalis
Rh HDN:
Treatment
- Prevent by administration of anti-D IgG to Rh ⊝ pregnant women during third trimester and early postpartum period (if fetus tests ⊕ for Rh).
- Prevents maternal anti-D IgG production.
ABO HDN:
Interaction
- Type O mothers
- Type A or B fetus
ABO HDN:
Mechanism
Pre-existing maternal anti-A and/or anti-B IgG antibodies cross placenta → HDN in the fetus.
ABO HDN:
Presentation
- mild jaundice in the neonate within 24 hours of birth
- usually less severe than Rh HDN
ABO HDN:
Treatment
- phototherapy
- exchange transfusion
Hemoglobin Electrophoresis
- On a gel, hemoglobin migrates from the negatively charged cathode to the positively charged anode.
- HbA migrates the farthest, followed by HbF, HbS, and HbC.
- This is because the missense mutations in HbS and HbC replace glutamic acid ⊝ with valine (neutral) and lysine ⊕, respectively, impacting the net protein charge.
A Fat Santa Claus
Coagulation and Kinin Pathways
Coagulation Cascade Components:
Procoagulation
- Vitamin K Deficiency: ↓ synthesis of factors II, VII, IX, X, protein C, protein S
- Warfarin inhibits vitamin K epoxide reductase. Vitamin K administration can potentially reverse inhibitory effect of warfarin on clotting factor synthesis. FFP or PCC administration reverses action of warfarin immediately and can be given with vitamin K in cases of severe bleeding.
- Neonates lack enteric bacteria, which produce vitamin K. Early administration of vitamin K overcomes neonatal deficiency/coagulopathy.
- Factor VII—shortest half life
- Factor II—longest half life
volksWagen Factories make gr8 cars.
- vWF carries/protects factor VIII
Coagulation Cascade Components:
Anticoagulation
- Antithrombin inhibits activated forms of factors II, VII, IX, X, XI, XII.
- Heparin enhances the activity of Antithrombin.
- Targets of Antithrombin:
- Thrombin
- Factor Xa
- Factor V Leiden mutation produces a factor V resistant to inhibition by activated protein C.
- tPA is used clinically as a thrombolytic.
Platelet Plug Formation
(Primary Hemostasis)
Thrombogenesis
- Formation of insoluble fibrin mesh.
- Aspirin irreversibly inhibits cyclooxygenase, thereby inhibiting TXA2 synthesis.
- Clopidogrel, prasugrel, and ticlopidine inhibit ADP-induced expression of GpIIb/IIIa by irreversibly blocking P2Y12 receptor.
- Abciximab, eptifibatide, and tirofiban inhibit GpIIb/IIIa directly.
- Ristocetin activates vWF to bind GpIb.
- Failure of aggregation with ristocetin assay occurs in von Willebrand disease and Bernard-Soulier syndrome.
Pathologic RBC Forms:
- liver disease
- abetalipoproteinemia (states of cholesterol dysregulation)
- spiny appearance
Acanthocytes
(“Spur Cells”)
Pathologic RBC Forms:
- Sideroblastic Anemias:
- lead poisoning
- myelodysplastic syndromes
- thalassemias
- seen primarily in peripheral smear, vs. ringed sideroblasts seen in bone marrow
- aggregation of residual ribosomes
Basophilic Stippling
Pathologic RBC Forms:
- bone marrow infiltration (eg. myelofibrosis)
- thalassemias
Dacrocytes
RBC “sheds a tear” because it’s mechanically squeezed out of its home in the bone marrow.
(“Teardrop Cells”)
Pathologic RBC Forms:
G6PD deficiency
Degmacytes
(“Bite Cells”)
Pathologic RBC Forms:
- end-stage renal disease
- liver disease
- pyruvate kinase deficiency
- different from acanthocyte; its
- projections are more uniform and
- smaller.
Echinocytes
(“Burr Cells”)
Pathologic RBC Forms:
- hereditary elliptocytosis
- usually asymptomatic
- caused by mutation in genes encoding RBC membrane proteins (eg. spectrin)
Elliptocytes
Pathologic RBC Forms:
megaloblastic anemia (also hypersegmented PMNs)
Macro-Ovalocytes
Pathologic RBC Forms:
- sideroblastic anemia
- excess iron in mitochondria
- seen in bone marrow with special staining (Prussian blue), vs. basophilic stippling in peripheral smear
Ringed Sideroblasts
Pathologic RBC Forms:
- Microangiopathic Hemolytic Anemias:
- DIC
- TTP/HUS
- HELLP syndrome
- mechanical hemolysis (eg. heart valve prosthesis)
- fragmented RBCs (eg. helmet cells)
Schistocytes
Pathologic RBC Forms:
- sickle cell anemia
- sickling occurs with dehydration, deoxygenation, and at high altitud
Sickle Cells
Pathologic RBC Forms:
K K Hereditary spherocytosis, drug- and
infection-induced hemolytic
anemia.
Small, spherical cells without
central pallor.
Spherocytes
Pathologic RBC Forms:
- HbC disease
- asplenia
- liver disease
- thalassemia
Target Cells
“HALT,” said the hunter to his target.
- HbC disease
- Asplenia
- Liver disease
- Thalassemia
RBC Abnormalities:
- seen in G6PD deficiency
- oxidation of Hb -SH groups to -S—S- → Hb precipitation, with subsequent phagocytic damage to RBC membrane bite cells.
Heinz Bodies (Hb)
RBC Abnormalities:
Howell-Jolly bodies B B Seen in patients with functional
hyposplenia or asplenia.
Basophilic nuclear remnants found
in RBCs.
Howell-Jolly bodies are normally
removed from RBCs by splenic
macrophages.
Anemias
Microcytic, Hypochromic Anemias
MCV < 80 fL
- Defective Heme Synthesis:
- iron deficiency (late)
- lead poisoning
- sideroblastic anemia
- anemia of chronic disease
- Defective Globin Chain:
- thalassemias
Anemias:
- microcytic, hypochromic
- ↓ iron due to chronic bleeding (eg. GI loss, menorrhagia), malnutrition, absorption disorders, GI surgery (eg. gastrectomy), or ↑ demand (eg. pregnancy) → ↓ final step in heme synthesis
- Labs:
- ↓ iron
- ↑ TIBC
- ↓ ferritin
- ↑ free erythrocyte protoporphyrin
- ↑ RDW
- ↑ central pallor
- Symptoms:
- fatigue
- conjunctival pallor
- pica (consumption of nonfood substances)
- spoon nails (koilonychia)
- May manifest as glossitis, cheilosis, or Plummer-Vinson syndrome (triad of iron deficiency anemia, esophageal webs, and dysphagia).
Iron Deficiency
_____ is the triad of iron deficiency anemia, esophageal webs, and dysphagia.
Plummer-Vinson Syndrome
Anemias:
- microcytic, hypochromic
- α-globin gene deletions → ↓ α-globin synthesis
- cis deletion (deletions occur on same chromosome) prevalent in Asian populations
- trans deletion (deletions occur on separate chromosomes) prevalent in African populations
- normal is αα/αα
α-Thalassemia
α-Thalassemia:
- 1 deleted α-globin gene (α α/α –)
- no anemia (silent carrier)
α-Thalassemia Minima
α-Thalassemia:
- 2 deleted α-globin genes
- (α –/α –; trans)
- (α α/– –; cis)
- mild microcytic, hypochromic anemia
- cis deletion may worsen outcome for the carrier’s offspring
α-Thalassemia Minor
α-Thalassemia:
- 3 deleted α-globin genes (– –/– α)
- excess β-globin forms β4
- moderate to severe microcytic hypochromic anemia
Hemoglobin H Disease (HbH)
α-Thalassemia:
- 4 deleted α-globin genes (– –/– –)
- no α-globin
- excess γ-globin forms γ4
- hydrops fetalis
- incompatible with life
Hemoglobin Barts Disease (Hb Barts)
Anemias:
- microcytic, hypochromic
- point mutations in splice sites and promoter sequences → ↓ β-globin synthesis
- prevalent in Mediterranean populations
β-Thalassemia
β-Thalassemia:
- heterozygote
- β chain is underproduced
- usually asymptomatic
- diagnosis confirmed by ↑ HbA2 (> 3.5%) on electrophoresi
β-Thalassemia Minor
β-Thalassemia:
- homozygote
- β chain is absent → severe microcytic, hypochromic anemia with target cells and increased anisopoikilocytosis requiring blood transfusion (2° hemochromatosis)
- marrow expansion (“crew cut” on skull x-ray) → skeletal deformities
- “chipmunk” facies
- extramedullary hematopoiesis → hepatosplenomegaly
- ↑ risk of parvovirus B19–induced aplastic crisis
- ↑ HbF (α2γ2), HbA2 (α2δ2)
- HbF is protective in the infant and disease becomes symptomatic only after 6 months, when fetal hemoglobin declines
β-Thalassemia Major
β-Thalassemia:
mild to moderate sickle cell disease depending on amount of β-globin production
HbS/β-Thalassemia Heterozygote
Anemias:
- microcytic, hypochromic
- inhibits ferrochelatase and ALA dehydratase → ↓ heme synthesis and ↑ RBC protoporphyrin
- also inhibits rRNA degradation → RBCs retain aggregates of rRNA (basophilic stippling)
- Succimer used for chelation for kids
- exposure risk ↑ in old houses with chipped paint
Lead Poisoning
Symptoms of Lead Poisoning
LEAD:
- Lead Lines on gingivae (Burton lines) and on metaphyses of long bones on x-ray
- Encephalopathy and Erythrocyte basophilic stippling
- Abdominal colic and sideroblastic Anemia
- Drops—wrist and foot drop, Dimercaprol and EDTA are 1st line of treatment
Anemias:
- microcytic, hypochromic
- Causes:
- genetic (eg. X-linked defect in ALA synthase gene)
- acquired (myelodysplastic syndromes)
- reversible (alcohol is most common; also lead, vitamin B6 deficiency, copper deficiency, isoniazid, chloramphenicol).
- Lab findings:
- ↑ iron
- normal/↓ TIBC
- ↑ferritin
- ringed sideroblasts (with iron-laden, Prussian blue–stained mitochondria) seen in bone marrow
- peripheral blood smear—basophilic stipplin of RBCs
- Treatment:
- Pyridoxine (B6, cofactor for ALA synthase)
Sideroblastic Anemia
Macrocytic Anemias
MCV > 100 fL
- Megaloblastic (Nuclear Defects):
- Defective DNA Synthesis:
- folate deficiency
- vitamin B12 deficiency
- orotic aciduria
- Defective DNA Repair:
- •Fanconi anemia
- Defective DNA Synthesis:
- Nonmegaloblastic
- Diamond-Blackfan anemia
- liver disease
- alcoholism
Anemias:
- macrocytic
- impaired DNA synthesis → maturation of nucleus of precursor cells in bone marrow delayed relative to maturation of cytoplasm
- RBC macrocytosis, hypersegmented
neutrophils, glossitis
Megaloblastic Anemia
Anemias:
- macrocytic
- megaloblastic
- Causes:
- malnutrition (eg. alcoholics)
- malabsorption
- drugs (eg. methotrexate, trimethoprim, phenytoin)
- ↑ requirement (eg. hemolytic anemia, pregnancy)
- ↑ homocysteine, normal methylmalonic acid
- no neurologic symptoms (vs. B12 deficiency)
Folate Deficiency
Anemias:
- macrocytic
- megaloblastic
- Causes:
- pernicious anemia
- malabsorption (eg. Crohn disease)
- gastrectomy
- insufficient intake (eg. veganism)
- Diphyllobothrium latum (fish tapeworm)
- ↑ homocysteine, ↑ methylmalonic acid
- Neurologic Symptoms:
- reversible dementia
- subacute combined degeneration (due to involvement of B12 in fatty acid pathways and myelin synthesis)—spinocerebellar tract, lateral corticospinal tract, dorsal column dysfunction
- historically diagnosed with the Schilling test, a 4-stage test that determines if the cause is dietary insufficiency vs. malabsorption
- anemia 2° to insufficient intake may take several years to develop due to liver’s ability to store B12 (as opposed to folate deficiency)
Vitamin B12 (Cobalamin) Deficiency
Anemias:
- macrocytic
- megaloblastic
- inability to convert orotic acid to UMP (de novo pyrimidine synthesis pathway) because of defect in UMP synthase
- autosomal recessive
- presents in children as failure to thrive, developmental delay, and megaloblastic anemia refractory to folate and B12
- no hyperammonemia (vs. ornithine transcarbamylase deficiency—↑ orotic acid with hyperammonemia)
- orotic acid in urine
- Treatment:
- uridine monophosphate
- uridine triacetate
- both bypass mutated enzyme
Orotic Aciduria
Anemias:
- macrocytic
- DNA synthesis is unimpaired
- Causes:
- alcoholism
- liver disease
- RBC macrocytosis without hypersegmented neutrophils
Nonmegaloblastic Anemia
Anemias:
- macrocytic
- nonmegaloblastic
- rapid-onset anemia within 1st year of life due to intrinsic defect in erythroid progenitor cells
- ↑ % HbF (but ↓ total Hb)
- short stature, craniofacial abnormalities, and upper extremity malformations (triphalangeal thumbs) in up to 50% of cases
Diamond-Blackfan Anemia
Normocytic, Hemolytic Anemias
MCV 80–100 fL, reticulocyte count > 2%:
- Intrinsic:
- Membrane Defects:
- hereditary spherocytosis
- paroxysmal nocturnal hemoglobinuria
- Enzyme Deficiencies:
- G6PD deficiency
- pyruvate kinase deficiency
- Hemoglobinopathies:
- sickle cell anemia
- HbC disease
- Membrane Defects:
- Extrinsic:
- autoimmune
- microangiopathic
- macroangiopathic
- infections
Normocytic, Nonhemolytic Anemias
MCV 80–100 fL, reticulocyte count ≤ 2%:
- iron deficiency (early)
- anemia of chronic disease
- aplastic anemia
- chronic kidney disease
Anemias:
- classified as nonhemolytic or hemolytic
- the hemolytic anemias are further classified according to the cause of the hemolysis (intrinsic vs. extrinsic to the RBC) and by the location of the hemolysis (intravascular vs. extravascular)
- hemolysis can lead to increases in LDH, reticulocytes, unconjugated bilirubin, urobilinogen in urine
Normocytic, Normochromic Anemia
Anemias:
- ↓ haptoglobin
- ↑ schistocytes on blood smear
- characteristic hemoglobinuria, hemosiderinuria, and urobilinogen in urine
- may also see ↑ unconjugated bilirubin
- notable causes are mechanical hemolysis (eg. prosthetic valve), paroxysmal nocturnal hemoglobinuria, microangiopathic hemolytic anemias
Intravascular Hemolysis
Anemias:
- macrophages in spleen clear RBCs
- spherocytes in peripheral smear (most commonly hereditary spherocytosis and autoimmune hemolytic anemia), no hemoglobinuria/hemosiderinuria
- can present with urobilinogen in urine
Extravascular Hemolysis
Anemias:
- nonhemolytic, normocytic
- inflammation → ↑ hepcidin (released by liver, binds ferroportin on intestinal mucosal cells and macrophages, thus inhibiting iron transport) → ↓ release of iron from macrophages and ↓ iron absorption from gut
- associated with conditions such as rheumatoid arthritis, SLE, neoplastic disorders, and chronic kidney disease
- ↓ iron, ↓ TIBC, ↑ ferritin
- normocytic, but can become microcytic
- Treatment:
- address underlying cause of inflammation
- judicious use of blood transfusion
- consider erythropoiesis-stimulating agents such as EPO (eg. in chronic kidney disease)
Anemia of Chronic Disease
Anemias:
- nonhemolytic, normocytic
- caused by failure or destruction of myeloid stem cells
- ↓ reticulocyte count, ↑ EPO
- pancytopenia characterized by anemia, leukopenia, and thrombocytopenia
- normal cell morphology, but hypocellular bone marrow with fatty infiltration (dry bone
- marrow tap)
- Symptoms: fatigue, malaise, pallor, purpura, mucosal bleeding, petechiae, infection
- Treatment:
- withdrawal of offending agent
- immunosuppressive regimens (eg. antithymocyte globulin, cyclosporine)
- bone marrow allograft
- RBC/platelet transfusion
- bone marrow stimulation (eg. GM-CSF)
Aplastic Anemia
Cuases of Aplastic Anemia
- Radiation and Drugs (eg. benzene, chloramphenicol, alkylating agents, antimetabolites)
- Viral Agents (EBV, HIV, hepatitis viruses)
- Fanconi Anemia (DNA repair defect causing bone marrow failure; macrocytosis may be seen on CBC); also short stature, ↑ incidence of tumors/leukemia, café-au-lai spots, thumb/radial defects
- Idiopathic (immune mediated, 1° stem cell defect); may follow acute hepatitis