Heme/Lymph Flashcards
What triggers coagulation in extrinsic pathway?
Tissue injury releases tissue factor (thromboplastin)
What is deficiency of Hemophilia B?
Coagulation factor IX (9) deficiency
What is deficiency of Hemophilia A?
Factor 8
What is rate limited of coagulation cascade?
Convergence of extrinsic and intrinsic at Factor 10
Function of Protein C and S?
Inhibit Factors Va and VIIIa
Why does Warfarin transiently increase clot formation?
Warfarin inhibits Factors 2, 7, 9 and 10; but it also inhibits protein C and S MORE rapidly than clotting factors –> this transiently increases clot formation before the other factors are inhibited
-This is why we start Heparin first
What is the final common pathway?
Factor 10 –>10a
10a + 5a activate prothrombin to thrombin
Thrombin + 13a activate fibrin monomers into fibrin mesh
What is function of Antithrombin?
Inhibits thrombin from activating fibrin
What drug increases effectiveness of thrombin?
Heparin
How does coagulase affect coagulation pathway? What produces coagulase?
Coagulase activates thrombin
Made by Staph aureus
What other ions/proteins are necessary for coagulation cascade?
Calcium
Phospholipid
What are the functions of factor 12a?
1) 12a activates 11 –> 11a
2) 12a converts prekallikrein to kallikrein –> then kallikrein cleaves plasminogen to form plasmin –> plasmin breaks down fibrin mesh
- Kallikrein also converts HMWK to bradykinin –> Bradykinin vasodilates, increases vascular permeability and mediates pain (coagulation and inflammation are interconnected)
What does the prothrombin time measure?
Take plasma and add tissue factor –> measure how long it takes clot to form
Tests how effectively tissue factor can activate the tissue factor pathway and the final common pathway
Testing factors 7, 10, 5 and 2 (prothrombin)
Always reported as INR (1 is normal)
What does partial thromboplastin time measure?
Plasma + silica or something that activates tissue activating pathway
- Also have to add phospholipids that normally combine with tissue factor to form thromboplastin
- Tests function of contact activation pathway and final common pathway
- Tests 12, 11, 9 and 8, 10, 5 and 2
What does bleeding time measure?
Should take 2-9 minutes
A function of platelet function
Disorders of coagulation cascade will not affect bleeding time
Hemophilia A and Hemophilia B
a. effect which pathway?
b. Effects on PT and PTT
a. Intrinsic pathway
b. Increased PTT, not effect on PT or INR
Symptoms of Hemophilia A/B
Macrohemorrhage –> hemarthroses, easy bruising, bleeding after trauma or surgery
Treatment for Hemophilia A, B and C
A - Desmopressin + factor 8 concentrate
B - factor 9 concentrate
C - factor 11 concentrate
Vitamin K Deficiency
a. Effects on PT, PTT
b. Mechanism
a. Increased PT, PTT
b. Decreased 10, 7, 9, 2
c. Vitamin K dietary deficiency, newborns (no gut bacteria), someone taking antibiotics, patients on Warfarin, end stage liver disease
Factor V Leidin
a. What does Factor V do?
b. Mechanism of disease
a. Factor V is a cofactor for factor 10 –> helps it activate thrombin
b. Factor V Leiden mutations makes Va resistant to inactivation by protein C –> increased coagulation
Prothrombin gene mutation (G20210A)
a. Mechanism
b. Effect
a. Mutation in 3’ intranslated region
b. Increased production of prothrombin –> increased plasma levels and venous clots
Antithrombin deficiency
a. Effect
b. PT/PTT
a. Unable to activate thrombin
b. No direct effect on PT, PTT or thrombin time but the increase in PTT is diminished after adding Heparin (reduced effect)
Protein C deficiency (or protein S)
Unable to activate factors 5 and 8 –> can’t shut off coagulation cascade –> increased risk of thrombotic skin necrosis with hemorrhage following administration of Warfarin
Skin and subcutaneous tissue necrosis after warfarin administration
Protein C deficiency
Mechanism of Heparin
Cofactor for activation of antithrombin –> decreased thrombin and factor 10a (only prevents clot from getting bigger or new clots from forming)
VERY SHORT HALF LIFE
Uses of Heparin
PE, acute stroke, MI, DVT
Can be used during PREGNANCY
What lab do we measure to monitor Heparin?
PTT
S/E of Heparin
Bleeding
Bone loss, osteoporosis
Heparin-Induced Thrombocytopenia (HIT) –> heparin binds to platelet factor 4 –> autoantibody complexes can then activate platelets to aggregate –> then they get removed from circulation and destroyed –> thrombosis and thrombocytopenia
What do you do for Heparin Induced Thrombocytopenia?
Stop Heparin
Start different anticoagulant like direct thrombin inhibitor (dabigatran, bivalirudin)
Direct Thrombin Inhibitors (specifically ones derived from Hirudin from leech spit)
Lepirudin
Bivalirudin
Desirudin
Direct Thrombin Inhibitors (NOT from hirudin)
Argatroban
Dabigatran
Low-molecular weight Heparins
Enoxaparin
Dalteparin
Advantages of low-molecular weight Heparins
Disadvantages?
Better bioavailability 2-4 times longer half life Administered SubQ Don't need lab monitoring Disadvantage - not easily reversible
Fondaparinux
Activates antithrombin to inhibit Factor Xa
Not a Heparin derivative
Mechanism of LMW Heparins?
Stimulate antithrombin to inactivate Factor Xa
Direct Factor 10a inhibitors
Rivaroxaban
Apixaban
Warfarin mechanism
Inhibits epoxide reductase –> interferes with gamma-carboxylation of vitamin K dependent clotting factors 2,7,9,10 Protein C and S
(Epoxide reducase recycles vitamin K)
Uses of Warfarin
Chronic antricoagulation –> Atrial fibrillation, DVT prophylaxis, DVT treatment, PE treatment
When is Warfarin C/I?
Pregnant patients - crosses placenta and is teratogenic
Toxicity of Warfarin
Bleeding, teratogen, skin/tissue necrosis, transient hyper coagulability
Reversal of Heparin
Protamine Sulfate
Reversal of Warfarin
Vitamin K (oral) - takes days to do anything to reverse effects because have to wait for liver to make more clotting factors Fresh frozen plasma
Half life in Heparin vs. Warfarin
Short half life - Heparin
LONG half life - Warfarin
Onset of action in Heparin vs. Warfarin
Rapid (seconds) - Heparin
Slow - Warfarin
Thrombolytics
a. mechanism
b. Use
a. activated Plasmin –> lyses fibrin clot
b. EARLY ST elevation MI (< 3-6 hours), acute stroke, severe PE
S/E of thrombolytics
Bleeding (C/I in active bleeding, recent surgery, HTN, history of intracranial bleeding, coagulation defect)
Used to monitor coagulation in patient taking Warfarn
PT and INR
Characteristics of RBC
a. life span
b. shape
c. source of energy
a. 120 days
b. biconcave (spectrin), anucleate
c. Glucose 90% anaerobical metabolized to lactate, 10% used in HMP shunt
What is anisocytosis?
RBC of varying sizes
What is poikilocytosis?
RBC of varying shapes
What is a reticulocyte? What dose it reflect?
Immature RBC; reflects erythroid proliferation
What is polycythemia or erythrocytosis?
Too many RBCs
Basophilic stippling
Associated pathology?
Little purple red dots (clumps of denatured RNA in basophil) Lead poisoning (also thalassemias, anemia of chronic disease, alcohol abuse)
Echinocyte (burr cell)
Regular, uniform spikes all over surface
Seen in uremia, renal failure
Spurr cell (Acanthocyte)
IRREGULAR spiked cells
Liver disease
Abetalipoproteinemia
Spherocyte
RBCs that lose biconcave shape
-seen in Hereditary Spherocytosis
Schistocytes
Fragments of RBC that look like helmets
-Seen in DIC, TTP/HUS, HELLP, (pathologic intravascular clotting that RBCs are being forced through) from mechanical hemolysis
Target cells
Look like bulls eye THAL Thalassemia Hemoglobin C disease Asplenia Liver disease (also see acanthocytes)
Sickle cells
Crescent shaped
In sickle cell anemia
Howell Jolly body
Basophilic nuclear remnants found in RBCs
-Normally removed from RBCs by splenic macrophages; seen in patients with functional hyposplenia or asplenia (trauma, immune thrombocytopenia purpora splenic removal)
Heinz bodies
When hemoglobin gets oxidized and precipitates out of solution in RBC –> little clumps of Hgb
- Spleen bites the Hgb clumps out of RBCs
- Seen in G6PD deficiency (oxidative damage causes Heinz bodies)
How do you tell Heinz body from Howell Jolly Body?
Can only have ONE Howel jolly body but can have MANY Heinz bodies
Teardrop cells
Shaped like teardrops
-Seen with myelofibrosis
Elliptical shape cells (pencil cells)
Hereditary Elliptocytosis
Ring Sideroblasts
ABNORMAL
- Seen in Bone marrow
- Lead poisoning*** (big one), drugs, myelodysplastic syndromes
- Sign of underlying diagnosis
Sideroblasts
Nucleated RBC precursor with granules of iron in mitochondria
- Found in BM of healthy people
- If you have disorder that affects heme synthesis and body can’t use all iron granules –> the granules surround and encircle the nucleus –> form ring
What happens if you transfuse incompatible blood type?
Antibody-mediated type II hypersensitivity
What is Erythroblastosis Fetalis?
Due to Rh incompatibility
Maternal Abs to fetal RBC antigens (Rh-D)
Rh- moms don’t have antibodies to Rh-D but after they are exposed to babies RBCs they form them (after first pregnancy)
-If babies blood comes into contact with babies blood in first pregnancy, mom’s immune system is sensitized to Rh- antigen and mom develops Abs –> then IgG can cross placenta and attack RBCs –> hemolysis –> Hgb breaks down into bilirubin and causes jaundice
Clinical features of Erythroblastosis Fetalis in infant
Anemia due to hemolysis of RBC by maternal Abs
Jaundice –> kernicterus possible
Hydrops fetalis (fetal edema)
Intrauterine death
Treatment of Erythroblastosis Fetalis
Administer RhoGAM (anti-Rh immunoglobulin) to Rh- pregnant women during 3rd trimester to prevent maternal anti-Rh IgG production (and any time there is trauma)
What kind of RBCs do you see in G6PD deficiency?
Bite cells
Heinz bodies
When do primitive blood cell progenitors appear in yolk sac?
at 3 weeks; come from mesonephros
Young Liver Synthesizes Blood
Yolk Sac (week 3-8) Liver (and spleen) Bone marrow (at 28 weeks)
Which part of skeleton is hematopoietically active?
Infancy and childhood - entire skeleton (sternum, pelvis, ribs, long bones, vertebrae, cranial)
Late adolescence, adulthood - vertebrae, sternum, ribs, pelvis
Fetal hemoglobin?
Adult hemoglobin?
Fetal - 2 alpha chains, 2 gamma chains (gamma has lower affinity for 2,3 DPG –> higher affinity for oxygen)
Adult - 2 alpha chains, 2 beta chains
Hemoglobin variants HbA HbA2 HbA1c HbF HbGower
HbA - 97% of normal (a2B2) HbA2 - 2% of normal (a2delta2) HbA1c - poorly controlled diabetes HbF - fetal hemoglobin (a2gamma2) HbGower - embryonic Hgb (2 zeta and 2 episilon chains)
HbS
Sickle cell Hgb
alpha 2, betaS2
Glu –> val in B chain
HbC
Hemoglobin C disease
alpha 2, betaC2
Glu –> lys in Beta chain
HbBart’s
Severe alpha thalassemia gamma 4 (no alpha chain)
HbH
Severe alpha thalassemia
B4 (no alpha chains)
What is rate limiting enzyme of heme synthesis?
What does it require?
aminolevulinic acid synthase (ALA synthase)
It makes glycine and succinyl-CoA into aminolevulinic acid
Requires Vitamin B6
What enzyme is defective in acute intermittent porphyria?
Porphobilinogen deaminase
Can’t make porphobilinogen into hydroxymethylbilane
Presentation of acute intermittent porphyria
Abdominal pain (neuropathic) Port wine- colored urine Polyneuropathy Psychological disturbanes Precipitated by drugs (cytochrome p450 inducers, alcohol, starvation)
How do you treat acute intermittent porphyria?
Glucose and heme –> inhibit ALA synthase (no build up of neuro toxic products)
5 P’s of acute intermittent porphyria
Pain in abdomen Polyneuropathy Port wine-colored urine Psychological disturbances Precipitated by drugs
What enzyme is defective in Porphyria Cutanea Tarda?
Uroporphyrinogen decarboxylase
Uroporphyrin accumulates and causes tea colored urine
Presentation of Porphyria Cutanea Tarda
Most common form! Blistering of skin and photosensitivity Hypertrichosis Facial hyperpigmentation Tea-colored urine Hepatitis C and alcoholism Elevation of LFTs (AST, ALT) (Think of homeless man)
How does lead poisoning affect heme synthesis pathway?
Inhibits Ferrochelatase –> Protoporphyin accumulates
Inhibits ALA dehydratase
Presentation of lead poisoning
Microcytic anemia (basophilic stippling) GI (abdominal colic) and Kidney disease
Mental deterioration in kids (also lead lines in bones, gingiva)
Headache, memory loss, demyelination in adults
Treatment of lead poisoning
EDTA or succimer to chelate lead
Dimercaprol + succimer in kids for very severe lead poisoning
What is Polycythemia vera?
Monoclonal proliferation of RBCs
Causes of polycythemia vera
Chronic hypoxia –> to increase O2 carrying capacity (pulmonary disease, cyanotic heart disease, high altitudes)
Tumors
Trisomy 21 at birth
Tumors that cause polycythemia vera
Potentially Really High Hematocrit
Pheochromocytoma
Renal cell carcinoma
Hepatocellular carcinoma
Hemangioblastoma
Relative Polycythemia
Plasma volume is reduced so that red cell count is increased relative to plasma volume
Absolute polycythemia
Plasma volume is normal and you have too many RBCs
Appropriate absolute polycythemia
a. plasma volume
b. RBC mass
c. O2 saturation
d. EPO levels
e. associations
a. no change
b. Increased
c. decreased
d. increased
e. seen in lung disease, congenital heart disease, high altitude
Inappropriate absolute polycythemia
a. plasma volume
b. RBC mass
c. O2 saturation
d. EPO levels
e. associations
a. no change
b. Increased
c. no change
d. increased
e. renal cell carcinoma, hepatocellular carinoma, hydronephrosis
Polycythemia vera
a. plasma volume
b. RBC mass
c. O2 saturation
d. EPO levels
e. associations
a. increased
b. really increased
c. no change
d. decreased
- EPO decreased due to negative feedback suppressing renal EPO production
Relative polycythemia
a. plasma volume
b. RBC mass
c. O2 saturation
d. EPO levels
e. Associations
a. decreased
b. no change
c. no change
d. no change
e. Decreased plasma volume like dehydration and burns
Microcytic Anemia
Iron Deficiency Anemia Alpha thalassemia Beta thalassemia Lead poisoning Sideroblastic anemia Anemia of Chronic Disease
Iron Deficiency Anemia - causes
Poor intake Blood loss (menstruation or GI chronic occult blood loss)
IDA - characteristics
Hypochromic
Microcytic
What is Plummer Vinson syndrome?
Iron deficiency anemia
Esophageal web
Atrophic glossitis
Alpha Thalassemia - cause
Affects who?
Defect in alpha globin gene deletions –> defect in alpha globin synthesis
African/Asian populations
alpha thalassemia
a. mutation of one allele
b. mutation in 2 alleles
c. mutate 3 alleles
d. mutate 4 alleles
a. no anemia
b. alpha thal trait, no anemia
c. Hemoglobin H disease (beta globins pair up with each other )
d. incompatible with life - Hemoglobin Barts - four gamma globes –> causes hydrous fetalis and death
Beta thalassemia cause
Affects who?
Defect in beta globin gene (point mutation) –> decreased beta globin synthesis
Mediterranean populations
B-thalassemia minor (heterozygote)
B chain is underproduced
Usually asymptomatic
Diagnosis confirmed by increased HbA2 (>3.5%) on electrophoresis
B-thalassemia major (homozygote)
B chain is absent –> severe anemia requiring blood transfusion
Marrow expansion (crew cut on skull X-ray) –> skeletal deformities, chipmunk facies
Extramedullary hematopoiesis leads to hepatosplenomegaly
-Increased risk of parvovirus B19 induced aplastic crisis
Why do you have to confirm diagnosis of iron deficiency in patients with microcytic anemia before you start iron supplements?
They might have beta thalassemia in which case they would have increased iron from thalassemia
Peripheral smear of thalassemia shows…
Target cells
What are two enzymes in heme synthesis that are affected by lead poisoning?
Ferrochelatase
ALA dehydratase
Causes of sideroblastic anemia
Lead poisoning
Alcohol
Drugs (seizure drugs, Rifampin)
Hereditary X linked defect in ALA synthase
Anemia of chronic disease
Iron, Ferritin levels
From defective iron utilization
Iron is trapped in macrophages so serum iron is LOW
Ferritin is normal or HIGH
Macrocytic anemia
a. Megaloblastic anemia
b. Non-megaloblastic anemia
a. B12 deficiency, Folate deficiency , orotic aciduria
b. Liver disease, Alcoholism, Reticulocytes
RBC appearance in B12/folate deficiency
Hypersegmented neutrophils (>6 lobes)
Causes of B12 deficiency
Insufficient intake Malabsorption (Crohn, removal of terminal ileum) Pernicious anemia Diphyllobothrium latum (fish tapeworm) Gastrectomy
Causes of folate deficiency
Malnutrition (alcoholics)
Malabsorption
Drugs (methotrexate, phenytoin, trimethoprim)
Increased requirement (pregnancy, hemolytic anemia)
Findings in
a. Folate deficiency
b. B12 deficiency
a. NO NEUROLOGIC SYMPTOMS; increased homocysteine, normal methylmalonic acid; megaloblastic anemia
b. Neurologic symptoms (subacute combined degeneration, spinocerebellar tract, lateral corticospinal tract, dorsal column dysfunction, dementia, neuropathy); Methylmalonic acid INCREASED, increased homocysteine
Why does B12 deficiency cause subacute combined degeneration?
B12 is involved in fatty acid pathways and myelin synthesis
Why should you not treat with empiric folic acid for megaloblastic anemia?
It might fix anemia but if B12 is deficient it will NOT correct neurologic deficits
What is orotic aciduria?
Defect in UMP synthase (pyrmidine synthase)
Causes orotic acid in urine, megaloblastic anemia Developmental delay
Failure to thrive
NO hyperammonemia (vs. ornithine transcarbamylase deficiency)
NON-megaloblastic macrocytic anemia cause
DNA synthesis is NOT impaired Alcoholism Liver disease Hypothyroidism Reticulocytosis Drugs (5-FU, Zidovudine, Hydroxyurea)
Normocytic NON-hemolytic anemia causes
Anemia of chronic disease
Aplastic anemia
Anemia of chronic disease
a. cause
b. Iron, TIBC, Ferritin levels
a. Lots of inflammation causes lots of inflammatory mediators like Hepcidin to be increased –> inhibits iron transport because iron is trapped in macrophages
b. Decreased iron, decreased TIBC, Increased Ferritin
Conditions associated with anemia of chronic disease
SLE, RA, Neoplastic disorders, CKD
Aplastic anemia
a. causes
b. Findings
c. symptoms
a. Radiation***** and drugs, Viral agents (parvovirus B19, EBV, HIV, HCV), Fanconi anemia (DNA repair defect), Idiopathic (immune mediated)
b. Pancytopenia (anemia, leukopenia, thrombocytopenia)
Normal cell morphology but HYPOCELLULAR BONE MARROW With fatty infiltration
c. Fatigue, malaise, pallor, purpura, petechiae, infection
Treatment of aplastic anemia
Withdrawal of offending agent
Bone marrow allograft
RBC/platelet transfusion
Bone marrow stimulation
What test can be used to diagnose Beta thalassemia minor?
Hemoglobin electrophoresis to look for higher than normal levels of HbA2
Megaloblastic anemia not correctable by B12 or Folate
Orotic Aciduria
Microcytic anemia reversible with B6
Sideroblastic anemia
Drugs that can cause sideroblastic anemia
Isoniazid (inhibits B6)
Lead
Copper deficiency
B6 deficiency
HIV patient with macrocytic anemia
Zidovudine
Normocytic anemia with elevated creatinine
Chronic kidney disease resulting in low EPO
Skull x-ray shows “hair on end” appearance
Result of marrow hyperplasia (crew cut)
Basophilic stippling of RBCs
Lead poisoning
Co-factor required for pyruvate dehydrogenase
Tender Loving Care For No-one
What other enzyme requires these?
Thiamine Lipoid acid Coenzyme A FAD NAD -Also required by Alpha-ketoglutarate dehydrogenase
Intravascular or Extravascular hemolysis?
a. Decreased serum haptoglobin
b. Increased LDH
c. Increased unconjugated bilirubin
a. Massive intravascular hemolysis causes haptoglobin to bind all free hemoglobin
b. released from RBCs (intravascular OR extravascular hemolysis)
c. Seen in extravascular hemolysis (with intravascular all the heme would be bound by haptoglobin)
Intravascular hemolysis Causes
Autoimmune hemolytic anemia
Paroxysmal nocturnal hemoglobinuria
Mechanical destruction of RBCs
Extravascular hemolysis
Causes
Hereditary spherocytosis (spleen recognizes abnormal cells)
G6PD Deficiency (extravascular AND intravascular)
Pyruvate kinase deficiency
Sickle cell
Hemoglobin C disease
Hereditary spherocytosis defect
Defect in Ankyrin and spectrin (proteins interacting with RBC membrane skeleton and plasma membrane) –> red cells are small round spheres with NO central pallor and less surface area
Hereditary spherocytosis
a. Increased MCHC - why?
b. increased RDW - why?
c. Why does it cause hemolysis
a. Increased Mean corpuscular hemoglobin content; same amount of Hgb but they are smaller so it is more concentrated
b. Not as much variability with red cell size
c. Spleen recognizes cells as normal and removes them –> splenomegaly
Diagnostic test for Hereditary spherocytosis
Osmotic fragility test (high percentage of lysis in NaCl)
Treatment for hereditary spherocytosis
Splenectomy (so that it doesn’t remove red cells) –> then you see Howell Jolly bodies
G6PD deficiency defect
X linked recessive
Defect in G6PD –> causes decreased glutathione and increased RBC susceptibility to oxidative stress
Stressors that cause anemia in G6PD deficiency
Fava beans
Sulfa drugs
Anti-malarials
Infections
Symptoms of G6PD deficiency
Back pain, hemoglobinuria a few days after oxidant stress
Pyruvate kinase deficiency causes…
Intrinsic hemolytic anemia
Defect in pyruvate kinase –> decreased ATP –> rigid RBCs
Hemolytic anemia in newborn
Paroxysmal Nocturnal Hemoglobinuria defect
Red cells missing surface markers CD55 and CD59 so complement attacks them and lyses them
What is test for PNH?
Ham’s test - add acid to lower pH and that activates complement and lyses RBCs
Triad of PNH
Coombs - hemolytic anemia
Pancytopenia
Venous thrombosis
Sickle cell disease defect
Hemoglobin S mutation is single aa replacement where valine is used instead of glutamic acid at position 6 –> allow Hgb to polymerize in RBC
What triggers sickling in SCD?
Hypoxemia
Dehydration
Acidosis
Complications of Sickle Cell Disease
Aplastic crisis
Autosplenectomy
Splenic infarct
Salmonella osteomyelitis
Painful crises (vaso-occlusive)–> acute chest syndrome, avascular necrosis, stroke, dactylitis
Renal papillary necrosis and microhematuria
What organism causes osteomyelitis in SCD?
Salmonella
Treatment for SCD
Hydroxyurea
BM transplantation
Hemoglobin C disease defect
Glutamic acid–> Lysine mutation in B globin
Microangiopathic anemia cause
RBCs are mechanically damaged as they pass through lumen of obstructed vessel –> in DIC, TIP/HUS, lupus, malignant HTN –> RBC gets chopped up by shear force or fibrin strands
Macroangiopathic anemia cause
Damage to cells by forces in LARGER vessels (prosthetic heart valves, aortic stenosis)
Autoimmune Hemolytic Anemia a. Warm agglutinins
b. Cold agglutinins
a. IgG Abs attach to red cells and cause them to agglutinate AT BODY TEMP
b. IgM Abs that only cause problems when temp is lower
Cold agglutinins occur in…
Infections with EBV, mycoplasma
Malignancies (CLL)
Warm agglutinins occur in…
SLE Malignancies (CLL) Drugs (methyldopa) Viruses (EBV, HIV) Congenital immune abnormality
Direct Coombs Test
Anti-Ig antibody (Coombs reagent) is added to patient’s blood –> the RBCs agglutinate if RBCs are coated with Ig
Indirect Coombs Test
Normal RBCs added to patient’s serum –> if serum has anti-RBC surface Ig, RBCs agglutinate when Coombs reagent is added
Direct Coombs test is positive in:
Hemolytic disease of newborn
Drug-induced autoimmune hemolysis anemia
Hemolytic transfusion reactions
Indirect Coombs test positive when:
Abs present to foreign blood (test blood prior to transfusion, screen maternal antibodies to a fetus’ blood)
Painful cyanosis of fingers and toes with hemolytic anemia
Cold autoimmune hemolytic anemia
Red urine in the morning, and fragile RBCs
PNH
Basophilic nuclear remnants in RBCs
Howell-Jolly bodies
Autosplenectomy
Sickle cell (from auto-infarcting)
Drug used to treat sickle cell disease
Hydroxyurea
Where do platelets come from?
Megakaryocytes
How long do platelets live?
8-10 days; have no nucleus
What is vWF? Where does it come from?
What is it’s function?
It comes from Weibel-Palade bodies of endothelial cells and alpha granules of platelets
It complexes with and stabilizes factor 8 (elevated PTT with deficiency)
It binds to exposed collagen and then platelets binds vWF via Gp2b receptor at site of injury
How do platelets become activated after adhesion?
They change shape and ADP binding to receptor induces Gp2b/3a expression at platelet surface
How do platelets aggregate after activation?
Fibrinogen binds Gp2b/3a and link platelets
Pro-aggregation of platelet factors
TXA2 (released by platelets)
Decreased blood flow
Increased platelet aggregation
Anti-aggregation of platelet factors
PGI2 and NO (endothelial cells)
Increased blood flow
Decreased platelet aggregation
Aspirin mechanism
Inhibits cyclooxygenase –> permanently blocks the conversion of arachidonic acid to thromboxane A2
Effects of Aspirin on bleeding, PT, PTT
Increased bleeding time
No effect on PT, PTT
Uses of Aspirin
Reduce fever
Treat pain
Anti-inflammatory
Anti-platelet
S/E of Aspirin
Bleeding
Peptic ulcers (no protective prostaglandins)
Hyperventilation (stimulates respiratory centers of brain) –> respiratory alkalosis (but transitions to metabolic acidosis)
Reye’s syndrome (Hepatoencephalopathy)
Mechanism of Clopidogrel
ADP receptor inhibitor (inhibits platelet aggregation by preventing expression of GP2b/3a)
Uses of Clopidogrel
ACS, Coronary stenting
2b/3a INhibitors
Abciximab
Eptifibatide
Tirofiban
ADP receptor blockers
Clopidogrel
Prasugrel
Ticagrelor (reversible)
Ticlopidine (causes neutropenia)
Uses for Gp2b/3a inhbitors
NSTEMI
Acute coronary syndrome
unstable angina
Percutaneous transluminal coronary angioplasty
Platelet abnormalities symptoms
Mucous membrane bleeding Epistaxis Petechiae Purpura Increased bleeding time
Immune Thrombocytopenia
a. mechanism
b. Signs
c. BM biopsy shows…
a. Autoimmune disease with Abs to Gp2b/3a –> immune system removes and destroys them
b. Platelet count is low
c. Increased megakaryocytic on BM biopsy
Treatment for ITP
Steroids
IV immunoglobulin
Splenectomy
Thrombotic thrombocytopenia purpura
a. mechanism
b. signs/symptoms
c.
a. platelets are excessively activated because of increased large vWF multimers –> widespread thrombosis –> uses up all the platelets and causes thrombocytopenia and bleeding
b. pentad of neurologic and renal symptoms: fever, thrombocytopenia, microangiopathic hemolytic anemia
Defect in TTP
Inhibition or deficiency of ADAMTS13 (metalloproteases) that cleaves and degrades vWF multimers
Treatment for TTP
Plasmapheresis
Steroids
What condition is TTP closely linked to?
Hemolytic Uremic Syndrome
What is triad of findings in HUS?
Microangiopathic hemolytic anemia
Renal symptoms
Thrombocytopenia
Five features of TTP/HUS
Nasty Fever Torched His Kidneys
Neurologic Fever Thrombocytopenia Hemolysis Kidney failure
What is HUS associated with in kids?
E. coli 0157H7
Bernard Soulier syndrome defect
Defect in glycoprotein 1b –> platelet can’t bind collagen –> defect of platelet plug formation from defect in adhesion
Glanzmann thrombasthenia defect
Defect in Gp2b/3a –> defect in platelet aggregation –> platelet count normal, bleeding time prolonged
von Willebrand disease
a. defect
b. causes
a. defect in vonWillebrand factor
b. defect in platelet plug formation from defect in adhesion AND intrinsic pathway coagulation defect
c. Increased PTT and increased bleeding time
Treatment of vWF disease
Desmopressin (increased release of vWF in storage sites of endothelial cells)
Disseminated Intravascular Coagulation
a. mechanism
a. widespread activation of clotting –> deficiency in clotting factors and platelets –> bleeding state
Causes of DIC
STOP Making New Thrombi
Sepsis Trauma Obstetric complications!!!!! acute Pancreatitis Malignancy Nephrotic syndrome Transfusion
DIC
a. PT and PTT
b. Bleeding time
c. Fibrinogen
d. D-dimer
a. Prolonged
b. increased bleeding time
c. low fibrinogen
d. high fibrin split products (d-dimer)
peripheral smear of DIC
Schistocytes
Presentation of DIC
Multi organ failure
Bleeding
Most common inherited bleeding disorder
vWF disease
What does leukemia affect?
What does lymphoma affect?
Bone marrow, maybe peripheral blood
Lymphoma is tumor in lymph nodes
What makes lymphoma a Hodgkin lymphoma?
- Presence of Reed Sternberg cells (bilobed nuclear, clearing around nuclei, owl eye appearance, clearing around cell from cell shrinking)
- Found in single group of lymph nodes (extra nodal involvement is rare)
- Painless, nontender lymphadenopathy (nodes feel firm and rubbery)
- Lymphadenopathy in mediastinum
- Constitutional B symptoms: Low grade fever, night sweats, weight loss
Who gets Hodgkin lymphoma?
- Bimodal age (age 20 and 65)
- More common in men (except nodular sclerosing)
What are most non-Hodgkin lymphomas? Age distribution?
B cell lymphomas
Age distribution is widely variable
How do symptoms of non-Hodgkin compare to Hodgkin?
Fewer constitutional symptoms
What are certain types of non-Hodgkin lymphoma associated with?
HIV and immunocompromised
How do Reed Sternberg cells relate to prognosis?
The fewer cells the better prognosis
What is the most common type of Hodgkin lymphoma?
Nodular sclerosing type
Which type of Nodular sclerosing Hodgkin lymphoma has the best prognosis?
Lymphocyte rich form
Lymphocyte mixed or depleted form has worst prognosis
What are cell markers of Reed Sternberg cells?
CD15+
CD30+
Most common type of NH lymphoma in adults
Diffuse large B cell lymphoma
Translocation in diffuse large B cell lymphomas
t(14:18)
Follicular lymphoma translocation
t(14;18) of heavy chain Ig (14) and BCL-2 (18) –> BCL2 inhibits apoptosis
Burkitt lymphoma translocation
t(8;14) –> translocation of c-myc and heavy chain Ig
Mantle cell lymphoma translocation
t(11;14) –> translocation of cyclin D1 and heavy chain Ig
Starry sky appearance (sheets of lymphocytes with interspersed macrophages)
Burkitt lymphoma
Associated with EBV
Burkitt lymphoma
Endemic form of Burkitt lymphoma
Jaw lesion
Indolent course of lymphoma; painless waxing and waning lymphadenopathy
Follicular lymphoma
Associated with Sjogrens, Hashimotos, and H. pylori
Marginal cell MALToma
Adults present with cutaneous lesions (Japan, West African, Caribbean)
Adult T cell Lymphoma
Lytic bone lesions, Hypercalcemia
Adult T cell Lymphoma
Caused by HTLV (associated with IV drug abuse)
Adult T cell Lymphoma
Presents with skin patches/plaques characterized by atypical CD4 cells with cerebriform nuclei
Mycosis fungoides
If mycosis fungoides progresses to blood
Sezary syndrome
Associated with long term celiac disease
Intestinal T cell lymphoma
Lymphoma equivalent of CLL
Small lymphocytic lymphoma
Cancer most commonly associated with a non-infectious fever
Hodgkin lymphoma
Large B cells with bilobed nuclei and prominent owl’s eye inclusions
Reed Sternberg Cells seen in Hodgkin Lymphoma
Large B cells with bilobed nuclei and prominent owl’s eye inclusions
Reed Sternberg Cells seen in Hodgkin Lymphoma
What’s the difference between acute and chronic leukemia?
Acute - rapid onset and rapidly progressive, >50% blasts on BM biopsy, (myeloblasts in AML, Lymphoblasts in ALL), numerous blast cells (>20% blasts), often associated with pancytopenia
Chronic -
ALL is most common in…
Children Female
Whites > Blacks
Common presentation of T-ALL
Mediastinal mass presenting as SVC like syndrome
Prognosis of ALL
Good prognosis in children (up to 90% remission)
TdT+, CD10+
TdT+ is a marker of preT and preB cells
CD10+ is markers of preB cells
ALL translocation that equals better prognosis
t(12;21)
ALL association
Down syndrome
Common ALL symptom
Bone pain
ALL association (We all fall down)
Down syndrome
Common ALL symptom
Bone pain
Age of onset for AML
median onset 65 years
AML blood smear shows:
Auer rods (peroxidase cytoplasmic inclusions seen in M3 AML) Increased circulating myeloblasts
Risk factors for AML
Prior exposure to alkylating chemotherapy, radiation, myeloproliferaetive disorders, Down syndrome
t(15;17)
M3 AML subtype responds to all-trans retinoid acid (vitamin A), inducing differentiation of myeloblasts (Acute promyelocytic AML)
DIC common presentation of:
M3 AML
CD13/33+
AML
PAS (-)
AML
What’s the difference between acute and chronic leukemia?
Acute - rapid onset and rapidly progressive, >50% blasts on BM biopsy, (myeloblasts in AML, Lymphoblasts in ALL), numerous blast cells (>20% blasts), often associated with pancytopenia
Chronic - Insidious onset and gradual progression (months to years), mature cells (
PAS (-)
AML
Most common adult leukemia seen in western countries
CLL
Who does CLL affect?
Adults over age 50
95% have B cell markers
CLL
Smudge cells
CLL
Autoimmune hemolytic anemia
CLL
Autoimmune hemolytic anemia
CLL
CD20+, CD5+ B cell Neoplasm
SLL/CLL
Defined by the Philadelphia chromosome t(9;22), BCR-ABL
CML
Presents with increased neutrophils, metamyelocytes, basophils; splenomegaly
CML
Responds to Imatinib
CML
Very low LAP as a result of low activity in mature granulocytes
(vs. Leukemoid reaction which has Increased LAP)
CML
Autoimmune hemolytic anemia
warm or cold agglutinins
CLL
Presents with increased neutrophils, metamyelocytes, basophils; splenomegaly, fatigue, abdominal pain
CML
Very low LAP as a result of low activity in mature granulocytes
(vs. Leukemoid reaction which has Increased LAP)
CML
Age of presentation of CML
25-60
a. CLL progress to ALL?
b. CML progress to AML?
a. 10% progress to ALL
b. 80% progress to AML; this is Blast crisis
What is Philadelphia chromosome?
t(9;22) BCR ABL mutation
Encodes constitutively activated tyrosine kinase –> malignant transformation
What is Philadelphia chromosome?
t(9;22) BCR ABL mutation
Encodes constitutively activated tyrosine kinase –> malignant transformation
t(8;14)
Burkitt lymphoma
t(15;17)
M3 AML (auer rods); treated with ATRA
t(8;21)
AML
This is why patients with Trisomy 21 have increased incidence of AML.
What is Leukemoid reaction?
Increased WBC as a reaction to a stressor Predominantly neutrophils Left shift (5-10% immature bands) Increased LAP (CML has decreased LAP)
What is Myelodysplastic syndrome?
Dysplasia of the hematopoietic cells in the myeloid tissue
What is Pseudo-Pelger Huet anomaly?
Neutrophils with bilobed nuclei; seen after chemotherapy
What are myeloproliferative disorders?
Neoplastic transformation of a single myeloid precursor –>
Monoclonal proliferation of mature myeloid cells
Polycythemia vera
Essential thrombocytosis
Myelofibrosis
Mutation common in myeloproliferative disorders
JAk2 –> encodes Janus kinase 2 –> switched on all the time –> constantly getting growth factor signal to make more cells
What is Polycythemia vera? What is the mutation?
Jak2 mutation in red cell precursor; causes increased hematocrit without elevated EPO
Presentation of polycythemia vera
Intense itching after hot shower (from increased basophils)
Erythromelalgia (severe, burning pain and red-blue coloration) from episode blood clots in vessels of extremities
Plethora (redness of face)
Hyper viscosity of blood
Splenomegaly
Headache
What is essential thrombocytosis
Overproduction of abnormal platelets –> bleeding, thrombosis
What does BM look like in Essential thrombocytosis?
Has enlarged megakaryocytes
What is myelofibrosis?
Fibrosis and obliteration of the marrow space
Causes teardrop red cells
What is myelofibrosis?
Fibrosis and obliteration of the marrow space
Causes teardrop red cells
What is multiple myeloma?
Monoclonal plasma cell cancer that arises in marrow and produces lots of IgG (55%) or IgA (25%)
Most common primary tumor arising within bone in people >40-50
Multiple myeloma
Most common primary tumor arising within bone in people >40-50
Multiple myeloma
How do you identify plasma cells?
Clock face chromatin and intracytoplasmic inclusions containing immunoglobulin
Presentation of multiple myeloma
Anemia (plasma cells interfere with production of other cells in BM)
Renal insufficiency (form casts and plug up kidneys)
Back Pain (bc they secrete ostend cytokines) Punched out lytic bone lesions!
Hypercalcemia
Susceptibilty to infection (decreased production of healthy immune cells)
Amyloidosis
Serum protein electrophoresis for Multiple myeloma shows:
Monoclonal antibody (M) spike
Bence Jones proteins
Immunoglobulin light chains in urine detected on urine protein electrophoresis
BUT Do NOT see elevated protein on regular urinalysis
Peripheral smear of multiple myeloma
Rouleaux formation (RBCs stacked like poker chips in bloos smear)
Peripheral smear of multiple myeloma
Rouleaux formation (RBCs stacked like poker chips in bloos smear)
What is Waldenstrom macroglobulinemia?
Shows M spike that is IgM
Hyperviscosity syndrome and Amyloidosis (blurred vision, Raynaud phenomenon)
No CRAB findings
Plasmacytoma
2 types: solitary plasmacytoma of bone and extra medullary plasmacytoma (predilection for head and neck -specifically nose)
What is Monoclonal Gammopathy of Undetermined significance?
Monoclonal expansion of plasma cells, asymptomatic, may lead to multiple myeloma
Need to be monitored
What is Monoclonal Gammopathy of Undetermined significance?
Monoclonal expansion of plasma cells, asymptomatic, may lead to multiple myeloma
Need to be monitored
Most common leukemia in children
ALL
Acute leukemia positive for peroxidase
AML
