Hematology 2 Flashcards
Normal range of WBC
4.4 – 11.3 x103 cells/ L
two general groups of cells that make up WBC
Granulocytes (Neutrophils, eosinophils, basophils)
Non-granulocytes (Lymphocytes/ monocytes)
Phagocytic cells which derive their name for the presence of granules within cytoplasm that store lysozymes and other chemicals needed to destroy foreign cells
Granulocytes
Produced by bone marrow during bacterial infection
Neutrophils
Normal range of Neutrophils
PMNs 45 – 73%; bands 3 – 5%
↑ in “Bands” during an infection ONLY
a “left shift”
‘margination’
Adhere to walls of vascular endothelium
Causes for Elevations in Neutrophils
Increased production = Bacterial infections
Demargination = Trauma, acute MI, Drugs (i.e., Corticosteroids)
Normal range for Eosinophils and basophils
eosinophils: 0 – 4%; basophils: 0 – 1%
Eosinophils elevations are highly suggestive of
parasitic infections or allergic reactions
Increase in Basophils are due to
allergic and hypersensitivity reactions (release histamine= causal)
May increase for chronic inflammatory diseases and leukemias
Responsible for “phagocytosis” (ingestion) of substances labeled by antibodies or compliment proteins
Monocytes & macrophages
Normal range of Monocytes & macrophages
2 – 8%
Increased monocytes seen in
tuberculosis/ malaria/ rickettsia
Give specificity & memory to foreign invaders
Lymphocytes
Normal range for Lymphocytes
20 – 40%
produce antibodies
B lymphocytes
Cytotoxic through antibody & complement activation
T lymphocytes & Natural Killer Cells (NK cells)
Effects of Infections on White Blood Cells
Increase in Neutrophils = Bacteria, and TB (lesser extent) Increase in Lymphocytes = Viral Decrease in Lymphocytes = HIV Increase in Eosinophils = Parasites Increase in Monocytes = TB
Effects of Non- infectious factors on WBCs
Stressors increase Neutrophils
Corticosteroids increase Neutrophils, decrease Lymphocytes
Radiation decreases Neutrophils and Lymphocytes
Allergies increase Eosinophils
Chronic infections increase Basophils
GW presents with fevers and severe body wide rash following initiation of Lyrica. No recent travel reported WBC’s: 14,000 cells/uL Neutrophils (50%); Band (3%); Lymphocytes (22%); Monocytes (4%) Eosinophils (20%); Basophils (1%) Which of the following caused elevated WBCs? Bacteria infection Viral infection Parasitic infection Rash
Rash
First to adhere to vascular injury
Form weak hemostatic plug= hemostasis
Platelets
Normal range of Platelets
150,000 – 450,000 cells/L
Platelet count < 150,000 cells/ μL
Thrombocytopenia
Hyperdestructive causes of Thrombocytopenia
Drugs (e.g., heparin) Autoimmune disease (e.g., SLE)
Hypoproductive cause of Thrombocytopenia
Aplastic anemia
Risk of bleeding from trauma
Platelet count < 50,000
Risk for spontaneous bleeding
Platelet count < 20,000
Platelet count > 450,000 cells/ μL
Thrombocytosis
Causes of Thrombocytosis
stress, infection, trauma, malignancy
platelet count > 800,000 cells/ μL
Thrombocythemia
Risk of clotting (i.e., ischemic stroke) and bleeding (i.e., GI)
Mean platelet volume (MPV)(for thrombocytopenia)
Normal range 7 – 11 fL (varies with laboratory)
Cause of Thrombocytopenia + High MPV
hyperdestructive
Cause of Thrombocytopenia + Low MPV
hypoproductive
Measure the ability of the platelet to aid in clotting
Platelet Function tests
Measure time to stop bleeding following an incision
Falling out of favor (lack of sensitivity/ specificity)
Bleeding time (BT) Normal range: 2 – 9 min
Measures the ability of platelets to aggregate after a platelet agonist is added (i.e. epinephrine)
Develop aggregation graph
Slope and curve of over time identifies platelet disorders
Platelet aggregation
Uses of Coagulation studies
Identify deficiencies in coagulation proteins
Monitor effects of anticoagulation therapy
Identifies deficiencies extrinsic clotting cascade & common pathways (factors II,V,VII,X)
Uses thromboplastin + Ca =promotes factor X to Xa
Prothrombin time (PT) Normal range = 10- 13 seconds
Problem with PT
Clotting time dependent on thromboplastin source
Animal versus human thromboplastin differ in sensitivity
‘PT’ test that accounts for thromboplastin sensitivity
International Normalized Ratio (INR)
Normal INR = 1.0 (0.9- 1.2)
Best possible ISI
1 (range from 1- 3)
Relation between thromboplastin and ISI
Larger the ISI, the less sensitive the thromboplastin
PT = 10 sec (baseline); PT= 30 sec (day #3 on warfarin); ISI = 1.0
What is the INR ?
INR = { 30 (sec) /10 (sec) }^1.0 = 3.0
Used in evaluating therapeutic effects of heparin
Antifactor Xa Assay
Mechanism of Antifactor Xa Assay
Uses patient plasma + antithrombin III + factor Xa
Heparin combines with antithrombin III to inhibit factor Xa
Assay measures remaining levels of factor Xa
Levels of factor Xa consumed are proportional to amount of heparin
Therapeutic range of Antifactor Xa Assay
- 5 – 1.0 units/mL = LMW Heparin (BID dose)
0. 35 – 0.7units/mL = UF Heparin
Byproduct of plasmin digestion of cross-linked fibrin
D- dimer (< 0.5 mcg/mL)
Uses of D- dimer
Helps diagnose or rule out thromboembolic event
e.g., DVT/ pulmonary embolism
Sensitive but nonspecific marker
Conditions where D-dimer is Falsely elevated
Malignancy, Infection, Pregnancy, & Acute Inflammation
23 y/o female patient presents with sudden, stabbing chest pain and SOB; Wgt= 70 kg
Medication Hx:
Oral contraceptives/ Ibuprofen prn
Proventil HFA inhaler (asthma)
D-dimer = 7.0 mcg/mL
1) What thromboembolic event do you suspect?
2) What INR would you suggest on Warfarin?
3) Would anti-factor Xa level be necessary on LMWH?
DVT
2-3
Yes
