Tietze Chapter 5.1 (Hematology)

ABO Blood Typing

The antigenic properties of blood are analyzed to avoid potentially lethal transfusion reactions. Blood types include A, B, AB, and O.

Blood Smear

The — is produced by spreading a drop of peripheral blood on a slide and examining the smear microscopically. The — is used to obtain a WBC count and differential, to estimate the platelet count, and to evaluate RBC morphology

Bleeding Time

it is the duration of bleeding after a standardized skin incision is made.

• It is used to evaluate platelet quantity and function.

Activate Partial thomboplastin time aPTT

It assesses the intrinsic clotting pathway (i.e., factors II, V, VIII, IX, X, XI, and XII).

• It is commonly used to monitor heparin therapy.

Prothrombin Time

It is used to assess the extrinsic and common clotting pathways (i.e., factors II, V, VII, and X and fibrinogen).

• It is used to monitor warfarin therapy and to assess hepatic synthetic function.

INR

It is a standardized expression of PT that takes into account differences in reagent activity

Thombin Time

It is used to evaluate the effect of heparin and thrombolytic drug therapy and coagulation abnormalities.

• 2.0-9.5 minutes

Bleeding Time RR

• 8.5-9.5% of BW in Kg

Blood Volume RR

• 22-35 sec

• Plasma

aPTT RR

• 11-13 sec

• Plasma

PTT RR

• Control +-5 sec

• Plasma

Thromb Time TT RR

Complete blood count CBC

It consists of the hemoglobin, hematocrit, RBC count, WBC count, mean cell volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration.

Crossmatching

It determines compatibility between donor and recipient blood. Agglutination between the donor’s RBCs and the recipient’s serum indicates incompatibility.

Fibrinogen

It is increased in disseminated intravascular coagulation. It is used to evaluate bleeding disorders.

Fibrin Degradation Products FDPs

They are released when fibrin is broken down. They are assessed in the diagnosis and monitoring of disseminated intravascular coagulation.

Hemoglobin Electrophoresis

It uses electrophoretic separation and immunodiffusion to screen for the presence of abnormal proteins such as Bence Jones and myeloma proteins.

Serum Electrophoresis

It is used to screen for serum protein abnormalities. The proteins albumin, alpha1 globulin, alpha2 globulin, beta globulin, and gamma globulin are identified by different migration patterns when subjected to an electric field

Platelets

What initiates homeostasis

20,000 cells/mm3.

The risk of spontaneous bleeding is greatly increased if the platelet count is lower than —

Decreased

The platelet count is — if

• the bone marrow fails to produce platelets

• there is peripheral platelet destruction

Increase

The platelet count may — in:

• after splenectomy

• in some myeloproliferative diseases

• chronic inflammatory disease, malignancy, and chronic infections.

True

True or false

• Platelet function is impaired by drugs such as aspirin, dipyridamole, and nonsteroidal antiinflammatory drugs and by disease states such as uremia, multiple myeloma, and severe liver disease.

• 150-350 ×10³ / mm³

• Whole blood

Platelet count RR

Indirect Coombs’ Test

It detects antibodies against human RBCs in the patient’s serum. It is used in crossmatching before blood transfusions.

Direct Coombs’ test

 It uses antibodies directed against human proteins (primarily immunoglobulin G [IgG] and complement [C3]) to detect whether these proteins are attached to the surface of RBCs.

Direct Coombs’ test

It is used to differentiate between immunologic (e.g., autoimmune) and nonimmunologic (e.g., drug-induced) hemolytic anemias.

Coombs’ test

It is performed using an antiserum containing antibodies that bridge antibody- or complement-coated RBCs. Agglutination (clumping) occurs when the cells are bridged.

Carboxyhemoglobin

It forms in the presence of carbon monoxide (e.g., house fires, automobile exhaust). Carbon monoxide attaches to hemoglobin, rendering the hemoglobin incapable of carrying oxygen.

Hematocrit

It is the percentage of the volume of blood occupied by RBCs

Erythrocyte Sedimentation Rate ESR

It measures the rate at which RBCs settle out of mixed venous blood

Erythrocyte Sedimentation Rate ESR

The settling rate, influenced by the shape of the RBC and membrane charges, is used as a nonspecific marker of inflammatory and malignant diseas

Megaloblastic Anemias

Decreased serum folate levels are associated with —

Hematocrit

It is the percentage of the volume of blood occupied by RBCs. It is used to diagnose anemia and assess patient response to replacement therapy.

• Increase

• Decreased

The hematocrit is — in vitamin B12 and folic acid deficiencies and is — in iron deficiency.

Hemoglobin

It is the oxygen-carrying RBC protein. It is decreased in blood loss and iron deficiency anemia. It is used to diagnose anemia, assess patient response to replacement therapy, and estimate arterial and venous oxygen content

• <2.5 mcg/ml

• Serum

Fibrin Degradation Products FDPs RR

• 3.1-17.5 ng/mL

• Serum, Plasma

Folic Acid RR

• 1-25 mm/hr

• Whole Blood

Erythrocyte Sedimentation Rate ESR

• Female RR

• 1-17 mm/hr

• Whole Blood

Erythrocyte Sedimentation Rate ESR

• Male RR

• 36-46%

• Whole Blood

Hematocrit

• Female RR

• 41-53%

• Whole Blood

Hematocrit

• Male RR

Ferritin

It is in equilibrium with tissue ferritin, which makes it a useful indicator of tissue iron stores.

• It is used to diagnose iron deficiency anemia.

• 12-16 g/dL

• Whole Blood

Hemoglobin

• Female RR

• 13.5-17.5 g/dL

• Whole Blood

Hemoglobin

• Male RR

Iron

Its levels are decreased in iron deficiency anemia, chronic infections, and some malignancies. Its levels may be increased in iron poisoning and hemolysis.

Total iron-binding capacity (TIBC)

THis test evaluates the capacity of transferrin to bind to iron.

• It is used to diagnose iron deficiency anemia and to monitor replacement therapy

Transferrin saturation

It evaluates the percentage of total iron-binding protein saturated with iron.

• It is used to diagnose iron deficiency anemia and to monitor replacement therapy.

• 30-300 ng/mL

• Serum

Ferritin

• Male RR

• 10-200 ng/mL

• Serum

Ferritin

• Female RR

• 30-160 mcg/dL

• Serum

Iron RR

• 228-428 mcg/dL

• Serum

Iron BInding Capacity RR

RBC Count

It is the number of RBCs per cubic millimeter (1 mL) of blood. It is used to diagnose anemia and to assess patient response to replacement therapy.

Mean Corpuscular Hemoglobin MCH

It is the average RBC hemoglobin content.

• It is decreased in iron deficiency anemia and increased in folic acid and vitamin B12 deficiencies and hemolytic anemia.

Mean corpuscular hemoglobin concentration MCHC

It is the amount of hemoglobin per volume of RBCs.

Mean Cell VOlume

It is the average volume of individual RBCs. It is decreased in iron deficiency anemia, thalassemia, and other chronic diseases (e.g., microcytic anemia). It is increased in folic acid and vitamin B12 deficiencies (e.g., macrocytic anemia).

Red Cell DIstribution WIdth

It is determined from a histogram of the distribution of RBC volumes as measured with automated equipment.

• It is used to diagnose anemia and to assess patient response to replacement therapy.

Reticulocytes

They are immature RBCs that contain residual ribonucleic acid (RNA) and protoporphyrin but no nucleus.

Reticulocytes count

It is used to assess the response of the bone marrow to blood loss, hemolysis, and replacement therapy for the treatment of anemia.

Megaloblastic Anemia

Decreased serum vitamin B12 levels are associated with

• 80-100 micrometer³

• Whole Blood

Mean corpuscular Volume MCV RR

• 26-34 pg/cell

• Whole Blood

Mean corpuscular hemoglobin MCH RR

• 31-37 g/dL

• Whole blood

Mean Cell Hemoglobin Cncentration MCHC RR

• 11.5-14.5%

• Whole blood

Red cell distribution width RR

• 0.5-2.5% of red cells

• Whole blood

Reticulocytes Count RR

• >250 pg/mL

• Serum, Plasma

Vit B12 RR