ASCP Hematology Review

Which one of the following factors, if deficient, would cause a prolongation of the PT assay without prolonging the aPTT?

Factor VII

Which of the following hemoglobins is known to migrate with HbS during electrophoresis when an alkaline gel, such as cellulose acetate, is used?

HbD is known to migrate with HbS

The autohemolysis test is MOST useful in the diagnosis of which condition?

Hereditary spherocytosis;

What is the role of a platelet's Open Canalicular System (OCS)?

a pore system that provides direct communication between intracellular and extracellular compartments; allows granule contents to be moved to surface, & plasma & coag factors to enter into plt.

Factor IX and VIII deficiencies would show:

an abnormal aPTT test with a normal PT test.

Factor X deficiency would show:

an increased PT and aPTT since factor X is utilized in both tests.

What is the platelet Organelle zone?

refers to all organelles scattered through cytoplasm; includes mitochondria, dense granules, alpha granules, glycogen granules, & lysosomes. Many such granules are released during plt. aggregation

Pappenheimer bodies (or siderotic granules) in erythrocytes can be detected using the following stain/s.

Wright's stain and Prussian blue stain.

A yellow coloration found in fresh cerebrospinal fluid supernatant is termed:

Xanthochromia

What is fibrinogen (Factor I)?

a plasma protein converted into fibrin by thrombin.

Factor VIII

anti-hemophilia factor (Hemophilia A) - Produced by hepatocytes - Factor VIII is *carried by vWF* (the binding of factor VIII to vWF extends the life of factor VIII to a few hours)

A laboratory professional will perform a mixing study to differentiate between a factor deficiency and a coagulation inhibitor as the cause of a prolonged prothrombin time (PT) or activated partial thromboplastin time (aPTT) test result. The mixing study should be performed within what time frame following collection of the specimen?

4 hours

What are dense platelet granules?

"Dense with energy" Migrate to plasma membrane and release their contents directly into the plasma on activation; contains ADP, ATP, Serotonin, and Calcium. These are thus important in providing *Energy* for platelet activation process.

What is the process of primary hemostasis ?

1. Adhesion (platelet activation) 2. Aggregation (platelets stick together; primary aggregation) 3. Degranulate (platelets secrete granule contents) 4. More Aggregation (secondary aggregation)

What would cause increased values in a bleeding time test?

1. Aspirin 2. von Willebrand Disease (decreased vWF) 3. congenital platelet abnormalities 4. platelet count below 100,000

What is the process of secondary hemostasis ?

1. Includes both Intrinsic & Extrinsic coag. pathways. 2. Leads to the formation of a stable fibrin clot around the plt. plug (which was previously formed by primary hemostasis).

What are the stages of hemostasis?

1. Primary hemostasis (formation of a platelet plug) 2. Secondary hemostasis (Incorporation of fibrin and coagulation factors to form the secondary hemostatic plug (fibrin clot). 3. Fibrinolysis (clot formed is broken down)

What is a prostaglandin?

A hormone-like substance made from essential fats used for things like blood clotting, body temperature, and contraction of the uterus

Factor VII

Stable factor (proconvertin)

Detecting the BCR/ABL1 mutation by molecular techniques is useful in the diagnosis of which of the following diseases/conditions?

CML (Chronic myelogenous leukemia)

Factor IV

Calcium

Which of the following lymphoid cells have the capability of spontaneous cytotoxicity of various target cells?

Natural Killer cells

What happens in a factor VII deficiency?

In factor VII deficiency, the PT test is abnormal, while the aPTT test is normal since factor VII is tested for in the PT test but not in the aPTT test.

What is a factor XI deficiency called?

Hemophilia C

Factor XI

Plasma thromboplastin antecedent (PTA)

In the steps involved in performing a bone marrow differential what objective is used and how many cells must be counted?

100x (oil), 200 cells

What is the reference range of platelets?

150,000 to 450,000

Which factors are vitamin K dependent?

2,7,9,10, Protein C/S

Factor V

Labile Factor

In what blood disease are Auer rods most commonly found?

AML (Acute Myeloid Leukemia)

Which of the following leukemias can be excluded as a possible diagnosis if Auer rods are seen in blasts on the peripheral blood smear?

Acute lymphoblastic leukemia. Auer rods are frequently found in the cytoplasm of myeloblasts, as seen in various subgroups of acute myeloid leukemia.

Which beta thalassemia shows no anemia and may not be detected using hemoglobin electrophoresis?

Beta thalassemia minima

Pelger-Huet anomaly is characterized by which of the following?

Bilobed neutrophils

What is the Coulter principle?

Blood cells or other particles are counted and sized based on changes in electrical resistance as they pass between two electrodes.

What are function(s) of the platelet?

CA125

Factor IX

Christmas factor (Hemophilia B) - Vitamin K dependent - Made in liver - Sex-linked (controlled by X-chromosome)

What is the function of ADAMTS13 enzyme?

Cleaving ultra-large von Willebrand factor to keep them out of the circulation

What is a role of cofactors?

Cofactors bind to the enzymes, making the enzymes more stable & reactive

Which of the following is the recommended method for preparing a cerebrospinal fluid (CSF) sample for a differential count?

Cytocentrifugation

Anemia of chronic inflammation, also known as anemia of chronic disease, can be caused by all of the following mechanisms EXCEPT:

Decreased ferritin

Which of the following represent other hemoglobin gene loci that occur on the same chromosome as the beta chain loci?

Delta and Gamma. The loci for globin chain production are found on Chromosomes 11 and 16.

Which of the following is the most common method for diagnosing malaria?

Demonstration of the organism in peripheral blood

Which of the following conditions will show an increased prothrombin time (PT) with a normal activated thromboplastin time (aPTT)?

Factor VII deficiency

Which of the following factors is known as Hageman factor?

Factor XII

Factor XIII

Fibrin stabilizing factor (Hageman factor)

Factor I

Fibrinogen

Prekallikrein

Fletcher factor, pre-K

A laboratory test that can detect the specific decrease in the platelet surface membrane receptor glycoprotein Ib and thus lead to a diagnosis of Bernard Soulier Syndrome (BSS) is:

Flow cytometry

What are alpha platelet granules?

Fuses with the OCS and participate in adhesion and aggregation and support plasma coagulation; contains Fibrinogen, platelet derived growth factor (PDGF), vWF, β-thromboglobulin (β-TG), platelet factor 4, and fibronectin.

Which abnormal hemoglobin may be formed in alpha thalassemia?

Hb Bart's

Laboratory tests which distinguish Polycythemia Vera (PV) from Chronic Myelogenous Leukemia (CML) include all of the following EXCEPT:

Hypercellular bone marrow; Both CML and PV are characterized by hypercellular bone marrow due to unchecked proliferation, so this is not a distinguishing test.

Which of the following inclusions are composed of DNA?

Howell-Jolly Bodies

What is the role of a platelet's Microtubular/microfilamentous cytoskeleton?

It provide an active means of platelet contraction to squeeze the contents of the cytoplasmic granules. - contains actin (contractile in plts. and muscle) which supports plt. shape & allows for its shape change from discoid to spiny once activated. (EDTA makes plts. "round up" artifictually).

In almost all cases of polycythemia vera, which of the following genetic abnormalities is present?

JAK2 Mutation

What is the bleeding time test?

Measures how fast small blood vessels in the skin stop bleeding. Reference range is 3-8 minutes.

Which of the following disorders is characterized by a stem cell mutation due to the PIGA gene that leads to clones of cells that bind abnormally large amounts of complement?

Paroxysmal Nocturnal Hemoglobinuria (PNH). It is an acquired erythrocyte disorder due to a mutation in the PIGA gene.

Which of the following conditions would produce the results listed below in an anemic patient? MCV = 115 fL MCH = 30 pg MCHC = 34 %

Pernicious anemia

Platelet Factor 3 (PF3)

Platelet phospholipid needed for proper platelet function and coagulation. Needed in production of thromboxane A2.

The most striking laboratory finding of this myeloproliferative neoplasms is an absolute erythrocytosis and hemoglobin concentrations of greater than 18.5 g/dL?

Polycythemia Vera

Factor II

Prothrombin

What are platelet glycogen granules?

Provide energy substrate

What is the intrinsic pathway?

Refers to the path of the coag. cascade in which factors Pre-K, HMWK, XII, XI, X, IX, VIII, V, II and I are involved in the formation of a *fibrin clot* *the activated partial thromboplastin time (APTT) tests for this pathway*

Which of the following blood smear observations would support the diagnosis of Multiple Myeloma if a patient demonstrated plasma cells in his bone marrow and had an elevated serum IgG?

Rouleaux formation

What RBC morphology on a Wright-stained smear may indicate the presence of an unstable hemoglobin?

Schistocytes

Factor X

Stuart-Prower factor

Study Intrinsic and Extrinsic pathway.

Study.

What is the platelet sol-gel zone?

The region of the platelet that contains a system of membranes running through the cytoplasm, to include: 1. the Open Canalicular System (OCS) 2. the Dense Tubular System 3. Microtubular/microfilamentous cytoskeleton

Factor III

Tissue thromboplastin

How is the intrinsic pathway initiated?

by the activation of Factor XII (Hageman factor). Vascular damage exposes negatively-charged subendothelial tissue. The inactive zymogen of factor XII is attracted to the neg.-charged endothelial surface of the damaged blood vessel. The negative polarity activates XII by causing the molecule to expose its active serine center. The activated form of XII is now XIIa.

What is the role of a platelet's Dense Tubular System (DTS)?

closed internal membrane system (sER remnant) that pumps Ca to trigger microtubular-controlled changes in plt. shape that occur once plt. is activated (acts like SR in voluntary muscle cells). DTS is made of phospholipids which support prostaglandin synthesis.

The PT test measures which factors of the extrinsic and common coagulation pathways ?

factors VII, X, V, II, and I

The APTT test measures which factors of the intrinsic and common pathways?

factors XII, Fletcher, Fitzgerald, XI, IX, VIII, X, V, II, and I

Fitzgerald factor

high molecular weight kininogen (HMWK)

What are zymogens?

inactive enzymes, they must be modified to become active.

What is platelet derived growth factor (PDGF)?

stimulates smooth muscle cell growth after blood vessel cell wall injury

What are the beta chain genotypes for beta thalassemia intermedia?

ß+/ß+, ß+/ß0

What is the normal beta chain genotype (no beta thalassemia)?

ß/ß

What are the beta chain genotypes for beta thalassemia minor?

ß/ß+, ß/ß0

What is the beta chain genotype for beta thalassemia major?

ß0/ß0