Hematology

Mentzer index ratios?

More than 13 is IDA. Less than 13 is thalassemia.

Which factor inhibitors are time and temp dependent and increase APTT a few hours after mixing?

Factor 8 inhibitors

CD5+ is a marker for?

T-cells

CD19+ is a marker for?

B-cells

CD23 + is a marker for?

CLL

CD23 - is a marker for?

Mantel cell lymphoma

Which white blood cell has a bean-shaped nucleus?

Monocyte

Haemophilia A is a deficiency of what factor?

Factor 8

What is the only factor in the extrinsic pathway?

Factor 7

Schistocytes are associated with what condition? and what associated underlying causes?

microangiopathic haemolytic anaemia. Causes: thrombotic thrombocytopenic purpura, DIC, prosthetic heart valves

TTP is caused by?

Deficiency or defect of ADAMTS13. Prevents cleaving of von willebrand factor

High MCV and hyper segmented neutrophils?

Megaloblastic anemia

RDW in genetic anemias?

Normal

What are Howell-Jolly bodies and how do they form?

small, round, dark-purple DNA remnants inside red blood cells. Caused by damaged or missing spleen or severe haematological stress.

What does direct Coombs test for?

Detects antibodies or complement proteins bound directly to the surface of red blood cells

Indirect coombs looks for? and its uses

antibodies in the patient plasma. Prenatal screenings and pre-transfusion crossmatching.

Spherocyte causes

Hereditary, Autoimmune haemolytic anaemia.

Echinocyetes. Another name and their characteristics

Burr cells. Small thorny projections

Echinocyetes. Causes

Artifact from EDTA. Uremia. Haemoltic anemia.

Acanthocyte anther name and characteristics.

Spurr cells. uneven spiky projections that vary in length and width.

Acanthocyte causes

Liver disease. Abetalipoproteinemia.

Codocyte other name

Target cell

Codocyte causes.

Liver disease. Thalassemia. IDA

Elliptocytes other name shape

Ovalocytes. Elongated or oval-shaped.

Elliptocytes causes.

Hereditary, IDA, megaloblastic anaemia, myelofibrosis

Poikilocytes?

significant variation in red blood cell shape.

Stomatocytes characteristics and causes

slit-like central pallor. Hereditary, Alcoholism, liver disease

What can increase haematocrit levels?

Dehydration

Methylmalonic acid (MMA) used to detect?

B12 deficiency

In the context of myeloproliferative neoplasms (MPNs), the JAK2 V617F mutation is most frequently associated with which condition?

PV and ET

During the process of fibrinolysis, which enzyme is responsible for the direct cleavage of fibrin into Fibrin Degradation Products (FDPs)?

Plasmin

Which malaria species is characterized by the presence of 'Schüffner's dots' in infected red blood cells?

Plasmodium vivax

What is the diagnostic significance of a 'leukoerythroblastic' blood film?

Indicates bone marrow infiltration

Which factor deficiency is the most common cause of a hereditary bleeding disorder?

vWD

What is polycythemia vera?

Slow growing cancer where bone marrow makes too many red blood cells and often white cells and platelets

What is the most likely technical cause of a high MCHC (>36 g/dL)?

Cold agglutination, Heamolysis or lipemia

Which of the following is characteristic of Lymphoproliferative disorders like Chronic Lymphocytic Leukemia (CLL)?

Smudge cells

Which pre-analytical factor is most likely to cause a falsely low platelet count?

EDTA dependent clumping

In the production of red blood cells, which stage is the last to possess a nucleus?

Orthochromatic erythroblast

Which of the following is the most appropriate test for monitoring low-molecular-weight heparin (LMWH)?

Anti-Xa assay

Which malaria species is associated with the most severe complications due to its high parasitemia and potential for organ failure?

Plasmodium falciparum

Which of the following is characteristic of a normocytic anemia, such as anemia of chronic disease?

Normal or increased serum ferritin, decreased serum iron, decreased TIBC

In automated cell counters utilizing the Coulter principle (impedance), what does the height of the electrical pulse represent?

Cell volume

Which protein acts as the master regulator of iron metabolism by inducing the degradation of ferroportin?

Hepcidin

What is the typical immunophenotype for Chronic Lymphocytic Leukemia (CLL)?

CD3+, CD19 +, CD23 +

Which bleeding disorder is characterized by a deficiency in the glycoprotein Ib/IX/V receptor, leading to impaired platelet adhesion?

Bernard-Soulier syndrome

On a peripheral blood film, a 'crescent' or 'banana-shaped' gametocyte is diagnostic for which Plasmodium species?

P. falciparum

Which coagulation factor has the shortest half-life and is usually the first to decrease during Warfarin therapy?

Factor 7

A patient with a high Hematocrit (> 55%) has a prolonged PT and aPTT. What is the most appropriate next step?

Adjust citrate volume

In the coagulation laboratory, what is the purpose of the 'reagent blank' or 'optical check' in photo-optical clot detection?

Account for lipemia

Which finding is typical of Primary Myelofibrosis in the peripheral blood?

Dacrocytes

What is the primary function of the D-dimer test in the clinical workup of a patient?

Rule out thrombosis

A patient on Heparin therapy develops a sudden drop in platelet count. Which mechanism is primarily responsible for Heparin-Induced Thrombocytopaenia (HIT)?

Antibodies to platelet factor 4

A peripheral blood film reveals large, pale blue-staining inclusions in neutrophils, along with giant platelets. Which condition is suspected?

May-Hegglin anomaly

What is the primary physiologic function of the protein Thrombomodulin in the regulation of fibrinolysis and coagulation?

Activating protein C

A patient with suspected Hereditary Spherocytosis would typically show which set of red cell indices?

Normal MCV, increased MCHC

Which iron study parameter is the first to decrease during the development of iron deficiency anaemia?

Serum ferritin

In the 'VCS' technology used by Beckman Coulter, what does the 'C' (Conductivity) parameter primarily measure?

Internal nuclear complexity

What is the primary role of von Willebrand Factor (VWF) in primary haemostasis?

Platelet adhesion to collagen

A patient with Haemophilia B has a deficiency in which factor?

Factor 9

In a patient with a cold agglutinin, which parameter is characteristically falsely elevated by the automated analyzer?

MCHC

Which Plasmodium species is characteristically identified by 'banana-shaped' or crescentic gametocytes in a thin blood film?

Plasmodium falciparum

Which stage of erythropoiesis is characterized by the first visible appearance of hemoglobin in the cytoplasm and the start of nuclear condensation?

Polychromatic erythroblast

What is the diagnostic significance of 'Ring Sideroblasts' observed on a Prussian Blue-stained bone marrow smear?

Abnormal iron in mitocondria

How does a band neutrophil look?

C or S-shaped nucleus

Toxic Granulation look and causes

Coarse, dark purple-blue, prominent primary granules in neutrophils. Indicates acute infection, inflammation, or tissue necrosis.

Döhle Bodies look and causes

Light blue, oval cytoplasmic inclusions near the periphery of neutrophils. Often seen alongside toxic granulation in severe bacterial infections or burns.

Cytoplasmic Vacuolation

Clear holes within neutrophil cytoplasm. Indicates active phagocytosis or sepsis

Reactive (Atypical) Lymphocytes (Downey cells)

Large, pleomorphic lymphocytes with indented borders molding to surrounding RBCs, abundant deep blue cytoplasm (often darker at the periphery), and variable nuclear chromatin. Seen in viral infections (e.g., EBV, CMV).

Pelger-Huët Anomaly (Pseudo-Pelger-Huët):

Hyposegmented neutrophils (bilobed or spectacle-shaped, or even unsegmented/round) with coarse, mature chromatin. Can be congenital (benign) or acquired (pseudo-Pelger in Myelodysplastic Syndrome or acute leukemias).

Which bleeding disorder is characterized by a prolonged Bleeding Time and APTT, but a normal Prothrombin Time and platelet count?

vWD

Which test uses a low concentration of phospholipid to make the reagent sensitive to the presence of Lupus Anticoagulant?

Dilute russell viper venom time

Chronic Lymphocytic Leukemia (CLL) is characterized by the clonal expansion of which cell type?

Mature B-cells

Where is EPO synthesised

Kidneys

pappenheimer bodies?

Mitochondrial iron