Erythrocyte and Leukocyte Pathology Lecture Review

A comprehensive set of vocabulary flashcards covering erythrocyte and leukocyte pathologies, diagnostic hallmarks, and automated hematology principles based on the lecture transcript.

Anemia (WHO Definition)

A condition where blood concentration of Hb is $<130\,g/L$ in men and $<120\,g/L$ in women.

Iron Deficiency Anemia (IDA)

The most common cause of anemia, characterized by microcytic hypochromic cells and the depletion of iron stores due to a prolonged imbalance between iron loss and intake.

Storage Iron Compartment

Consists of ferritin and hemosiderin found in liver cells and bone marrow macrophages.

Transport Iron Compartment

Primarily composed of serum ferritin used for the movement of iron through the body.

Functional Iron Compartment

Consists of hemoglobin ($90\%$ of total distribution), myoglobin, and cytochromes.

Stage I IDA (Storage Iron Depletion)

The latent stage where iron storage is lost but hemoglobin remains normal and red cell morphology is unaffected.

Stage II IDA (Transport Iron Depletion)

Defined by the exhaustion of iron storage; hemoglobin of reticulocytes starts to decrease and Total Iron Binding Capacity (TIBC) increases.

Stage III IDA (Functional Iron Depletion)

Stage where anemia becomes evident with microcytic hypochromic RBCs and depleted storage iron.

Pica

An important clinical manifestation of Iron Deficiency Anemia involving the craving for non-nutritive substances.

Koilonychia

A clinical sign of severe IDA characterized by spoon-shaped nails.

Vitamin $B_{12}$ Anemia

A condition resulting from inadequate cobalamin levels, leading to macrocytic normochromic anemia and hypersegmented neutrophils.

Pernicious Anemia

An autoimmune disease causing the destruction of gastric parietal cells, leading to a loss of intrinsic factor and Vitamin $B_{12}$ deficiency.

Methylmalonic Acid (MMA)

A toxic byproduct that accumulates in Vitamin $B_{12}$ deficiency and can lead to Axonal neuropathy.

Folate Trap

A biochemical state where a deficiency of Vitamin $B_{12}$ prevents the production of THF from $5$-methyl THF, trapping folate in an unusable form.

Hereditary Spherocytosis (HS)

An inherited disorder caused by defects in proteins (Ankyrin, Band 3, Spectrin) that disrupt vertical linkages in the RBC membrane, leading to spherical cells.

Osmotic Fragility Test (OFT)

The confirmatory test for Hereditary Spherocytosis; a shift to the left indicates increased fragility.

Hereditary Elliptocytosis (HE)

A red cell disorder where defects disrupt horizontal linkages in the protein cytoskeleton, resulting in more than $25\%$ elliptocytes on a blood film.

Overhydrated Hereditary Stomatocytosis (OHSt)

A condition associated with a mutation in the $RHAG$ gene where excessive sodium and water enter the cell, causing it to swell.

Dehydrated Hereditary Stomatocytosis (DHSt)

The most common form of stomatocytosis, associated with the $PIEZO1$ gene mutation and characterized by decreased osmotic fragility.

Glucose-$6$-Phosphate Dehydrogenase (G6PD) Deficiency

An X-linked recessive disorder where RBCs cannot generate sufficient $NADPH$ to reduce glutathione, leading to hemolysis under oxidative stress.

Heinz Bodies

Denatured hemoglobin precipitates seen in $G6PD$ deficiency and alpha thalassemia.

Pyruvate Kinase Deficiency (PKD)

The second most frequent enzymatic defect, caused by a mutation in the $PKLR$ gene, characterized by decreased $ATP$ production and echinocytes.

Sickle Cell Anemia (SCA)

A severe hemolytic anemia caused by the homozygous inheritance of $Hb\,S$, where valine replaces glutamic acid at position $6$ of the beta-globin chain.

Vaso-occlusion

The hallmark symptom of sickle cell anemia where sickled cells block blood flow in capillaries, causing intense pain and tissue hypoxia.

Hemoglobin C disease

An autosomal recessive hemoglobinopathy where glutamate is replaced by lysine at position $6$ of the beta-chain, forming hexagonal or rod-shaped crystals.

Alpha Thalassemia

A condition stemming from deletions in the alpha-globin gene complex on chromosome $16$, often characterized by $Hb\,H$ inclusions.

Beta Thalassemia Major

The most severe type of beta thalassemia where both beta-globin alleles are mutated, leading to severe hemolytic anemia and 'chipmunk face' prominence.

Paroxysmal Nocturnal Hemoglobinuria (PNH)

An acquired stem cell disorder caused by a mutation in the $PIG-A$ gene, leading to a deficiency of $GPI$-anchored protective proteins like $CD55$ and $CD59$.

Paroxysmal Cold Hemoglobinuria (PCH)

An autoimmune hemolytic anemia caused by cold-reacting $IgG$ antibodies, confirmed by the Donath-Landsteiner Test.

Aplastic Anemia

A hematopoietic stem cell disorder characterized by peripheral blood pancytopenia and a markedly hypocellular bone marrow ($<30\%$ cellularity).

Polycythemia Vera (PV)

A neoplastic clonal myeloproliferative disorder characterized by panmyelosis and the $JAK2\,V617F$ mutation.

Acute Granulocytic Leukemia (AML)

A blood cancer characterized by the clonal expansion of immature 'blast cells' ($\ge 20\%$) and the presence of Auer rods.

Auer Rods

Collections of primary granules found in the cytoplasm of myeloblasts; the hallmark of $AML$.

Acute Lymphocytic Leukemia (ALL)

A rapid-progressing cancer where lymphoblasts never mature; it is characterized by the marker Terminal deoxynucleotidyl transferase (TdT).

Philadelphia Chromosome

A specific genetic anomaly ($t(9;22)$ forming the $BCR-ABL1$ gene) which is the hallmark of Chronic Granulocytic Leukemia.

Chronic Lymphocytic Leukemia (CLL)

A slow-growing cancer of B cells characterized by lymphocytosis and the presence of smudge cells (basket cells).

Multiple Myeloma

A plasma cell cancer characterized by lytic bone lesions, Bence Jones Protein in urine, and Rouleaux formation in the RBCs.

Waldenström’s Macroglobulinemia

A malignant lymphoproliferative disorder characterized by a large concentration of monoclonal $IgM$ leading to hyperviscosity.

Franklin’s Disease

Also known as Gamma Heavy Chain Disease, characterized by the production of monoclonal gamma-heavy chains that lack matching light chains.

Agammaglobulinemia

A group of inherited deficiencies marked by low or absent antibody concentrations, often due to mutations in Bruton tyrosine kinase (BTK).

Systemic Lupus Erythematosus (SLE)

A chronic autoimmune inflammatory disease characterized by a scaly butterfly-shaped rash and the presence of $LE$ cells.

Reed-Sternberg Cells

Large, malignant B cells with an 'owl-eyed' appearance found in Hodgkin’s disease.

Infectious Mononucleosis

A contagious disease caused primarily by the Epstein-Barr virus (EBV), characterized by the presence of Downey cells (atypical lymphocytes).

Gaucher’s Disease

An inherited metabolic disorder caused by a lack of glucocerebrosidase, leading to cells with a 'crumpled tissue paper' appearance.

Niemann-Pick Disease

A group of rare conditions affecting fat breakdown, characterized by the presence of foamy macrophages (Niemann-Pick cells).

Impedance Principle

The Coulter method of counting and sizing cells based on changes in electrical resistance as a particle passes through a small aperture.

Leukocyte Alkaline Phosphatase (LAP)

An enzymatic stain used to differentiate chronic granulocytic leukemia (low score) from leukemoid reactions (high score).

Sudan Black B (SBB)

A non-enzymatic stain used for the demonstration of phospholipids and lipoproteins, helping to identify cells of $AML$.

Periodic Acid-Schiff (PAS)

A stain that reacts with glycogen; neoplastic lymphoblasts in $ALL$ often show 'chunky' granular positivity.