Heme PACCC 10.2026

Iron deficiency anemia - Most sensitive and specific initial diagnostic lab test

ferritin

source of b12 dietary

animal products, such as meat, dairy, and eggs.

Iron deficiency anemia - First-line oral therapy and co-administration recommendation

Oral iron, with vitamin C and no calcium for enhanced absorption.

Anemia of chronic disease - Key regulatory hormone and its mechanism of action

Hepcidin; degrades ferroportin to block iron release from enterocytes and macrophages

Anemia of chronic disease - Typical iron study profile (Ferritin, TIBC, Serum Iron)

Normal or elevated ferritin, decreased TIBC/transferrin, and decreased serum iron

Iron deficiency anemia - Typical iron study profile (Ferritin, TIBC, Serum Iron)

Decreased ferritin, increased TIBC/transferrin, and decreased serum iron.

Anemia of chronic disease vs. Iron deficiency anemia - Differentiating iron parameter

Serum ferritin (normal to elevated in chronic disease; low in iron deficiency)

Pernicious anemia - Pathophysiologic etiology

Autoimmune destruction of gastric parietal cells causing intrinsic factor deficiency leading to impaired vitamin B12 absorption.

Folate deficiency - Critical congenital complication associated with maternal deficiency

Neural tube defects (e.g., spina bifida, anencephaly)

Folate deficiency - Characteristic hematologic and neurologic features

Macrocytic megaloblastic anemia ($MCV > 100\,fL$) with hypersegmented neutrophils, but without neurological deficits

Alpha thalassemia - Hemoglobin H (HbH) disease gene configuration and abnormal globin tetramer

Three-gene deletion ($--/-a$); abnormal beta-globin tetramers ($\beta_4$)

Hydrops fetalis - Alpha-globin gene status and tetrameric hemoglobin variant

Four-gene deletion ($--/--$); Hemoglobin Barts composed of gamma-globin tetramers ($\gamma_4$); fatal in utero

Alpha thalassemia minor / trait - Typical laboratory findings

Target cells, microcytic, normal iron studies, normal Hb electrophoresis

Beta thalassemia minor (trait) - Characteristic hemoglobin electrophoresis findings

Elevated Hemoglobin A2 ($HbA_2 > 3.5\%$) and mildly elevated Hemoglobin F ($HbF$)

Beta thalassemia major (Cooley anemia) - Classic skull radiographic appearance

'Hair-on-end' or 'crew-cut' skull appearance resulting from severe extramedullary hematopoiesis

Beta thalassemia major - Complication of chronic transfusion therapy and its mitigation

Secondary hemochromatosis (iron overload); managed with iron chelation therapy

Thalassemia Tx

Blood transfusions, iron chelation therapy, bone marrow transplantation

Sickle cell disease - Mechanism of action of hydroxyurea

Increases production of fetal hemoglobin ($HbF$), reducing hemoglobin S polymerization and painful vaso-occlusive crises

sickle cell anemia tx

Blood transfusions, hydroxyurea

Sickle cell disease - ACS diagnostic criteria and acute management

New pulmonary infiltrate on CXR. SSx = fever, CP, SOB

Tx = Abx, transfusion, pain meds

Autoimmune hemolytic anemia - Gold standard diagnostic test

Direct antiglobulin test (Direct Coombs test), positive for IgG

Warm autoimmune hemolytic anemia - First-line pharmacological tx

Systemic corticosteroids (e.g., prednisone)

Hemophilia A and B - Inheritance pattern

X-linked recessive (They mostly affect males)

Hemophilia - Characteristic coagulation profile (PT, aPTT, Platelet count)

aPTT: prolonged

PT/INR, platelets: normal

Ix tests to get for hemophilia

aPTT, PT/INR, platelets

Factor assays to determine specific deficiency

vWF antigen test (to r/o vWD)

von Willebrand disease - Dual physiological functions of von Willebrand factor

Facilitates platelet adhesion + and binds/stabilizes circulating Factor VIII

Decreased vWF ⇒ decreased platelet adhesion, decreased Factor 8 stabilization ⇒ prolonged clotting time, excessive bleeding

von Willebrand disease - Classic clinical bleeding pattern

Mucocutaneous bleeding (epistaxis, gingival bleeding, menorrhagia, and easy cutaneous bruising)

Contrast to Hemophilia = deep bleeding (hemarthrosis)

von Willebrand disease - Diagnostic laboratory findings

aPTT: normal or prolonged

PT/INR, platelets: normal

vWF tests (antigen = quantity, Ristocetin = function): decreased

von Willebrand disease - tx

Desmopressin (DDAVP), vWF concentrate

Platelet vs. Coagulation factor bleeding - Characteristic physical exam differences

Platelet disorders manifest as superficial/mucocutaneous bleeding (petechiae, purpura); coagulation factor deficiencies manifest as deep bleeding (hemarthroses, large hematomas)

Disseminated intravascular coagulation - Central pathophysiologic event

Systemic and uncontrolled activation of the coagulation cascade, leading to widespread microvascular thrombosis and secondary consumptive coagulopathy

Disseminated intravascular coagulation - Classic coagulation profile abnormalities

PT/INR: Prolonged

aPTT: prolonged

platelets: decreased

fibrinogen: decreased (consumptive)

D-dimer: elevated (fibrin degradation product)

Disseminated intravascular coagulation - Hallmark peripheral blood smear finding

Schistocytes (fragmented RBCs from microangiopathic shearing)

Disseminated intravascular coagulation - RFs (MITS)

Malignancy, infx, trauma, sepsis

ITP - Typical presentation difference in children vs. adults

Children: acute onset after a viral infection, usually self-limiting; Adults: insidious onset with a chronic, relapsing course

Immune thrombocytopenic purpura - Initial pharmacologic therapy for platelets $<30{,}000/\mu L$ with bleeding

Systemic corticosteroids (prednisone or dexamethasone) + (IVIG)

Thrombotic thrombocytopenic purpura - Classic clinical pentad (mnemonic: FAT RN)

Fever, Anemia (microangiopathic hemolytic), Thrombocytopenia, Renal dysfunction (AKI), Neurologic changes

Thrombotic thrombocytopenic purpura - Enzyme deficiency and pathogenesis

ADAMTS13 mutation ⇒ decreased ADAM activity ⇒ vWF accumulation ⇒ widespread microthrombi ⇒ plt consumption ⇒ microthrombi + thrombocytopenia

Thrombotic thrombocytopenic purpura - Coagulation panel parameter distinguishing it from DIC

Normal coagulation panel (normal PT/INR, normal aPTT, and normal fibrinogen)

Thrombotic thrombocytopenic purpura - Definitive life-saving treatment

Plasma exchange (plasmapheresis)

Hemolytic uremic syndrome - Classic clinical triad (TAR mnemonic)

Microangiopathic hemolytic anemia, thrombocytopenia, and AKI

Typical Hemolytic uremic syndrome - Most common pathogen and causative exotoxin

Enterohemorrhagic E coli producing Shiga toxin

Hemolytic uremic syndrome - Preceding clinical prodrome

Prodromal bloody diarrhea

Heparin-induced thrombocytopenia - Classical timing and magnitude of platelet drop

A $>50\%$ decline in baseline platelet count occurring $5$ to $10$ days after initiating heparin therapy

Polycythemia vera - Hallmark genetic mutation

JAK2 mutation

Polycythemia vera - Expected serum erythropoietin (EPO) level

low EPO (negative feedback from increased RBCs)

Polycythemia vera SSx

Headache, dizziness, itching after bathing due to increased blood viscosity and histamine release. Other symptoms may include fatigue, ruddy complexion, and an increased risk of thrombotic events.

Polycythemia vera - Tx

Phlebotomy

ASA (thrombosis prevention)

Hydroxyurea (reduce RBCs)

Antihistamines

Essential thrombocythemia - First-line cytoreductive therapy in high-risk patients

Hydroxyurea + ASA

Acute lymphoblastic leukemia - Primary demographic and peak age incidence

Children between ages $2$ and $5$ years (most common childhood cancer)

Acute lymphoblastic leukemia - Diagnostic bone marrow blast threshold

$\ge 20\%$ lymphoblasts in the bone marrow

Hemolytic anemia panel

Haptoglobin (decreased), bilirubin, LDH, reticulocytes

Acute myeloid leukemia - Pathognomonic microscopic inclusion on peripheral smear or bone marrow

Auer rods

Acute myeloid leukemia - Clinical presentation resulting from pancytopenia

Fatigue and pallor (anemia), recurrent bacterial/fungal infections (neutropenia), and mucocutaneous bleeding or petechiae (thrombocytopenia)

Chronic myeloid leukemia - First-line targeted pharmacological therapy class

Tyrosine kinase inhibitors

Chronic lymphocytic leukemia - Most common clinical scenario at initial diagnosis

Asymptomatic elderly adult discovered to have incidental, marked absolute lymphocytosis on a routine CBC

Chronic lymphocytic leukemia - Classic peripheral blood smear finding

'Smudge cells'

Hodgkin lymphoma - Pathognomonic neoplastic giant cell and microscopic appearance

Reed-Sternberg cells (binucleated or multinucleated giant cells with prominent eosinophilic nucleoli, yielding an 'owl's eye' appearance)

Hodgkin lymphoma - Distinctive symptom occurring immediately after alcohol consumption

Alcohol-induced pain within involved lymph nodes

Non-Hodgkin lymphoma - Most common aggressive histological subtype in adults

Diffuse Large B-Cell Lymphoma (DLBCL)

Hodgkin vs. Non-Hodgkin lymphoma - Typical anatomical spread pattern and extranodal involvement

Hodgkin lymphoma spreads contiguously along axial lymph node chains with rare extranodal disease

Non-Hodgkin lymphoma spreads non-contiguously with frequent extranodal involvement (GI tract, skin, bone marrow)

Sickle cell anemia - Common joint complication secondary to recurrent microvascular occlusion

Avascular necrosis (osteonecrosis) of the femoral or humeral head