Hematopoietic System

Flashcards covering key concepts from the hematology notes, including acute blood loss, various anemias, labs, and related conditions.

What CBC finding may be normal immediately during active acute blood loss?

Hemoglobin and hematocrit may be within the normal range right after bleeding; changes may take hours to appear.

When does the reticulocyte count typically rise after acute blood loss?

Within a few days; reticulocytosis is a normal compensatory response.

In class I hemorrhage (up to 15% blood volume lost), what are the expected vital signs?

Minimal tachycardia with no changes in blood pressure or respiratory rate.

What are the hemodynamic and respiratory changes in class II hemorrhage (15–30% loss)?

Tachycardia 100–120 bpm, tachypnea 20–24 breaths/min, and decreased pulse pressure.

At approximately what blood loss percentage does significant blood pressure drop typically occur?

Around 30% to 40% blood loss (severe hemorrhage).

What signs accompany severe hemorrhage beyond blood pressure drop?

Tachycardia >120 bpm, weaker pulse, elevated respiratory rate, reduced urine output, and mental status changes.

What is the most common type of hemophilia in the United States and its basic cause?

Hemophilia A, caused by factor VIII deficiency (X-linked recessive).

What laboratory finding is commonly prolonged in Hemophilia A, and which tests are usually normal?

Activated partial thromboplastin time (aPTT) is often prolonged; prothrombin time (PT), fibrinogen, and platelets are usually normal.

Which medications should generally be avoided in patients at risk of excessive bleeding?

Anticoagulants, aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs).

What cell type is characteristic of Hodgkin’s lymphoma?

Reed–Sternberg cells.

List typical symptoms and signs of Hodgkin’s lymphoma.

Night sweats, fevers, pruritus with painless lymphadenopathy, anorexia/weight loss.

Which age groups are most commonly affected by Hodgkin’s lymphoma?

Young adults (20–40) and older adults (>60); median age ~39 in the U.S.

What is the primary malignant cell type in Multiple Myeloma?

Malignant plasma cells.

Name two common symptoms and two lab findings in Multiple Myeloma.

Fatigue and bone pain; hypercalcemia and normocytic anemia; proteinuria with Bence–Jones proteins.

What defines neutropenia and its common adult causes?

ANC < 1,500 cells/mcL; commonly due to inherited disorders and drug-induced causes.

List several drug classes that can cause neutropenia.

Psychotropics, antivirals, antibiotics, NSAIDs, antithyroids, ACE inhibitors, propranolol.

What is a normal adult WBC differential distribution for neutrophils, bands, lymphocytes, monocytes, eosinophils, and basophils?

Neutrophils 55–70%; bands 0–5%; lymphocytes 20–40%; monocytes 2–8%; eosinophils 1–4%; basophils 0.5–1%.

Define thrombocytopenia and its common thresholds for symptoms.

Platelet count <150,000/mcL; symptoms typically appear when <100,000/mcL.

What are the hallmark features of iron deficiency anemia (IDA) on ferritin, serum iron, and TIBC?

Low ferritin, low serum iron, and elevated TIBC.

What RBC indices characterize iron deficiency anemia?

Microcytic (MCV <80 fL) and hypochromic (low MCHC) RBCs.

How can you differentiate thalassemia trait from IDA using ferritin, iron, and TIBC?

IDA: low ferritin and low serum iron with high TIBC; thalassemia trait: ferritin, iron, and TIBC are normal.

What key RBCs and iron studies support thalassemia trait, particularly beta-thalassemia?

Microcytosis with elevated HbA2 and HbF; normal to high ferritin/iron.

What is the most sensitive test for iron deficiency anemia and what other roles does it have?

Serum ferritin; also an acute phase reactant that can rise with inflammation.

How do serum iron and TIBC typically present in thalassemia compared with IDA?

Thalassemia: normal or high serum iron, normal TIBC; IDA: low iron and high TIBC.

What is reticulocytosis and its normal percent range in the total RBC count?

An elevated percentage of reticulocytes; normally 0.5%–2% of RBCs.

What is a common peripheral smear finding in IDA and thalassemia trait?

Poikilocytosis and anisocytosis; microcytosis in both; target cells may be seen in thalassemia.

What is the definitive test for most hemoglobinopathies, including thalassemias?

Hemoglobin electrophoresis.

Describe the macrocytic anemia picture in vitamin B12 deficiency and the typical RBC changes.

Macrocytic anemia (MCV >100 fL) with macro-ovalocytes and hypersegmented neutrophils.

What are the typical neurologic features of vitamin B12 deficiency?

Paresthesias, neuropathy, gait disturbance, cognitive changes; may be irreversible if untreated.

What are common laboratory findings in vitamin B12 deficiency besides CBC?

Low B12; hypersegmented neutrophils; low reticulocytes; MMA and homocysteine may be elevated; intrinsic factor antibodies.

How is pernicious anemia defined and what risk is increased with it?

Autoimmune destruction of parietal cells causing intrinsic factor deficiency and B12 malabsorption; increased gastric cancer risk (2–3x).

What is the treatment approach for vitamin B12 deficiency?

Parenteral B12 (1000 mcg) weekly for 1 month, then monthly; or high-dose oral B12 (1000–2000 mcg daily) if adherence is good.

What is the typical CBC pattern in folate deficiency compared with B12 deficiency?

Macrocytic Hb with macrocytosis; similar CBC patterns; MMA is normal in folate deficiency, homocysteine may be elevated.

What is the hallmark of folate deficiency in lab tests and the recommended supplementation for women of childbearing age?

Low folate; treat with folic acid 1–5 mg/day; 0.4 mg/day to all women of childbearing age; higher doses (4 mg/day) for prior neural tube defect risk.

What are the main features and lab findings of aplastic anemia?

Destruction of pluripotent stem cells causing pancytopenia; bones marrow biopsy required; refer to hematology.

How is erythrocytosis (polycythemia) categorized and defined?

Absolute polycythemia (primary due to mutation; secondary due to hypoxia or EPO therapy) and relative polycythemia (hemoconcentration from low plasma volume). Thresholds: Hct >48% in women or >49% in men; Hb >16.0 g/dL (women) or >16.5 g/dL (men).

What is hereditary hemochromatosis and its main treatment?

Iron overload due to increased intestinal iron absorption; treated with therapeutic phlebotomy; ferritin often >500 ng/mL.

What triggers hemolysis in G6PD deficiency and what populations are most affected?

Oxidative stress from drugs (e.g., primaquine, sulfa drugs, dapsone), fava beans, infections; X-linked recessive; more common in males.

What is a key diagnostic approach for sickle cell disease and trait?

Hemoglobin solubility testing, peripheral smear; definitive diagnosis with HPLC or IEF or gel electrophoresis; autosomal recessive.

Why is newborn screening for sickle cell disease important?

Careful early detection enables early management; universal newborn screening is recommended in the U.S.

What pattern helps distinguish iron deficiency anemia from thalassemia trait on iron studies and ferritin?

IDA: low ferritin and low serum iron with high TIBC; thalassemia trait: ferritin, iron, and TIBC normal.

What are common complications and diagnostic tests for sickle cell disease?

Complications include pain crises, acute chest syndrome, anemia, stroke; diagnose with HPLC/IEF; manage with hematology.

What dietary and lifestyle guidance is given for patients with iron deficiency anemia?

Ferrous sulfate 325 mg PO TID; take with vitamin C; absorption best on empty stomach but GI upset often requires meals; avoid taking with antacids/dairy/quinolones/tetracyclines (iron binding).