hematology Flashcards
Composition of blood
92% water and 8% solutes
Plasma
50%–55% of the blood volume
Aqueous liquid with organic and inorganic elements (electrolytes)
Serum
Component of plasma
Clear liquid that remains after blood clots
What is hematopoiesis?
Process of blood cell production in adult bone marrow or in the liver and spleen of the fetus
Two stages:
Maturation which is the cell’s function and proliferation which is the cells division
Hematologic Neoplasms
Leukemia (neoplastic proliferation of blood cells
Lymphoma (proliferation of B or T lymphocytes in lymphoid tissue)
-lymphomas are more common than leukemia
Symptoms: anemia, leukopenia, thrombocytopenia, bone pain, enlarged lymph node, and splenomegaly
Acute Lymphocytic Leukemia (ALL)
Aggressive, more common in children than adults (survival rate is over 80% for children)
- The faster the response to treatment the better the prognosis
Many chromosomal and genetic alterations
- Ph chromosome
Immature T or B cells (lymphoblasts)
Signs and symptoms
- May be nonspecific, anemia, increased bleeding, lymph node enlargements, splenomegaly, increased infection risk, bone pain
- May migrate to CNS
Chronic Lymphocytic Leukemia (CLL)
Most common leukemia type in US
Individuals over 70 years of age, male
Etiology
- Any agent that can disrupt DNA
- Occupational history important
Zeta-chain-associated protein tyrosine kinase 70 (ZAP-70)
- Positive: indicates worse prognosis
- Negative: better prognosis
B cell malignancy
- B-CLL cells: express proto-oncogene bcl2 allowing constant proliferation
- Do not synthesize functional Igs
Typical signs and symptoms of leukemia
Diagnosis
- Lymphocytosis with WBC greater than 20,000/microliter
- Bone marrow biopsy: “smudge cells”—abnormal lymphocytes
Acute Myelogenous Leukemia
Proliferation of undifferentiated myeloid blast cells
Myeloid blasts can invade other tissues
- Skin, lungs, spleen, liver
Risk increased with previous chemotherapy and radiation treatments for other cancers
Commonly: activation of oncogenes such as FLT3, c-KIT
Diagnosis
- CBC, genetic translocation between chromosome 8 and 12 is common
Typical signs and symptoms of leukemia
Chronic Myelogenous Leukemia CML
Overproduction of mature myeloid cells
Age 65 years or older
95% of adults with CML have PhC
Clinical course: 3 phases
- Chronic : Neutrophils begin to lose differentiation
- Accelerated : Neutrophils more undifferentiated
- Blast crisis phase : Myeloid blast cells do not differentiate, large clusters of blast cells spread to other tissues
Usual symptoms of leukemia
- Anemia, increased infection, increased bleeding
- WBC count greater than 100,000 cells per microliter
Diagnosis
- CBC, PCR
Non-Hodgkin’s Lymphoma (NHL)
B, T, or NK cells
Middle aged or older adults; more common in men
Chromosomal translocations (chromosomes 14 and 18)
Some pathogens (HIV, Hep C, H. pylori) associated with NHL development
Immunosuppressive treatment may increase NHL risk
Enlarged, painless lymph node is often first sign
Diagnosis
- Lymph node biopsy
Hodgkin’s Lymphoma
B cell
Most common lymphoma in young adults and children over 10 years of age
Unknown cause, but EBV may play a role
Diagnosis
- Reed-Sternberg cells : malignant B cell with two nuclei (appear as owl eyes),
Signs and symptoms
- No dramatic symptoms, Enlarged lymph node may be present .
Diagnosis
- Lymph node biopsy
Anemia
Major pathophysiologic condition of RBC’s
- Insufficient oxygen delivery to tissues due inadequate healthy, mature RBC’s
- In United States, 6.6% of men and 12.4% of women have anemia
- Some races and ethnic groups have increased risk of some forms of anemia
Example: Sickle cell anemia (SCA) is common in poor socioeconomic countries.
Reticulocytes
Less than 1% of reticulocytes live in the blood
More than 1% of reticulocytes is normal in the bone marrow
More than 1% of reticulocytes in the blood is abnormal
Erythropoietin
In states of hypoxia:
- Kidney releases erythropoietin (EPO)
- EPO simulates bone marrow to produce RBC’s
- Increased RBC’s to compensate for the hypoxia
low oxygen in arterial blood —-> kidney —> erythropoietin stimulates bone marrow —–> bone —-> synthesis of erythrocytes —-> RBC —-> increase oxygen carriage in the blood
RBC Formation and Breakdown
RBC synthesis
- Protein, iron, vitamin B12, folic acid
Hemoglobin
- Composed of heme and globin component
- Metabolized to biliverdin (pigmented)
- Biliverdin broken down to bilirubin (yellow pigment)
Hyperbilirubinemia
- Accumulation of bilirubin in blood
- Can lead to jaundice
-Iron is the main substrate for synthesis of hemoglobulin
RBC —–> Heme + Globin
| |
Iron |
Porphyrin
Biliverdin
Bilirubin
Jaundice
Anemia
Possible etiologies
- Deficiencies (Iron, vitamin B12, folic acid)
- Blood loss (Chronic and acute)
- Hemoglobinopathies
- Medications
- Hemolysis
Signs and Symptoms
- Can be asymptomatic
- GI tract blood loss
- Heavy menstrual periods (menorrhagia)
– Tachycardia
- Jaundice
- Splenomegaly
- Nutritional anemias can cause glossitis, cheilitis, koilonychia, or pica
Anemia Diagnosis
Diagnosis
- Complete blood count: Hb, Hct, RBC count
- Peripheral blood smear: size, shape, color of RBC’s
- Bone marrow aspiration
- Echocardiogram/electrocardiogram
- Nutritional status assessment