Red Blood Cell Disorders 1 Flashcards
What three things are affected primarily by hematopoietic and lymphoid disorders?
1 RBCs (erythrocytes) 2 WBCs (leukocytes) 3 hemostasis (thrombocytes)
What is hematopoiesis?
Formation and development of blood cells, hematology
What is the location of hematopoiesis in children?
Marrow of long bones (tibia and femur)
Where does hematopoiesis occur in adults?
Pelvis, cranium, vertebral bodies, sternum, ribs
What is the location of extramedullary hematopoiesis?
Spleen, liver, lymph nodes, thymus
What is the clinical term for rupture of erythrocytes?
Hemolysis
What is released during hemolysis?
Hemoglobin (Hb)
What is the clinical term for erythrocyte production?
Erythropoiesis
What is the term for an immature RBC?
Reticulocyte
Reticulocytes make up what percentage of overall red blood cells?
1-3%
What can you assume with a patient who has reticulocytopenia?
Marrow failure (decreased circulating reticulocytes)
When do reticulocytes mature?
After 1 day in circulation
What is the clinical term for the condition involved increased RBC count?
Polycythemia (rare)
What is the prevalence of anemia in the US?
4% of men
8% of women
What is the clinical term for the condition involving decreased RBC mass and decreased O2 capacity?
Anemia
What are the three main causes of anemia?
1 blood loss (hemorrhage)
2 increased RBC destruction (hemolysis)
3 decreased RBC production (marrow failure)
What effect does anemia have on body tissue?
Hypoxia (decreased O2 supply)
During anemia, which organ increases its production of erythrocytes?
Kidneys (renal fibroblasts release more erythropoietin)
What are the signs and symptoms of anemia?
Pallor, fatigue, weakness (lassitude), decreased growth, osseous abnormalities, cachexia
Why does jaundice appear in severe cases of anemia?
Hemolysis leads to release of hemoglobin leading to a buildup of bilirubin from the breakdown of heme causing jaundice/gallstones
What is the appearance of RBCs with hemorrhagic anemia?
Normocytic, normochromic
What mineral is needed for hemoglobin synthesis?
Iron
What effect does chronic blood loss have on iron stores?
Decreases it
What are the effects of hemolytic anemia on the body?
1 decreased RBC life span (120 days)
2 increased erythropoiesis, extra medullary hematopoiesis, and reticulocytes (up to 8% of blood)
3 retention of RBC debris (iron)
What are the two categories of the effects of hemolytic anemias?
1 intracorpuscular defects
2 extracorpuscular defects
Which type of hemolytic anemia is hereditary? Which is acquired?
Hereditary = intracorpuscular defects Acquired = extracorpuscular defects
How do intracorpuscular defects associated with hemolytic anemia affect RBCs?
Enzyme deficiency and disordered hemoglobin synthesis
What things can cause extracorpuscular defects associated with hemolytic anemia?
Antibodies, RBC trauma, infections (like malaria)
What is a corpuscle in vascular terminology?
Free floating cell
What condition is most likely present if reticulocytes make up 8% of the overall blood?
Hemolytic anemia (due to increased erythropoiesis)
What are the two ways in which hemolysis can occur with hemolytic anemia?
Intravascular or extravascular
What is the most common way in which hemolysis can occur with hemolytic anemia?
Extravascular hemolysis
How does intravascular hemolysis occur?
Trauma to RBC membrane
How does extravascular hemolysis occur?
Macrophages attacking spleen/liver leading to RBC damage and antibody opsonization
What is the characteristic sign of intravascular hemolysis?
Hemoglobin in urine (hemosiderinuria)
What is hemosiderinuria?
Dark urine due to presence of hemoglobin
What are the signs of extravascular hemolysis?
Splenomegaly and jaundice
What is the general term for an abnormally shaped RBC?
Poikilocyte
What is the term for an irregularly shaped RBC post-hemolysis?
Schistocyte
What is the term for a teardrop-shaped RBC?
Dacrocyte
What kind of defect is associated with hereditary spherocytosis?
Intracorpuscular
What is the specific damage involved to the RBC with hereditary spherocytosis?
Abnormal RBC membrane (increased fragility)
Why is there a decreased life span associated with the RBCs during hereditary spherocytosis?
Removed by spleen
What is the treatment for hereditary spherocytosis?
Partial splenectomy
What type of inheritance pattern is involved with hereditary spherocytosis?
Autosomal dominant
What is the appearance of the RBCs in hereditary spherocytosis?
Spherical (spherocytes) and less elastic in nature
What particular infection can cause severe aplastic crisis with hereditary spherocytosis?
Parvovirus B19 (Fifth disease)
Spherocytes lack what appearance seen in normal RBCs?
Central pallor
What type of inheritance pattern is involved with sickle cell anemia?**
Autosomal recessive: beta-globin**
What type of anemia is caused by hereditary spherocytosis, sickle cell disease, thalassemia, glucose-6-phosphate dehydrogenase deficiency, paroxysmal nocturnal hemoglobinuria, immunohemolytic anemias, trauma, and malaria?
Hemolytic
8% of what race are heterozygous “carriers” for sickle cell disease?
African Americans
What ratio of African Americans are homozygous and HAVE sickle cell disease?
1:600
What specifically causes the sickling of the RBCs seen in sickle cell disease?
Decreased O2 due to microvascular thrombosis
Sickle cell formation is common in what kind of areas of the body?
Areas of stasis
What are the signs and symptoms of sickle cell diseases?
Thrombosis, chronic low-level pain, joint pain, priapism, fever, malaise, splenomegaly/infarction, gallstones, decreased growth and osseous distortion
What is the acute chest syndrome seen with sickle cell disease?
Lung infections/PE due to pulmonary vascular obstruction from reduced O2 causing thrombosis
Why are infection and septicemia common among those with sickle cell disease?
Patients are functionally asplenic
What are four complications seen with sickle cell anemia?
1 acute chest syndrome
2 stroke (cerebrovascular obstruction)
3 infection/septicemia
4 hypoxia-inducted fatty changes (from stress)
What are the locations of hypoxia-induced fatty changes seen with sickle cells disease?
Heart, kidneys, liver
Are heterozygous “carriers” of sickle cell disease symptomatic?
Rarely
What is the prognosis for those homozygous for sickle cell anemia?
50% survive beyond 5th decade
What are the two most common causes of death in those with sickle cell disease?
Acute chest syndrome or stroke
What is the most common location of congestion/infarction in sickle cell patients?
Bone marrow (can also occur in spleen, liver, kidneys, retina, brain, lungs, or skin)
What sign on X-ray is associated with sickle cell anemia?
Lincoln log vertebra (H-shaped vertebral bodies due to central depression and microvascular endplate infarctions)
Do all sickle cell anemia patients present with Lincoln log vertebra?
No, only 10%
What type of inheritance pattern is involved with thalassemia?
Autosomal recessive
What is the appearance of red blood cells with thalassemia?
Microcytic and hypochromic
What is thalassemia?
Abnormal hemoglobin production
In what areas of the world do we see a lot of thalassemia?
Areas of endemic malaria like Africa or southeastern Asia
What are the two types of thalassemia?
Beta (chromosome 11) or alpha (chromosome 16)
In beta-thalassemia, which globin genes are mutated, and what is the result?
Beta; excess alpha-globin
In alpha-thalassemia, which globin genes are mutated, and what is the result?
Alpha; excess beta-globin
What structures are damaged by thalassemia?
RBCs (hemolysis) and erythroblasts
What are the differences between beta-thalassemia minor and major?
Minor = involves 1 allele and is very mild Major = involves 2 alleles and leads to sever hemolysis/anemia
What condition is also known as beta-thalassemia trait”?
Beta-thalassemia minor
What is the appearance of RBCs with beta-thalassemia trait?
Microcytic and hypochromic (due to decreased hemoglobin formation)
Which form of thalassemia does not affect the lifespan of the RBCs?
Beta-thalassemia minor
How is beta-thalassemia minor diagnosed?
Electrophoresis
What is the treatment for beta-thalassemia minor?
Monitoring serum ferritin and occasional transfusions with iron chelation (to remove excess)
What is the treatment for beta-thalassemia major?
Repeated transfusions and iron chelation
What benefit does treatment for beta-thalassemia major have?
Extends survival into 20s and decreases symptoms and deformities
What is the eventual cause of death of beta-thalassemia major?
Lethal cardiomyopathy from hemochromatosis (iron overload)
What may possibly cure beta-thalassemia major?
Bone marrow transplant
What unique X-ray signs may be seen in those with beta-thalassemia major?
“Hair on end” appearance of the skull, lace-like appearance in bones of the hand
Which form of thalassemia is less damaging: beta or alpha-thalassemia?
Alpha-thalassemia (excess beta-globin is less worse)
Why is alpha-thalassemia highly variable in nature?
4 total alpha-globin genes that could be affected
What condition results from only 1 alpha-globin gene being affected? 2, 3, or all 4?
1 = silent carrier and asymptomatic 2 = alpha-thalassemia trait and asymptomatic 3 = HbH disease which is severe 4 = hydrous fetalis which is lethal in utero without transfusions
Alpha-thalassemia trait is similar to which beta-thalassemia condition?
Beta-thalassemia minor
HbH disease resembles what beta-thalassemia condition?
Beta-thalassemia intermedia
