Robbins CH 14 RBCs Flashcards
What does basophilic stippling of RBCs suggest?
A marrow injury–drug/toxin
Hypochromic RBCs are seen with what 2 disorders?
Iron deficiency and Thalassemias
Associated with reduced Hb synthesis
What do Schistocytes suggests?
Microangiopathic hemolytic anemia–shock/sepsis
What is seen with acute and chronic blood loss?
Reticulocytosis and marrow hyperplasia
Marrow responding to a decrease in RBCs
Very hypo cellular marrow and unable to respond to anemia–associated with pancytopenia
Aplastic marrow
What does the Coombs test, test for?
Testing for autoimmune hemolytic anemia
Impairs the ability of the marrow to mount a significant and sustained reticulocytosis. Typically microcytic and hypo chromic
Iron deficiency anemia
What is haptoglobin
Serum protein that binds to free Hb
How can SLE cause decreased haptoglobin levels?
SLE can result in hemolysis which causes a decrease in haptoglobin
What does an elevated D-dimer suggest?
microangiopathic hemolytic anemia
A condition in which a mutation affects one of several membrane cytoskeletal proteins–important in maintaining RBCs shape (spectrin, ankyrin, band 4.2 and 3, Protein 4.1, glycophorin A). The RBCs lack central pallor on peripheral blood smear…
Hereditary spherocytosis
What is suggested by the lack of central pallor on blood smear of RBCs?
Hereditary spherocytosis
What disease may lead to an aplastic crisis precipitated by a parvovirus infection?
Hereditary spheocytosis
What is the treatment of hereditary spheocytosis?
Splenectomy–beneficial because the spherocytes are no longer detained by the spleen
What are the 3 characteristics of disseminated intravascular coagulation?
Gives rise to thrombocytopenia
Bleeding
Appearance of fragmented RBCs on blood smear
B-thalassemia major causes a-globin chain aggregation causing apoptosis. This leads to anemia and iron overload. What can the iron overload cause?
Results in hemochromatosis with infiltrative cardiomyopathy, hepatic cirrhosis, and bronze diabetes from pancreatic islet dysfunction
Why are maxillofacial deformities seen with B-thalassemia major?
Severe anemia–increases EPO production which leads to the expansion of the marrow
What group of individuals has the highest incidence of developing B-thalassemia major?
patients from mediterranean descent
How can sickle cell anemia lead to a risk for infection with encapsulated bacterial organisms?
Cumulative ischemic damage to the spleen results in autosplenectomy – impaired splenic function and resultant inability to clear bacteria from the bloodstream can occur in childhood
What individuals are most likely to have alpha-thalassemia major?
southeast Asian ancestry
What is alpha-thalaseemia major?
Complete lack of a-globin chains precludes formation of Hb A1, A2 and F
Only tetramer of gamma chains (Bart’s Hb) en be made–severe fetal anemia
Sensitivity to oxidizing agents causing a hemolytic anemia–X-linked disorder that affects about 10% of african-american males
G6PD deficiency
What are the drugs that subject Hb to damage by oxidants seen with G6PD deficiency?
Primaquine Sulfonamides Nitrofurantioin Phenacetin Aspirin
What are bite cells?
Result from the attempts of overeager splenic macrophages to pluck out the heinz bodies–addingto the hemolysis seen with G6PD deficiency
Abnormal HFE gene…
seen in hereditary hemochromatosis–iron overload
What is the mechanism of action of hydroxyurea therapy given for sickle cell anemia?
increases the concentration of HbF in RBCs
Interferes with polymerization of HbS
How is B-thalassemia minor and iron deficiency anemia differentiated since both are characterized by hypo chromic and microcytic RBCs?
With iron deficiency anemia there is no increase in HbA2 and there would a a decreased ferritin level as well
Anemia of chronic disease is associated with an increase in____.
serum ferritin
Disorder that results from an acquired stem cell membrane defect produced by a PIGA gene mutation that prevents the membrane expression of certain proteins that require a glycolipid anchor?
Paroxysmal nocturnal hemoglobinuria (PNH)
Complement distraction of RBCs, Granulocytes, and Platelets. Patient presents with hemoglobinuria (dark urine) is at an increased risk of venous thrombosis due to platelet defects and has recurrent infections caused by impaired leukocyte fucntions?
Paroxysmal nocturnal hemoglobinuria
What 2 disorders by results from paroxysmal nocturnal hemoglobinuria?
Acute leukemia
Aplastic anemia
Spectrin mutations…
Hereditary spherocytosis
What cause the dark urine with G6PD deficiency?
Intravascular hemolysis
Postive Coombs test
Indicates the presence of anti-RBC antibodies