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
IgM binds RBCs at low temperature at peripheral body sites and fix complement–within increased temp the IgM is dissociated from the cell and leaves C3b behind–extravascular hemolysis of RBCs…
Cold agglutinin disease
What are disorders/infections that can cause cold agglutinin disease?
Lymphoid neoplasms Mycoplasma EBV HIV Influenza CMV
What phenomenon is seen with cold agglutinin disease?
Raynauds
What lab values are increased in cold agglutinin disease and what causes this?
Increased MCV and Bilirubin caused by increased RBC turnover
What immunoglobin is involved in warm antibody hemolytic anemia?
IgG–chronic and not triggered by cold
Spherocytes are seen with paroxysmal nocturnal hemoglobinuria, what causes this?
Incrased osmotic fragility of RBCs
Increased serum ferritin -mild and marked?
Anemia of chronic disease–mild increase
Hemochromatosis– marked increase
What type of malaria are sickle cell trait ind. resistant to?
P. Falciparum
What is erythroblastosis fetalis?
Maternal antibodies coating fetal RBCs–sensitization occurred during previous delivery–IgG made crossing placenta, attaching to fetal RBCs, causing hemolysis
Immune-mediated mechanism caused, in many causes, by cephalosporin therapy?
Drug-induced hemolytic anemia
What is hepcidin?
Liver-derived plasma peptide
Iron absorption regulator
When are hepcidin levels increased?
when iron stores are high
When are hepcidin levels decreased?
hereditary and acquired hemochromatosis
Iron transporter that moves nonheme iron from he gut lumen to the duodenal epithelium?
DMT-1
What is hemosiderin?
Aggregated from of ferritin
Does not circulate like ferritin and is found in tissue
HFE gene mutation
Leads to excessive absorption of dietary iron and hemochromatosis
What is transferrin?
Transports iron btw plasma, iron stores, and developing RBCs
What are the characteristics of anemia of chronic disease?
Increased ferritin with reduced total iron-binding capacity
What is the pathophysiology of anemia of chronic disease?
Chronic inflammatory or neoplastic disease increase the secretion of cytokines–IL-1, TNF, Interferon-g–promote sequestration of iron in storage compartments and depress EPO production
Disease often seen with chronic alcohol abuse, Is a megaloblastic anemia. Often presents with neutrophils showing defective segmentation–extra nuclear lobes?
Folate deficiency
What is indicated by tear drop RBCs?
Myelophthisic disorder–immature RBCs and WBCs and splenomegaly with extensive fibrosis
What are the two best know causes of high MCV– macrocytosis?
Vit B12 deficiency
Folate deficiency
What are causes of aplastic anemia?
Exposures to chemo drugs or chemicals
Viral infections–ALMOST NEVER Bacterial infection
ADAMTS13 deficiency
accumulation of large von willebrand multimers–results in thrombotic thrombocytopenia purpura (TTP)
Heat stroke caused by hyperthermia and loss of perspiration from dehydration leads to…
Hemoconcentration
Can cause arterial and DVTs with increased risk of cerebral artery thrombosis. Patient often false positively tests for syphilis? A thrombocythopenia often present. Women with multiple miscarriages should be consider for this disease?
Antiphospholipid syndrome
false + caused by anticardiolipin antibody
With DIC what lab values are increased and what are decreased?
PT/PTT increased
Thrombocytopenia
Low fibrinogen concentration
Helmet cells
Typical of conditions that den produce a microangiopathic hemolytic anemia–DIC, thrombocytopenia purpura, SLE, hemolytic-uremic syndrome, lamignant HTN
Platelets destroyed in spleen after being coated with antibodies to platelet membrane glycoproteins IIb/IIIa or Ib-IX
Immune thrombocytopenic purpura (ITP)
Does giving a blood transfusion to a patient with immune throbocytopenic purpura help?
No–antibodies coat both the patient’s platelets and any transfused platelets
What is the the treatment for immune throbocytopenic purpura if corticosteroid therapy fails?
Splenectomy
Seen with Glanzmann thrombasthenia and Chronic immune throbocytopenic purpura?
Glycoprotein IIb/IIIa dysfunction/deficiency
Von willebrand factor metalloproteinase deficiency is a feature of what disorder?
Thrombotic thrombocytopenia purpura
What is the pathophysiology of heparin-induced thrombocytopenia?
Formation of IgG antibodies to heparin-platelet factor 4 complexes that bind to Fc receptors on the surface of platelets–causes platelet activation and thrombosis
What isn’t given if a patient present with a protein C deficiency?
Warfarin
What is the classic pentad of Thrombotic thrombocytopenia purpura?
Transient neurologic problems Fever Thrombocytopenia Microangiopathic hemolytic anemia Acute renal failure
The activity of what is decreased in thrombotic thrombocytopenia purpura?
ADAMTS13–which acts as a von willebrand factor multiuser protease
Patients with liver disease have defects in what clotting factors?
Extrinsic pathway coagulation–causing changes in PT
Inherited bleeding disorder with normal platelet count and prolonged bleeding time?
Von willebrand disease
Which clotting factor will be decreased with von willebrand disease?
Factor VIII-because vWF acts as a carrier for this factor
What is the pathophysiology of von willebrand disease?
Reduction in quantity of vWF impairing platelet adhesion to damaged vessel walls
HUS is related to what?
preceding infectious gastroenteritis with diarrhea E. coli infection
What clotting factor is decreased with Hemophilia A?
Decreased factor VIII activity
What is the characteristic finding of hemophilia A?
Bleeding into soft tissue–joints
If gone untreated what can hemophilia A lead to?
Hemathroses
What lab value is prolonged due to hemophilia A?
PTT–intrinsic pathway affected
If a patient with hemophilia A gets a transfusion to + factor VIII and their PTT is not corrected then what has occur?
An inhibitor of factor VIII is present
If there is no inhibitor then the PTT will be corrected with transfusion
What deficiency is involved in hemophilia B?
Factor IX deficiency
A rare autosomal recessive disorder that involves defective platelet aggression from deficiency or dysfunction of glycoprotein IIb/IIIa?
Glanzmann thrombasthenia
Caused by antibodies to platelet membrane glycoproteins IIb/IIIa or Ib/IX?
Immune thrombocytopenic purpura
If a patient receives a platelet transfusion what are they more likely to contract?
More likely to cause sepsis due to the storage at room temp making platelets more susceptible to contamination
Caused when donor plasma contains HLA or granulocyte-specific antibodies–granulocyte enzymes are released and increase capillary permeability and result in sudden pulmonary edema and respiratory distress.
Transfusion-related acute lung injury (TRALI)
