wk 1-3 Flashcards
What are the three main functions of blood?
Transportation (oxygen, nutrients, waste)
Balance (pH, temperature, water)
Protection (immune defense, clotting).
What are the percentages of blood components?
55% plasma, 1% buffy coat (WBCs, PLTs), 45% RBCs.
What hormone stimulates RBC production? Where is it made?
Erythropoietin (EPO), made by the kidney; stimulates bone marrow stem cells.
Reduced in kidney failure, HIV/AIDS, cancers, RA.
What is the structure of fetal hemoglobin (HbF)?
HbF = 2 alpha, 2 gamma chains; higher oxygen affinity than adult hemoglobin (2 alpha, 2 beta chains).
What are the roles of WBC types?
Neutrophils = bacteria;
Eosinophils = parasites, allergies;
Lymphocytes = viruses + tumors;
Monocytes = macrophages;
Basophils = small %, hypersensitivity reaction with food or drugs, ATTRACT OTHER WBCS
What are atypical lymphocytes a key indicator of?
Infectious mononucleosis, often the first sign of EBV infection.
What is the CBC Rule of 3s?
RBC x 3 ≈ Hemoglobin x 3 ≈ Hematocrit.
What does MCV measure, and why is it important?
Measures RBC size; microcytic (<80), normocytic (80-100), macrocytic (>100).
What does RDW indicate?
Variation in RBC size (anisocytosis); high RDW = greater variation, often seen in anemia.
Who is the universal blood donor and recipient?
O- = universal donor; AB+ = universal recipient.
What happens if an Rh-negative mother carries an Rh-positive baby?
Antibodies against Rh+ develop, leading to erythroblastosis fetalis in later pregnancies.
RH negative mother has Rh positive baby = antibodies can build against Rh + blood =
erythroblastosis fetalis (hemolytic disease of the newborn) = problem for 2nd Rh + baby,
Rhogam is given after delivery to prevent development of these antibodies
Prevented with Rhogam postpartum or during pregnancy.
What is TRALI, and how is it managed?
Transfusion-related acute lung injury:
- transfused product has anti-HLA or anti-neutrophil antibodies
sx: FEVER, HYPOTENSION, dyspnea, hypoxemia, bilateral chest infiltrates
Stop transfusion immediately, manage airway, supplemental O2
MCC of death associated with transfusions
MCC of transfusion-related death.
What is TACO, and how does it differ from TRALI?
Transfusion-associated circulatory overload: dyspnea, edema, HYPERTENSION (volume overload signs, no immune reaction)
- Manage with slow transfusion, diuretics.
- often occurs in
elderly and chronically anemic
- TRALI= hypotension; FEVER
Common in elderly, chronically anemic.
What defines anemia?
Decreased RBC count, hemoglobin, or hematocrit, reducing oxygen-carrying capacity of blood.
What are reticulocytes, and what do they indicate?
precursor to RBC, have remnant genetic material. Retic counts measure
the rate of RBC production by the bone marrow, appear as polychromasia on a wright
stained blood smear
Appear as polychromasia on Wright stain.
How are platelets (PLTs) formed?
From megakaryocytes in the bone marrow.
What organ is at greatest risk in hemolytic anemia?
The kidney, due to hemoglobinuria.
What is the recommended hemoglobin level for transfusion?
<7 grams per deciliter in asymptomatic patients.
What are the lab findings in iron deficiency?
Serum Iron = low
Ferritin = Low *
Transferrin = High, TIBC = High,
*
Tsat = low,
UIBC = high,
RDW = high*
MCV < 80 -> microcytic hypochromic anemia.
What is iron deficiency anemia (IDA)? cause
MC type
causes: decreased intake, hemolysis, hemorrhage (most cases), increased utilization.
What are the symptoms of IDA?
Fatigue, pallor, poor concentration, syncope, weakness, dyspnea, angular cheilitis, koilonychia, pica, atrophic glossitis, aphthous ulcers, RLES.
What is the best treatment for iron replacement in IDA?
Oral ferrous sulfate is best for treating IDA.
What are the features of lead poisoning?
Mimics IDA; features Burton lines on gums, elevated ICP, learning/IQ issues, basophilic stippling; history of lead exposure critical.
What is hereditary hemochromatosis?
Autosomal recessive HFE mutation -> inc iron absorption, high ferritin, high Tsat.
Triad: hepatomegaly, skin hyperpigmentation, diabetes.
Managed with phlebotomy.
What defines macrocytic megaloblastic anemia? (b9 vs b12)
Folate (B9) deficiency: reduced intake of leafy greens and fortified veggies, absorption, metabolism, pregnancy utilization; risks: neural tube defects.
B12 deficiency: reduced intake of meats, absorption (needs intrinsic factor/terminal ileum), neurological symptoms (paresthesias); stored in liver. Intrisic factor important
for B12 absorption, done in terminal ileum, methylmalonic acid elevated, B12 stored in liver
What are the lab findings in hemolytic anemia?
Inc reticulocytes, bilirubin, LDH; dec haptoglobin.
What is hereditary spherocytosis?
Autosomal dominant. ( membrane issue with spectrin and ankyrin)
Features: anemia, jaundice, dark colored urine, splenomegaly;
RBC shape: hyperchromic spherocytosis, reticulocytosis.
Increased MCHC (most reliable)
Osmotic fragility test positive.
negative coombs
tx: folic acid, splenectomy
What is G6PD deficiency?
X-linked. Enzyme protects against oxidative stress. Hemolysis triggered by infections, medications, fava beans. Features: Heinz bodies, blister/bite cells.
new onset of fatigue, skin discoloaration, dark urine from starting sulfa drug
What are the features of thalassemia? - name of ds based on number of deletions
○ If 1 gene missing = silent carrier
○ 2 genes missing = thalassemia trait
○ 3 genes missing/deleted (1 present) = Hemoglobin H disease (HbH inclusion
bodies, target cells) HbH is formed by beta globin tetramers (B4), tetramers precipitate as heinz bodies (golf ball looking) in RBCs and reduce lifespan of affected RBCs
○ 4 genes missing (0 present) = Hb BARTS (gamma globin tetrameres) Hydrops fetalis (alpha thal major)
Beta:
- minor = heterozygous, most are asymptomatic, mild anemia, increased Hb A2, Hb F
major = homozygous (severe anemia, skeletal deformities); increased Hb A2, Hb F
note:
- IDA: LOW HbF and HbA2
What are the features of thalassemia? when to suspect
Autosomal recessive: decreased production of globin chains
- severe anemia if either major ds goes untreated
skeletal changes (ex. Chipmunk facies, pathological fx,
short stature)
suspect:
- microcytic hypochromic
- normal or increased serum iron
- normal or increased ferattin
Thalassemia: how to differentiate Alpha vs beta
4 is normal # of alpha globin genes, differentiate from beta with Hb electrophoresis (normal levels of Hb A2 and F in A; B will have increased A2 and F)
Alpha:
- 1-2 genes: normal Hb ration = no tx
- 3 genes: Hb H (beta chain tetrameres); HEINZ BODIES
- 4: hb BART - GAMMA TETRAMERES (yyyy)
What is sickle cell anemia?
- Autosomal recessive disorder characterized by sickle-shaped cells.
- Vaso-occlusion leads to tissue infarction and organ damage.
- Normocytic with high reticulocytes (retics), RDW, and Howell-Jolly bodies present.
- Caused by a point mutation in the B-globin chain of glutamic acid (glutamate) to valine.
- Risks: Infection, dehydration, hypoxia, hemorrhage, and strenuous exercise.
when do you see schistocytes?
- hemolysis and microangiopathic diseases: DIC, TTP/HUS
- TTP: schistocytes and polychromasia
What is warm autoimmune hemolytic anemia?
IgG-mediated (‘Gas = warm’).
- autoimmune hemolytic anemia caused by circulating IgG antibodies against red blood cells (Rh antigen) that are active at ≥ 37°C
- Causes: primary = idiopathic; secondary = lupus, CLL, methyldopa.
Features: jaundice, splenomegaly.
Positive Coombs test (IgG and C3+)
Tx: steroids, splenectomy.
What is cold agglutinin disease?
IgM-mediated (‘Mittens = cold’).
- against I antigen
Causes: primary = idiopathic; secondary = lymph disorders, infections.
Features: Raynaud’s, no splenomegaly.
Positive Coombs test ( C3+)
Tx: immunosuppressants (NO STEROIDS OR SPLENECTOMY)
What vaccinations are required pre-splenectomy? what happens post splenectomy and how does this relate to howell jolly
Pre-splenectomy: pneumococcal, meningococcal, Hib vaccines (2 weeks prior).
(this is bc you are more susceptible to strep pneumoniae, Hae influenzae, and neisseria meningitidis)
Post splenectomy (asplenism) = pt. Is found to have Howell-Jolly bodies (or if they’re hyposplenic = sickle cell)
Howell jolly bodies:
- small dense basophilic RBC includsions (usually removed by spleen)
- found in things with decreased splenic function: sickle cell ds, severe hemolytic anemia, megaloblastic anemia
Post-splenectomy: Howell-Jolly bodies.
What is the relationship between IDA and PUD?
PUD increases likelihood of IDA.
What does Hb electrophoresis differentiate?
Differentiates IDA (low RBC count) vs. thalassemia (high RBC count).
What are the risks of a sickle cell crisis?
Infection, dehydration, hypoxia, hemorrhage, strenuous exercise.
What precautions should be taken for sickle cell anemia if on hydroxyrurea?
For sickle cell: avoid sick people, maintain strict hygiene.
What is dactylitis in sickle cell anemia?
Swelling in hands/feet in infants; aka hand-foot syndrome.
What are the risks associated with thalassemia major and frequent transfusion?
Frequent transfusions -> iron overload.
What does a positive Coombs test for IgG indicate?
Positive for IgG in warm antibody-induced hemolysis.
What are Howell-Jolly bodies?
Nuclear remnants in RBCs, seen post-splenectomy or in hyposplenic conditions (e.g., sickle cell anemia).
What increases the likelihood of IDA in PUD?
Chronic blood loss from ulcers.
Why is Hb electrophoresis important? for IDA vs thalassemia
Differentiates IDA (low RBC count) from thalassemia (high RBC count).
What are the features of sickle cell crisis risks?
Infection, dehydration, hypoxia, hemorrhage, strenuous exercise.
What are the therapies for sickle cell anemia?
- Chronic therapy: Hydroxyurea (Hydrea)
-Blood transfusions are avoided due to hyperviscosity risk; exchange transfusions are reserved for severe cases (e.g., Acute Chest Syndrome).
What is paroxysmal nocturnal hemoglobinuria (PNH)?
- RBC breakdown leads to hemoglobin release in urine, causing dark-colored urine in the morning.
- Acquired genetic mutation causing a membrane defect due to the absence of the PIG-A gene -> no cd55 or 59 - intravascular hemolysis
What is aplastic anemia (AA)?
- Can be caused by Parvovirus B19 during pregnancy, leading to severe complications for mother and fetus.
- Bone marrow transplantation is the gold standard treatment for AA.
What is myelodysplasia (MDS)?
Acquired bone marrow disorders with abnormalities in all three myeloid lines. characterized by
- abnormal maturation of cells
- clonal hematopoeisis
- over 1 cytopenia
- precursure to AML
Symptoms include anemia, infection, and bleeding from pancytopenia
- Auer rods within blasts are uncommon but diagnostic of MDS with excess blasts
- Differs from AA with normal/increased marrow cellularity, often increased blasts, and positive megakaryocytes. but Blast percentage <20%.
think this in elderly with unexplained pancytopenia with hx of chemotherapy
What are the features of myeloproliferative disorders?
- Disorders involving one or more bone marrow cell lines, often associated with JAK2 mutation. (Polycythemia vera, essential thrombocytopenia, myelofibrosis).
What are the features of polycythemia vera (PV)?
Over 95% have acquired mutations of JAK2, inc in all blood cells, can lead to strokes and organ damage, caused by a genetic mutation.
- Secondary can be caused by high altitude, pulm/cardio ds, etc.
- pt can present with tiredness, depression, vertigo, tinnitus, visual disturbnce, HTN, angina, intermittent claud, bleeding, Itching after showers is common. -Thrombosis and hemorrhage are the main complications.
- Phlebotomy and Hydrea are used to keep Hct below 45% and PLT count under 400k, Aspirin also important in Mx.
What are the features of essential thrombocythemia (ET)?
PLT elevated, get thromboembolic issues
- JAK 2 mutation tests are useful but is present in much lower % of cases that PV.
- A person who has a very high PLT count (> 1 mil microL), who is clinically normal and in good health probably has ET.
- > 450k is the criteria for ET tho, itchiness is very uncommon unlike PV, can see livedo reticularis, atypical chest pain.
- Tx is with hydroxyurea to control PLT count to less than 400k.
What are the features of myelofibrosis?
Increased fibrosis in bone marrow, fullness in upper abdomen, can see massive splenomegaly, tear drop shaped RBCs (dacrocytes), anemia with leukoerythroblastic features.
- JAK mutation present, splenectomy can be helpful.
- Overall = enlarged liver/spleen, impaired blood cell production from build up of fibrosis, and constitutional symptoms.
What are the features of immune thrombocytopenic purpura (ITP)?
Acquired d/o immune related destruction of PLT, children = acute, adults = chronic.
- Characterized by mucocutaneous bleeding (ex. Oral mucosa) and a very low PLT count, otherwise normal peripheral smear.
- Pt.’s present with bruising and petechiae.
- Tx starts under 30k PLT = can use prednisone.
What are the features of thrombotic thrombocytopenic purpura (TTP)?
TTP = FAT RN”
Thrombocytopenia, microangiopathic hemolytic anemia.
- Primarily in Adults
- Presents with classic pentad = anemia, thrombocytopenia, renal failure, neuro findings, fever.
- Related to deficiency of ADAMTS13 which cleaves VWF, levels < 10% more clearly assosc with idiopathic TTP.
- ADAMTS13 deficiency -> increase in von Willebrand factor (like sticky paper) -> more platelet adhesion -> microthrombosis in vessels
- ADAMTS13 tests are required for confirming dx,
- < 10% is diagnostic of TTP, peripheral smear can have schistocytes and polychromasia.
- Plasma exchange therapy is Tx of choice, Rituximab if that fails.
What are the features of hemolytic uremic syndrome (HUS)?
- Acute renal failure, microangiopathic hemolytic anemia, and thrombocytopenia.
- E.COLI O157:H7,
- cytotoxic effect of shiga toxins.
- Primarily in children,
- Diarrhea is a common finding, hematuria, thrombosis, significant purpura,
- Tx primarily supportive.
What are the features of HIT1 and HIT2?
HIT 1 - non immune related, 1-4 days after, resolves spontaneously when heparin is stopped.
HIT 2 - Immune mediated, 5-14 days after, may cause serious thromboembolic consequences, heparin MUST be discontinued.
What defines myelodysplastic syndrome (MDS)?
Bone marrow 15% blasts reduced erythropoesis
Bone marrow with <20% blasts, reduced erythropoiesis, and abnormal blood cell production.
