Anemias Flashcards
What is on a CBC
WBC differential RBC Hgb Hct MCV MCH MCHC Plt
What is normal RBC count
M: 4.7-6.1
F: 4.2-5.4
Normal lifespan: 120 days, then spleen eats them
RBC carry Hgb
What does Hgb do
bind and transport oxygen
M: 14-18
F: 12-16
What is the Hct
measure of % of total blood volume that is made up of RBC
Should be 3x the Hgb
What is the MCV
Volume determining average volume (size) of RBC
Normal: 80-100
Tells you micro vs macro vs normocytic
What is the MCH/MCHC
Avg mass of Hgb per RBC in a sample of blood. Less Hgb = less red. more Hgb = more red
Tells you hyper vs hypochromic
What is RDW
Red cell Distribution Width AKA measure of variation in size of RBC’s
Normal is 11-15%
What is anisocytosis
Increased variation in size of RBC
Increased RBC count can indicate
Dehydration
COPD (chronic hypoxemia)
Polycythemia vera
Decreased RBC count can indicate
Anemia 2/2: bleeding iron deficiency B12, folate deficiency hemolytic cirrhosis bone marrow failure pregnancy
What is anemia
Reduction in 1+ of major RBC measurements
What are reticulocytes
Immature RBC
Takes 1-2 days to mature
Indicate the bone marrow is producing RBC!
Normal: 1-2%
What is a pearl about recognizing reticulocytes in a peripheral smear
Lots of blue means Lots of new
Reticulocytes have a blue tint, and are larger than normal RBC
What are some causes of anemia
Impaired RBC production: iron, B12, folate deficiency, chronic disease, insufficient erythropoiesis
Increased RBC destruction: hemolysis
Blood loss: menses, GI, trauma, post-op
What are the characteristics of the different types of anemia*
Microcytic: small size, low MCV. Iron deficiency or Thalassemia
Normocytic: nl size, nl MCV. chronic disease
Macrocytic: large size, high MCV. Folate or B12 deficiency
How does anemia present clinically
Varies based on age, underlying condition, etiology, severity, and onset
Acute may have Sx even if mild
Chronic often doesn’t show Sx until Hgb <7!
S/Sx of anemia are
Fatigue weakness light headed/ syncope dyspnea palpitations pallor tachy hypotension orthostatic changes \+/- heme in stool
Late signs of anemia are
Glossitis (big tongue)
Chelitis
Jaundice
Koilonichia
What is your differential for Microcytic anemia
Iron deficiency (MC) Thalassemia Sideroblastic Lead poisoning -All with MCV <80
Common etiologies of iron deficiency anemia are
Menstrual blood loss
GI blood loss
Decreased iron absorption (celiac, bariatric surgery, H pylori infx)
Increased iron requirement (pregnancy)
Labs for Iron deficiency anemia will show
Microcytic (MCV <80) MCHC is low RDW increased Ferritin <12 (low stores) Serum Fe is low TIBC is high Rarely need marrow Bx, but if you got it, it'd show absence of iron stores
What is Ferritin
an indicator of iron storage! If low, iron stores are depleted
Also an acute phase reactant! Will falsely elevate with acute illnesses
Clinical findings in iron deficiency anemia are
Glossitis, chelitis, koilonychia
Pica (cave ice, clay, dirt)
Dysphagia 2/2 esophageal webs (plummer vinson syndrome)
Restless leg syndrome
How do you treat iron deficiency anemia
ID and Tx cause**
R/o underlying occult malignancy
Replace iron stores (Ferrous sulfate 325 mg BID-TID until anemia corrects + 3-6 months after)
Blood transfusions (depending on Hgb), but not for iron replacement
What is thalassemia
inherited disorder MC affecting mediterraneans
Reduced synthesis of globin chains (alpha or beta)
What are the types of thalassemia
Alpha and Beta
Normally, you have 4 alpha and 2 beta chains per Hgb
How do alpha deletions affect manifestations of thalassemia
1 deletion: silent carrier
2: alpha thalassemia trait 2/ mild MICROcytic anemia
3: Hemolytic anemia
4: Hydrops fetalis
How does Beta thalassemia manifest
Minor (trait): dysfunction of one b chain. ASx, microcytic, hypochromic anemia
Major (Cooley’s anemia): severe dysfunction of both chains. Fatal if untreated
Thalassemia labs will show
MCV is low
Microcytic, hypochromic
RDW is normal
Iron is normal
Ferritin is high
Peripheral smear: Poikilocytosis (abn shape), Target cells*
Hgb electrophoresis helps Dx by detecting type of Hgb present
How do you treat thalassemia
Regular transfusions if severe +/- iron chelation therapy. AVOID iron supplementation
Folic acid supp.
Consider splenectomy
Hematopoietic stem cell transplant for severe B-thalassemia
What can falsely elevate MCV
Large number of reticulocytes (baby RBC)
RBC clumping together to mimic larger RBC
What are the types of macrocytic anemia
Megaloblastic: 2/2 abn cell division in RBC precursors (hypersegmented neutrophils)- B12 deficiency, folate deficiency
Non-megaloblastic: alcoholism, liver disease, reticulocytosis (hemorrhage, hemolysis)
Megaloblastic anemia is characterized by
Defective DNA synthesis
Disordered RBC maturation and accumulation of cytoplasmic RNA
Larger RBC
Info about Folate
Folic acid is in the diet
Need 200 mcg daily, 400-800 if regnant or trying to become
Half life: 3 weeks! total body stores are small
4-5 months deprivation causes macrocytic anemia
Absorption occurs in jejunum
Needed for DNA synthesis
Folate deficiency occurs in
Alcoholism Hemodialysis Elderly End of pregnancy Anticonvulsant therapy (enzyme inhibition reduces folate absorption) Malabsorption syndromes Hemolytic anemia
Clinical features of folic acid deficiency are
Sx related to anemia
Glossitis, vague GI Sx
NO neurologic abnormalities (but neural tube defects in baby)
Lab findings for folic acid deficiency are
Low serum folate
Peripheral smear: Macro-ovalocytes, hypersegmented PMN
Homocysteine level elevated!! (methylmalonic acid is normal)
How do you treat folic acid deficiency
Tx underlying cause (if known)
Replace 1mg PO, 5mg PO if w/ malabsorption
Rule out co-existing B12 deficiency!!
Info about B12 (cobalamin)
Available from diet only
MCC is inability to absorb B12!
Need 1-2 mcg daily
How is B12 absorbed
Taken in by diet
Binds IF in stomach (IF made by gastric cells)
Travels to small intestine together
Cobalamin is released in the jejunum where it is absorbed
What conditions can cause B12 deficiency (impair the absorption)
Partial or complete gastrectomy (prevents IF secretion)
Ileal disease or resection
Bacteria overgrowth
Intestinal parasites
What is pernicious anemia
Immune mediated atrophy of gastric parietal cells causing absent gastric acid and IF secretion
Autoantibodies against gastric parietal cells impair IF secretion
B12 deficiency that is AUTO IMMUNE
Clinical features of pernicious anemia are
Typical anemia Sx
Glossitis, jaundice, splenomegaly
Atrophic glossitis, increased risk of gastric cancer
Neuro: Decreased vibratory and position sense, Ataxia, Paresthesias, confusion, dementia
Lab findings in B12 deficiency and pernicious anemia are
High MCV
Leukopenia, thrombocytopenia
Periph: hypersegmented PMN, anisocytosis, poikilocytosis, macro-ovalocytes
Low serum B12
Elevated Methylmalonic AND homocysteine levels
+ Schilling test or Abs to IF (prenicious anemia)
How do you treat pernicious anemia
Parenteral B12 (daily IM 100 mcg x 1 wk, then weekly for 1 mo, then monthly for life)
How do you treat B12 deficiency
Supplement B12 PO
**NEVER treat B12 deficiency with Folate alone. this will mask a worsening PA and result in neurologic damage!
What is hemolytic anemia
Decreased RBC survival time (20-100 days)
Can be compensated for by increased marrow production, but marrow can’t compensate for <20 days survival time!
How do you classify hemolysis
Acute or chronic
Acquired or inherited
According to main site of hemolysis:
-intravascular: RBS destroyed in bloodstream
-extravascular: RBC destroyed in the spleen
Lab findings in hemolytic anemia are
Elevated reticulocyte count (polychromasia)
Peripheral smear: immature RBC, nucleated RBC, +/- schistocytes (fragmented RBC)
Unconjugated bili increased
Elevated LDH
What is Haptoglobin
Mucoprotein produced in the liver that binds Hgb released from lysed RBC
Will be low in intravascular hemolysis because it is binding all the lysed RBC Hgb
Clinical features of hemolytic anemia are
Usual anemia Sx
Jaundice
Gallstones (bilirubin stones)
Increased risk of infection with salmonella and pneumococcus
Infection with ParvoB19 can cause transient aplastic crisis
What can cause intravascular hemolysis
Fragmentation syndromes (Macroangiopathic 2/2 trauma, Microangiopathis 2/2 RBC disruption from fibrin strand) Red cell enzyme deficiencies (G6PD deficiency) Paroxysmal nocturnal hemoglobinuria
What is G6PD deficiency
X linked recessive disorder causing deficiency in G6PD, which is needed to keep RBC alive for full 120 days
Low G6PD= RBC undergo oxidative damage and precipitation of Hgb
What can cause hemolysis in G6PD deficiency
Oxidative drugs= episodic hemolysis
Severe G6PD deficiency= chronic hemolysis
Clinical features of G6PD deficiency are
Id episodic hemolysis, usually healthy with no splenomegaly
Women carriers rarely affected
Lab findings in G6PD deficiency include
During hemolytic episodes: reticulocytes and serum indirect bilirubin increase
*Periph: Bite cells, Heinz bodies (denatured Hgb)
G6PD levels low
How do yuo treat G6PD deficiency
Most cases are self limited
Avoid oxidative drugs
What causes extravascular hemolysis
Hereditary spherocytosis Sickle cell anemia AI hemolytic anemia Incompatible transfusion Drug induced hemolytic anemia
What is hereditary spherocytosis
auto dominant d/o w/ mild hemolytic anemia
RBC have normal MCV, but smaller surface area. They are dense, round, and lack central pallor
They’re poorly deformable and get trapped in splenic sinusoids and are eaten by spleen macrophages
RBC lifespan is reduced if you have a spleen, and normal if you’ve had a splenectomy
Clinical features of hereditary spherocytosis are
ASx (adapt well)
Mild jaundice/scleral icterus
Splenomegaly
Chronic hemolysis creates need for increased folate to avoid megaloblastic anemia
Labs in hereditary spherocytosis are
Osmotic fragility test (RBC have increased hemolysis on exposure to hypotonic fluid)
How do you treat hereditary spherocytosis
*Splenectomy! Restores nl RBC lifespan, removes risk of bilirubin gallstones
-Must give pneumovac 2/2 spleen cant fight off pneumococcal infection anymore
Wait to do splenectomy until adult, if possible
What is Sickle cell disease
Autosomal recessive disorder where RBC contain HgbS under deoxygenated conditions
Homozygous= sickle cell disease (Sx)
Heterozygous= sickle cell trait (carriers, ASx)
MC in african american descent
Clinical features of sickle cell disease are
Onset: In childhood (4-6 months) when fetal Hgb changes to adult Hgb
Delayed growth and development
Increased susceptibility to infections
Sx precipitated by dehydration, hypoxia, high altitude, intense exercise
Chronic hemolysis
Vaso-occlusive phenomenon
What happens in chronic hemolysis (sickle)
Aplastic crisis= sudden decrease in Hgb
Bilirubin rises
May be life threatening!**
What indicates a vaso-occlusive ischemic tissue injury (sickle)
Pain crisis (give fluids and analgesics)
Osteonecrosis of femoral and humeral heads
CVA, MI
Splenic infarcts causing fxnl asplenism
Leg ulcers
What are lab findings in sickle cell disease
Hgb 5-11
RBC normochromic, normocytic
Elevated reticulocytes
+/- thrombocytosis
Hgb electrophoresis shows Hgb S (best confirmation test)
Periph: Howell-Jolly bodies*, target cells, nucleated RBC, few sickled RBC, thrombocytosis
How do you treat sickle cell disease
Avoid precipitating factors (high altitude, dehydration, intense exercise)
RBC transfusions as needed
Analgesics, fluids, oxygen during crisis
Hydroxyurea*: decrease incidence of painful crisis by suppressing marrow fxn
Bone marrow transplant
What is autoimmune hemolytic anemia (AHA)
caused by Abs that adhere to the surface of RBC and induce hemolysis by fixing complement and damaging cell membrane
RBC with Ag-Ab complex are phagocytized by macrophages and spherocytes are formed, that are destroyed by spleen
What will labs for AHA show
Periph: Polychromasia, spherocytosis, nucleated RBC
+ Coomb’s test
What happens with an incompatible blood transfusion
Most Abs to RBC are directed against ABO/Rh antigens
Incompatible blood results in hemolysis
What is Coomb’s test
can detect Abs of patient coating transfused red cels
What are the 3 blood transfusion reactions
Allergic
Febrile
Hemolytic
How do you treat hemolysis
ID and Tx underlying cause
Corticosteroids
Splenectomy advised
Folic acid supplementation
What is anemia of chronic disease
Can occur with Inflammation, organ failure, or in elderly
Caused by abnormal iron metabolism, impaired EPO production, or upregulation of hepcidin in response to inflammatory mediators
Labs in anemia of chronic disease show
Normocytic, Normochromic
Nl-High ferritin
Variable serum Fe and TIBC (both low if inflammatory*)
Diagnosis of exclusion!
How do you treat anemia of chronic disease
Treat underlying cause!
EPO may be beneficial
What is myelodisplastic syndrome
Acquired disorder of hematopoietic stem cells characterized by dysplasia and cytopenia
Idiopathic or secondary
Mild-Severe
Dx: bone marrow biopsy*
May progress to marrow failure or leukemia*
What is Sideroblastic anemia
Congenital or acquired RBC d/o
Inadequate marrow utilization of iron for heme synthesis despite normal iron levels being present
Bone marrow then produces ringed sideroblasts instead of healthy RBC
What are ringed sideroblasts
Erythroblasts (precursor to RBC) with perinuclear iron engorged mitochondria
What causes sideroblastic anemia
*Myelodysplastic Syndrome Chronic alcoholism lead poisoning Meds Chronic infection or inflammation Malignancy
Diagnostics for Sideroblastic anemia include
MCV: low, normal, or high Moderate anemia (20-30%) Anisocytosis, Poikilocytosis Systemic iron overload* BM Bx: Ringed sideroblasts*, RBC may be stippled, blue stained iron , erythroid hyperplasia
How do yu treat Sideroblastic anemia
Tx underlying cause Supportive Tx Tc iron overload if necessary (phlebotomy) Pyridoxine (B6) can help if CONGENITAL Acquired does not have a real cure Refer!
What is aplastic anemia
Acquired abn of marrow stem cells, MC idiopathic
May be 2/2 drug exposure (benzene, chemo, chloramphenicol) or viral illness (EBV, CMV, hepatitis), or ionizing radiation
Clinical features of aplastic anemia are
Pancytopenia*** (low Plt, RBC, WBC)
Bone marrow shows absence of precursors to all cells
Weakness, infections, bleeding
How do you treat Aplastic anemia
ID cause and eliminate it R/o other dz: acute leukemia, myelodysplasia, TB, etc. Hematology referral *Bone marrow transplant* Immunocuppressives if no transplant
Associate buzz words
Target cells: thalassemia or liver disease
Rouleax formation: multiple myeloma
Heinz bodies: G6PD deficiency (aggregates of denatured Hgb)
Howell Jolly bodies: Sickle cell, spleen isn’t present or functioning
Smudge cells: CLL
Helmet cells: hemolytic anemias
