Heme: Anemia

What is leukocytosis?

increase in WBCs

What is leukopenia?

decrease in WBCs

What is the normal range of Hgb?

males 14-18 g/dl

females 12-16 g/dl

What is the normal range of Hct?

males 42-52%

females 37-47%

What is the normal range of MCV?

80-100 um

What is the best test to classify anemias?

MCV

What is the normal range of MCH?

30-34 pg/cell

What is the normal range of MCHC?

31-37 g/dl

What is the normal range of WBC?

5-10 K/uL

What is the normal range of platelets?

150,000-450,000 /uL

What can contribute to an increased reticulocyte count?

post bleeding, post hemolysis, response to therapy (iron, b12, folic acid, etc)

What can contribute to a decreased reticulocyte count?

anemia, decrease erythropoietin, post radiation therapy

What are the youngest circulating platelets?

reticulated platelets

What is the role of Hgb?

O2 & CO2 transport

How many chains is Hgb made up of?

4: 2 a-chains, 2 B-chains

What are granulocytes?

neutrophil, eosinophil, basophil

What are agranulocytes?

lymphocytes, monocytes

What is the most abundant cell type? (45% of BV)

erythrocytes

What leukocyte is the 1st cell recruited to sites of infection/inflammation and the most abundant circulating phagocytes?

neutrophils

What leukocyte plays a role in resisting parasitic worm infections?

eosinophils

What leukocyte appears only in the blood, responds to inflammation, and release histamine?

basophils

What leukocytes are phagocytic, differentiate into circulating macrophages, and present foreign antigens to lymphocytes?

monocytes

What leukocyte differentiates into T cells and B cells?

lymphocytes

What is anisocytosis?

abnormal variation in size

What is poikilocytosis?

abnormal cell shape

What is the range to classify microcytic anemia?

MCV < 80 fL

What is the range to classify macrocytic anemia?

MCV > 100 fL

What is the range to classify normocytic anemia?

MCV 81-99 fL

Someone with anemia may present to the clinic with complaints of:

fatigue, nail defects, tachycardia, dyspnea, pale skin

What labs do you order when checking for anemia?

CBC w/ diff (dec H&H), RBC indices, Reticulocyte count, fecal hem occult, urinalysis

If the reticulocytes are low where is the problem?

bone marrow (decreased RBC production)

If the reticulocytes are high where is the problem?

not in the marrow; reflects appropriate compensation response

Where is iron primarily absorbed?

duodenum

What protein is designed to store iron in the cells?

ferritin

What happens to ferritin in the presence of iron deficiency?

decreases

What is the most useful test for iron deficiency?

ferritin; no other cause of low ferritin

What measures the amount of free iron in the serum?

Serum Iron (Fe)

What is an indirect measure of transferrin, which holds iron in the serum?

TIBC (total iron binding capacity)

What happens to transferrin in the presence of iron deficiency?

increases

What anemia results from under production of RBCs due to lack of adequate amount of iron?

iron deficiency anemia

What type of anemia does iron deficiency present as?

hypochromic, microcytic anemia

What is the most common cause of anemia?

iron deficiency

What is the most common cause of iron deficiency anemia?

chronic blood loss

What are signs of iron deficiency anemia?

asymptomatic, fatigue, SOB, weakness, pallor, palpitations, HA, tinnitus, dizziness

What are the unique manifestations of iron deficiency anemia?

glossitis, angular cheilitis, koilonychias, pica

What would be seen in an iron study done on a pt with iron deficiency anemia?

dec Hgb, low MCV, low MCH, high RDW, low reticulocytes, low serum iron, high TIBC, low ferritin, decreased % transferrin saturation

What vitamin can enhance absorption of iron?

Vit C

What tx can you give to manage Iron Deficiency Anemia?

Oral iron supplements, correct underlying problem, IV iron, blood transfusion

What anemia is genetic and characterized by mutations that result in a reduction or absence of one or more globin chains?

Thalassemia

Thalassemia can result in?

hemolysis

What is a classic finding of Thalassemia?

microcytosis out of proportion to the degree of anemia; normal iron studies

What will be seen on an iron study of a pt with Thalassemia?

normal values

How many B-globin genes are there? Where are they located?

2; chromosome 11

If you inherit only one abnormal Beta allele (b/b+) or (b/bo) what happens?

pt has Thalassemia trait or is a silent carrier

What happens if you inherit both abnormal B-Globin alleles (bo/bo)?

Thalassemia Major: marked hemolysis, profound anemia, and transfusion dependency

How many a-globin genes are there? Where are they located?

4; chromosome 16

What happens if there is a deletion of 1 a-globin gene (-a/aa)?

silent carrier of SCD

What happens if there is a deletion of 2 a-globin genes (-a/-a) or (--/aa)?

Thalassemia trait or Thalassemia minor

What happens if there is a deletion of 3 a-globin genes (--/-a)?

Hgb H disease: Hgb precipitates → hemolysis → splenomegaly

Hgb H disease presents as what type of anemia? What can be seen in a blood smear?

moderate/severe microcytic anemia

hypochromic, targets cells, basophilic stippling

What happens if there is a deletion of 4 a-globin genes (--/--)?

Thalassemia major or hydrops fetalis: total hemolysis

What is the Gold Standard test for diagnosing Thalassemia?

Hemoglobin Electrophoresis

What symptoms would a pt with Thalassemia have?

asymptotic or S/sx of anemia

What would you seen on a PE of a pt with Thalassemia?

hepatosplenomegaly, jaundice

What would you see in the lab smear of a pt with Thalassemia?

microcytosis, hypochromica, stippled cell, target cell, elliptical cell

Upon Hgb electrophoresis, what would lead to a dx of B Thalassemia?

inc levels of Hgb F and A2

Management of Thalassemia is only required for severe symptoms. If needed what would you do to treat it?

chronic transfusion therapy, iron chelation, splenectomy

What is the only curative measure for Thalassemia Major?

allogeneic stem cell transplant

Why can thalassemia trait be confused with iron deficiency anemia?

low MCV

Thalassemia trait is most prevalent in what population?

Asian, Mediterranean, and African population

Thalassemia trait presents as what type of anemia?

mild (no tx), asymptomatic, mild/moderate microcytic hypo chromic anemia

When should you suspect thalassemia?

low MCV w/ iron deficiency r/o, pt fails to respond to Fe replacement

What would the labs look like in a pt w/ Thalassemia?

low MCV, high RBC, normal RDW, normal or inc iron studies

What type of anemia would lead poisoning anemia present as?

microcytic hypochromic anemia w/ basophilic stippling

What are S/sx of lead poisoning?

vague non-specific sx, appetite changes, wt loss, anemia, learning disability, cranial nerve paralysis, seizures, coma

What would a lead level above 10 mcg/dl indicate?

toxicity

What would a lead level above 45 mcg/dl indicate?

chelation therapy

What would a lead level above 70 mcg/dl indicate?

medical emergency

What is the tx for lead poisoning?

prevention, chelation (promote excretion), supportive care

Normocytic anemia of blood loss can be caused by?

chronic and acute blood loss

Hemolytic anemia is caused by?

accelerated destruction of erythrocytes resulting in anemia (can be intra or extravascular)

What would the labs look like for a pt w/ hemolytic anemia?

CBC: normocytic anemia, inc total Bilirubin, inc LDH, dec haptoglobin, markedly inc reticulocytes

What is the most common RBC enzyme defect?

G6PD deficiency

G6PD deficiency is what type of inherited trait?

X-linked

G6PD deficiency most commonly affects what populations?

Mediterranean, Africa, China

What can be seen in a blood smear of a pt w/ G6PD deficiency?

Heinz Bodies

What forms Heinz Bodies?

inappropriately oxidized Hgb precipitates

What prompts hemolysis in G6PD deficiency?

“bite cells” formed by abnormal “pitted” Hgb from the RBC in the spleen

When does hemolysis occur in individuals w/ G6PD deficiency?

only under oxidative stress

What symptoms would you see in a pt with G6PD deficiency when they are in steady state?

asymptomatic

What test would you order to dx G6PD deficiency?

quantitative enzyme assay

What causes autoimmune hemolytic anemia (AIHA)?

antibodies and complement develop against RBCs resulting in their destruction

Warm Antibody AIHA is due to what?

-this form is most common

antibodies that are active at room temp (IgG)

Cold Antibody AIHA is due to what?

antibodies that are active in the cold (IgM)

What is the mainstay of treatment for Warm AIHA?

corticosteroids

What is the treatment for Cold AIHA?

supportive measures

When should a direct Coomb’s test (DAT) be ordered?

once hemolysis is suspected

What is a DAT used for?

distinguish immune from non-immune causes of hemolytic anemia using pt’s RBCs

What indicates that a DAT is positive (+)?

agglutination

What does a + DAT result indicate?

warm AIHA