Anemia I Flashcards
What are formed elements?
RBS, WBC, platelets
What are blood forming products?
Yolk sac, liver, spleen, bone marrow
What kind of tissue is blood?
Connective tissue (formed elements suspended in plasma)
What is plasma?
Liquid portion of blood (55% total volume)
What is plasma made up of?
Mostly water (90%), proteins, clotting factors, electrolytes, antibodies, hormones
What are formed elements?
Cellular components aka blood cells (45% total volume)
What are formed elements made up of?
RBCs (highest conc.), WBC, PLT
What is hematopoiesis?
Development of formed elements/blood cells
Fetal hematopoiesis?
Yolk sac primary site for first 8wks
2nd month: liver & spleen, then bone marrow
Pediatric hematopoiesis?
Axial and appendicular skeleton, distal long bones
Adult hematopoiesis?
Axial skeleton (skull, vertebral column, sternum, ribs), pelvis, proximal femur & humerus
*long bones - yellow and fatty
Myeloid cell line in hematopoiesis (bone marrow) that creates platelets?
Hematopoietic stem cell –> Myeloid stem cell –> Megakaryoblast –> Megakaryocyte –> Platelets
Myeloid cell line in hematopoiesis (bone marrow) that creates RBC?
Hematopoietic stem cell –> Myeloid stem cell –> Proerythroblast –> Reticulocyte –> Erythrocyte
Myeloid cell line in hematopoiesis (bone marrow) that creates Basophils, Neutrophils, Eosinophils?
Hematopoietic stem cell –> Myeloid stem cell –> Meyloblast –> Basophils, Neutrophils, Eosinophils
Myeloid cell line in hematopoiesis (bone marrow) that creates Monocytes?
Hematopoietic stem cell –> Myeloid stem cell –> Monoblast –> Monocyte
Lymphoid stem cell line in hematopoiesis (bone marrow) that creates Natural killer cells, T-lymphocytes and B-lymphocytes
Hematopoietic stem cell –> Lymphoid stem cell –> Lymphoblast –> NK cell or small lymphocyte (T and B cells)
Do RBCs contain nucleus when in circulation?
No, expel nucleus and cannot repair themselves through nuclei
Why do RBCs expel their nucleus?
Allows for max amount of hemoglobin w/in each cell
Mature RBCs are oval bioconcave disks, allowing for what?
Free movement in small capillaries
Average lifespan of RBC?
120d, then recycled for re-use
Can direct or indirect hemoglobin spill into urine?
Only direct *will be tea color
Composition of hemoglobin?
Heme (red pigment): iron & protoporphyrin
Globin (alpha & beta) aka globulin protein
What is the ptotoporphyrin part of heme broken down into?
Indirect bilirubin
What happens to the iron in heme after RBC breakdown?
Reused: stored in liver or transported by transferrin back to bone marrow to make new RBCs
What is globin broken down into?
Amino acids & recycled
Is hemoglobin strongly or loosely bound to oxygen?
Loosely
How many globin chains are in hemoglobin?
4
Globin chains in Hgb F (highest in utero)?
2 alpha + 2 gamma
Globin chains in Hgb A (highest after birth by 6 mos of age)?
2 alpha + 2 beta
Globin chains in Hgb A2 (variant: 1-3% in red cells)?
2 alpha + 2 delta
Proportions of Hgb change depending on what?
Based on affinity to carry O2 for the body
Hemoglobin transition during development?
At birth Hgb F is 80% and Hgb A is 20%, by 6mos of age –> transition to mostly Hgb A (adult) 97% + Hgb A2 (1-3%) and minimal amounts of Hgb F
What is needed for RBC production (erythropoiesis)?
B12, folic acid, iron, globin, EPO (erythropoietin)
What is EPO?
GF essential for erythropoiesis
Made by kidneys, levels rise when kidneys recognize low O2 (stimulate bone marrow to make more RBC)
Conditions which can effect EPO?
OSA (higher EPO), CKD (won’t respond), altitude changes (inc. altitude = inc. EPO)
What is a reticulocyte?
Immature RBC (in blood stream ~24hrs before maturing), contains RNA nuclear remnants
What does reticulocyte count reflect?
Rate of RBC production and overall health of bone marrow
Normal range of reticulocytes on CBC?
0.5-2%
When would reticulocyte count be high?
Hemolysis, bleeding
When would reticulocyte count be low?
Underproduction or failure of bone marrow (iron def, B12/folate def, bone marrow issue)
What are leukocytes involved in?
Pathogen recognition, phagocytosis, pathogen destruction, inflammation mediation, antigen presentation
Average WBC count?
4,000-11,000/mcL
How much volume do WBCs make up in total blood volume?
1%
What is leukocytosis?
Elevated WBC, frequently occurs as part of healthy immune system, occasionally elevated in neoplastic process/autoimmune d/o
What is leukopenia?
Dec. WBC count
What is neutropenia?
Dec. neutrophil count
What WBC type typically drives leukocytosis?
Neutrophils
N>L>M>E>B
Role of neutrophils?
Bacterial/fungal
Role of lymphocytes?
Viral
Role of monocytes?
Chronic illness, inflammation (mono, subacute endocarditis, Tb)
Role of eosinophils?
Parasitic infection, allergic response, autoimmune
Role of basophils?
Inflammatory, allergic response, histamine release
Causes of leukocytosis?
Infection, Myeloproliferative disease (CML), Cancer (acute leukemia), Meds (steroids), Stress (trauma, MI, pain)
What may be seen in acute bacterial infection?
Left shift (neutrophilia and bands aka immature neutrophils)
What is ANC?
Absolute neutrophil count (normally <1500)
Severe infection risk with what ANC?
<500
Causes of leukopenia?
Congenital/inherited conditions (chronic benign neutropenia-autosomal dominant inheritance), infections (HIV, CMV, EBV, RIckettsial), Meds, bone marrow dysfunction (malignancy, aplastic anemia)
Which meds can cause leukopenia?
Clozaril**, Bactrim, Chemo, Immunosuppressants
(usually onset is w/in 3 mos of new drug)
What is the main risk for a neutropenic patient?
Infection
What are platelets responsible for?
Initiation of the hemostatic mechanisms for clotting
Four major platelet functions?
Adherence, activation/secretion, aggregation, interaction with coagulation factors
What is thrombocytosis?
Too many platelets
Primary cause of thrombocytosis?
Bone marrow dysfunction (Myeloproliferative disease, essential thrombocytosis, polycythemia vera)
Secondary causes of thrombocytosis?
Recovery from bone marrow suppression, response to bleeding/infection/inflammation
What is thrombocytopenia?
Too few platelets
Causes of thrombocytopenia?
Bone marrow cannot make them (underproduction), platelets are destroyed/used up in peripheral circulation (clotting, severe infection, meds like chemo/heparin, TTP, ITP, HIT, DIC)
Components of a CBC?
WBC w/ diff, RBC, Hgb, HCT, red cell indices
RBC count in males vs females?
M: 4.6-6.2 mill/mcL
F: 3.8-5.4 mill/mcL
Hgb count in males vs females?
M: 13.5-16.2 g/dL
F: 12-15.2 g/dL
HCT in males vs females?
M: 41-50%
F: 36-47%
Normal RBC MCV?
80-100 fL
Normal RBC MCH?
27-33 pg
Normal RBC MCHC?
33-37 g/dL
Normal RBC RDW?
10-15%
Is reticulocyte count normally included in CBC?
No
How to determine if sufficient # of RBC?
RBC count, HCT, Hgb
How to determine quality/size/shape of RBCs?
RBC indices:
-mixed bag? RDW –> anisocytosis = variation in RBC size
-size? –> MCV
-Hgb content? –> MCH, MCHC
Peripheral smears show what?
Direct visualization (morphology, whether or not they contain bodies)
What is RDW?
Expression of homogeneity of the RBC population size
Inc=wide variation in size
RBC age vs size?
Younger = larger
Mature = smaller
Microcytic anemia MCV?
<80 fL
Normocytic anemia MCV?
80-100 fL
Macrocytic anemia MCV?
> 100 fL
What are MCH and MCHC used to assess?
Whether or not RBCs are normochromic, hypochromic, hyperchromic
What is MCH?
Mean cell hemoglobin - avg. hemoglobin content in a single RBC
What is MCHC?
Mean cell hemoglobin conc. - avg. hemoglobin content in a cell compared to the avg size of the cells
Which takes the size of RBCs into account- MCH or MCHC?
MCHC
Definition of anemia?
Low Hgb, RBC, or HCT resulting in insufficient erythrocytes to carry O2 to tissues
Hgb values for anemia in males vs females?
M: <13.5 g/dL
F: <12 g/dL
General sx of anemia?
Fatigue, DOE, dizzy, angina, orthostatic hypotension, pallor (skin, conjunctiva, mucosa)
Mild vs. Mod vs. Severe anemia?
Mild: <10-12
Mod: 8-10
Severe: <8
(g/dL)
Common sx w/ iron def. anemia?
Cheilosis, koilonychia, pagophagia
Common sx w/ B-12 def. anemia?
Paresthesia, confusion
Common sx w/ hemolytic anemias?
Jaundice, icterus, pruritis, hemoglobinuria
Hx of anemia from bleeding?
menstrual cycle, melena, hematuria
Hx of anemia from family/hereditary?
Sickle cell, sphereocytosis, G6PD deficiency, ethnic background
Hx of anemia from meds?
Hemolytic? cephalosporin, oxidative (Bactrim, Nitrofurantoin)
Hx of anemia from travel?
Infection (parasitic? hookworm)
Hx of anemia from social features?
Diet? (vegetarian, vegan), PICA, ETOH or toxin exposure (lead)
General workup for anemia?
Best initial test: CBC, blood smear (Hgb and MCV conc.)
-Hx, PE, initial CBC, retic/blood smear can guide further w/u
Further w/u for anemia may include what tests?
Iron, B12 & folate, Homocysteine level & MMA, LDH, Haptoglobin, Bilirubin, ESR/CRP, COOMBs (DAT) test for autoimmune, Osmotic fragility test/EMA binding, Hgb electrophoresis or high performance liquid chromatography, Bone marrow bx
Best test if MCV<80?
Iron studies (Iron def anemia, sideroblastic anemia, thalassemia, anemia of chronic dz)
Best test if MCV 80-100 and low reticulocytes?
Iron studies, Bun/Cr, ESR/CRP
(Anemia of chronic disease, aplastic anemia, early iron def. anemia)
Best test if MCV 80-100 and high reticulocytes?
Hemolysis labs, Haptoglobin, LDH, bilirubin (G6PD def, sickle cell, hereditary spherocytosis, autoimmune hemolytic anemia, blood loss)
Best test if MCV>100?
B12, folate, MMA, homocysteine, LFTs, TSH, Bone marrow (B12 def, Folate def, Hypothyroid, Liver dz, MDS)
Most common type of anemia in primary care?
Microcytic
Causes of microcytic anemia?
Iron def, thalassemia, Chronic disease 30% (may also be normocytic –> 70%), Sideroblastic anemia (ETOH, heavy metal poisoning –> lead, Isoniazid, B6 def.)
Workup for microcytic anemia?
-Serum iron (circulating iron attached to transferrin)
-TIBC (capacity of blood to bind to iron) –> indirectly measures transferrin
-Transferrin Saturation (% of transferrin saturated w/ iron)
-Ferritin (protein stores iron, acute phase reactant)
Most common anemia worldwide?
Iron deficiency
Causes of iron deficiency anemia?
Blood loss (GI/GU - colorectal CA?, menorrhagia), Dietary def. (pregnancy, dec. intake), Malabsorption
Where is iron absorbed?
Stomach, duodenum, proximal jejunum
*Celiac, Gastritis, H. Pylori may affect bc need ACID for absorption (PPIs can inhibit)
Iron def. anemia sx?
fatigue, weakness, exercise intolerance, DOE, vertigo, angina pectoris, PICA*, Pagophagia (ice cravings)
PE for iron def. anemia?
Pallor of skin/mucosa/palmar creases/conjunctiva, Koilonychia (nail spooning), Atrophic glossitis (smooth tongue), Angular cheilosis
RDW in iron def workup?
Elevated in early disease d/t anisocytosis (different RBC sizes), population gets hypochromic over time
Iron studies for iron def. anemia?
Serum iron: low
Ferritin: Low (<20ug/L - depleted iron stores)
TIBC: high (attempt to get more iron)
Trans. saturation: low
Size of RBCs in iron def. anemia?
Normocytic in early disease and then microcytic
Tx for iron def. anemia?
Find underlying cause
-PO iron supplements best on empty stomach (Vit. C inc. absorption, PPIs inhibit absorption)
-IV iron replacement (non-PO tolerated, more rapid correction)
Side effects of iron supplements?
Constipation MC, N/V, metallic taste
What is thalassemia (alpha/beta)?
Genetic d/o of Hgb: decreased alpha or beta chain production
(Hgb A = 2 alpha chains + 2 beta chains)
Who does thalassemia most often affect?
African, Asian, Mediterranean, Middle Eastern descent
How does thalassemia present?
Normal iron studies, varying degrees of hemolysis, may have TARGET cells on blood smear
Severity of thalassemia varies on what?
Number of alleles that are affected in the globin chain
Hemolysis labs?
Haptoglobin, LDH, indirect bilirubin, reticulocytes
What is haptoglobin?
Protein that transports free hemoglobin from lysed RBCs
What is LDH?
Enzyme in all living calls that is elevated in tissue/cell destruction
What is indirect bilirubin?
Waste product from RBC lysis
What are reticulocytes?
Immature RBCs elevated d/t bone marrow overdrive to keep up with blood loss or hemolysis
Overview of alpha thalassemia?
Reduced/absent alpha globin chain synthesis, overabundance of BETA chains, severity of disease relates to how many genes are defective (4 alpha genes on chromosome 16)
Who is alpha thalassemia most commonly seen in?
Individuals from Southeast Asia/Africa (less common in Mediterranean)
What is a silent carrier of alpha thalassemia?
1 alpha globin gene defective on chromosome 16 (-a/aa)
Sx: asx but can pass disease to offspring
*no lab abnormalities
*confirmed w/ DNA test
What is having the alpha thalassemia trait?
2 alpha genes defective on chrom. 16 (aa/–) or (-a/-a)
Sx: Asx but can pass to kids
Labs: mild microcytic anemia w/ unproportionally low MCV (60-75) and normal iron studies
*confirm with DNA test
What is having the alpha thalassemia trait often confused with?
Iron def. anima (commonly tx with iron supplements w/ no improvement in H&H)
What is alpha thalassemia intermedia (Hgb H disease)?
3 genes defective (-a/–) with excessive beta chain formation forming a tetramer called Hgb H (4 beta chains)
S/Sx of alpha thalassemia intermedia (Hgb H disease)?
Usually present @ birth: Splenomegaly, jaundice, anemia, varying degrees of hemolysis, inc. hematopoiesis resulting in bony deformities (frontal bossing)
Labs for alpha thalassemia intermedia (Hgb H disease)?
Microcytic hypochromic, Normal iron studies
Target cells on smear, Heinz bodies (insoluble beta chain tetramers of Hgb H)
Varying degrees of abnormalities in hemolysis labs (elevated reticulocytes, LDH, indirect bilirubin, dec. haptoglobin –> hemolysis)
*confirmed w/ DNA test or Hgb electophoresis w/ Hgb H (4 beta chains)
What is alpha thalassemia major (Hydrops fetalis)?
4 alpha chain genes defective (–/–)
Incompatible w/ life (no alpha globin produced)
Hgb Bart = tetramer of 4 gamma chains
Die in utero/shortly after birth
*confirmed by DNA test or Hgb electrophoresis (Hgb Bart - 4 gamma)
Overview of Beta thalassemia?
Dec. production on beta chains resulting in over abundance of alpha chains (2 beta chain genes on chromosome 11)
Who is beta thalassemia most common in?
Individuals of Mediterranean origin (greek, italian)
What is beta thalassemia minor (trait)?
1 gene defective, asx, target cells and microcytic/hypochromic RBCs
*confirm w/ Hgb electrophoresis or HPLC aka high performance liquid chromatography (slightly inc. HgbA2 4-8%), HgbA remains dominant
What is beta thalassemia major (Cooley’s anemia)?
Both genes defective, not making beta chains, excessive alpha chains that precipitate in RBCs leading to hemolysis
S/Sx of beta thalassemia major (Cooley’s anemia)?
Do not occur until 2-6 mos (because making Hgb F in absence of ability to make Hgb A)
-Pallor, fatigue, jaundice, hepatosplenomegaly, abnormal bone expansion/bony deformities (frontal bossing), “hair on end” appearance on skull frames
Labs for Cooley’s anemia?
Severe hemolytic anemia w/o transfusion, HCT may fall to <10%, normal iron studies, hemolysis labs (elevated reticulocyte count, elevated LDH/bilirubin, decreased haptoglobin)
Smear: hypochromic, microcytic, target cells
*confirmed by Hgb electrophoresis or HPLC (Hgb F predominant)
Tx for alpha thalassemia trait or beta thalassemia minor?
None, should be identified so not subjected to repeat evaluation or treatment for iron def.
Treatment for severe thalassemia (HgbH disease or Cooleys anemia)?
Regular transfusions & folic acid supplementation
Complications of thalassemia?
Iron overload (hemachromatosis) d/t transfusions - can lead to heart failure & liver damage (dec. risk w/ chelation therapy to remove excess iron) *Deferasirox
What is the only definitive tx for Cooley’s anemia or Hgb H disease?
Allogenic stem cell transplant, only available cure
Causes of Sideroblastic anemia?
-Inherited genetic defects (rare)
-Acquired (MC) –> chronic ETOH, heavy metals (lead, zinc, copper poisoning), Meds (Isoniazid), Vit. B6 def
Pathophys of sideroblastic anemia?
Defect in heme synthesis, inability to incorporate iron into heme molecule to make Hgb
*results in iron buildup in mitochondria
Workup for sideroblastic anemia?
CBC: microcytic
*may see basophilic stippling if lead poisoning
Iron studies: serum iron/ferritin: normal/elevated
TIBC: dec
Transferrin sat: normal/elevated
How to confirm dx of sideroblastic anemia?
Bone marrow bx: will show accumulation of iron w/in RBC nucleus –> form ringed sideroblasts in bone marrow
*using prussian blue stain to see iron
Treatment if sideroblastic anemia?
Elimination of drug/toxin that triggered acquired sideroblastic anemia, Supplementation of B6 (try in all cases, many respond to this, low toxicity profile)
If no response to B6 for inherited –> transfusion response if sx
If metal toxicity –> chelation
How does lead cause acquired sideroblastic anemia?
Inhibit enzymes needed for heme synthesis
RF for lead sideroblastic anemia?
MC in children ingestion (paint chips)
Clinical manifestations of lead sideroblastic anemia?
S/sx of anemia, lack of concentration, irritability, fatigue, coognitive impairment, abd pain, nausea, lack of appetite, constipation
Workup for lead sideroblastic anemia?
Same as sideroblastic plus lead levels (>10mcg/dL), microcytic w/ basophilic stippling, serum Fe normal or high, low TIBC, chronic toxicity can cause lead lines in metaphyseal plates in kids
Treatment for lead sideroblastic anemia?
Mild (<45): removal of exposure
Mod (>/= 45): chelation *Succimer first line
Severe (70+): chelation *Succimer PO + IV calcium disodium EDTA (edetate)