More Anemias Flashcards
Anemia of Chronic Disease:
general and labs
Anemia of chronic inflammation
Anemia of organ failure
Anemia of older adults
Usually normocytic
may become microcytic and hypochromic if long-standing
Mild-to-moderate anemia as a result of RBC underproduction
Low serum iron, low TIBC (transferrin), normal to increased serum ferritin
Sources: Cancer, infection, inflammation
anemia of inflammation/chronic disease
inflammation causes
Inflammation causes:
1. Dysregulation of iron homeostasis (hepcidin)
Abnormal iron metabolism, trapping of iron in macrophages, iron unavailable for new hemoglobin synthesis (and unavailable for pathogens)
2. Impaired marrow RBC development
3. Blunted EPO response (CKD)
Inability to increase erythropoiesis in response to anemia
4. Increased phagocytosis of RBCs
case study
Confirmed anemia: Hgb 11.3
MCV is Normocytic
RDW is Normal (no anisocytosis)
Iron and % sat slightly low
Ferritin Elevated
Normocytic Anemia likely due to: Anemia of Inflammation / Chronic Disease
ferratin
is iron store, will not have with iron deficiency.
anemia of chronic disease/inflammation
Tx
Treat underlying disease (most important)
Erythropoietin (Procrit) if low EPO level from renal disease
PRBC transfusion
likely to be on meds for life.
sickle cell
general
Irreversibly sickled cells and recurrent painful crisis (vasoocclusive phenom and hemolysis)
Group of inherited autosomal recessive disorders
More common in African American population
Causes the erythrocyte to stiffen & elongate
Sickle shape in response to lack of oxygen
Sickle cells contain abnormal hemoglobin called hemoglobin S
Sickle hemoglobin causes the cells to develop their sickle shape
Blocks blood flow causing pain and organ damage
Bone marrow is unable to reproduce RBCs quick enough
sickle cell
genetics
Both parents have Sickle Cell Trait THEN offspring has:
25% chance of disease
25% will not carry a sickle cell allele
50% will have heterozygous condition
Autosomal Recessive
Sickle cell trait
Heterozygous hemoglobin genotype AS
50% chance to pass the sickle hemoglobin gene to offspring
sickle cell
pathology
Mutation occurs in the amino acid sequence of the Hgb Beta chain
RBCs become sickled when oxygen saturation is low
Impairs the flexibility of the RBCs through vessels
Repeated deoxygenation damages cells leading to permanent sickling
Sickled cells live shorter
10 to 20 days
sickle cell
Prognosis/Epidemiology
SCD affects approximately 100,000 Americans
SCD occurs among about 1: 365 in the black or African American population
SCD occurs among about 1:16,300 Hispanic-American births
About 1:13 black or African American newborns have sickle cell trait (SCT)
sickle cell
Signs & Symptoms of Children
Anemia
Fatigue
Episodes of pain
Hand-Foot syndrome
Frequent infections
Delayed growth
Vision difficulties
sickle cell
delayed growth Sx in children
Shortened height
Smaller stature
Delayed puberty
Smaller hand and feet
Hypermetabolic syndrome
burn more calories
Poor nutrition/mineral deficiencies
Endocrine - Insulin Like Growth Factor I
Sickle cell
PE findings
Hepatomegaly
Splenomegaly (in children)
Cardiomegaly
Hyperdynamic precordium
Systolic murmurs
Nonhealing cutaneous ulcers of the lower extremity
Retinopathy
Jaundice
Sickle Solubility Test:
Mixture of Hgb S in a reducing solution gives a turbid appearance and normal Hgb is clear
*Hgb Electrophoresis
Shows various types of hemoglobin move at varying speeds on a gel electrophoresis
Pattern of hgb electrophoresis from several different individuals
Lanes 1 and 5 are hemoglobin standards
Lane 2 is a normal adult.
Lane 3 is a normal neonate
Lane 4 is a homozygous HbS individual
Lanes 6 and 8 are heterozygous sickle individuals
Lane 7 is a patient with SickleCell disease
sickle cell
Howell-Jolly Bodies and target cells which indicate
hyposplenism
Sickle Cell Disease
Dactylitis:
acute pain in the hands and/or feet
sickle cell
risks of disease
Vaso-occlusion can occur in virtually every organ system, acute and chronic multisystem failure
Acute fall in hemoglobin may be superimposed upon the chronic anemia:
splenic sequestration crisis
aplastic crisis
hyperhemolytic crisis
sicklecell crisis
general
Triggered by, lasts how long
Hypoxemia
Triggered by stress, surgery, blood loss, viral or bacterial infection (most common), dehydration, acidosis
Hemolyzed in the spleen
Sickling initially reversible
Becomes irreversible due to chronic sickling
Frequency peaks 19-39 years old
Significant variability in severity & frequency
Range of pain is mild to severe requiring hospitalization
Last approximately 5 to 7 days
Pain may be precipitated by weather conditions, dehydration, stress, menses, alcohol consumption, and nocturnal hypoxemia.
sickle cell crisis
general Tx
IV fluids
Oxygen
Transfusion Therapy
Aplastic crisis
Hemolysis crisis
Example: patient with G6PD deficiency
CVA
Pain Crisis
sickle cell
splenic sequestration
Splenic pooling of red cells produce marked fall in hemoglobin concentration and a rapidly enlarging spleen
Risk of hypovolemic shock, particularly in children
sickle cell
Acute chest syndrome
A new pulmonary infiltrate with dyspnea and hypoxia
The 2nd most common complication
25% of death in patients with SCD
Frontal chest radiograph demonstrates bilateral diffuse airspace disease (blue circle) in a patient with sickle cell disease, fever and hypoxemia. There is avascular necrosis of the left humeral head (red arrow) and replacement of the right humeral head (white arrow) because it was affected by avascular necrosis as well.
sikle cell
complications
- CVA
Narrowing of blood vessels
Prevents oxygen from reaching the brain - Vision
Proliferative retinopathy
Vitreous hemorrhage
Retinal detachment
Blindness - Avascular Necrosis
Result of ischemia - Chronic Pain (in the absence of acute vaso-occlusive pain)
Opioid tolerance and addiction - Decreased Immune reactions due to hyposplenism
- Severe Bacterial infections
Increased risk for infection caused by encapsulated organisms
Streptococcus pneumonia
Haemophilus influenza - Primary Pulmonary hypertension
Increase strain on the right ventricle
Risk of heart failure - Chronic Renal Failure
- Cholelithiasis & Cholecystitis
Excessive bilirubin production and precipitation due to prolonged hemolysis - Iron Overload
Requires chelation - Lower extremity ulcers
Sickle cell disease
general management, referral
Refer to hematologist or sickle cell center
Maintain vaccination schedule
Pneumococcal vaccine
sickle cell
Tx
Transfusions
Folic Acid 1mg daily (lifelong)
Hydroxyurea- Improves overall survival and quality of life, Decreases number and severity of crises (33%), Reactivates fetal hemoglobin production in place of Hgb S
Omega-3 fatty acid supplementation
Decrease vaso-occlusive episodes
Reduce transmission needs
- Crizanlizumab (monoclonal antibody) infusions- Reduce vasoconstrictive episodes by 44%
- Chelating agents
Iron overload due to transfusion therapy - Bone Marrow Transplant
Only known cure (up to 80%)
Consider if severe pain crises and recurrent vaso-occlusions
Hydroxyurea (Hydrea)
MOA, precautions, pregnancy, indications
Antimetabolite: MOA unclear
Usage: Sickle Cell Anemia, Chronic Myelogenous Leukemia, Polycythemia Vera, Essential Thrombocythemia
Dosage: 500mg capsule. Varies, mostly weight based
Precautions:
Avoid use of live vaccines during hydroxyurea therapy
Radiation recall
Use with antiretroviral therapy, risk of pancreatitis, hepatotoxicity, and peripheral neuropathy
Discontinue at least 3 months prior to conception
Pregnancy: May cause fetal harm
hydroxyurea (hydrea)
side effects
Side Effects:
Myelosuppression
Macrocytosis
Secondary Leukemia
Skin Cancer
Rash
Hepatotoxicity
Nausea/vomiting
thalassemias
definition
Reduced alpha or beta globin chain synthesis
-Leads to decreased hgb synthesis intramedullary and peripheral hemolysis
-Hypochromic microcytic anemia
β-Thalassemia
Point mutation resulting in reduced (beta+) or absent (beta0)beta globin chain synthesis
α-Thalassemia
Gene deletion causing reduced alpha globin chain synthesis
thalassemias
classification
-Hypochromic microcytic anemia
thalassemia
epidemiology
Association with malaria
Southeastern and southern Asia, Middle East, Mediterranean countries, and northern and central Africa
Prevalence in these regions up to 10%
Rate in U.S. unknown as no effective screening in place
thalassemia
pathophys
Unequal production of one of the globin chains—imbalance in chain ratio
Mechanisms
β-Thalassemia
α-Thalassemia
Categories of Thalassemia
Thalassemia trait
Lab features without clinical significance (mild microcytic anemia)
>= 2 intact globin chains
categories of thalassemia
Thalassemia intermedia
Occasional treatment needed and/or moderate clinical impact
Chronic hemolytic anemia
categories of thalassemia
Beta Thalassemia major
Life threatening and/or transfusion dependent
Severe anemia
Growth failure
Bony deformities
abnormal facial structure (prominent forehead and flattened nose due to expansion of facial bones to accommodate hyperplastic marrow)
pathologic fractures
Hepatosplenomegaly and jaundice
Β-Thalassemia
general
With reduced β-chains
Bone marrow becomes hyperplastic
Bony deformities
Osteopenia
Pathologic fractures
β-Thalassemia minor
general
β-Thalassemia minor
Heterozygous mutation
Clinically insignificant microcytic anemia
β-Thalassemia minor
Lab Evaluation
HgB F is fetal hemoglobin
Red blood cells (RBCs) from a patient with β-thalassemia minor, showing microcytic, hypochromic RBCs with target cells, other poikilocytes, and basophilic stippling (arrow).
β-Thalassemia Intermedia
general
β-Thalassemia intermedia
Homozygous mutation but higher rate of beta-globin synthesis
Chronic hemolytic anemia
Clinical features (as adults)
Hepatosplenomegaly
Bony abnormalities
β-Thalassemia Intermedia
Lab Evaluation
Perph smear
Moderate anemia
RBC: normal or ↑
Hct: 17-33%
MCV: 55-75fL
Peripheral blood smear: microcytic hypochromic anemia
Target cells
Basophilic stippling
Reticulocyte count: ↑
Iron studies: Normal
Hemoglobin electrophoresis:
Increased Hgb A up to 30%
Increased Hgb A2 up to 10%
Increased Hgb F , 6-10%
β-Thalassemia Intermedia:
Treatment
Refer to hematologist
May require transfusions during periods of stress
Offer genetic counseling
β-Thalassemia Major
general
“Cooley anemia”
Homozygous mutation
Normal at birth
Within 6 months develops severe anemia
β-Thalassemia Major
Clinical features (as children)
Clinical features (as children)
Stunted growth
Bony deformities
Abnormal facial structures
Pathologic fractures
Hepatosplenomegaly (from constant hemolysis)
Jaundice (hemolysis)
Thrombophilia
fetal hemoglobin is not affected by thalassemia
Β-Thalassemia major
bony deformities
Abnormal facial structure
Prominent forehead and flattened nose due to expansion of facial bones to accommodate hyperplastic marrow
Severe osteoporosis, pseudofractures, thinning of the cortex, and bowing of the femur.
B thalassemia major
β-Thalassemia Major
Lab Evaluation
(without transfusion)
Severe anemia
Hct: < 10% without transfusions
Peripheral blood smear: microcytic hypochromic anemia
Severe poikilocytosis
Target cells
Basophilic stippling
NRBCs (nucleated immature RBCs)
Hemoglobin electrophoresis
Minimal Hgb A
Variable Hgb A2 seen
Predominantly Hgb F
β-Thalassemia Major
Red blood cells from a patient with β-thalassemia major. Note basophilic stippling, microcytosis, hypochromia, target cells, nucleated red blood cells, and red cell fragments.
β-Thalassemia Major
Treatment
Refer to hematologist
- Transfusion therapy (Transfusion dependant)
Scheduled
Causes hemosiderosis (iron deposition in organs)
Heart failure
Cardiac arrhythmias
Cirrhosis
Endocrinopathies
Pseudoxanthoma elasticum - Iron chelation (oral or parenteral)
- Allogenic stem cell transplant
80% long term survival in children (before organ damage occurs)
α-Thalassemia categories
α-Thalassemia Minor
2 α-globin genes
Hct 28–40%
MCV 60–75
A- thalessemia
Hemoglobin H disease
1 α -globin gene
Hct 22–32%,
MCV 60–70
A thalassemia categories
Hydrops fetalis
No α -globin genes
α-Thalassemia Minor
general
2 alpha globin genes present
Homozygous or heterozygous
Clinically normal with mild microcytic anemia
Normal lifespan
α-Thalassemia Minor
labs
Hemoglobin H Disease
general and clinical features
HgB H disease
1 alpha globin chain intact
Alpha chains are reduced, beta chains pair together to form Hb H
Chronic hemolytic anemia
Clinical features
Pallor
Splenomegaly
Hemoglobin H Disease:
Lab Evaluation
Anemia present
RBC: normal or increased
Hct: 22-32%
MVC: 60-70fL
Peripheral blood smear: Marked microcytic hypochromia
Target cells
Poikilocytosis
Reticulocyte count: Increased
Hemoglobin electrophoresis: Hemoglobin H 10-40%
Hemoglobin H Disease
Red blood cells from a patient with hemoglobin H disease, incubated with brilliant cresyl blue, which have acquired fine, evenly dispersed granular inclusions and “golf ball” appearance.
Hemoglobin H disease
Hemaglobin H
HbH has a high affinity for oxygen and is an ineffective supplier of oxygen to tissues under physiologic conditions.
RBCs that contain HbH are sensitive to oxidative stress
Hemoglobin H Disease
Tx
Refer to hematologist
Transfusions not normally needed
Folic acid 1mg PO daily
Avoid iron supplementation and oxidative drugs (sulfonamides)
May develop hemolytic exacerbation requiring PRBC transfusion
Infection
Bone marrow stress
Offer genetic counseling
α-Thalassemia Major
Hydrops fetalis
No functional alpha globin chain
Results in stillbirth
thalassemia
gold standard for Dx
Electrophoresis is Gold Standard for diagnosing thalassemia
mild Thalassemias
Tx
Mild thalassemias (α-thalassemia or β-thalassemia minor/trait)
Usually require no treatment
Identify in order to avoid repeated evaluations for iron deficiency and inappropriate administration of supplemental iron
May require transfusion during infection/stress
Thalassemia
Tx
Thalassemia
Prognosis
