Introduction to Anemia Flashcards
definition of anemia
-reduction of hemoglobin concentration
-is a symptom of disease, not entire disease
-
what does hemoglobin do?
-(Hb) in red blood cells, carries O2 from lungs to diff tissues
two different causes of anemia?
1) bone marrow working too hard (sickle cell; cells not survive marrow works harder to balance it)
2) bone marrow not working hard enough (in iron deficney, not enough materials to make RBC so bone marrow decreases production)
stages of RBC production?
1) stem cells
2) progenitors
3) early precursors
4) reticulocytes
5) mature RBC
6) RBC destruction/turn over
stem cells
- when activated produce many different differentiated cell including RBC
- make progenitors
progenitors
cells have been determined to go forward a certain direction, are committed to be one cell type
early precursors
-cells already committed to a lineage; begin to develop morphological characteristics of the lineage (RBC develop hb)
reticulocytes
- last stage of RBC maturation
- are in blood circulation
- survive ~24hr, then become mature RBC (survive ~121 days)
- make up 1% of bone marrow
what does it mean if we have 10% reticulocytes in bone marrow?
- bone marrow is overworked, have an increased demand for RBC
- potentially anemia
mature RBC destruction/turnover?
-break down after 121 days
& replaced by new cells
bone marrow composition?
- usually 50% fat and 50% RBC
- if 90% fat, indicates aplastic anemia (not making enough blood)
- has variety of diff cell types to perform range of functions
aplastic anemia
-when bone marrow doesn’t produce enough blood cells
erythropoiesis mean?
-production of red blood cells
requirements for normal erythropoiesis?
1) healthy bone marrow env
2) DNA Synthesis (B12& Folic Acid)
3) Heme synthesis
4) global synthesis
5) erythropoietin
6) other cytokines
hemoglobin structure synthesis?
- made form protein
- 4 polypeptides (globin); 2 alpha, 2 beta chains
- 4 heme with iron (non protein) bind one O2 each
erythropoietin?
- hormone produced in kidneys
- stimulates bone marrow cells to mature into RBC
- is why kidney failure leads to anemia
causes of anemia?
1) bone marrow disorders
2) B12 or Folic acid deficiency
3) chemo
4) iron deficiency
5) protein malnutrition
6) chronic kidney failure
7) chronic blood loss
8) global gene abnormalities effecting protein structure of Hb
hemolytic anemia
when RBC are destroyed & removed from bloodstream before normal lifespan is over
-bone marrow can’t make RBC fast enough to replace the lost ones
how classify anemia (x2)?
1) RBC size: microcytic, normocytic, macrocytic
2) by mechanism: decreased/increased production, blood loss
microcytic anemia?
- small RBC
- typically due to low iron
macrocytic anemia?
- large RBC
- blood with an insufficient concentration of hemoglobin
- due to B12 & folic acid deficiency
steps to diagnose anemia?
1) history
2) physical exam
3) CBC & reticulocyte count
4) peripheral smear
5) Hb electrophoresis
6) chemistry & other labs
7) bone marrow biopsy
erythrocytes?
-are RBC
-normal hemoglobin? how can one person w/ 9hb be totally fine & other be winded & exhausted?
- 13-15g
- if born w/ 9hb; body adapts to it and feel fine
- other has acute anemia; a sudden bleeding ulcer and suddenly hit hb 9 & feel exhausted
- need to ask about periods & any bleeding when diagnosing
Why see jaundice in anemia?
-because heme breaks down to billirueben, if have excess hemoglobin means excess heme means breakdown will affect the liver & billirueben amount in your body
-CBC results?
-if CBC shows low RBC and WBC, platelets means effecting all cells in bone marrow means BONE MARROW disease; anemia just effects RBC
high reticulocytes mean?
-short RBC cycle, bone marrow being overproduced (hemolytic anemia)
two parts of hemoglobin synthesis?
1) heme synthesis (iron + protoporphyrin)
2) globin chain synthesis (alpha & beta)
all components of RBC?
1) alpha chain
2) beta chain
3) iron
4) heme group
5) reversibly bound O2
hemoglobinopathies? two ways it can happen?
disorders due to abnormal globin chain synthesis
1) decrease synthesis of the normal chain (thalassemia)
2) AA substitution resulting in abnormal chain (sickle cell)
genetic mutations in hemoglobinopathies?
1) Point mutations–> AA substitution
2) point mutations–> defective splicing
3) point mutations–> premature termination codon
4) frame shift mutation
5) deletion of whole gene
hemoglobin electrophorus qualitative & quantitative capabilities?
- qualitative: IDs diff types of hemoglobin
- quantitative: IDs percentages of diff types of hemoglobin
normal human adult elesctophoresis results?
- HbA= 95%
HbA2= <3.5%
HbF =<1%
HbS (sickle)= 0%
diff in adult vs children
thalassemia and what looks like?
- type of anemia varying severity “anemia of the sea”
- fucks up spleen
- jaundice& gall stones
- bone marrow expansion & bone deformity
- inadequate O2 delivery, growth retardation
- iron overload (cirrhosis)
thalassemia types & mechanism of anemia?
- types: alpha, beta, others
- mechanism:
1) inadequate hemoglobin (globin chain) production (less RBC)
2) unbalanced accumulation of globin sub-units (make too much alpha subunit, less Beta subunit
bone marrow expansion & bone deformity in thalassemia?
- enlargement of facial bones since bone marrow over working to produce more RBC
how prevent bone marrow expansion & bone deformity in thalassemia?
need to treat at early age w/ hyper fusion (10g) to suppress bone marrow impulse to expand & prevent facial deformities
what is normal MCV?
80-98
if normal reticulocytes, decreased Hb, decreased iron…what does that suggest?
- not iron deficiency since iron def. is seen as DECREASED RBC production (reticulocytes= baby RBCs)
- is thalassemia because this causes overproduction of RBC by bone marrow therefore causing increased reticulocytes
thalassemia major?
- when kid gets 2 mutant genes for Beta Hb
- Cooley’s anemia
- chronic fatigue, defomritities if not treated soon
treatment of thalassemia major?
1) early diagnosis (so prevent bone deformities)
2) folic acid
3) hypertransfusion
4) iron chelation
5) stem cell transplant
complications of thalassemia major treatment?
1) iron overload
- transfusions cause extra RBC, when break down hard to recycle all components, so end up w/ excess iron
2) hepatitis C (from blood transfusion b4 knew how to screen for it )
3) line infections
sickle cell anemia clinical picture?
- chronic hemolytic anemia (not enough RBC)
- splenic crisis
- acute painful crisis
- acute chest syndrome (hypoxic chest pain, life threatening)
- neurological damage: if sickled cels block arteries can get stroke
sickle cell anemia treatment?
1) stem cell transplant
2) induction of fetal Hb (hydroxyurea therapy)
hydroxyurea therapy
the induction of fetal Hb into patients w/ sickle cell anemia
-fetal Hb shown to resist sickling of RBC
