normocytic anemias Flashcards
1
Q
normocytic anemia
A
- 80-100 MCV
- issue with destruction, production, kidneys, or malignancy
- peripheral smear is key
2
Q
causes of normocytic anemias
A
- heomlytic anemia
- hereditary spherocytosis
- autoimmune hemolytic anemia
- cold agglutin disease
- paroxysmal nocturnal hemaglobinuria
- G6PD def
- sickle cell disease
3
Q
why does anemia occur with continued hemolysis
A
- extremely short RBC survival
- ability of bone marrow to compensate is impaired
4
Q
intrinsic/ inherited causes of hemolytic anemia
A
- genes that control how we make RBCs are abnormal
- membrane defects
- enzyme deficiency/ oxidation vulnerability
- hemoglobinopathies
5
Q
acquired/ extrinsic causes of hemolytic anemia
A
- something else destroying the cells
- immune: autoimmune, drug toxicity
- microangiopathic
- infection
- hypersplenism
- burn
6
Q
si/sx of hemolytic anemia
A
- fatigue, weakness, pallor
- easy bruising, petechiae, purpura
- yellow discoloration of eyes and skin
- abd pain
- dark urine
- splenomegaly
7
Q
lab findings for hemolytic anemia
A
- bilirubin accumuation d/t heme breakdown
- increased retic count
- decreased haptoglobin
- pos urine hemosiderin
- increased serum LDH
- increased methemalbuminemia and hemoglobinemia
8
Q
hereditary spherocytosis
A
- abnormal spectrin and ankyrin (abnormal cell membrane)
- causes small, hyperchromic, inflexible cells
- get trapped in spleen and hemolyzed
9
Q
key findings for hereditary spherocytosis
A
- family hx
- splenomegaly
- spherocytosis and reticulocytes on smear
- may or may not be anemic
10
Q
diagnosis of hereditary spherocytosis
A
- spherocytosis
- familial hemolytic anemia
- abnormal osmotic fragility
- coombs negative
11
Q
treatment of hereditary spherocytosis
A
- supportive care
- transfusions as needed
- folic acid cupplementation
- consider splenectomy if sx are severe
12
Q
paroxysmal nocturnal hemoglobinuria (PNH)
A
- rare hematopoietic stem cell disorder
- abnormal sensitivity of RBC membranes to lysis by complement
- lack of CD55 and CD59 proteins
13
Q
what is the most common cause of death in PNH
A
- thrombosis
14
Q
si/sx of PNH
A
- episodic hemoglobinuria- reddish brown urine usu first thing in AM
- fatigue, weakness
- esophageal spasms
- ED
- abd pain
- dyspnea
- thrombosis**
- pulm HTN
- end organ damage, CKD
15
Q
common sites of thrombosis in PNH
A
- mesenteric v
- hepatic v
- CNS veins
- skin vessels- formation of painful nodules
16
Q
lab findings in PNH
A
- CBC variable
- retic variable
- peripheral smear is non-diagnostic
- direct coombs neg
- urine hemosiderine elevated
- serum LDH elevated
- iron def anemia
- MUST get flow cytometry*
- bone marrow bx
17
Q
essentials of PNH dx
A
- episodic hemoglobinuria
- thrombosis common
- suspect in confusing case of hemolytic anemia or pancytopenia
- flow cytometry shows def of CD55 and CD59
18
Q
treatment of mild PNH
A
- no intervention required
19
Q
treatment of severe PNH
A
- transfusion needed
- eculizumab therapy- improved QOL, reduced hemolysis
- allogenic SCT
- treat iron def anemia if indicated
20
Q
G6PD deficiency
A
- def in G6PH enzyme
- x linked recessive
- RBCs cant handle oxidative stress -> episodic hemolysis
- hemoglobin denatures under these conditions
- extravasc hemolysis in spleen
- different variants exist in def populations
21
Q
beneficial part of G6PD
A
- protection from malaria
- less CAD
- possibly fewer cancers
- greater longevity
22
Q
si/sx of G6PD def
A
- usu healthy
- no splenomegaly
- suspect when hemolytic anemia
- worse with fava beans
23
Q
lab findings with G6PD def
A
- hemolytic labs appear normal between episodes
- hgb < 8
- increased retic count
- increased serum indirect bili
- peripheral smear shows bite cells, blisters
- heinz bodies
- decreased G6PD enzyme assay 6-8 weeks after hemolysis
24
Q
essentials of G6PD dx
A
- x linked recessive disorder
- common in AA men
- episodic hemolysis in response to oxidant drugs or infections
- bite cells and blister cells on periph smear
- reduced level of G6PD btwn hemolytic episodes
25
treatment for G6PD def
- episodes self limited
- avoid known oxidant drugs
- pregnant/ nursing- avoid drugs with oxidant potential
- transfusion if severe epoisode
- avoid fava beans
- avoid dapsone*
26
autoimmune hemolytic anemia (AIHA)
- autoab attacking RBCs
- classified as warm or cold
- anemia onset can be rapid and life threatening
- results in spherocytic cells
- cells get hemolyzed by spleen, if bad enough et hemolyzed by liver
27
what are spherocytic cells
- decreased deformability -> inability to pass through spleen
- decreased surface area
- increased fragility
28
si/sx of AIHA
- fatigue
- dyspnea
- angina pectoris, possible HF
- jaundice
- splenomegaly
29
lab findings
- anemia varies
- can be severe with hc < 10%
- increased retic count
- peripheral smear: spherocytes, NRBCs
- direct coombs pos*
- indirect coombs test pos or neg
- decreased haptoglobin
- increased direct bili
30
essentials of dx for AIHA
- acquired hemolytic anemia d/t IgG autoab
- spherocytes and retic on peripheral smear
- pos coombs
31
treatment of AIHA
- prednisone
- transfusions- may be difficult to cross match d/t ab
- splenectomy
- therpaeutic plasma pheresis
- refer to hematology
- sx pts or rapidly falling hbg should get referred
32
cold agglutinin disease
- hemolytic anemia d/t IgM ab
- coombs test + IgM ab
- cold ab react with RBCs peripherally
33
what can cause cold agglutinin disease
- waldenstrom
- macroglobulinemia
- lymphoma
- CLL
- post mycoplasma pneumonia
34
si/ sx of cold agglutinin disease
- sx related to RBC agglutinationon expsoure to cold
- mottled or numb fingers, toes, ears
- acrocyanosis
- episodic LBP
- dark colored urine
- hemoglobinuria on exposure to cold
35
essentials for dx of cold agglutinin disease
- increased retic on blood smear
- coombs pos test for compliment only, neg ab
- pos cold agglutinin titer
36
treatment for cold agglutinin disease
- avoid exposure to cold
- rituximab or immunosuppressive therapy
- if transfusing use in line blood warmer
37
sickle cell disease
- autosomal recessive disorder
- abnormal hemoglobin
- predominantly in AA
- causes chronic hemolytic anemia
- life span of 40-50 years
38
sickle cell trait
- one good and one bad gene
- hematologically normal
- normal life span
39
RBC components in sickle cell
- hemoglobin S (HbS)
- substitution of valine for glutamic acid
- poorly soluble when deoxygenated
40
how does sickling occur
- HbS is unstable
- sickles with deoxygenation
- undergo hemolysis
- lifespan of 10-20 days
- sickle cells can occlude microvasc
41
stressors that can lead to sickle cell crisis
- anything that causes oxidative stress
- infection
- hypoxia
- dehydration
- acidosis
- extreme exercise
- ETOH
- pregnancy
- cold weather
42
what is the hallmark sx of sickle cell anemia
- pain due to occlusion
43
si/sx of sickle cell
- pain*
- anemia, jaundice
- pigmented gallstones
- early splenomegaly
- poor healing ulcers over tibia
- life threatening anemia
- chest pain
- stroke
- priapism
- retinopathy
44
types of sickle cell crises
- vaso-occlusive
- hematologic
- infection
45
exam findings in sickle cell disease
- dactylitis
- chronically ill, jaundiced
- hepatomegaly
- spleen not palpable
- cardiomegaly
- hyperdynamic precordium and systolic murmurs
- non healing ulcers
- retinopathy
46
complications of sickle cell disease
- retinopathy
- pulm htn- poor prognosis
- delayed puberty
- infex
- bone necrosis
- cardiomegaly
- chlelithiasis
47
lab studies for sickle cell anemia
- hct 20-30%
- WBC and platelets elevated
- blood smear: irreversibly sickled cells, reticulocytes, howell-jolly bodies, target cells
- HgS screening
- Hgb electrophoresis
- increased indirect bili
48
essentials of dx of sickle cell anemia
- recurrent pain
- + family hx and lifelong hx of hemolytic anemia
- irreversibly sickled cells on smear
- HbS on electrophoresis
49
treatment for sickle cell anemia
- supoprtive care
- folic acid PO
- pneumococcal vaccine
- avoid precipitating factors
- exchange transfusion if indicated
- hydroxyurea if severe
- omgea 3 fatty acid supplementation
- allogenic HSCT
50
treatment in acute crisis of sickle cell disease
- generous analgesia*
- transfusion for aplastic or hemolytic crisis
- ID precipitating factors and treat/ avoid
- keep well hydrated, O2 if hypoxic
- abx, VTE ppx
51
sickle cell trait
- heterozygous genotype
- AS instead of SS
- hematologically normal
- screening for sickle cell hg +
- no tx needed
52
clinical risk sof sickle cell trait
- sudden cardiac death or rhabdo with vigerous exs, esp at night
- increased risk VTE
- microscopic and gross hematuria
- hyposthenuria
- possible CKD
53
when to refer for sickle cell anemia
- all pts referred to hematology
- all pts referred to comprehensive sickle cell center
- prenatal dx avail for couples at risk
54
benefits of sickle cell anemia
- resistance to malaria
- cells have shorter life
- eliminated in spleen
- cell membrane stretched by its shape, becomes porous and leaks nutrients like K
- parasite needs those nutrients for survival
