Normocytic-Normochromic Anemias Flashcards
(44 cards)
What are the three types of N-N anemias?
Aplastic anemia
Hemoglobinopathies
Hemolytic anemias
What is an aplastic anemia?
disorder or group of disorders characterized by cellular depletion and fatty replacement of the bone marrow. The bone marrow stain is hypocellular and failing.
Name the most common, the four secondary, and the congenital cause of aplastic anemia.
Main - idiopathic
secondary - chemicals, drugs (chloramphenical), radiation, chronic infections
congential - Fanconi’s anemia
What are the clinical features and course for aplastic anemia?
Gradual onset but as pancytopenia worsens.. Decreased WBC -> infection Decreased RBC -> fatigue, pallor, SOB Decreased PLT -> bleeding, bruising Hypocellular BM Decreased to absent retics
What are the treatments for aplastic anemia?
Take away offending agent if possible. Support therapy including antibiotics, blood products, growth factors. Immunosuppressive therapy or a bone marrow transplant.
What is the most common poik found in almost every hemoglobinapathy?
sickle cells
What is the amino acid substitution found in sickle cell anemia?
On the beta chain at the sixth position, glutamic acid is replaced by valine
What should you think of when you see a N-N anemia with a predominance of target cells?
hemoglobinopathy and look for tell tale poik
Describe the pathophysiology of sickle cell anemia
Hypoxic state in tissues causes the HGB S molecule to realign and the RBCs take on a sickle shape. The more the small vessels get occluded the lower the pH gets. This causes more sickling and tissue damage causing painful crises and infarction of organs.
What are three factors that contribute to the sickling process?
Hypoxia, acidosis, and dehydration
Discuss the cause for Painful crises, acute chest syndrome, and high risk of infections in sickle cell anemia
Painful crises - tissue damage precipitated by infection, fever, dehydration, exposure to extreme cold
acute chest syndrome - is caused by infaction of organs like an autosplenectomy in which the spleen becomes nonfunctional
high risk of infections - when the spleen gets nonfunctional it cannot fight infections
Describe the reason and method of the sickledex solubility test
Blood is added to a reducing agent, sodium dithionite or sodium metabisulfite. if HGB S is present, it will precipitate out giving a turbid (+) solution.
This will not differentiate between sickle trait and disease.
What are causes for false pos and false neg on the solubility screening test?
False pos - proteinemia and > 18 g/dL HGB
False neg - testing a newborn (gamma to beta switch hasnt occured) or < 7 HGB or multiple transfusions
What is the expected results for HGB electrophoresis with sickle cell anemia?
S > F (no A)
What is the RBC morphology for sickle cell anemia?
Targets plus sickles schistos spheres
polychromasia, increased retics
inclusions H-J pappenheimer
nRBC
What are the differences in sickle cell trait compared to sickle cell anemia?
The trait is heterozygous (AS) rather than homozygous (SS)
Electrophoresis for the trait is A > S whereas A is nonexistant with sickle cell disease.
The trait will show no sickles on a smear unless under a severe hypoxic state
No significant clinical features or treatment.
What are the treatments for Sickle Cell Anemia?
Stay hydrated, pain relief for crises, antibiotics, blood transfusions hydroxyurea to increase HGB F, transplant
What is the amino acid substitution for HGB C disease?
Lysine substitution for glutamic acid
Compare and contrast HGB C disease and trait
HGB C disease is homozygous CC while the trait is heterozygous AC
The disease is mildly hemolytic with splenomegaly while the trait is asymptomatic
Electrophoresis - Disease = 100% C (no A)
Trait = A > C
The disease will have targets plus C crystals and polychromasia (increased retics)
The trait will only have targets
What is the inheritance pattern of SC disease?
its a double heterozygous syndrome in which one parent donates a lysine substitution (C) and another parent donates a valine substitution (S)
Clinically it is less severe than sickle cell disease but still a mild-mod sever hemolytic anemia with crises
What are the electrophoresis results and RBC morphology for SC disease? S = C
Targets plus sickles, C crystals, and S-C crystals, polychromasia/ increased retics, H-J, Pappenheimer, nRBC
What is the inheritance pattern of sickle cell-beta thalassemia?
double heterozygous syndrome
one valine substitution (S) from one parent and a Bo or B+ from the other
S/Bo will be a severe hemolytic anemia whereas S/B+ can be mild to moderate hemolytic
What is the hemoglobin electrophoresis results for S/Bo and S/B+
SBo - S > F(^) > A2(^) with no A
SB+ - S > A > F(^) > A2(^)
What is the RBC morphology for sickle cell beta thal?
Rule of 3 is affected, too many reds for the hemoglobin. Hypochromic-microcytic, targets plus sickles (usually) spheres, schistos, nRBC