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6 Cards in this Set
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Acanthocytes |
This patient could have abetalipoproteinemia which connotes absence of apolipoprotein beta. Patients have retinitis pigmentosa, neurologic defects, steatorrhea and problems with coordination.
It is an autosomal recessive disorder that interferes with absorption of fat and fat-soluble vitamins (A, D, E, K) from food. A mutation occurs in microsomal triglyceride transfer protein which leads to deficiencies in apolipoproteins
Acanthocytes (Spur cells) are characterized by irregular red blood cell projections that often occurs in end-stage liver disease. Nonesterified cholesterol incorporates into the RBC membrane.
Stomatocytes occur when there is no reduction in deformability of RBC membrane. Normally MCHC is decreased and MCV is increased
**Pearl: McLeod Phenotype: Lack of Kell antigen expression on RBCs. X-linked |
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Stomatocytes |
Stomatocytes occur when there is no reduction in deformability of RBC membrane. Normally MCHC is decreased and MCV is increased |
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Eichinocytes |
PYRYVATE KINASE DEFIN This is the most common enzymatic deficiency in the glycolytic pathway. Patients may need iron chelation even if they have not received red cell transfusions.
2,3-diphosphoglycerate is created in erythrocytes during glycolysis. The production of 2,3-DPG is an adaptive mechanism, because the production increases for several conditions in the presence of diminished peripheral tissue O2 availability, such as hypoxemia, chronic lung disease, anemia, and congestive heart failure, among others. High levels of 2,3-DPG shift the curve to the right, while low levels of 2,3-DPG cause a leftward shift, seen in states such as septic shock.
Think about enzymopathies with hemolytic anemia that is nonspherocytic, negative Coombs test, and have a normal Hb electrophoresis
G-6PD and Phosphoglycerate kinase: X-linked Adenosine deaminase: Autosomal dominant
Treatment: Folic acid. Splenectomy if poor quality of life, transfusion dependence and severe anemia. Be careful for post-operative thromboembolic events s/p splenectomy |
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Heinz bodies |
Do not send G-6PD in the acute setting as one can see falsely normal results. Reticulocytes have more G-6PD and are found more in the acute setting. Older red blood cells have a lower G6PD levels and are lysed/destroyed. Wait over 1 week prior to sending G-6PD levels. G-6PD deficiency is the most common enzyme deficiency in the world. It is X-linked and affects males more commonly. There is felt to be a survival advantage having this against P. falciparum malaria. Patients can develop acute hemolytic crisis after exposure to drugs/oxidant stressors Can see episodic nonspherocytic hemolytic anemia. Smear in the acute setting can show blister cells and Heinz bodies (precipitated aggregates of hemoglobin). Within 1 week, the spleen will remove these abnormal red cells Oxidant stressors include Fava beans (Mediterranean variant is affected), infections, drugs (Sulfa, methylene blue, nitrofurantoin, dapsone, primaquine, phenazopyridine)
G-6PD deficiency: G6PD B wild type G6PD A+: Normal enzyme activity. Single Amino acid substitution G6PD A-: 10-15% enzyme activity. Higher in young reticulocytes. 10% African Americans G6PD Mediterranean: Decreased activity in RBCs of all ages. Chronic hemolysis |
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Enzyme deficiencies and anemia |
Lead deficiency --A) Pyrimidine-5-nucleotidase deficiency
Triosephosphate isomerase deficiency: Severe neurologic problem Mitral regurgitation Cardiac arrhythmias
Phosphoglycerate kinase deficiency: X-linked Behavioral problems with motor regression Cerebellar tumors
Hexokinase deficiency: Acquired form in Wilson’s disease
Phosphofructokinase deficiency: Glycogen storage disease with myopathy
sephosphate isomerase deficiency: Myopathy, ataxia |
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Target cells on smear |
Patients with Hb SC disease have a longer life expectancy than Hb SS. They also are less anemic than patients with Hb SS disease and some actually have a normal Hb and Hct
HbC does not polymerize as readily as HbS so there is less sickling. Blood smear is characterized by a few sickle cells but lots of target cells.
An important thing to note though, is that compared to HbSS, patients with HbSC have more significant retinopathy, ischemic necrosis of bone, and priapism. Acute chest syndrome can also occur with HbSC disease. HbC leads to dehydration of the SC red cell leading to serious clinical sequelae. |
