Module 4 Hematologic Disorders Flashcards
Multifactoral atherosclerosis: genetic factors
- 50% of risk has been attributed to genetics.
- Chromosome 9 has been associated with risk
- Usually many different genes working together with each single gene having a small effect.
Multifactoral atherosclerosis: environmental factors
- Smoking
- Hypertension
- Glucose intolerance
- Elevated cholesterol and low density lipoproteins
- Decreased physical activity
- Obesity
- Weight fluctuations
- Ineffective stress management
Familial hypercholesterolemia
- Most common single-gene cause of atherosclerosis
- Autosomal dominant
- Affects 1 in 500 people
- 50% of affected men die fromm MI before age 60 and 15% of women will have fatal MI before age 60
Factor V Leiden
- Genetic thrombophilia that increases risk of blood clots
- Hormonal birth control increases risk even without the factor present
- Not everyone with Factor V Leiden will have a problem
- 1 bad copy of the gene increases risk of astrokeby 8times
Define macrocytic normochromic anemia
Disruption of DNA synthesis of blast cells in bone marrow produces Megaloblasts- large abnormally shaped RBC with normal hemoglobin
What two deficiencies cause macrocytic normochromic anemia?
Folate deficiency and B12 deficiency
Pernicious anemia etiology and pathogenesis.
Lack of intrinsic factor which prevents absorption of vitamin B12. This causes megaloblastic dysplasia. Some evidence it results from genetically determined autoimmune disease. Affects older people, esp. women.
Pernicious anemia clinical manifestations.
Mild: few symptoms
Severe: marked anemia, neurologic deficits, peripheral nerve degeneration. May progress to megaloblastic madness.
Pernicious anemia treatment.
B12 replacement. Neuro damage cannot be reversed.
Folate deficiency etiology and pathogenesis.
Alcoholism is primary cause.
Results in abnormal DNA synthesis of RBC.
Folate deficiency clinical manifestations.
Similar to B12 deficiency without the neuro defects.
Pernicious anemia lab results.
Low RBC Low Reticulocytes Low WBC Low Platelets Increased MCV Normal MCHC Normal MCH Normal to low serum colbalamine Increased homocysteine Increased methymalonic acid
Folate deficiency lab results
Low RBC Low Reticulocytes Low WBC Low Platelets Increased MCV Normal MCHC Normal MCH Low serum folate Increased Homocysteine Normal methymalonic acid
Microcytic Hypochromic Anemia
Blood cell is small and pale
Causes of microcytic hypochromic anemia
**Iron deficiency is most common Nutritional deficiency (Iron), bleeding, decreased GI absorption, pregnancy, and renal failure.
Iron deficiency anemia labs.
Low RBC Low Reticulocytes Low MCV, MCH, MCHC Decreased serum ferritin and serum iron Increased TIBC (total iron binding capacity-#of receptors.)
General anemia symptoms.
Fatigue, exercise intolerance, weakness, headaches, irritability, palpitations.
Iron Deficiency anemia symptoms
General plus sore tongue, pica, brittle nails, spoon shaped nails (loilonychias), blue sclerae
Thalassemia
Group of inherited disorders caused by variant or missing genes.
Trait or minior may not have symptoms. Major may require blood transfusions.
Thalassemia lab results.
Microcytic RBC’s
Low MCV, MCH, and MCHC
Hgb Electrophoresis to determine type of abnormal hgb.
Hemolysis will release unconjugated bilirubin.
Thalassemia symptoms
General plus leg cramps and pale skin.
Sickle Cell Anemia etiology and pathogenesis.
Autosomal recessive disorder.
Defect in hemoglobin synthesis resulting in Hgb S.
Valine is substituted for glutamic acid.
Sickle cell anemia progression
Increased hemolysis of RBC’s in spleen leads to Low RBC’s and severe anemia, which leads to hyperbilirubinemia (jaundice)
When do sickle cell symptoms appear?
Age 6 months
What is the most frequent cause of death in sickle cell?
Infection.
What causes hemolytic anemia of the newborn?
RH Neg mother’s body mounts an immune response to RH pos fetus due to prior sensitization. IgG antibodies cross the placenta and attack the Positive RH featal RBCs, causing hemolysis
Will Rhogam work if mom already has developed antibodies?
no.
Outcome of hemolytic anemia of the newborn.
Severe jaundice and in worst cases erythroblastosis fetalis and possibly death.
What is polycythemia?
Excessive RBCs which cause blood viscosity.
What is the most common polycythemia and the cause?
Secondary polycythemia - caused by chronic hypoxemia. It is a compensation for decreased O2. **Heavy smokers, increased altitude, CHF
What causes relative polycythemia?
Due to dehydration or stress. Causes spurious increase in RBCs.
What is polycythemia vera?
Rare. Occurs most often in men. Associated with gene mutation. Increased uric acid. Increased risk for hypertension and stroke.
