Hematology Flashcards

Question

What is aplastic anemia?

Answer 1

- majority idiopathic cause such as drugs, viruses, radiation - destruction of bone marrow- stem cells damaged that produce myeloid cells and further produce RBC's, plts and WBC's (pancytopenia) - tx: bone marrow transplant, transfusions - may have increased infections, increased bleeding (bruises, petechiae)

Answer 2

- common in mediterranean ancestry - Hb is altered in composition (not 2 alphas, 2 betas) - microcytic (MCV <90 fL) - Tx: transfusions, Fe, O2, bone stem cell transplant - types: minor, intermedia, major - dx: CBC (MCV, Hb), hb electrophoresis, blood smear, normal ferritin level

Answer 3

- second most common anemia - decreased RBC production by bone marrow - normochromic, normoccytic - causes: CRF, cancer, liver cirrhosis, hepatitis B/C, autoimmune disorders (RA/SLE), infection (HIV, osteomyelitis, endocarditis), DM, HF - dx: CBC (normal MCV), low reticulocyte count, normal or high ferritin level, low serum iron/TIBC/soluble transferrin receptor, increased CRP/ESR (inflam markers) - tx: treat the underlying cause

Answer 4

- most often paediatric concern - chronic exposure to lead can = microcytic, hypochromic anemia - lead interferes with the synthesis of heme - dx: serum lead level

Answer 5

- In humans with sufficient iron absorption, the body will uptake the iron and store it in the enterocytes, spleen, and liver to maintain a tight balance of iron in circulation. - Iron is held in storage by a protein called ferritin. The transporter transferrin carries the iron to the cells for uptake. The iron binds to hemoglobin and is transported through the circulatory system. - In the event of iron deficiency, hemoglobin is reduced in the RBC. The decrease in hemoglobin decreases oxygen-carrying capacity resulting in hypoxia. - To maintain hemostasis the hypoxia stimulates the kidneys to release erythropoietin signalling erythropoiesis in the bone marrow. - The RBC production increases but the cells are microcytic and hypochromic due to the lack of hemoglobin. - Fatigue and shortness of breath will be noted at this stage due to decreased oxygen transportation capacity

Answer 6

- Physiologic anemia of pregnancy and iron deficiency anemia are the two most common causes of anemia in pregnant women - Dilutional anemia results from natural physiologic changes during pregnancy, meaning this is not a pathological condition. Two things happen: 1) There is an overall increase in RBC mass of about 15- 25%. 2) Total gain of plasma volume by term is 1100-1600 mls which is 40-50% that of a non-pregnant woman. Hemoglobin and hematocrit levels will therefore be lower. Since the increase in RBC mass is less than the total gain of plasma volume, a mild physiologic anemia of 10-11 g/dl occurs. It also leads to an increased iron requirement. Erythropoietin (EPO) is the mediator of increased RBC mass and it increases by 50% during pregnancy to help with physiologic anemia. The RBC lifespan is also slightly shorter. Iron deficiency anemia in pregnancy is centred around iron deficiency in women in general. With the exception of dilutional anemia, the other risk factors and physiology are the same and centre around lifestyle and diet requirements. - Dosing for IDA in pregnancy is recommended at 100mg – 200mg of iron orally per day- hemoglobin levels will improve in 1-2 months - In prenatal women IDA is defined as a Hb < 100 g/L in the 1st and third trimester and < 105 g/L in the second trimester. A ferritin level of < 15 ug/L is a diagnosis of IDA and you would treat with iron supplementation. A ferritin of < 30 ug/L, you would consider treatment with oral supplementation as this suggests early iron depletion.

Answer 7

- Screening: should occur at 6 and 18 months for those infants/children from high-risk groups- low socioeconomic status, indigenous communities, immigrant children or those infants/children fed whole cow’s milk before 9 months or with a sub-optimal intake of iron containing foods - Increased iron is needed to support the rapid growth and development children undergo in early years of life - As iron supply is decreased low levels of hemoglobin lead to iron deficient anemia (IDA). This process can have a profound, and sometimes irreversible effect on a child’s cognitive or psychomotor development - G6PD deficiency - Sickle cell anemia: Infants born heterozygous will be carriers but those born homozygous will display sickle cell anemia. - Thalassemia: autosomal recessive pattern - Universal prenatal screening programs aim to identify those at risk for thalassemia and sickle cell disease - Hemolytic Disease of the Fetus and Newborn (HDFN) occurs during pregnancy instead of childhood: caused by an ABO or Rh incompatibility between mother and child - the requirements of iron per kilogram of weight are higher in infancy and early childhood compared to any other developmental stage, owing to rapid growth and associated blood volume expansion during this time - Most healthy children carried to term are born with iron stores that are sufficient at meeting all physiologic requirements, until about six months - For infants aged seven to 12 months, the introduction of iron-rich complementary foods is required to meet the Recommended Dietary Allowance (RDA) of elemental iron: 11mg/day

Answer 8

- aka Immune Thrombocytopenia - complex immunologic process generally involving platelet destruction and impaired platelet production - Acute ITP is common in pediatric populations, is often self-limited, usually resolves within 6 months and is commonly secondary to an infectious or immune process - Chronic ITP is more common in adults, the condition usually lasts longer than 6 months, often gets progressively worse and often has an unknown precipitating cause - In ITP we have IgG autoantibodies which attack the GPIIa/IIa (Glycoproteins) which normally adhere to platelets to activate fibrinogen to promote aggregation of a platelet clot - Once the platelets are covered with these IgG antibodies, they start to be removed from the circulation by Fc receptor binding by our mononuclear phagocytes through the spleen by the process of phagocytosis - Remission in 3 to 12 months in most of the children - Some children might develop other problems in the long term as consequence of the affected organs: cognitive deficit, kidney insufficiency - If bleeding occurs: tx includes corticosteroids, IVIG, if severe: hospital