Flashcards in Hematology Deck (48):
____ are responsible for the production of myeloid and lymphoid cell lines.
The lymphoid line leads to production of the _____, and the myeloid line is responsible for the production of ____
-the remainder of WBC types,
Describe the progression of hematopoiesis
Stem cell--> Myelodi progenitor and lymphoid progenitor
-Myloid progenitor--> Megakaryocytes (--> thrombocyte/platelet), reticulocytes (--> erythrocyte), myelobast (--> Neutrophils, basophils, eosinophils and monocytes)
-Lymphoid progenitor--> lymphoblast--> lymphocyt
Notice that the reticulocyte ___ the erythrocyte, and all of us have a small percentage (~___%) of these in our peripheral blood under normal conditions
*Higher percentages of reticulocytes will make it out into peripheral circulation under high demand situations.
the preceding cell to the thrombocyte, or platelet, is the___. We won’t have these circulating in the periphery, but in times of high demand, the ___ will break down into larger, immature ___
CBCs is full of helpful information with regard to
1. BM function
2. renal fxn
4. hydration status
5. infection response
Describe a methodical approach to CBCs with anemias
1. look at at cell lines, (WBCs, RBCs and platelets) as an evaluation of the patient’s bone marrow and RBC’s provide a look at renal fxn
2. look at Hgb and Hct
3. MCV (mean corpuscular volume)
4. Peripheral blood smear for abnormal shapes of RBC’s, evaluate an increased number of WBCs, or in the case of lymphoblastic leukemia, lymphoblasts may be present in the peripheral blood
Patients can have a normal RBC count, but if the cells are poorly configured, such as in a hemoglobinopathy, or an iron deficient state, then the amount of hemoglobin in those RBC’s will be ____
___ often mirrors ___
*i.e. if the hemoglobin is low the hematocrit is low
The hematocrit represents ___
the percentage of the whole blood that consists of RBC’s with their hemoglobin.
In patients with iron-deficiency anemia, the Hgb, Hct, and RBC will be ___
-Hgb will be low,
-Hct will also be low because the RBC’s are smaller due to the smaller hemoglobin, and
-therefore the RBC’s are taking up less space in the whole blood.
in an iron-deficient patient who also has acute dehydration, the Hgb and Hct will be __
-Hgb will still be low but
-the Hct may be normal
*due to the decrease in overall blood volume from the dehydration
Causes of leukocytosis (increased WBCs)
1. Platelet clumping/lab error
2. Acute infection
3. Chronic Inflammation (JIA, Kawasaki)
4. Down Syndrome
5. Chronic myelogenous leukemia (CML)
6. Recent steroid use (40mg/d +)
*In primary care, we look at WBC almost exclusively as an evaluation of fever
Recent high dose steroid use causes ___ so that more are present in the periphery
demargination of WBCs,
Causes of leukopenia (low WBCs)
1. Post-infectious bone marrow suppression
-HIV, Parvovirus, EBV, CMV , Varicella
2. Bone Marrow Failure- Aplastic anemia or leukemia
3. Cyclic neutropenia- occurs every 21 days
4. Autoimmune neutropenia
5. African ancestry
Causes of post-infectious bone marrow suppression that lead to leukopenia
Causes of thrombocytosis
Almost exclusively reactive:
2. Kawasaki syndrome
3. Inflammatory/Autoimmune Disorders
Causes of thrombocytopenia
1. Immune thrombocytopenic purpura (ITP)
2. Viral suppression of platelet production
3. Bone marrow failure- ALL, CML, aplastic anemia
4. Thrombocytopenia of the newborn
Other causes of unusual bleeding:
1. Inherited bleeding disorders-Factor deficiencies (hemophilia), Von Willebrand
2. Acquired bleeding disorders- DIC, Liver dz, Vit K deficiency
What should you do when you find thrombocytopenia in a patient, if they are not having problems with bleeding in the form of nosebleeds, petechial or purpuric rashes?
no further investigation is usually warranted
Sx of thrombocytopenia
1. bleeding of nose
2. petechial or purpuric rash
It is important to think of thrombocytopenia in terms of a __ or __
- a producing problem (bone marrow failure, viral suppression) or
-a losing problem (ITP-immune thrombocytopenic purpura)
How does RBC production depend on the kidney?
the production of RBC’s depends upon renal production of erythropoietin
*Erythopoiein stimulates the BM to produce RBCs
Once mature RBC’s enter the peripheral circulation, they live approximately __ days before they are removed by the ___
Describe what the spleen breaks down RBCs into
The hemoglobin is broken down in the spleen into heme and globin and the heme is further broken down into iron and bilirubin
What happens to iron after it is produced in the spleen (via break down of heme)
The iron is then recycled with some being transferred, via transferrin, directly back to the bone marrow and some being stored as ferritin in the liver and spleen.
*This provides a mostly closed system for iron, with some healthy people needing very little dietary iron to replenish any losses
What groups need iron supplement
1. young children who are growing and therefore increasing their blood volume rapidly
2. menstruating women who are losing blood monthly, and, of course,
3. patients who are losing blood in the periphery due to pathologic processes.
Differential for microcytic anemia
1. Iron deficiency anemia (**MC)
2. Lead poisoning (?)
3. Thalassemias (alpha, minor)
4. Anemia of Chronic Inflammation (sometimes)
Differenital for normocytic anemia
1. BM Failure syndromes (Acquired Aplastic Anemia, Leukemia)
2. Transient Erythroblastopenia of Childhood
3. Anemia of Chronic Inflammation (initially)
4. Lead poisoning
5. Chronic Renal Failure
6. Hereditary Spherocytosis
7. Sickle cell disease
Differential for macrocytic anemia
2. Fanconi Anemia
3. Folic Acid/B12 deficiency
5. Congenital Cyanotic Cardiac Defects
7. Down syndrome
*rare in children
Most common causes of childhood folic acid/B12 deficieny
1. Celiac dz
3. Goat's milk
Generally speaking, normocytic anemias are usually a __ problem in children
Hemoglobinopathies usually result in __ anemias, although sickle cell can be __.
Exhausted iron stores due to sickle cell destruction will eventually result in a __ anemia in patients with sickle cell disease or other RBC- losing pathologies, such as ___.
When an otherwise healthy-appearing child has a macrocytic anemia, think about __ and __
celiac disease and goat’s milk use
Similarly to thrombocytopenia, I would encourage you to think of anemias in terms of a __ or __ problem
producing or losing problem.
a ___ is an immature RBC
in a losing problem, ___ will be pushed out into the periphery in greater numbers.
*A reticulocyte count is not usually included in a CBC, so if you are working up an anemia, you will need to order it specifically.
When is iron deficiency most likely to occur in children
-it usually develops in the 2nd year of life when children should have transitioned from formula or breast milk to whole milk at 12-16oz/day with an increase in solid foods to provide their necessary nutrients. In some children, however, they remain on a 40-48oz/day liquid diet of just whole milk. That amount of fluid will suppress their appetite for solid foods, and whole milk does not contain iron or other necessary nutrients.
Presentation of an iron deficient kid
When do you screen kids for anemia
2nd yr of life-- preferably after 15 months old
What should you do if you find a microcytic anemic kid with screening
1. it is acceptable to begin empiric treatment with iron (Fe 4-5mg/day) without proving with iron studies (serum Fe, ferritin, TIBC) that they are iron-deficient.
2. A repeat CBC in 1 month should show significant improvement if they have been compliant--> continue for 3 months total
3. If they are compliant, but not improving, it is appropriate to do the iron studies.
When do you screen for lead poisoning in kids?
At the same time as the routine CBC (2nd yr of life- preferably after 15 months), we also screen for lead poisoning, as this is the time that children are putting things in their mouth and can ingest lead. Additionally, being iron deficient appears to increase the risk of lead toxicity, so we screen these together.
When a child with microcytic anemia does not improve on iron, and the iron studies do not show a deficiency, consider ____ as the diagnosis.
*It is important to establish this diagnosis, only to prevent children from being treated multiple times over their lifetime for iron deficiency unnecessarily
On newborn screening, these infants will have ___ present along with ___
F and A (fetal and adult hemoglobin respectively).
On newborn screening, these infants will have Bart’s hemoglobin present along with F and A (fetal and adult hemoglobin respectively). Because it is not possible to know how much hemoglobin is Bart’s hemoglobin, it is necessary to perform a CBC at ___ old to see if they are severely anemic, indicating ___
6-9 months old
more deletions of the alpha chains (up to 4) vs. just 1 or 2 of alpha thalassemia minor or trait.
___ often accompanies Fe-deficiency anemia
What is considered microcytic, normocytic and macrocytic
Micro: MCV <78 fL
Normo: 78-100 fL
Macro: >100 fL