Hematology Flashcards
Reticulocyte count
1st step up in work-up in any anemia. Young RBC. Takes 24h -> mature one (biconcave). If low/inappropriate response, bone marrow problem. If high, not bone marrow problem b/c responding well. Takes 5-7 days for reticulocyte response.
Correct the reticulocyte count for the degree of anemia?
Corrected = HCT/45 * reticulocyte count. 3% or greater = good response
Reticulocyte
Still synthesizing Hgb. Black lines are RNA filament (w/ stain). POLYCHROMASIA (basophilic) = means that bone marrow is really responding and bringing out even younger cells. These cells take 2-3 days to mature. We don’t want polychromasia cells in our corrected reticulocyte count. DIVIDE by two if see polychromasia.
Rule of 3
Multiply hgb x 3 ~ HCT. BTW, transfusion of pRBC. For every unit of pRBC transfuse - hgb by 1 and HCT by 3%.
Fe deficiency anemia
Most common cause is GI bleed.
MCV
Mean corpuscular volume. MCV < 80 is microcytic. MCV > 100 is macrocytic (usu. B12 or folate). But what if dimorphic population, then MCV looks normal but you are not normal (RDW increased).
Fe, Folate, B12 absorption where?
Duodenum, jejunum, terminal ileum
RDW
Reports size distribution. Anemia doesn’t happen immediately. Developing microcytic anemia will give you a low MCV with higher RDW. Low MCV and higher RDW = Fe-deficiency. Can’t be thalassemia b/c genetic and congenital.
Spherocyte
Too little membrane. Spherocyte is an Anorexic cell. NO central pallor.
Target cell
Too MUCH membrane. Obese cell right in the middle more membrane and more hgb to be red. Markers for Alcoholics (Chol conc.) and hemoglobinopathy (thalassemia, sickle cell)
Microcytic anemia
GREATER area of pallor b/c less hgb.
Physical signs of anemia
Spoon nails (iron deficiency, koilonychia), cheilosis, pallor of conjunctiva, Lead line
Iron studies
4 studies: Serum Fe (100); Ferritin - soluble, circulating form of iron storage = iron stored in bone marrow; transferrin = carrying protein for Fe made in the liver;
Transferrin and TIBC
ARE THE SAME.
Fe storage and transferrin are related
When the Fe stores are deficient, signal for liver to make more TRANSFERRIN. TIBC increases in Fe-deficiency.
% Saturation
= Serum Fe / TIBC. Normal is 100/300 = 0.33.
Pathogenesis of microcytic anemia
Can’t make Hgb. Hb concentration in developing red blood cell that determines the # of cell division. If Hb is LOW, increases the number of mitoses. All 4 microcytic anemias have LOW Hb.
What makes hemoglobin is how you think of microcytic anemia?
Heme = Fe + protoporphyrin. HbA1 = alpha + beta. Alpha + Delta = A2. Alpha + gamma = Fetal.
Fe-deficiency anemia
No Fe to make Heme. Low hgb. Microcytic.
Anemia of chronic disease
Response to inflammation. Bacteria likes Fe, so decrease Fe availability. Fe is usually in MACROPHAGES in bone marrow. Lock away the Fe but lose the key. Serum Fe low. TIBC is LOW (high iron stores = dec. transferrin). %Sat = low. Serum ferritin = high.
Sideroblastic anemias
Sidero = Iron. Porphyrin synthesis begins in the mitochondria. 3 main causes: (1) EtOH (not the most common anemia in alcoholics) b/c it’s a mitochondrial poison that uncouples oxidative phosphorylation. Fe filled in mitochondria = RINGED sideroblast. And iron overload disease. (2) B6 deficiency (e.g. INH treatment) - no B6, no ALA-synthase. Fe can’t get out of mitochondria again = ringed sideroblast (3) Lead poisoning - lead denatures proteins, esp. FERROkelotase > ala dehydratase. And, again, Fe gets stuck in mitochondria.
Porphyrin synthesis
Succinyl-CoA + Glycine (btw inhibited by tetatnospasmin) -(ALA-synthase; pyridoxine)-> delta-aminolALA ->->->-(in mito)->protoporphyrin + Fe -(Ferrokelotase)-> Heme. Feedbacks against ALA-synthase.
Thalassemias
Genetic diseases AR.
Hb electrophoresis
HbA is 95%. HbA2 is 1-2%. HbF is 1%. PERCENTAGES.