Chapter 5: RBC Disorders - High Yield Flashcards
Fe absorption
in duodenum. Enterocytes transport Fe across cell membrane into blood via FERROPORTIN (key regulatory step). absorbed in Fe2+ state.
Transferrin
Transport Fe in blood and deliver it to liver an dbone marrow macrophages for storage.
Ferritin.
Fe is bound to this intracellular for storage.
TIBC
measure of transferrin molecules in the blood
Serum Ferritin
Reflects Fe stores in macrophages and liver
Koilonychia, Pica; Lab: inc RDW; microcytic; hypochromic; dec ferriting; inc TIBC; dec serum Fe; Dec % sat; INC FREE ERYTHROCYTE PROTOPORPHYRIN
Iron deficiency anemia
Fe deficiency anemia with esophageal web and atrophic glossitis - “Beefy red tongue”
Plummer-Vinson Syndrome
Hepcidin
Sequesters Fe storage in storage sites, suppresses EPO production
Inc Ferritin; dec TIBC; Dec Serum Fe; Dec % saturation; Inc Free erythrocyte protophorphyrin
Anemia of Chronic disease.
Inc ferritin; dec TIBC; inc serum Fe; Inc % saturation
Sideroblastic anemia.
Thalassemia protects against what?
Plasmodium falciparum malaria
Folate is absorbed in the
jejunum
Marocytic RBC, hypersegmented neutorphils, glossitis, inc serum homocysteine, nml methylmalonic acid
Folate deficiency
Vitamin B12 (cobalamin) is absorbed in the
ilieum
Autoimmune destruction of parietal cells leading to intrinsic factor deficiency
Pernicious anemia
Macrocytic RBC, hypersegmented neutrophils, glossitis, subacute combined degeneration of the spinal cord (poor proprioception, vibratory sensation, and spastic paresis); inc serum homocysteine; increase methylmalonic acid
B12 deficiency anemia
Spherocytes. Inc RDW; Inc MCHC; Increased risk for aplastic crisis with Parvo B19; dx with osmotic fragility test.
Hereditary sperhocytois. Tx = splenectomy. Sperhocytes will persist and Howell-Jolly bodies emerge on blood smear
Autosomal recessive mutation in B-chain of hemoglobin. Replaces glutamic acid with valine. Protective against falciparum malaria
Sickle Cell anemia
> 90% HbS in RBC.
Sickle cell disease. alpha2 beta 2^S
Tx of Sickle Cell anemia
Hydroxyurea - increases levels of HbF
< 50% HbS
Sickle Cell trait
Metabisulfite screen
causes cells with any amount of HbS to sickle; positive in both disease and trait
Autosomal Recessive mutation in Beta chain of hemoglobin. Glutamic acid is replaced by lysine. HbC CRYSTALS ARE SEEN IN RBC IN BLOOD SMEAR
Hemoglobin C
Absence of Glycosylphosphatidylinositol (GPI). Therefore, no Decay accelerating factor (DAF). Sucrose test = screen. Acidified serum test or flow cytometry to detect lack of CD 55 (DAF) on blood cells = confirmatory.
Paroxysmal Nocturnal Hemoglobinuria (PNH) - Normocytic anemia with intravascular hemolysis
X-linked recessive. Susceptible to oxidative stress. decreased NADPH [therefore decreased glutathione]. Protective against Falciparum malaria. Heniz bodies (Hb). Bite cells.
Glucose 6-Phosphate Dehydrogenase Deficiency (G6PD). Normocytic anemia with intravascular hemolysis.
Causes of oxidative stress
Infections; drugs (primaquine, sulfa drugs; dapsone) and fava beans.
Direct Coombs test
Test for immune hemolytic anemia. Confirms the presence of antibody-coated RBC. Anti-IgG is added to the patient RBC
Malaria cause with daily fever
P. falciparum
Malaria cause with fever every other day
P. vivax and P. ovale
Source of EPO
peritubular interstitial cells
Biopsy = empty, fatty marrow. Pancytopenia
Aplastic anemia
