Anemias Flashcards
Hb
Men- 14-18 g/dL Women 12-16 g/dL 90-95% of the cytoplasm of RBC
Hct
Men- 42-52% Women- 37-47%
MCV
Mean red blood cell volume/size estimate Hct/Rbc 80-100 fL (10^-15 L) 100 macrocytic 80-100- normocytic
Mean cell Hb concentration
Hb/ Hct Differentiate bt hypo and normo chromatic 32-36 g/dL
RDW
Red cell distribution width Std of MCV Tells how much cells differ in size, low = uniform / minimal anisocytosis 12-13.5 %
WBC
4.5-11*10^9/L
4,500 to 11,000/mm3
PMNs
45-70% 2-8 *10^9
Lymphocytes
25-33%
1-4 *10^9
Monocytes
1-8% 0.1-0.8
Eosinophils
0-6% 0-0.5
Basophils
0-1% 0-0.3
Platelet count
150-450*10^9/L
Mean platelet volume
Depends on count Low count body tries to compensate by making platelets bigger
Common causes of iron deficiency anemia
- Infants/Children: diet, breastfeeding
- Adults: GI bleed, peptic ulcer, menorhhagia, pregnancy, colon polyps, carcinoma
- Tropical: hookworm (nicator and anstilastima)
- Celiac/ Malabsorption
- Gastrectomy ( acidity of stomach maintains iron as fe2+ which binds to heme better so loss of some of stomach means less fe2+)
Megloblastic anemia
Impaired DNA synthesis
B12 or folate deficiency (methotrexate, folate anagonist)
Other rapidly dividing cells effected too - enlarged epithelial cells in gut; macrocytic RBCs and hyper segmented PMNs (greater than 5 lobes) giant red cells and neutrophil precursors (band cells) also seen in bone marrow ; increased lactic acid dehydrogenase (LDH-2); glossitis
Pathophysiology of hereditary spherocytosis
Autosomal Dominant; Extravascular normocytic anemia
RBC cytoskeleton membrane tethering protein defect in spectrin or ankyrin, band 3.1, which causes instability and breakage of RBCs
Change in shape makes cells less able to navigate splenic sinusoids and consumed by macrophages in spleenic sinusoids
G6PD deficiency
X linked recessive disorder that reduces half life of RBC that renders cell vulnerable to O2 stress; common in black males
RBCs use glutathione to protect against oxidative stress (H2O2 +GSH (reduced glutathione)–> GS-SG; needs to be reduced back to GSH via NADPH which is produced by G6PD)
In red cells African variant: mildly reduced half life G6PD; older cells destroyed
Mediterranean variant: marked reduced G6PD half life; when ox stress more cells die
Protective against falciparum malaria
Infections, drugs (antimalarials, sulfadrugs, aspirin, vit K), fava beans
The increased free radicals denature the bonds between heme and glob in making globin form a glob –> Heinz bodies–> bite cells by spleen –> intravascular hemolysis, Hemoglobinuria, and back pain (nephrotoxic)
Enzymatic studies after disease has resolved (during crisis all the cells without the enzyme are dead)
Sickle cell anemia mutation
Autosomal recessive point mutation at residue 6 in beta globin gene where glutamic acid gets replaced with valine
Protective against Plasmodium falciparum malaria
Thalassemia
Decreased production of a globin chain, leading to decreased hemoglobin production and also tetramers due to unpaired chains
Common in Mediteranian/Greek, Asian, and African populations
Warm antibody Immunohemolytic Anemia
IgG anti red blood cells antibodies that bind well at 37 Celsius (central body) and are consumed by macrophages in the spleen; slow loss of membrane from cell results in spherocytosis
- Idiopathic
- Secondary immune system disease: SLE, RA, or Drugs (PCN- haptens, methyldopa- production of antibodies and binds existent antigens)
Chronic mild anemia with moderate splenomegaly
Diagnosis: Coomb +
Treat: IVIG (splenic marcophages will eat IVIG instead of red cells); Steroids, removal of drug; splenectomy (removes antibodies and destruction)
Microangiopathic Hemolytic Anemia
Pathology in small blood vessels that results in a hemolytic anemia (some sort of thrombus that blocks the vessel partially)
Tear up blood cells –> Schitocytes ( pointy red cell fragments)
Causes: TTP ; HUS; DIC; Maligant hypertension, SLE, disseminated cancer
Pathophysiology of anemia of chronic disease
Associated with chronic disease or cancer (inflammation, infection, malignancy)
Inflammation (IL6) produce acute phase reactant Hepcidin (made in liver) that sequesters iron by blocking ferroportin and also suppresses EPO; protective mechanism because bacteria need iron to proliferate (body thinks any inflammation is bacterial)
Aplastic anemia
Multipotent myeloid stem cells are supressed resulting in pancytopenia
- Idiopathic
- Myelotoxic agent (choramphenicol, benzene, alkalating agents, antimetabolites, or idiosyncratic hypersentitivity rxn)
- Viral agents (parvovirus b19, EBV, HIV, HCV)
- Congenital: Fanconi anemia
Empty marrow on marrow biopsy (>90% fat)
Cessation of causative drugs, transfusion, marrow stimulating factors (EPO, GM-CSF, G-CSF); immunosuppression (if etiology is autoimmune); bone marrow transplant
Anemia
Decrease in the oxygen -transporting capacity of the blood usually steming from a decrease in the red blood cell mass to subnormal levels
Measure of mass of rbcs Less than 13.5 g/dl males and 12.5 g/dl females