Hemolytic Anemias 2 Flashcards
Extravascular vs Intracascular Hemolysis
Ex: defective and deformed RBCs are removed by the spleen
In: RBCs are damaged/destroyed while in circulation, haptoglobin binds to free hemoglobin to prevent the oxidizin effects of free hemoglobin
Autoimmune Hemolytic Anemia (AIHA)
Caused by antibodies produced by the body that bind to antigens on RBCs
Can be warm or cold
Warm AIHA
Antibodies that bind to RBCs and cause RBC lysis at body temperature (37C)
Usually IgG antibodies
Against Rh system (D, C, E)
WAIHA Labs
Decreased RBC, Hgb, Hct, Haptoglobin
Increased RDW, Retic
Normal MCV, MCHC
Positive DAT
WAIHA Microscopics
Polychromasia, spherocytes, micro-spherocytes
Cold AIHA
Antibodies that bind to RBCs and activate complement at temperatures lower than body temp
Usually IgM antibodies
AKA Cold agglutinin syndrome
Idiopathic: IgM against I antigen
Secondary: due to mycoplasma = IgM against I antigen, due to infectious mono = IgM against i antigen
CAIHA Labs
Falsely decreased RBC, Hct Falsely increased MCV, MCH, MCHC Get accurate results by pre-warming Decreased RBC, Hgb, Hct, Haptoglobin Increased Retic Normal MCV, MCH, MCHC DAT negative with anti-IgG, positive with polyspecific AHG
CAIHA Microscopics
Polychromasia, spherocytes, possible NRBCs
Hemolytic Transfusion Rxn
Immediate: usually ABO incompatibility, but also happens with other blood groups
Delayed: associated with antibodies to Kidd antigens (Jka, Jkb)
HTR Labs
Variable CBC
Variable DAT based on hemolysis
Decreased haptoglobin
Hemolytic Disease of the Fetus and Newborn (HDFN)
Caused by Rh incompatibility between mother and fetus
Causes hemolysis in the fetus and can lead to anemia and intramedullary hematopoiesis
Quantified by Kleihauer Betke Test or by flow cytometry for fetal hemoglobin
HDFN Labs
Decreased Hgb, Hct
Increased Retic
Normal MCV (newborn RBCs are large)
HDFN Microscopics
Polychromasia, numerous NRBCs, possible poikilocytosis
Microangiopathic Hemolytic Anemia (MAHA)
Group of disorders that are caused by microcirculatory lesions
Fibrin strands in the microcirculation activate platelets and cleave RBCs
Cause thrombocytopenia and hemolysis
MAHA Labs
Decreased Hgb, Hct, Plt
Increased WBC, RDW, Retic
MAHA Microscopics
Schistocytes, thrombocytopenia, anemia, polychromasia, possible NRBCs, possible left shift
Hemolytic Uremic Syndrome (HUS)
Associated with acute renal failure
Divided into HUS with or without diarrhea
Caused by infectious damage to the capillaries of the glomerulus by E coli/Shigella
Thrombotic Thrombocytopenia (TTP)
Caused by ADAMTS13 deficiency or autoantibodies against ADAMTS13
ADAMTS13 cleaves vWF which helps prevent excessive platelet aggregation in the circulation
DIsseminated Intravascular Coagulation (DIC)
Causes a consumption of clotting factors resulting in severe bleeding complications
HELLP syndrome can lead to DIC
HELLP Syndrome
Obstetric complication, severe form of pre-eclampsia
Hemolysis, elevated liver enzymes, low platelet count
Can lead to DIC
Traumatic Cardiac Hemolytic Anemia
AKA Waring Blender syndrome
Arises as a complication to the presence of a prosthetic heart valve
Shear stress around the valve causes RBC hemolysis
Thermal Injury
RBCs fragment at 48 to 50 C
Causes membrane budding, spherocytes, and schistocytes
Hemoglobinuria lasts for 48 hours after the injury
Exercise Induced Hemoglobinuria
Hemoglobinuria appears for a few hours after exercising
CBC and peripheral smear are normal
