Hemolytic Anemia Flashcards
Hemolytic Anemia
-Shortened RBC lifespan
-Hemolysis: Destruction of RBCs
-Bone marrow production cannot keep up
Hemolytic Anemia: Clinical Findings
-Clinical findings: Fatigue, malaise, pallor, jaundice, splenomegaly, hepatomegaly
Hemolytic increases the risk of:
Gallstones
Hemolytic Anemia: Laboratory Tests
- Lactate dehydrogenase (LDH): Increased
-LDH-1 found in heart and RBCs
-Destruction of RBC: Increased LDH-1 and total LDH - Serum unconjugated bilirubin: Increased
-Often elevated in hemolysis - Reticulocyte Count (Immature RBC): Increased
-Often elevated in hemolysis - Serum Haptoglobin
-Finds feee hemoglobin released from RBC destruction
Hereditary Spherocytosis: Etiology
Defect in RBC membrane
-Spherocytes
-Destroyed by spleen
Hereditary Spherocytosis: CBC
-Mild to moderate anemia: >8g/dL
-Peripheral Blood Smear: Spherocytes
-Additional Tests: Osmotic fragility test (Increases)
Hereditary Spherocytosis: Management
-Blood transfusions
-Splenectomy
-Folate Supplementation
G6PD: Etiology
-X-linked genetic abnormality of the enzyme
-Triggers: Certain drugs/chemicals, infections (viral & bacterial), stressors, certain foods (fava beans)
G6PD: Clinical Findings
-Difficulty fighting infections
-Typical signs of hemolytic anemia
G6PD: Lab Findings
-CBC: Moderate anemia
-Peripheral blood smear: Bite cell
Sickle Cell Anemia: Heterozygous vs. Homozygous
-Genetic hemoglobinopathy
-Homozygous (S/S): Sickle Cell anemia (more severe)
-Heterozygous (A/S): Sickle Cell trait, usually asymptomatic w/o anemia, exertional sickling (PA, dehydration, high altitude, pain, fatigue)
Sickle Cell Anemia: Etiology
-Inflexible
-Odd shape, rigidity
-Increased blood viscosity
-Stasis
-Obstruction of arterioles/capillaries
-Ischemia
-Fragile->hemolysis
-Vaso-occlusive crisis
-Progressive organ failure possible
Sickle Cell Anemia: Clinical Findings
-After 6 months of age (HbF->HbA)
-Hemolytic anemia symptoms: Pallor, fatigue & jaundice (severe)
Vaso-occlusive crises
-Symmetrical painful swelling of hands and feet
-Functional asplenia by 5-6 years of age (loss of function of the spleen)
-Increased infection risk
-Delayed physical/sexual maturation
-Painful crises-bones, joints, abdomen, back, viscera
-Chronic abdominal pain
-Lung and kidney problems
Sickle Cell Anemia: Lab Findings
-CBC: Moderate to severe anemia, RBC indices are usually normal, In crisis: Leukocytosis, Thrombocytosis
-Peripheral Blood Smear: Sickle Cells
-Miscellaneous: Decreased ESR
Sickle Cell Anemia: Special Tests
-Test: Hb electrophoresis (SCA: 80-100% Hb S (no Hb A)/SCT: 20-40% Hb S; 60-80% HbA1 (HbS>60%)
-Screening Tests: “SickleDex”
Sickle Cell Anemia: Treatment/Prognosis
-Anemia is lifelong
-In 2nd decade in life, fewer crises, complications more frequent
-Crises start at 1-2 years
-Life expectancy 40-50 years: Infections, thrombosis, pulmonary emboli, pulmonary hypertension, renal failure
Thalassemias
-Genetic disorder: Impacts rate (slow) of synthesis of adult hemoglobin (Hb A):
Alpha/Beta Thalassemia
-Inadequate Hb and unbalanced accumulation of globin chains: hypochromic, microcytic red cells & hemolytic anemia
Thalassemias are more prevalent in:
Mediterranean, Middle East, Africa, SE Asia
Types of Thalassemia
-Thalassemia Trait/Minor (alpha or beta): mild anemia, hypochromic, microcytic
-B-Thalassemia intermedia
-B-Thalassemia major (Cooley’s anemia): severe anemia; Transfusions necessary to sustain life
Thalassemia Major: Etiology
-Homozygous
-Defective production rates of B-globin polypeptide
Thalassemia Major: Management/Treatment
-Regular transfusions: Hb>9.3 g/dL
-Folate supplementation
-Treat bacterial infections promptly
-Splenectomy
-Iron management: Avoid iron rich foods/Reduce absorption with certain foods
-Iron overload causes most morbidity & mortality (Average lifespan-30 years of age)
Thalassemia Major: Clinical Findings
-Severe anemia
-Jaundice
-Splenomegaly
-Hemolytic faces: maxillary hypertrophy, prominent forehead
Thalassemia Major: Lab Findings
-CBC: Severe anemia
-Peripheral smear: Target cells
-Special Tests: Hb ELP (hemoglobin electrophoresis)->Significant reduction or absent HbA, increased HbF (>50%), increased HbA2
Thalassemia Minor: Etiology
-Heterozygous
-Defective rate of production of beta globulin chains
Thalassemia Minor: Management
-No treatment, live healthy
-NL iron panels
-No iron supplement unless warranted
Thalassemia Minor: Clinical Findings
-Asymptomatic to mild symptoms of anemia
Thalassemia Minor: Lab Findings
-CBC: Mild anemia (Hb>10g/dL), Slight elevation in RBC count, MCV/MCH/MCHC decrease, RDW: NL
-Peripheral blood smear: Hypo/micro RBCs, Target Cell (may be present)
Thalassemia Minor: Special Tests
Reticulocytosis (~3%), Hb electrophoresis (Hb ELP), Calculate Mentzer index (MCV/RBC count): <13 thalassemia more likely/>13 iron deficiency more likely
Traumatic Hemolytic Anemia: Etiology
-March hemoglobinuria
-Karate
-Bongo playing
-Prosthetic heart valves
Traumatic Hemolytic Anemia: Lab Findings
-Low MCV, high RDW, anemia
-Peripheral blood smear: Schistocytes
Hemolytic anemia d/t infectious agents: Etiology
-Malaria
-Bacterial toxins-clostridium perfrigens, streptococci, meningococci
Hemolytic Anemia d/t immunologic abnormalities
-Transfusion of incompatible blood
-Hemolytic disease of the new born: May be d/t ABC incompatibility (more common/less severe) or Rh incompatibility (More severe/less commo
HA d/t immunologic abnormalities: Clinical Findings
-Anemic newborn
-Jaundice
-Pathological: W/I first 24 hours
-Physiological: After 24 hours after birth
HA d/t immunologic findings: Lab Findings
-CBC: Anemia
-Special Tests: + Coombs Test (Direct antiglobin test)
HA d/t Autoimmune (AIHA)
-Acquired anemia induced by binding autoantibodies to RBC -membrane
-Main types defined by maximal binding temperature of antibodies:
HA d/t Autoimmune: Warm vs. Cold
-Warm (98.6 F) reacting IgG antibody
-Cold (32-39F) reacting IgM antibody (Cold exposure, Elderly, Acrocyanosis-blue discoloration of distal extremities, Raynaud’s Phenomenon
HA d/t autoimmune: Risk Factors
(MMAP)
-Malignancy
-Autoimmune disorders (Warm IgG)
-Medications
-Prior blood transfusion, hematopoietic cell transplant
HA d/t autoimmune: Lab Findings
-Direct Coombs’ (DAT-direct antiglobulin tests): Positive test indicates presence of antibodies or complement on RBC surface. Warm (IgG antibodies)/Cold (IgM antibodies)
-CBC: Anemia (normochromic, normocytic)
Thalassemia Minor vs. IDA
-RDW: Thalassemia Minor (Normal)/IDA (Elevated)
-RBC Count: T Minor (Slight increase)/IDA (Decreased)
-Serum Ferritin: T Minor (Normal)/IDA (decreased)
-Serum Iron: T Minor (normal)/IDA (decreased)
-Target Cells: BOTH may be present
-Mentzer Index: T Minor <13/IDA >13
