hemolytic anemia wk7 mon9am Flashcards
Lab Eval of hemolysis
- reticulocytosis with any MCV
- polychromatophila of erythrocytes
- erythroid hyperplasia of bone marrow
- increased indirect bilirubin
increased urinary and fecal urobilinogen
- increased endogenous CO production
- depleated unbound haptoglobin
Erythrocyte features in hemolytic anemias
- fragmentation
- spherocytosis
- distinct erythrocyte morphology
- erythrocyte inclusion
DDX of splenomegaly
- portal hypertension
- infiltrative disorders of spleen
- cardiomyopathy
- autoimmune disease
- subcapsular hemmorrhage
- hematologic disorders (hemolysis, hemoglobinopathy, neoplastic)
vascular disorders
- macroangiopathic hemolytic anemias- heart valves sheer RBC
- microangiopathic hemolytic anemias
- disseminated intravascular coagulation
- malignant hypertension
- thrombotic thrombocytopenic purpura
- hemolytic uremic syndrome
- other physical causes of hemolysis such as March hemoglobinuria and thermal injury
Membraneopathies
- membrane defects
- congenital
- hereditary sphereocytosis, elliptocytosis, stomatocytosis and acanthocytosis - acquired
- immunohemolytic anemias, immune hemolysis, Rh incompatibility, autoimmune hemolytic anemia, drug-induced heolytic anemia
Hemoglobinopathies
The change in the amino acid may give new charecteristics to the hemoglobin and lead to:
- increased HG precipitation (sickle cell)
- instability of HG
- Inability to keep iron in reduced form within the HG molecule (methemoglogins)
- altered O2 affinity of the HG molecule (high affinity or low affinity molecules)
Hemoglobin genes
Chromosome 16- 2 alpha
Chromosome 11- 1 beta
Hemoglobin types
Hg A- a2b2 Major adult (>95%)
Hg A2= a2d2 minor adult (<3%)
Hg F = a2g2 major Hg in fetus (<2%in adults)
SS anemia (sickle cell) clinical findings
Lab
- low grade anemia
- erythroid hyperplasia
- extravascular hemolysis
- hyperbilirubinemia (indirect)
Symtoms
- pain, bone infarcts, lungs, CNS, heart, renal, autosplenectomy, infections
SS clinical course
Variable
85% to age 20
60% to age 50
cause of death
- age 0-10: infection, splenic sequestration, acute chest syndrome, stroke, cardiovascular
- age >10: acute and chronic chest syndrome, infection, CVA, renal , cardiac, other
Thalassemias
Hereditary anemias with diverse clinical expressions, due to a quantitative decrease in the synthesis of one or more globin chains resulting in an unbalanced synthesis of globin chains and a decreased hemoglobin production
Beta thalaseemia major
- decreased beta globin
- decreased Hg/cell
- microcytic hypochromic RBCs
- anemia
- bone marrow expands (xray of head)
- mediterranean heritage
Beta thalassemia
- decreased beta globin synthesis.
MAJOR (homozygous)
- severe anemia, hepatoslenomegaly, hypercellular marrow, bone changes, iron overload, infections, early death if untreated
Rx: transfucion, iron chelation
**MINOR **
- mild anemia or symptomatic lab finding, may worsen with infections or pregnancy
Rx: genetic counseling, prenatal dx
alpha thalassemia
- decreased alpha globin synthesis
- usually oriental or asian
- 2 alleles for alpha chain synthesis (4 gene)
Hemoglobin H disease
- Hg H is a tetramer of beta chains. Precipitate in RBCs as intra-erythrocytic inclusions, hemolytic anemia.
- Micro/hypo cytic, target cells
- only one good alpha gene
Enzymopathies
- G6PD deficiency
- pyruvate kinase deficiency
- hemolytic anemias caused by other derangement of the Embden-Meyerhoff pathawy (gycolysis)
- abnormalities of nucleotide metabolism
