Case of the Week: Hemolysis Flashcards
What are two things that might be going on if you have anemia and a HIGH RETICULOCYTE COUNT?
active bleeding
red cell destruction
What clues would favor RBC destruction instead of blood loss?
elevated LDH elevated indirect bilirubin spherocytes of peripheral smear low haptoglobin positive DAT
Two mechanisms of hemolysis?
intravascular: destruction of RBCs within the vasculature, releasing free Hb into circulation
extravascular: macrophages in spleen, liver, and marrow remove damaged or antibody coated red cells
What are some clues that make you think of increased red cell production:
in the blood?
in the bone marrow?
in the bones?
blood: elevated reticulocyte count or circulating nucleated RBCs
bone marrow: erythroid hyperplasia
bones: deformities in long bones
What’s the diagnosis?
Etiology: Mechanical destruction of red blood cells in circulation
Causes: TTP, DIC, HUS, Pre-eclampsia, malignant HTN, prosthetic values
Diagnosis – Schistocytes
Treatment of underlying disorder
microangiopathy
What’s the diagnosis?
Etiology – Malaria, babesiosis, clostridium
Diagnosis – cultures, thick and thin smears, serologies
Treatment - Antibiotics
Infection
What are 3 inherited/hereditary defects in RBCs?
- enzyme probs: G6PD deficiency
- membranopathies: hereditary spherocytosis
- hemoglobinopathies: thalassemia and sickle cell diseases
What are two general mechanisms you think of when you are presented with ANEMIA?
- decreased bone marrow production
2. increased destruction
What are some clinical clues unique to intravascular hemolysis?
hemoglobinuria
hemosidinuria
This is a feature of neutrophils in Vit B12 deficiency (also seen in folate deficiency).
hypersegmented neutrophils
When would you see spherocytes?
hereditary spherocytosis (look at history for clues) immune hemolytic anemia
What do reticulocytes look like?
retics have bluish staining compared to normal RBCs
When would you see bite cells?
intravascular hemolysis (like G6PD deficiency, membrane defects, hemoglobin defects)
When do you get aplastic anemia?
parvovirus B19 infection
**infects erythroid precursors so all red cell line cells are affected
Immune hemolytic anemia can involve warm agglutinins or cold agglutinins. Which Ig is involved in warm agglutinins? Cold agglutinins?
IgG; IgM/complement
