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Autoimmune hemolytic anemia
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
Hemolytic disease of the newborn
Paroxysmal nocturnal hemoglobinuria
Pyruvate kinase deficiency
Sickle cell disease (NORD)
Folate (Vitamin B9) deficiency
Vitamin B12 deficiency
Anemia of chronic disease
Iron deficiency anemia
Vitamin K deficiency
Langerhans cell histiocytosis
Essential thrombocythemia (NORD)
Polycythemia vera (NORD)
Acute intermittent porphyria
Porphyria cutanea tarda
Disseminated intravascular coagulation
Von Willebrand disease
Monoclonal gammopathy of undetermined significance
Thrombotic thrombocytopenic purpura
Antithrombin III deficiency
Factor V Leiden
Protein C deficiency
Protein S deficiency
Coagulation disorders: Pathology review
Extrinsic hemolytic normocytic anemia: Pathology review
Heme synthesis disorders: Pathology review
Intrinsic hemolytic normocytic anemia: Pathology review
Leukemias: Pathology review
Lymphomas: Pathology review
Macrocytic anemia: Pathology review
Microcytic anemia: Pathology review
Mixed platelet and coagulation disorders: Pathology review
Myeloproliferative disorders: Pathology review
Non-hemolytic normocytic anemia: Pathology review
Plasma cell disorders: Pathology review
Platelet disorders: Pathology review
Thrombosis syndromes (hypercoagulability): Pathology review
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Meet Aly: Hemolytic Uremic Syndrome - Akron Children's Hospital video
Hemolytic Uremic Syndrome (HUS)
hemolytic-uremic syndrome p. 432
Escherichia coli p. , 143, 176
exotoxins p. 130
platelet disorders p. 432
schistocytes in p. 422
‘Hemo’ refers to the blood, ‘lytic’ refers to breaking down, and ‘uremic’ refers to increased urea levels in the blood.
And this helps explain hemolytic uremic syndrome because the two main effects are destruction of red blood cells and the declining function of the kidney causing uremia - both of which result from tiny blood clots that form in tiny blood vessels - predominantly in the kidneys.
Classically, especially in children, hemolytic uremic syndrome is triggered by a bout of bloody diarrhea.
When that happens, it’s called diarrhea-positive or D positive hemolytic syndrome, sometimes shortened to HUS or simply typical HUS.
Escherichia coli or E. coli is usually the culprit, and children often pick it up through contaminated food or drink, like contaminated beef or unpasteurised milk from an infected cow.
The particular strain of E.coli responsible for hemolytic uremic syndrome is known as enterohemorrhagic E. coli or EHEC, serotype O157:H7.
These numbers and letters refer to the specific antigens on the surface of the bacteria.
‘157’ refers to the O-antigen present in the lipopolysaccharide cell wall and ‘7’ refers to the H-antigen located on the flagella of the bacteria.
Other strains of E. coli as well as other bacteria can also cause hemolytic uremic syndrome, but E. coli O157:H7 is the most common culprit.
After entering the digestive tract, E. coli O157:H7 attaches to the intestinal wall and secretes a toxin called Shiga-like toxin.
The toxin gets its name due to its structural similarity with shiga toxin produced by Shigella dysenteriae, another bacteria that causes bloody diarrhea and subsequent hemolytic uremic syndrome.
So that toxin gets absorbed by intestinal blood vessels and is then picked up by immune cells like eosinophils, basophils and neutrophils.
From there, the toxin is carried on the surface of these cells to the site of blood filtration - which is the glomerular capillaries of the kidney.
Hemolytic-uremic syndrome (HUS) is a serious condition that's characterized by microangiopathic hemolytic anemia, thrombocytopenia, and renal failure. It is usually caused by E. coli O157:H7 infection and presents with fever, jaundice, stomach cramps, vomiting, and diarrhea. A person with HUS may also have a rash, red or purple dots on the skin, and tiredness.
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