Hemolytic-uremic syndrome
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Hemolytic-uremic syndrome
Hematological system
Anemias
Iron deficiency anemia
Beta-thalassemia
Alpha-thalassemia
Sideroblastic anemia
Anemia of chronic disease
Lead poisoning
Hemolytic disease of the newborn
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
Autoimmune hemolytic anemia
Pyruvate kinase deficiency
Paroxysmal nocturnal hemoglobinuria
Sickle cell disease (NORD)
Hereditary spherocytosis
Anemia of chronic disease
Aplastic anemia
Fanconi anemia
Megaloblastic anemia
Folate (Vitamin B9) deficiency
Vitamin B12 deficiency
Fanconi anemia
Diamond-Blackfan anemia
Heme synthesis disorders
Acute intermittent porphyria
Porphyria cutanea tarda
Lead poisoning
Coagulation disorders
Hemophilia
Vitamin K deficiency
Platelet disorders
Bernard-Soulier syndrome
Glanzmann's thrombasthenia
Hemolytic-uremic syndrome
Immune thrombocytopenic purpura
Thrombotic thrombocytopenic purpura
Mixed platelet and coagulation disorders
Von Willebrand disease
Disseminated intravascular coagulation
Heparin-induced thrombocytopenia
Thrombosis syndromes (hypercoagulability)
Antithrombin III deficiency
Factor V Leiden
Protein C deficiency
Protein S deficiency
Antiphospholipid syndrome
Lymphomas
Hodgkin lymphoma
Non-Hodgkin lymphoma
Leukemias
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Acute leukemia
Leukemoid reaction
Leukemoid reaction
Dysplastic and proliferative disorders
Myelodysplastic syndromes
Polycythemia vera (NORD)
Myelofibrosis (NORD)
Essential thrombocythemia (NORD)
Langerhans cell histiocytosis
Mastocytosis (NORD)
Plasma cell dyscrasias
Multiple myeloma
Monoclonal gammopathy of undetermined significance
Waldenstrom macroglobulinemia
Hematological system pathology review
Microcytic anemia: Pathology review
Non-hemolytic normocytic anemia: Pathology review
Intrinsic hemolytic normocytic anemia: Pathology review
Extrinsic hemolytic normocytic anemia: Pathology review
Macrocytic anemia: Pathology review
Heme synthesis disorders: Pathology review
Coagulation disorders: Pathology review
Platelet disorders: Pathology review
Mixed platelet and coagulation disorders: Pathology review
Thrombosis syndromes (hypercoagulability): Pathology review
Lymphomas: Pathology review
Leukemias: Pathology review
Plasma cell disorders: Pathology review
Myeloproliferative disorders: Pathology review
Assessments
Hemolytic-uremic syndrome
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10 pages
Flashcards
Hemolytic-uremic syndrome
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Questions
USMLE® Step 1 style questions USMLE
of complete
| Laboratory value | Result |
| Hematologic | |
| Hemoglobin | 12 g/dL |
| Hematocrit | 40% |
| Platelet count | 95,000/mm3 |
| Leukocyte count | 9,000/mm3 |
| Coagulation studies | |
| Prothrombin time (PT) | 12 seconds |
| Activated partial thromboplastin time (aPTT) | 29 seconds |
| Bleeding time* | 15 minutes |
Which of the following conditions is the patient at greatest risk of developing?
Memory Anchors and Partner Content
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2016
Enterohemorrhagic Escherichia coli (EHEC) p. 130, 143, 176
hemolytic-uremic syndrome p. 434
Hemolytic-uremic syndrome (HUS)
Escherichia coli p. , 143, 176
exotoxins p. 130
platelet disorders p. 434
schistocytes in p. 424
Pediatric patients
hemolytic-uremic syndrome p. 434
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Transcript
Content Reviewers
Rishi Desai, MD, MPH‘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.
Summary
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.
Sources
- "Robbins Basic Pathology" Elsevier (2017)
- "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
- "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
- "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
- "Pathogenesis of Atypical Hemolytic Uremic Syndrome" Journal of Atherosclerosis and Thrombosis (2019)
- "Shiga Toxin-Associated Hemolytic Uremic Syndrome: A Narrative Review" Toxins (2020)
- "Pediatric Atypical Hemolytic Uremic Syndrome Advances" Cells (2021)
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