laboratory features
Last reviewed 08/2021
Haematological abnormalities:
- red cells:
- anaemia, usual values 7-9 gHb/dL
- fragmented red blood cells - schistocytes, helmet cells, triangle forms - in peripheral blood smear
- normocytic, normochromic
- marked reticulocytosis; occasional nucleated red cell
- haemolysis - increased serum indirect bilirubin, LDH, and serum haemoglobin; absent haptoglobin
- negative Coomb's test
- platelets - usually around 50x10^9/L - reduced by consumption in microthrombi
- leucocytes:
- neutrophil leucocytosis
- a poor prognosis is associated with leucocyte counts of greater than 20x10^9/L
- kaolin clotting time and prothrombin time are usually normal; a clotting abnormality is suggestive of septicaemia
Biochemical abnormalities:
- uraemia, out of proportion to the mild degree of apparent dehydration
- hyponatraemia is common, which may be a consequence of diarrhoea and vomiting, or a result of endothelial damage causing capillary leak.
- hypoalbuminaemia occurs in severe cases
Urine:
- generally HUS presents with oliguria but patients can present with polyuria - a proteinuria of typically, 1-2g of protein per day