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Thrombotic microangiopathy - Symptoms
Last reviewed: 04.07.2025
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The symptoms of thrombotic microangiopathy are varied. They can be divided into three groups:
Symptoms of typical hemolytic uremic syndrome
Typical postdiarrheal hemolytic uremic syndrome is preceded by a prodrome, which manifests itself in most patients as bloody diarrhea lasting from 1 to 14 days (on average 7 days). By the time of admission to hospital, 50% of patients have already stopped having diarrhea. Most children experience vomiting, moderate fever, and may have intense abdominal pain, simulating the picture of an "acute abdomen". Following the diarrheal prodrome, an asymptomatic period of varying duration may occur.
Symptoms of hemolytic uremic syndrome are as follows: severe pallor, weakness, lethargy, oliguria, although in some cases diuresis does not change. Jaundice or skin purpura may develop.
Most patients develop oliguric acute renal failure, requiring treatment for glomerulonephritis in 50% of cases. However, cases with minor or no renal impairment have been described. The average duration of anuria is 7-10 days; a longer duration is prognostically unfavorable. Arterial hypertension develops in most patients, usually mild or moderate, disappearing by the time of discharge from the hospital. Urinary syndrome is represented by proteinuria not exceeding 1-2 g/day and microhematuria. Macrohematuria and massive proteinuria with the formation of nephrotic syndrome are possible. In most cases, severe hyperuricemia, disproportionate to the increase in creatinine and urea levels, is observed due to erythrocyte hemolysis. By the time of admission to the hospital, patients may be either dehydrated due to intestinal fluid loss or, more often, hyperhydrated due to anuria.
Hyperhydration and arterial hypertension in combination with severe anemia and uremia can be complicated by congestive circulatory failure.
CNS damage is observed in 50% of children with postdiarrheal hemolytic uremic syndrome and may manifest as seizures, drowsiness, visual impairment, aphasia, confusion, and coma. In 3-5% of cases, cerebral edema may develop. Neurological disorders may be caused by hyperhydration and hyponatremia that develop as a result of diarrhea. However, it is currently believed that these factors only aggravate microangiopathic brain damage.
Gastrointestinal tract damage in patients with hemolytic uremic syndrome develops as a result of severe microcirculatory disorders and may manifest itself as infarction or perforation of the intestine, intestinal obstruction. In some cases, severe hemorrhagic colitis may be complicated by rectal prolapse, which is a prognostically unfavorable factor. Hepatosplenomegaly is observed in 30-40% of patients, pancreatic damage with the development of diabetes mellitus in 20%, and in the most severe cases, organ infarction.
Rare symptoms of hemolytic uremic syndrome include damage to the lungs, eyes, and development of rhabdomyolysis.
Symptoms of atypical hemolytic uremic syndrome
Atypical hemolytic uremic syndrome often develops in adolescents and adults. The disease is often preceded by a prodrome in the form of a respiratory viral infection. Sometimes symptoms of gastrointestinal tract damage (nausea, vomiting, abdominal pain) are noted, but bloody diarrhea is not typical.
Symptoms of thrombotic thrombocytopenic purpura
Most patients with thrombotic thrombocytopenic purpura experience a single acute episode of the disease that does not recur after successful therapy, but chronic recurrent forms of thrombotic thrombocytopenic purpura have been increasingly observed recently. The acute episode is preceded by a prodrome, usually occurring as a flu-like syndrome; diarrhea is rare. Thrombotic thrombocytopenic purpura is characterized by high fever, skin purpura (in almost all patients), which can be combined with nasal, uterine, and gastrointestinal bleeding.
CNS damage is the dominant symptom of thrombotic thrombocytopenic purpura, observed in 90% of patients. At the onset of the disease, intense headaches, drowsiness, and lethargy are most often observed; disturbances of consciousness may occur, which are combined with focal neurological symptoms. Cerebral coma develops in 10% of patients. In most cases, these symptoms are unstable and disappear within 48 hours.
Kidney damage is manifested by moderate urinary syndrome (proteinuria no more than 1 g/day, microhematuria) with impaired renal function. Oliguric acute renal failure is rare, but some degree of renal failure is present in 40-80% of patients. In addition to damage to the central nervous system and kidneys, damage to the heart, lungs, pancreas, and adrenal glands may develop.