Hemolytic Uremic Syndrome

Signs and symptoms

The classic childhood case of HUS occurs after bloody diarrheaa caused by E.Colii 0157,H7, a strain of EColi that expresses verotoxin (also called Shige,toxin. The toxin enters the bloodstream, attaches to renal endothelium and initiates an inflamatory reaction leading to acute renal failure (ARF) and DIC. The fibrin mesh destroys red blood cells and captures thrombocytes, leading to a decrease of both on full blood count. The usual age of onset is between 2 and adolescence.

HUS occurs after 2-7% of all E. coli O157:H7 infections.

Adult HUS has similar symptoms and pathology but is an uncommon outcome of the following: HIV; antiphospholipid syndrome (associated with Lupus erythematosis and generalized hypercoagulability); post partum renal failure; malignant hypertension ; scleroderma; and cancer chemotherapy (mitomycin, cyclosporine, cisplatin and bleomycin).

A third category is referred to as Familial HUS. It represents 5-10% of HUS cases and is due to an inheritied deficiency leading to uncontrolled complement system activation. Recurrent thromboses result in a high mortality rate.

Epidemiology

HUS has a peak incidence between 6 months and 4 years of age.

Diagnosis

Clinically, HUS can be very hard to distinguish from thrombotic, thrombocytopenic purpura (TTP). The laboratory features are almost identical, and not every case of HUS is preceded by diarrhea. The only distinguishing feature is that in TTP, neurological symptoms occur more often, but this is not always the case.

Treatment

Treatment is generally supportive with dialysis as needed. platelet transfusion may actually worsen outcome.

In severe cases or when there is diagnostic uncertainty between HUS and TTP, plasmopheresis is the treatment of choice.

Prognosis

With aggressive treatment > 90% survive acute phase. About 9% may develop end stage renal disease. About one-third of persons with hemolytic-uremic syndrome have abnormal kidney function many years later, and a few require long-term dialysis. Another 8% of persons with hemolytic uremic syndrome have other lifelong complications, such as high blood pressure, seizures, blindness, paralysis, and the effects of having part of their colon removed. The overall mortality rate from HUS is 5-15%. Older children and adults have a worse prognosis.

Impact on society

HUS and the E. coli infections which caused it have been the source of much negative publicity for the Food and Drug Adminstrationd (FDA), meat industries, and fast food restaurants since the 1990's, especially in the Jack In The Box contaminations. It was also featured in the Robin Cook novel Toxin. In 2006, an epidemic of harmful E. coli emerged in the United States due to contaminated spinach. 183 known cases have been reported, including 29 cases of HUS

Source:
Wikipedia

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Hemolytic Uremic Syndrome

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Pediatric GI HUS Hemolytic Uremic Syndrome|
Anemia Diarrhea bloody stools dialysis E.Coli OX 157