Hemolytic Uremic Syndrome Follow-up

Updated: Jun 25, 2019
  • Author: Sombat Muengtaweepongsa, MD, MSc; Chief Editor: Amy Kao, MD  more...
  • Print
Follow-up

Further Outpatient Care

Support groups for individuals with HUS have been formed. A British example is Hemolytic Uremic Syndrome Help (HUSH). This group may be contacted at PO Box 1303, Loxley, Sheffield, England S6 6YL.

Next:

Deterrence/Prevention

E coli–related HUS is a serious but almost entirely preventable disease.

Careful practices in slaughterhouses and the butcher shops can prevent the contamination of meat products.

Washing of other raw foodstuffs should substantially reduce risk of E coli entering the food chain.

Personal sanitation by food handlers reduces the risk of transferring E coli to foodstuffs, particularly raw meat.

Consumption of contaminated meat is the primary route by which children in developed nations acquire the organism.

If the aforementioned safeguards fail, adequate cooking of meat prevents children who are most subject to HUS from acquiring viable organisms.

Meat should be cooked to at least 70°C. Cooking that imparts a gray color to raw hamburger is not adequate.

E coli may also be acquired by bathing in contaminated lakes, rivers, or even swimming pools. This form of exposure may be more common in certain developing or impoverished areas of the world.

Previous
Next:

Complications

Although approximately 80–85% of patients who have acute renal failure with Stx-HUS recover function, 15–20% develop hypertension within 3–5 years after the onset of acute HUS.

Previous
Next:

Prognosis

Improved supportive therapy, including transfusion, dialysis, and careful management of fluids, electrolytes, and hypertension, has substantially reduced acute mortality from HUS.

Infants and children

The infantile form of HUS preceded by a viral prodrome, and usually associated with diarrhea, has a relatively good prognosis.

Childhood forms of HUS carried a 50% mortality risk half a century ago. Pooled data obtained since 1950 (chiefly consisting of E coli–related HUS) demonstrate that the overall risk for death or end-stage renal disease is about 12%, including 3–5% risk of death in the acute phase of illness. The inclusion of studies from a period prior to the development of current methods of neurologic and renal intensive care likely paint a poorer picture of outcome than is currently enjoyed by individuals with HUS. [83, 84, 3]

In children who develop HUS after a prodromal respiratory illness without GI disturbance, the prognosis is distinctly worse than that of children who develop HUS after a diarrheal prodrome.

Renal transplantation is necessary in severe HUS, which accounts for approximately 25% of all childhood cases.

Adults

Adult mortality in both the acute and chronic phases of illness are high, probably because adult HUS most often occurs as a complication of systemic illnesses that are more severe than those encountered in children with HUS.

Pooled data from 3476 cases of HUS followed up for a mean interval of 4.4 years showed a 12% risk of death or development of end-stage renal disease after the acute phase of HUS.

Risk factors for a worsened long-term outcome, particularly with E coli-related HUS, are the severity of the initial illness, the need for initial dialysis, and the presence of neurologic signs or complications.

S dysenteriae-related HUS poses a considerable risk of bacteremia or septic shock, DIC, and acute cortical necrosis of kidney. The overall mortality rate is at least 30%; the risk for end-stage renal disease is also high.

HUS-associated renal failure usually persists for several weeks.

About 30–50% of patients require dialysis, which indicates a worsened prognosis. [13]

Adult HUS, which constitutes a tiny minority of all cases of HUS, tend to result from a pathogenesis different from that of most childhood cases, and adult HUS may be relatively unresponsive to therapies effective in children. [12, 11]

Prognostic factors

Considerable interest is attached to the identification of reliable prognostic factors early in the course of HUS.

Such factors should be important in stratifying treatment groups to assess the effectiveness of various therapies.

Such factors might also permit the start of aggressive novel strategies early in the course of diseases with the poorest prognoses.

A review of 387 children with HUS greatly contributed to this important objective. [14]

  • About 60% of 276 subjects tested had Stx-E coli–related HUS. The age at onset, leukocyte count, and evidence of CNS involvement did not help in predicting the time to recovery.

  • The combined absence of prodromal diarrhea and/or of Stx toxin in stool was associated with worsened outcome. Only 34% of individuals who lacked both features recovered normal renal function, as compared with 65-76% of those who had 1 or both features.

  • For 118 patients followed up after postdiarrheal HUS with kidney transplantation, the recurrence rate was 0.8%; recurrence caused graft loss in a single patient.

  • Stx-E coli–related HUS had the lowest risk for graft loss of any HUS associated with end-stage renal disease.

  • For 63 patients with nondiarrheal HUS who had a kidney transplant without factor H deficiency, 21% had recurrence with graft loss.

  • Nearly 30% of 7 transplanted nondiarrheal cases with factor H gene mutations recurred.

In transplanted cases without factor H deficiency or genetic defect, low C3 levels may enhance risk for recurrence with graft loss.

Tacrolimus-associated HUS improves in only 45% of patients despite their receiving various combinations of treatment, including anticoagulation, antiplatelet therapy, dialysis, or plasma exchange, even when tacrolimus is replaced with cyclosporine.

Graft loss occurs in 25% of such cases and even in cases that receive a new allograft, HUS-related death occurs in approximately one third. If associated liver failure is present, 60% die. [56]

As disappointing as the various statistics might be, they are better than the recurrence risk for heritable adult HUS, which is about 60% for both autosomal recessive and autosomal dominant forms.

In nonindustrialized nations, dysentery due to S dysenteriae distinctly worsens the patient's prognosis for ensuing HUS. However, in industrialized nations, HUS occurring after a respiratory prodrome (which is often due to Diplococcus pneumoniae infection) distinctly worsens the prognosis.

Previous
Next:

Patient Education

Education about risks associated with exposure to Stx-elaborating infectious agents, such as E coli or S dysenteriae should reduce the risk for postinfectious HUS.

Previous