Hemolytic Uremic Syndrome Treatment & Management

Updated: Oct 30, 2019
  • Author: Sombat Muengtaweepongsa, MD, MSc; Chief Editor: Amy Kao, MD  more...
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Treatment

Medical Care

Management of HUS is supportive and chiefly involves dialysis for individuals with renal failure. Acute medical issues involve the management of renal failure and hypertension, the maintenance of fluid status in the face of renal failure, and the treatment of fever and catabolic status. Adult HUS and its underlying illnesses respond poorly to various forms of medical therapy.

Among the therapeutic options considered in adults are anticoagulation; antiplatelet or antioxidant agents; fibrinolytics; thrombolysis (with streptokinase); plasmapheresis and plasma exchange; and infusions of plasma, prostacyclin, or gamma globulin. [70, 71, 72] None of these approaches has been proven effective beyond excellent supportive care. Plasma manipulations do not appear to have the same degree of benefit in HUS as such manipulations have shown in TTP. [73] Among other forms of therapy that have been tried in adults, prednisone, azathioprine, vincristine, and intravenous immunoglobulin (IVIg) are the medications for which the evidence of efficacy is strongest.

Eculizumab

Eculizumab (Soliris) is the first treatment approved by the US Food and Drug Administration (FDA) (September, 2011) for adults and children with atypical hemolytic uremic syndrome (aHUS). Approval was based on data from adults and children who were resistant or intolerant to, or receiving, long-term plasma exchange/infusion. Data also included children (aged 2 mo to 17 y) who received eculizumab with or without prior plasma exchange/infusion. Eculizumab demonstrated significant improvement in platelet count from baseline (P = .0001). Thrombotic microangiopathy events were reduced, and maintained or improved kidney function was also reported. [74, 75, 76, 77]

Ravulizumab

Another monoclonal antibody against C5 component of the complement system is ravulizumab. In October 2019, FDA approved ravulizumab (Ultomiris) for the treatment of aHUS to inhibit complement-mediated thrombotic microangiopathy (TMA) in adult and pediatric patients aged 1 month and older.

Approved was based on data from 2 single-arm open-label studies that evaluated the efficacy of ravulizumab in patients with aHUS. Both ongoing pediatric (n=13) and adult (n=56) studies evaluated efficacy based on complete TMA response during the 26-week initial evaluation period, as evidenced by normalization of hematological parameters (platelet count and LDH) and ≥ 25% improvement in serum creatinine from baseline. Findings from each study demonstrated a complete TMA response in 71% of children and 54% of adults during the initial 26-week treatment period. Additionally, ravulizumab treatment resulted in reduced thrombocytopenia in 93% of children and 84% of adults; reduced hemolysis in 86% of children and 77% of adults; and improved kidney function in 79% of children and 59% of adults. [78]

Antibiotics

The value of antibiotics has been debated. Antibiotics may be required where sepsis or lung infections complicate HUS, as in HUS associated with S pneumoniae infection. In 1 study, antibiotic treatment in the acute enteric stage of E coli enteritis increased the risk for HUS 17-fold. [36] A meta-analysis did not show such an effect. In 1 adult with E coli O157:H7 bacteremia and urinary tract infection who developed HUS, both renal and hematologic abnormalities promptly improved with antibiotic treatment. Antibiotics may be lifesaving in patients with S dysenteriae–related HUS if started early enough. The treatment of sepsis associated with S pneumoniae HUS is similarly important.

Transfusion

Blood transfusion is required in as many as 70–90% of children with postinfectious HUS, particularly those with hemorrhagic colitis. Platelet transfusion is necessary in about 30% of children with HUS.

Although some regard platelet transfusions as dangerous in TTP, as many as 30% of patients with HUS receive platelet transfusions in addition to other supportive therapies.

Management of blood pressure

Blood pressure support is required for individuals who develop septic shock. Shock occurs in more than 30% of individuals with S dysenteriae–related HUS and in some patients with sepsis due to S pneumoniae–related HUS.

Arterial hypertension develops in two thirds of patients and is often severe. Arterial hypertension may lead to cardiac failure and pulmonary edema.

Management with antihypertensives may be important in the management of HUS-associated posterior leukoencephalopathy.

Plasma treatment

Plasma administration and manipulations appear to be less beneficial in HUS than in TTP.

Plasma treatment has been particularly advocated in HIV-associated HUS and in HUS occurring as a postpartum complication. It has been used in sporadic idiopathic non–Stx-HUS; HUS as a complication of antineoplastic, antiplatelet, or immunosuppressive drugs; and in sporadic or familial HUS associated with abnormalities of complement pathway regulatory proteins, such as factor H, membrane cofactor protein (MCP), and factor I.

Anticoagulation

Anticoagulation, which is sometimes attempted in adults with HUS, entails risk in children because childhood HUS is frequently complicated by both bleeding and hypertension. Where tried, anticoagulation does not appear to be beneficial, even when combined with oral antiplatelet agents. Indeed, heparin therapy may significantly increase mortality; [79, 80] therefore, this approach is probably contraindicated.

Adsorption

Investigations have been undertaken to evaluate the effectiveness of administering preparations containing inert adsorptive surfaces that can bind circulating verocytotoxin and thereby prevent their attachment to endothelial surfaces, where they can cause injury. SYNSORB-pk ingestion was among the first approaches tried. [21] Despite initial enthusiasm, this approach appears to have been abandoned. Other similar preparations have also been evaluated, but none have been effective. [81]

About one third of patients become anuric. In combination with their catabolic state, severe acidemic uremia may develop. Renal failure usually persists for several weeks, and 30–50% of patients require dialysis.

Angiotensin-converting enzyme (ACE) inhibitors used in the treatment of hypertension appear to have a beneficial effect on renal outcomes of postinfectious Stx–E coli HUS. [82]

Other medical therapies

Trials of gamma globulin are under way, with promising preliminary results. Findings suggest the possibility of some benefit in children.

Azathioprine and vincristine are potent drugs with potential benefit in the management of HUS. Their use falls beyond the scope of this review. Oncologists or others familiar with the use of these drugs should be consulted to review the emerging data about safety and efficacy in HUS and to discuss the risks and principles of management before these agents are administered.

About 25% of patients with HUS who develop neurologic complications (eg, seizures, stroke, coma) may require intensive care.

A small study in Germany used immunoadsorption to rapidly ameliorate severe neurological complications in patients with E Coli 0104:H4-induced HUS. [83] Of the 12 patients enrolled, 10 had total neurological and renal function recovery.

Anticonvulsant therapy may be required to control seizures.

HUS occurring in association with tacrolimus occasionally responds to lowering the dose.

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Consultations

Pediatric or adult renal specialists should be consulted to manage renal failure.

Pediatric or adult rheumatologists should be consulted in cases of HUS associated with neoplasia.

Pediatric or adult hematologists may be consulted for the diagnosis and management of hematologic aspects of HUS.

Pediatric infectious disease specialists may be consulted for the diagnosis and management of associated infectious illnesses.

Pediatric gastroenterologists may be consulted for the management of associated gastroenterologic disease.

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Diet

Special dietary consultation may be necessary to manage renal or gastroenterologic manifestations of HUS. In patients with renal failure, early reduction in protein intake appears to improve long-term renal outcomes.

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Activity

Individuals who are shedding infectious agents that elaborate Stx or who may spread other contagions should be restricted, as appropriate for the particular infectious agent.

No other specific limitations on activities are needed, except as indicated by the severity of disease and the patient's need for support. Therefore, activities should be advanced as tolerated.

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