Emergency Referrals

How to refer to the National aHUS Service?

 

If you have a patient with a potential new diagnosis of aHUS, please call the Newcastle upon Tyne Hospitals switchboard on 0191 2336161 and ask for the on-call consultant for aHUS.

 

WHY REFER? PRIOR TO APPROVAL OF ECULIZUMAB FOLLOWING APPROVAL | FORMS | C3G REFERRAL

 

Why refer to the National aHUS Service?

The National aHUS Service offers a complete diagnostic toolkit to assess a potential new case of aHUS. This helps to rapidly and reliably exclude ADAMTS13 deficiency (TTP), STEC-HUS and other secondary causes of aHUS.

The National aHUS Service is then able to offer treatment to patients who are likely to have aHUS as early as clinically appropriate to maximise the chances of recovery of renal function.

 

Differentiating ADAMTS13 deficiency (and other causes of HUS)

When aHUS is suspected, the first critical diagnostic step is to exclude ADAMTS13 deficiency. We recognise the importance of prompt use of plasma exchange until ADAMTS13 deficiency has been excluded. To help reduce any diagnostic uncertain (often when ADAMTS13 deficiency has been excluded), we recommend all samples relating to the possible diagnosis of ADAMTS13 deficiency, STEC-HUS and complement-mediated aHUS are taken prior to plasma exchange.

We therefore encourage EARLY REFERRAL to the National aHUS Service to access our diagnostic toolkit (that includes 7-days a week ADAMTS13 testing) even before (though not delaying) ADAMTS13 testing and initial plasma exchange.

 

Timing of treatment with eculizumab

With respect to the timing of eculizumab in a possible case of aHUS, and prior to the exclusion of ADAMTS13 deficiency, our recommendations are in accordance with KDIGO guidelines:

● In adults, we recommend that plasma therapy is undertaken until ADAMTS13 deficiency has been reliably excluded.
● In children, it may be possible to commence eculizumab prior to the availability of the ADAMTS13 activity result.
● In all cases, early referral to the National aHUS Service allows timely clinical discussion, investigations and decision making.

Please note: The decision to initiate Eculizumab (following exclusion of ADAMTS13 deficiency) may be made prior to the availability of diagnostic tests that would support a diagnosis of STEC-HUS or a secondary TMA. A decision to await additional diagnostic tests before commencing eculizumab will depend on the clinical presentation with the ultimate aim to maximise clinical efficacy in patients who subsequently are confirmed to have primary complement mediated aHUS.

There is currently no evidence as to the efficacy of Eculizumab in STEC–HUS or secondary TMAs and consequently NHS England do not fund its use in this situation. Therefore in some cases where initial doses of eculizumab have been given, additional doses are not authorised once confirmation of an alternative diagnosis has been made.

 

WHY REFER? PRIOR TO APPROVAL OF ECULIZUMAB FOLLOWING APPROVAL | FORMS | C3G REFERRAL

 

Prior to the approval of Eculizumab.

As part of the assessment and approval process for funding of Eculizumab in a potential new case of aHUS, we will require a diagnostic checklist and a signed shared care protocol. Once the patient has been referred, complement profile testing and ADAMTS13 activity can be accessed from our combined aHUS lab diagnostics service in Newcastle.

Ideally all bloods relating to the possible diagnosis of ADAMTS13 deficiency, STEC and complement-mediated aHUS should be taken prior to plasma exchange.

Please note that our assay for ADAMTS13 activity testing is available 7 days a week allowing minimal delay to exclude ADAMTS13 deficiency prior to commencing eculizumab.

Additionally, STEC testing can be accessed.

All forms are available on our website on the following page

Please note that as of October 2017, approval for funding of Eculizumab will only be possible via Blueteq as mandated by NHS England.

 

WHY REFER? PRIOR TO APPROVAL OF ECULIZUMAB FOLLOWING APPROVAL | FORMS | C3G REFERRAL

 

Following approval of Eculizumab.

Key information at time of initial commencement of Eculizumab has been summarised.

Vaccination before Eculizumab can be given

● Vaccinate with a tetravalent (ACWY) vaccine and Bexsero (against serotype B).
● Prescribe prophylactic antibiotic for the duration of Eculizumab treatment.

Full advice on reducing the risk of meningococcal infection is available here.

Dosing of Eculizumab

Full dosing regimens are available in the eculizumab dosage section.

The initial dose only is summarised below. 

Initial Dose of Eculizumab

Adult dosing schedule

900 mg via 25-45 minute IV infusion

Paediatric dosing schedule

Patient body weight 40 kg or more

900 mg via 25-45 minute IV infusion

Patient body weight 30 kg to less than 40 kg

600 mg via 1-4 hour IV infusion

Patient body weight 20 kg to less than 30 kg

600 mg via 1-4 hour IV infusion

Patient body weight 10 kg to less than 20 kg

600 mg via 1-4 hour IV infusion

Patient body weight 5 kg to less than 10 kg

300 mg via 1-4 hour IV infusion