Hemolytic-uremic syndrome
ICD-10 D59.3 · ICD-11 3A21.2

When Plasma Exchange and Immunosuppression Fail in Anti-Factor H Antibody aHUS (Ages 5–15)

Clinical Scenario

This protocol addresses atypical hemolytic uremic syndrome (aHUS) caused by anti-factor H (FH) antibodies in children aged 5–15 years — a subtype that accounts for roughly half of all pediatric aHUS cases in some settings and requires a distinct treatment pathway.

Previous Treatment Did Not Achieve Goals

The first-line approach — prompt daily plasma exchange (PEX) with fresh frozen plasma combined with immunosuppression (prednisolone plus cyclophosphamide or rituximab) — targets a substantial reduction in anti-factor H antibody titers and full hematological remission: platelet count above 100,000/μl, schistocytes below 2%, and LDH normalisation on two consecutive days. When these goals are not met, escalation to a next-line agent is required.

Next-Line Treatment Approach

When PEX-based therapy does not achieve remission — or when specific clinical circumstances arise — a targeted complement inhibitor (a humanized anti-C5 monoclonal antibody) is the next intervention considered. The complete indications, management algorithm, and monitoring plan are set out in the full structured protocol.

Instant Access to Structured Evidence-Based Regimens

References

DOI: 10.1007/s00467-019-04233-7

Anti-FH antibody-associated illness constitutes ~ 50% of pediatric patients with aHUS in India, chiefly affecting children between the age of 5–15 years.
We recommend a combination of prompt PEX (with fresh frozen plasma as replacement fluid) and immunosuppressive therapy for patients with anti-FH antibodies.
We suggest therapy with eculizumab in the following: (i) lack of remission despite 7–10 PEX; (ii) life-threatening features (seizures, cardiac dysfunction); (iii) complications due to PEX or vascular access; and (iv) inherited defect in complement regulation.
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