Thrombotic microangiopathy (TMA) arising in the context of lupus nephritis with normal ADAMTS13 activity presents a specific diagnostic and therapeutic challenge. When thrombotic thrombocytopenic purpura has been formally excluded, complement pathway activation emerges as the suspected underlying driver — requiring a targeted management strategy distinct from other TMA aetiologies.
This protocol applies when lupus nephritis is complicated by TMA and ADAMTS13 activity is within normal limits — making TTP an unlikely cause. In this setting, complement pathway activation is the suspected mechanism, consistent with complement-mediated haemolytic uraemic syndrome (CM-HUS). The approach described here is specifically indicated once TTP has been ruled out and this complement-mediated aetiology is being pursued, particularly in patients with significant kidney injury.
When complement pathway activation is the suspected underlying mechanism in this setting, management centres on targeted complement inhibition combined with initial high-dose immunosuppressive therapy. Observational evidence supports this approach, with complement inhibitor-based strategies showing particular promise in patients with pronounced kidney involvement.
Full agent selection, sequencing, dosing, and supporting measures are detailed in the structured protocol — access it below.
DOI: 10.1016/j.ard.2025.09.007