Diagnostic Tests

LES ASSOCIATIONS CLINIQUES

Complement Panel 5 evaluates both classical and alternative complement pathway involvement in thrombotic microangiopathy (TMA). This panel is particularly useful in identifying complement-mediated TMAs, such as atypical hemolytic uremic syndrome (aHUS), by assessing key functional and activation markers. AP50 and CH50 (CG50) provide functional insights into the integrity of the alternative and classical pathways, respectively, while mannose-binding lectin (MBL) adds additional perspective on the lectin pathway status. Soluble C5b-9 (sC5b-9) serves as a marker of terminal complement activation and systemic complement consumption. The detection of Factor H autoantibodies is especially important in aHUS, where this autoantibody is known to mediate dysregulation of the alternative pathway contributing to pathogenesis. Together, these markers aid in differentiating aHUS from other TMAs such as Thrombotic Thrombocytopenic Purpura (TTP) and Shiga toxin-associated HUS, as well as supporting the diagnosis, a guide to therapeutic decisions—particularly the use of complement inhibitors like eculizumab or ravulizumab—and allow for disease monitoring over time.