In complement-driven thrombotic microangiopathies, failure to regulate complement activation leads to end-organ damage. The modified Ham (mHam) test measures complement-mediated killing of a nucleated cell in vitro but lacks a confirmatory assay and reliable positive controls. We demonstrate that C5b-9 accumulation on the surface of TF1 PIGAnull cells correlates with cell killing in the mHam. We also show that Sialidase treatment of cells or addition of Shiga toxin 1 to human serum serve as a more reliable positive control for the mHam than cobra venom factor or lipopolysaccharide. Simultaneously performing the mHam and measuring C5b-9 accumulation either in GVB⁺⁺ or GVB⁰ MgEGTA buffer with the addition of complement pathway specific inhibitors (anti-C5 antibody or a factor D inhibitor, ACH-145951) can be used to localize defects in complement regulation. As more targeted complement inhibitors become available, these assays may aid in the selection of personalized treatments for patients with complement-mediated diseases.

在补体驱动的血栓性微血管病中，未能调节补体激活会导致终末器官损伤。改良的火腿 (mHam) 测试在体外测量补体介导的有核细胞杀伤，但缺乏验证性分析和可靠的阳性对照。我们证明 TF1 PIGA无效细胞表面上的 C5b-9 积累与mHam 中的细胞杀伤相关。我们还表明，与眼镜蛇毒液因子或脂多糖相比，唾液酸酶处理细胞或向人血清中添加志贺毒素 1 作为 mHam 的更可靠阳性对照。同时执行 mHam 并测量 GVB ⁺⁺或 GVB ^{0 中的}C5b-9 积累添加了补体途径特异性抑制剂（抗 C5 抗体或因子 D 抑制剂，ACH-145951）的 MgEGTA 缓冲液可用于定位补体调节中的缺陷。随着更多靶向补体抑制剂的出现，这些检测可能有助于为补体介导的疾病患者选择个性化治疗。