Positive Crossmatch Kidney Transplant Recipients Treated With Eculizumab: Outcomes Beyond 1 Year

This study examined outcomes beyond 1 year in eculizumab‐treated (EC) positive crossmatch kidney transplants (+XMKTx) compared to a historical control group. +XMKTx received desensitization with either plasma exchange (PE) alone (N = 48) or PE and EC (N = 30). EC, given for at least 1 month, was continued in the setting of persistently high DSA (B flow cytometric crossmatch [BFXM] >200) including: 4 weeks (n = 14); 9 weeks (n = 6), 6 months (n = 2), and 12 months (n = 8). All patients had at least 2 years follow‐up. The incidence of acute clinical ABMR was lower in the EC group than controls (6.7% vs. 43.8% p 0, 26.7% versus 31.9% (p = 0.62), ptc score ≥ 2, 60.0% versus 60.0% (p = 1.00), or C4d + , 33.8% versus 13.5% (p = 0.08). A persistently high BFXM in EC‐treated patients was associated with cg score >0 at 1 year, while EC appeared to protect against cg if the BFXM remained low. We conclude that despite decreasing acute clinical ABMR rates, EC treatment does not prevent chronic ABMR in recipients with persistently high BFXM after +XMKTx. The authors report the later posttransplant histologic findings of protocol biopsies on positive crossmatch kidney transplant recipients who received eculizumab, a C5 inhibitor, as compared to a historical control group, and find overall similar rates of antibody‐associated chronic histologic changes in the two groups, particularly in patients with high posttransplant serum donor‐specific antibody levels. See editorial by Loupy et al on page 1139.