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Abstract: TH-PO828

Long-Term Outcome of Kidney Transplant Recipients with History of Complement-Mediated Thrombotic Microangiopathy

Session Information

Category: Transplantation

  • 2102 Transplantation: Clinical


  • Haq, Kanza, Johns Hopkins University, Baltimore, Maryland, United States
  • Dasgupta, Alana, The Ohio State University Wexner Medical Center, Columbus, Ohio, United States
  • Bagnasco, S.M., Johns Hopkins University, Baltimore, Maryland, United States
  • Maggiore, Umberto, Azienda Ospedaliero-Universitaria di Parma, Parma, Emilia-Romagna, Italy
  • Alachkar, Nada, Johns Hopkins University, Baltimore, Maryland, United States

The long-term outcome of kidney transplant recipients with history of complement-mediated thrombotic microangiopathy (cTMA) is unknown.


We retrospectively studied all kidney transplant recipients with TMA as primary disease or developed TMA post-transplant between Jan 2000 and Dec 2020 in our center. We estimated the crude survival probability via Kaplan-Meier methods starting at date of transplant until graft failure or death. The adjusted hazard ratio (aHR) associated with primary cTMA was estimated using Cox regression models with time-varying cTMA effect and biopsy diagnoses included as time-varying variables.


We identified 129 patients (20 with cTMA as primary disease) who had 460 biopsies. After a mean follow-up of 4.5 years, 73 started dialysis and 22 died. Compared to others, patients with cTMA were younger both at cTMA diagnosis and at transplantation (age at diagnosis, 28.9±16.3. vs 46.5±16.0 years; P<0.001). Crude survival probability is reported in Figure 1. After adjusting for non-linear age, sex, ethnicity, biopsy diagnoses, cTMA was associated with 4-fold increase in the hazard of transplant failure shortly after transplant (adjusted hazard ratio (aHR): 3.97 [95%CI:1.52-10.38; P=0.005]); then, the aHR decreased by 0.87 (95%CI: 0.77-1.00; P=0.046) per year elapsed since transplantation (Figure 2). Banff diagnoses were all associated with increased hazard of transplant failure: grade 1 & 2 TCMR, borderline rejection, and CNI-toxicity (P<0.05), and ABMR (P=0.077), the strength of their association with transplant failure not being affected by cTMA history (P=0.38 for interaction).


Patients with cTMA have an increased risk of early transplant failure which vanishes with time elapsed since transplant when standard Banff diagnoses seem to take over cTMA history in determining transplant prognosis.

Figure 1. Crude survival probability. Figure 2. Hazard ratio associated with cTMA as primary diagnosis.