Incidence of Subclinical Rejection and De Novo Donor Specific Antibodies in Calcineurin Sparing Regimens
Nephrology, Universidade Federal de São Paulo, São Paulo, Brazil
Pathology, Universidade Federal do Paraná, Curitiba, Brazil
Pathology, Universidade Federal de São Paulo, São Paulo, Brazil
Meeting: 2013 American Transplant Congress
Abstract number: 16
Introduction: The incidence and impact of subclinical acute rejection (SCR) and of emergence of donor specific antibodies (DSA) on renal graft function remains poorly understood, especially with calcineurin inhibitors (CNI) sparing strategies. This study analyzed the incidence of SCR and de novo DSA in low risk recipients of renal transplant receiving reduced tacrolimus(TAC) exposure, mycophenolate sodium(MPS) and steroid(ST) with planned conversion to sirolimus (SRL) at 3 months in a randomized fashion.
Methods: Protocol biopsies were performed before the conversion at month 3 (N= 149) and at month 24 (N= 127) and the histological findings were evaluated according to Banff 2007 criteria. C4d staining was performed in all graft biopsies samples and DSA were evaluated at month 24. Patients were divided into 3 groups: those converted to SRL (SRL Group, n= 49), those who remain TAC (TAC Group, n=50), and those without criteria for conversion (SF Group, n= 28).
Results: The mean age was 44.7±13.1 years, 47.7% Caucasian, 68.5 % male and 55% recipients of kidney transplants from living donors. At 3 months, mean TAC trough blood concentration was 5.9±2.4 ng/ml, mean MPS dose was 1384±191 mg/day, mean ST dose was 5.6±3.0 mg/day, and the incidence of SCR was 4.7% (N=7/149): 2 borderline changes; 3 IA; 3 IA and 1 IIA, and 1IIB. One patient had C4d staining positive, without rejection. At 24 months, mean creatinine was 1.3±0.4 in SRL group, 1.2 ± 0.3 in TAC group and 1.6 ± 0.7 in SF group. 2.3% patients presented SCR (3/127), all borderline changes, one episode in each group; 73 patients (57.5%) presented some degree of interstitial fibrosis/tubular atrophy (IFTA) and TAC group presented the lowest incidence of IFTA (65.3 vs. 44.0 vs. 67.9, p=0.046); C4d staining was positive in 2 patients in TAC group and 1 patient in SRL group; there were no differences between groups regarding DSA at month 24 (17.3 vs. 9.6 vs 13.5%, p =0.517); one patient in SRL group and 1 patient in TAC group had criteria for chronic antibody-mediated rejection.
Conclusions: These results showed low incidence of SCR in low risk kidney transplant recipients receiving low exposure of TAC and in those submitted to CNI-sparing regimen with SRL. The incidence of de novo DSA is apparently higher in the SRL group.
To cite this abstract in AMA style:
Sandes-Freitas T, Felipe C, Campos E, Soares M, Tedesco H, Franco M, Medina-Pestana J. Incidence of Subclinical Rejection and De Novo Donor Specific Antibodies in Calcineurin Sparing Regimens [abstract]. Am J Transplant. 2013; 13 (suppl 5). https://atcmeetingabstracts.com/abstract/incidence-of-subclinical-rejection-and-de-novo-donor-specific-antibodies-in-calcineurin-sparing-regimens/. Accessed May 14, 2025.« Back to 2013 American Transplant Congress