Subclinical Inflammation and Chronic Renal Allograft Injury in a Randomized Trial on Steroid Avoidance in Pediatric Kidney Transplantation

The BIOMARC Program for Personalized Medicine, California Pacific Medical Center Research Institute, Sutter Health Care, San Francisco, California, USA Department of Surgery, Stanford University Medical School, Stanford, CA, USA Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA Division of Pediatric Nephrology, Mattel Children's Hospital UCLA, Los Angeles, CA, USA Division of Pediatric Nephrology, University of Florida College of Medicine, Gainesville, FL, USA Department of Pediatrics, Harvard Medical School, Children's Hospital Boston, Boston, MA, USA Department of Pediatrics, University of California San Francisco (UCSF) Medical Center, San Francisco, CA, USA.
American Journal of Transplantation (Impact Factor: 5.68). 06/2012; 12(10):2730-2743. DOI: 10.1111/j.1600-6143.2012.04144.x
Source: PubMed


Steroid avoidance is safe and effective in children receiving kidney transplants in terms of graft function and survival, but the effects on allograft histology are unknown. In this multicenter trial, 130 pediatric renal transplant recipients were randomized to steroid-free (SF; n = 60) or steroid-based (SB; n = 70) immunosuppression, and underwent renal allograft biopsies at the time of graft dysfunction and per protocol at implantation and 6, 12 and 24 months after transplantation. Clinical follow-up was 3 years posttransplant. Subclinical acute rejection was present in 10.6% SF versus 11.3% SB biopsies at 6 months (p = 0.91), 0% SF versus 4.3% SB biopsies at 1 year (p = 0.21) and 0% versus 4.8% at 2 years (p = 0.20). Clinical acute rejection was present in 13.3% SF and 11.4% SB patients by 1 year (p = 0.74) and in 16.7% SF and 17.1% SB patients by 3 years (p = 0.94) after transplantation. The cumulative incidence of antibody-mediated rejection was 6.7% in SF and 2.9% in SB by 3 years after transplantation (p = 0.30). There was a significant increase in chronic histological damage over time (p < 0.001), without difference between SF and SB patients. Smaller recipient size and higher donor age were the main risk factors for chronic histological injury in posttransplant biopsies.

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Available from: Maarten Naesens, Nov 21, 2014
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    ABSTRACT: To determine whether steroid avoidance in pediatric kidney transplantation is safe and efficacious, a randomized, multicenter trial was performed in 12 pediatric kidney transplant centers. One hundred thirty children receiving primary kidney transplants were randomized to steroid-free (SF) or steroid-based (SB) immunosuppression, with concomitant tacrolimus, mycophenolate and standard dose daclizumab (SB group) or extended dose daclizumab (SF group). Follow-up was 3 years posttransplant. Standardized height Z-score change after 3 years follow-up was -0.99 ± 2.20 in SF versus -0.93 ± 1.11 in SB; p = 0.825. In subgroup analysis, recipients under 5 years of age showed improved linear growth with SF compared to SB treatment (change in standardized height Z-score at 3 years -0.43 ± 1.15 vs. -1.07 ± 1.14; p = 0.019). There were no differences in the rates of biopsy-proven acute rejection at 3 years after transplantation (16.7% in SF vs. 17.1% in SB; p = 0.94). Patient survival was 100% in both arms; graft survival was 95% in the SF and 90% in the SB arms (p = 0.30) at 3 years follow-up. Over the 3 year follow-up period, the SF group showed lower systolic BP (p = 0.017) and lower cholesterol levels (p = 0.034). In conclusion, complete steroid avoidance is safe and effective in unsensitized children receiving primary kidney transplants.
    Full-text · Article · Jun 2012 · American Journal of Transplantation
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    ABSTRACT: Monitoring of renal graft status through peripheral blood (PB) rather than invasive biopsy is important as it will lessen the risk of infection and other stresses, while reducing the costs of rejection diagnosis. Blood gene biomarker panels were discovered by microarrays at a single center and subsequently validated and cross-validated by QPCR in the NIH SNSO1 randomized study from 12 US pediatric transplant programs. A total of 367 unique human PB samples, each paired with a graft biopsy for centralized, blinded phenotype classification, were analyzed (115 acute rejection (AR), 180 stable and 72 other causes of graft injury). Of the differentially expressed genes by microarray, Q-PCR analysis of a five gene-set (DUSP1, PBEF1, PSEN1, MAPK9 and NKTR) classified AR with high accuracy. A logistic regression model was built on independent training-set (n = 47) and validated on independent test-set (n = 198)samples, discriminating AR from STA with 91% sensitivity and 94% specificity and AR from all other non-AR phenotypes with 91% sensitivity and 90% specificity. The 5-gene set can diagnose AR potentially avoiding the need for invasive renal biopsy. These data support the conduct of a prospective study to validate the clinical predictive utility of this diagnostic tool.
    No preview · Article · Oct 2012 · American Journal of Transplantation
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    ABSTRACT: Background: Subclinical antibody-mediated allograft rejection (AMR) has been characterized in serial biopsies from presensitized recipients but has not been systematically studied in conventional renal transplants. Methods: We evaluated 1101 consecutive kidney transplant biopsies (400 surveillance biopsies [SBx] and 701 for cause biopsies [FCBx]) with concurrent donor-specific antibody (DSA) studies, C4d staining, and ultrastructural examination. Results: A comparison of AMR-related features (DSA and DSA class, C4d staining, and microvascular injury) demonstrated that these were qualitatively and quantitatively associated with each other and with graft dysfunction. A major difference between SBx and FCBx was that the complete AMR phenotype was more common in FCBx. Among SBx, 8.5% showed complete or incomplete AMR with predominance of an incomplete phenotype (according to the Banff schema, these were acute AMR [23.5%], chronic active AMR [14.7%], suspicious for acute AMR [41.1%], suspicious for chronic active AMR [2.9%], and only microvascular injury insufficient to consider AMR [17.5%]). Persistence or worsening of AMR in a subsequent biopsy occurred in 38.2% of cases independently of the strength of AMR findings in the first biopsy (e.g., progression to chronic AMR occurred also in cases with suspicious or nondiagnostic findings). Temporal progression from subclinical to clinically evident AMR is consistent with the fact that, overall, the biopsies with incomplete phenotype (DSA±C4d) occurred between 14.52 and 20.86 months, whereas the complete phenotype occurred much later (36.71 months). Conclusion: An accurate diagnostic interpretation of the potentially important but incomplete, subclinical, AMR phenotype represents a serious challenge that may impact clinical management.
    Full-text · Article · Dec 2012 · Transplantation
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