Influence of HLA-DQ Matching on Allograft Outcomes in Deceased Donor Kidney Transplantation.

BACKGROUND AND OBJECTIVES: HLA matching at the A, B, and DR loci influences the graft survival rate of deceased donor kidney transplants. The effect of HLA-DQB1 matching on transplant outcomes is still controversial. The aim of this study was to investigate the association of HLA-DQB1 matching with allograft outcomes in deceased donor kidney transplant recipients. METHODS: A retrospective analysis of deceased donor kidney transplant recipients between 2008 and 2014 at the Faculty of Medicine Ramathibodi Hospital, Bangkok, Thailand, was performed. Donor-recipient HLA matching at DQB1 locus was analyzed. The association between HLA-DQB1 mismatches and transplant outcomes was investigated using adjusted Cox regression analysis. RESULTS: A total of 383 deceased donor kidney transplants were performed during the study period, of which 297 with complete clinical and laboratory data were analyzed. The median follow-up time of all patients was 41 months (range, 16.4-65.6 months). Of the 297 recipients, 107 (36.03%) received 0 HLA-DQB1 mismatched kidneys and 190 (63.97%) received 1 or 2 HLA-DQB1 mismatched kidneys. Recipients who have received 1 or 2 HLA-DQB1 mismatched kidneys had a higher risk of acute rejection, with the adjusted hazard ratio of 4.35 (95% CI, 1.41-13.42; P = .01). However, HLA-DQB1 mismatching was not associated with chronic rejection and graft survival. CONCLUSION: Donor-recipient HLA-DQB1 mismatching is associated with acute rejection in deceased donor kidney transplants. However HLA-DQB1 mismatching does not have a negative impact on chronic rejection or graft survival.

Dual Kidney Transplantation: A Single-Center Experience in Thailand.

BACKGROUND: Dual kidney transplants (DKTs) from expanded criteria donors (ECDs) have been performed in our hospital since 2014. We needed to review our clinical outcome and update criteria to selected ECDs for DKTs. MATERIALS AND METHODS: Between January 2014 and December 2016, 4 DKTs and 269 deceased donor kidney transplants were performed. The outcome of DKTs was reviewed. The literature was reviewed for surgical technique and indication for DKT. RESULTS: Four DKTs were performed between 2014 and 2016. One-year graft survival rate was 100%. One patient developed delayed graft function. No morbidity or mortality occurred. CONCLUSIONS: DKTs in our center were safe and had good outcome with optimized selected criteria. DKT can improve the rate of kidney transplant in a developing country.

Successful Treatment of Anti-angiotensin II Type 1 Receptor Antibody-Associated Rejection in Kidney Transplantation: A Case Report.

Angiotensin II type 1 receptor (AT1R) antibody, a non-HLA antibody, has been found to have a detrimental effect on kidney allografts. Similarly to HLA antibodies, recipients who have AT1R antibodies are at risk for allograft rejection and poor long-term graft outcome. Besides mediating allograft rejections via direct effects on endothelial and vascular smooth muscle without complement activation, AT1R antibodies may lead to accelerated hypertension via the renin-angiotensin pathway. There has been no definite level of AT1R antibody that predicts allograft rejection. Because of a low incidence of AT1R antibody-associated rejection, there are few reports on specific treatment. The results of conventional treatment, which aims to remove these pathologic antibodies similarly to the treatment of HLA antibody-associated rejection, have been unsatisfactory. Some studies recommend using angiotensin receptor blocker to attenuate the adverse effects of AT1R antibody on kidney allograft. Herein we present a kidney transplant recipient with AT1R antibody-associated refractory allograft rejection who was successfully treated with the use of steroid, plasmapheresis, intravenous immunoglobulin, and rituximab.

Role of Pretransplant Complement-fixing Donor-specific Antibodies Identified by C1q Assay in Kidney Transplantation.

BACKGROUND: Kidney transplant recipients who have pretransplant donor-specific human leukocyte antigen (HLA) antibodies have greater risk for developing allograft rejection and allograft loss. However, there is a varied effect of graft injury among patients with pretransplantation donor-specific antibodies (DSA). The difference of complement activating ability may be the reason why some DSA are detrimental to kidney allograft. This study aimed to investigate the association between pretransplantation C1q-binding DSA and clinical outcomes. METHODS: This retrospective study included 48 pretransplant sera from kidney transplant recipients who had pretransplant DSA with negative complement-dependent cytotoxic (CDC) crossmatches. The IgG DSA testing and C1q testing were performed on a Luminex platform with single antigen bead assay. The clinical outcomes between C1q-positive and C1q-negative groups were compared. RESULTS: C1q-positive DSA were detected in 12 out of 48 patients (25%). The incidences of antibody-mediated rejection (AMR) were higher among patients with C1q-positive DSA than patients with C1q-negative DSA (66.7% vs 41.7%). Nevertheless, there were no statistically significant associations between C1q-DSA and AMR (odds ratio 2.8, 95% CI 0.68-11.6, P = .13) and between C1q-DSA and graft loss (odds ratio 0.52, 95% CI 0.09-2.89, P = .44). The C1q-positive DSA group had significantly higher IgG DSA MFI than the C1q-negative DSA group (P < .001). CONCLUSION: C1q-binding ability of DSA in pretransplant sera of kidney recipients was not associated with antibody-mediated rejection and graft loss post-transplantation. In contrast with the clinical relevance of C1q testing in the post-transplantation setting, C1q testing in pretransplant sera has limited use for immunological risk assessment.

Significance of HLA Antibody Detected by PRA-Bead Method in Kidney Transplant Outcomes.

BACKGROUND: The impact of specific HLA antibodies on the allograft function in the Luminex era is not clearly known. This study aimed to investigate kidney transplantation outcomes in patients with different anti-HLA antibody status as detected by Luminex PRA. METHODS: This retrospective study included 106 deceased-donor kidney transplantation (DDKT) patients divided into 3 groups by PRA status as detected by PRA-bead: (1) PRA = 0; (2) positive PRA but with negative antibody against donor's HLA antigens; and (3) positive PRA with positive anti-HLA antibody specificity against donor's HLA antigens. RESULTS: There were 65, 23, and 18 patients in groups 1, 2, and 3, respectively. Early allograft rejections were highest in group 3 (22.2%) (P = .02). In multivariate analysis, delayed graft function was the only factor that was associated with allograft rejection (hazard ratio, 8.9; 95% confidence interval, 1.9-39.8; P = .004). Estimated glomerular filtration rates at 1 year of the 3 groups were 54.6, 55.8, and 60.0 mL/min (P = .71). One-year allograft failure and death were not different among the 3 groups. Expanded-criteria deceased donors were associated with both allograft failure (P = .003) and patient death (P = .02). CONCLUSIONS: Anti-HLA antibody as detected by Luminex PRA was associated with early allograft rejection but not graft or patient survival. The effect of newer treatment modalities can improve the outcomes of PRA-positive patients to be similar to nonsensitized patients at 1 year.