Outcomes of Adult Dual Kidney Transplants by KDRI in the United States

UNOS guidelines provide inadequate discriminatory criteria for kidneys that should be transplanted as single (SKT) versus dual (DKT). We evaluated the utility of the kidney donor risk index (KDRI) to define kidneys with better outcomes when transplanted as dual. Using SRTR data from 1995 to 2010 of de novo KTX recipients of adult deceased‐donor kidneys, we examined outcomes of SKT and DKT stratified by KDRI group ≤1.4 (n = 49 294), 1.41–1.8 (n = 15 674), 1.81–2.2 (n = 6523) and >2.2 (n = 2791). DKT of kidneys with KDRI >2.2 was associated with significantly better overall graft survival [adjusted hazard ratio (aHR) 0.83, 95% confidence interval (CI) 0.72–0.96] compared to single kidneys with KDRI >2.2. DKT was associated with significantly decreased odds of delayed graft function (top 2 KDRI categories) and significantly decreased odds of 1‐year serum creatinine level >2 mg/dL (top 3 KDRI categories). Among SKT and DKT from KDRI >2.2 there were 16.1 and 13.9 graft losses per 100 patient follow‐up years, respectively. KDRI >2.2 is a useful discriminatory cut‐off for the determination of graft survival benefit with the use of DKT; however, the benefit of increased graft years was less than half of single kidneys from donors in the same KDRI range.     

Pretransplant anti-HLA-Cw and anti-HLA-DP antibodies in sensitized patients

We investigated the prevalence and the strength of anti-HLA-Cw and DP antibodies and clinical outcomes in kidney transplant recipients with isolated donor-specific anti-HLA-Cw antibodies. Patients on the waiting list were screened by Luminex single antigen beads (One Lambda). The strength of antibodies was determined by mean fluorescence intensity (MFI) values of the beads. Of the 1069 patients on the waiting list, 251 (24%) were sensitized with calculated panel reactive antibody >0%. The frequency and the median MFI values of anti-HLA antibodies to Cw (56%, 4955) and DP (35%, 2945) were lower than anti-HLA-A (79%, 10,194), B (86%, 11,235), DR (66%, 7866) and DQ (69%, 8283) (p<0.01). Among three major sensitizing events, only previous transplant was associated with development of all anti-HLA antibodies and history of pregnancy was associated only with development of anti-HLA-A antibodies. Eight patients with donor-specific anti-HLA-Cw antibodies received transplantation. During a median 6months of follow-up (range 3-24months), patient and graft survival was 100% without any acute rejection. In summary, the prevalence and the strength of anti-HLA-Cw and HLA-DP were lower compared to anti-HLA-A, B, DR, and DQ antibodies and previous organ transplantation was the main sensitizing event in our cohort of patients.     

Import kidney offers and DonorNet: a view from the trenches

Sokolich J, Magliocca J, Kayler LK. Import kidney offers and DonorNet: a view from the trenches.
Clin Transplant 2011: 25: 856–863. © 2010 John Wiley & Sons A/S. Abstract: The ability of DonorNet2007^® screening functions to expedite placement of locally rejected kidneys is unknown. We separately evaluated non‐mandatory share regional (n = 641) and national (n = 720) kidney offers to our center between 5/2007 and 2/2009 for cold ischemia time at offer (oCIT) with respect to candidate ranking to identify donor factors associated with early oCIT and assess the impact of screening functions. oCIT was <7 h after recovery in 83.2% of regional and 34% of national offers. Of national offers, donor characteristics significantly (p < 0.05) associated with oCIT less than median (10 h) were as follows: age <4 yr (vs. 4–35 yr), age >69 yr (vs. 60–69 yr), serum creatinine peak >2.0 and terminal >2.0 mg/dL, and glomerulosclerosis >15% (vs. 0–5%). The trend in early offers was predominantly attributed to greater proportions of pre‐recovery offers. Only one factor, age >69 yr, was significantly associated with proportionately more offers at low sequence numbers. Our data suggest an effect of age within DonorNet^® screening functions to reduce candidate list size and result in earlier offers. Shorter offer oCITs are otherwise occur largely because of pre‐recovery offers from donors with certain types of pre‐recovery characteristics.     

Single versus en bloc kidney transplantation from pediatric donors less than or equal to 15 kg

BACKGROUND: Kidney transplantation from small pediatric donors is being performed with increased frequency as single (SK) or en bloc (EBK) kidneys. METHODS: Between 2002 and 2006, 19 EBK and 14 SK transplants from pediatric donors less than or equal to 15 kg were performed. SK arterial anastomoses were performed to the aortic patch (n=8), aortic conduit (n=1), or renal artery orifice (n=5). RESULTS: En bloc kidney donors were on average younger (12+/-10 vs. 24+/-8 months, respectively; P=0.0102) and weighed less (10+/-3 vs. 13+/-3, respectively; P=0.0184). There were no differences between the two groups in recipient age, race, body mass index, degree of sensitization, retransplantation, and cold ischemia time; however, EBK recipients were somewhat better matched at the human leukocyte antigen DR locus (P=0.0515). Delayed graft function was more frequent in the SK group (25% vs. 0%; P=0.0542). Acute rejection occurred in 21% of recipients in both groups. Glomerular filtration rates were significantly higher with EBK than SK at 12-months posttransplantation. At 1 year, graft survival for SK and EBK was 86% and 79%, respectively (P=1.000). Graft thrombosis occurred in 0% (0/9) of SK recipients in which an aortic cuff or conduit was used, 40% (2/5) of SK recipients without an aortic cuff, and 5% (1/19) of EBK recipients (P=0.03). CONCLUSION: Short-term outcomes of kidneys from small pediatric donors are satisfactory when transplanted as SKs or en bloc; however, the absence of an aortic patch in SK transplantation is a risk factor for early thrombosis.     

Acute renal allograft rejection: diagnostic significance of focal peritubular capillary C4d

BACKGROUND: Focal PTC C4d staining in acute renal allograft rejection has not been studied extensively. METHODS: Renal allograft biopsies performed after October 2003, representing the first episode of acute rejection (AR) in recipients with > or = 12 months follow-up postbiopsy, were assessed for extent of C4d and correlated with morphology, ELISA screen, donor-specific antibodies (DSA), response to treatment, and outcome. RESULTS: In 106 biopsies (16 C4d-diffuse; 24 C4d-focal; 66 C4d-negative), there were no differences among the three groups in terms of timing or grade of AR, creatinine level, tacrolimus level, and grade of interstitial fibrosis/tubular atrophy or graft loss. The C4d-diffuse group was significantly associated with less tubulitis (P=0.0021), and more chronic allograft arteriopathy (P=0.0527). Incomplete response to steroid therapy was more frequent in C4d-diffuse/focal compared with negative cases (P=0.0492). DSA frequency within 1 year of AR was highest in the C4d-diffuse (94%), followed by C4d-focal (38%), and C4d-negative (17%) groups (P<0.0001). CONCLUSION: Focal PTC C4d was associated with circulating antibodies, with a 2-fold greater diagnostic sensitivity than negative C4d staining. The finding of diffuse C4d on follow-up biopsy was significantly associated with graft loss at 1 year, regardless of index biopsy C4d results.