Mona D. Doshi

IL-18 and Urinary NGAL Predict Dialysis and Graft Recovery after Kidney Transplantation

Current methods for predicting graft recovery after kidney transplantation are not reliable. We performed a prospective, multicenter, observational cohort study of deceased-donor kidney transplant patients to evaluate urinary neutrophil gelatinase-associated lipocalin (NGAL), IL-18, and kidney injury molecule-1 (KIM-1) as biomarkers for predicting dialysis within 1 wk of transplant and subsequent graft recovery. We collected serial urine samples for 3 d after transplant and analyzed levels of these putative biomarkers. We classified graft recovery as delayed graft function (DGF), slow graft function (SGF), or immediate graft function (IGF). Of the 91 patients in the cohort, 34 had DGF, 33 had SGF, and 24 had IGF. Median NGAL and IL-18 levels, but not KIM-1 levels, were statistically different among these three groups at all time points. ROC curve analysis suggested that the abilities of NGAL or IL-18 to predict dialysis within 1 wk were moderately accurate when measured on the first postoperative day, whereas the fall in serum creatinine (Scr) was not predictive. In multivariate analysis, elevated levels of NGAL or IL-18 predicted the need for dialysis after adjusting for recipient and donor age, cold ischemia time, urine output, and Scr. NGAL and IL-18 quantiles also predicted graft recovery up to 3 mo later. In summary, urinary NGAL and IL-18 are early, noninvasive, accurate predictors of both the need for dialysis within the first week of kidney transplantation and 3-mo recovery of graft function.

Marked variation in the definition and diagnosis of delayed graft function: a systematic review

BACKGROUND The term delayed graft function (DGF) is commonly used to describe the need for dialysis after receiving a kidney transplant. DGF increases morbidity after transplantation, prolongs hospitalization and may lead to premature graft failure. Various definitions of DGF are used in the literature without a uniformly accepted technique to identify DGF. METHODS We performed a systematic review of the literature to identify all of the different definitions and diagnostic techniques to identify DGF. RESULTS We identified 18 unique definitions for DGF and 10 diagnostic techniques to identify DGF. CONCLUSIONS The utilization of heterogeneous clinical criteria to define DGF has certain limitations. It will lead to delayed and sometimes inaccurate diagnosis of DGF. Hence a diagnostic test that identifies DGF reliably and early is necessary. Heterogeneity, in the definitions used for DGF, hinders the evolution of a diagnostic technique to identify DGF, which requires a gold standard definition. We are in need of a new definition that is uniformly accepted across the kidney transplant community. The new definition will be helpful in promoting better communication among transplant professionals and aids in comparing clinical studies of diagnostic techniques to identify DGF and thus may facilitate clinical trials of interventions for the treatment of DGF.

Cardiovascular disease in kidney donors: matched cohort study

Objective To determine whether people who donate a kidney have an increased risk of cardiovascular disease. Design Retrospective population based matched cohort study. Participants All people who were carefully selected to become a living kidney donor in the province of Ontario, Canada, between 1992 and 2009. The information in donor charts was manually reviewed and linked to provincial healthcare databases. Matched non-donors were selected from the healthiest segment of the general population. A total of 2028 donors and 20 280 matched non-donors were followed for a median of 6.5 years (maximum 17.7 years). Median age was 43 at the time of donation (interquartile range 34-50) and 50 at the time of follow-up (42-58). Main outcome measures The primary outcome was a composite of time to death or first major cardiovascular event. The secondary outcome was time to first major cardiovascular event censored for death. Results The risk of the primary outcome of death and major cardiovascular events was lower in donors than in non-donors (2.8 v 4.1 events per 1000 person years; hazard ratio 0.66, 95% confidence interval 0.48 to 0.90). The risk of major cardiovascular events censored for death was no different in donors than in non-donors (1.7 v 2.0 events per 1000 person years; 0.85, 0.57 to 1.27). Results were similar in all sensitivity analyses. Older age and lower income were associated with a higher risk of death and major cardiovascular events in both donors and non-donors when each group was analysed separately. Conclusions The risk of major cardiovascular events in donors is no higher in the first decade after kidney donation compared with a similarly healthy segment of the general population. While we will continue to follow people in this study, these interim results add to the evidence base supporting the safety of the practice among carefully selected donors.

Short- and long-term outcomes with the use of kidneys and livers donated after cardiac death.

The shortage of deceased donor kidneys and livers for transplantation has prompted the use of organs from donors deceased after cardiac death (DCD). We used the UNOS database to examine patient and graft survival following transplantation of DCD organs compared to those following grafts from donors deceased after brain death (DBD; for livers, grafts from donors < 60 years old were labeled ‘< 60 yrs’). Of 44035 deceased donor kidney transplant recipients, 1177 (3%) received a DCD kidney. There was no difference in patient or graft survival at 5 years (DCD vs. DBD: 81.3% vs. 80.8% and 66.9% vs. 66.5%; p = 0.70 and p = 0.52 respectively). Of 24688‐deceased donor liver transplant recipients, 345 (1.4%) were from DCD donors and 20289 (82%) were from ‘< 60 yrs’ DBD donors. Three‐year patient and graft survival were inferior in the DCD group (DCD vs. ‘< 60 yrs’ DBD: 77% vs. 80% and 65% vs. 75%; p = 0.016 and p < 0.0001 respectively) but were comparable to current alternatives, ‘≥ 60 yrs’ DBD livers (donor age ≥ 60) and split livers. DCD livers are a reasonable option when death is imminent. Our study demonstrates good outcomes using DCD kidneys and livers and encourages their use.

Preliminary Experience With Cinacalcet Use in Persistent Secondary Hyperparathyroidism After Kidney Transplantation

Background. There is limited experience with the use of cinacalcet in the treatment of persistent secondary hyperparathyroidism after kidney transplantation. Methods. We retrospectively analyzed our experience in 18 renal allograft recipients who initiated cinacalcet therapy from 1 month to 23 years (median 3 years) posttransplantation and were maintained on the drug for 6 months. The daily dose was titrated from 30 mg up to a maximum of 180 mg to achieve a reduction in serum intact parathyroid hormone (PTH) levels. Results. Sustainable, significant decreases in mean calcium and alkaline phosphatase were noted at 1 month and intact PTH by 3 months, with 50% of patients achieving at least a 30% drop in PTH levels at 6 months. Serum phosphorous increased at 6 months, whereas urine N-telopeptides decreased. There were no significant changes in serum osteocalcin, albumin, and hemoglobin levels. We did not observe a tachyphylaxis phenomenon. Two patients reported occasional nausea, but did not require medication discontinuation. Estimated glomerular filtration rate did decrease progressively over the 6-month period. Conclusion. Cinacalcet appears to be an effective drug for the treatment of posttransplant hypercalcemia due to persistent secondary hyperparathyroidism. Further studies with more patients and longer follow-up will be needed to better elucidate the efficacy/safety profile for this agent, particularly with regard to long-term bone histology and renal outcomes.

Recipient risk factors associated with delayed graft function: a paired kidney analysis.

Background. Delayed graft function (DGF) is a common complication of deceased donor kidney transplantation that occurs because of a complex interplay between donor organ quality and the biologic milieu of the recipient. The purpose of the study is to better understand the recipient risk factors leading to DGF. Methods. We performed a retrospective cohort study using United Network for Organ sharing data and identified pairs of primary, adult kidney-only transplants that were procured from the same adult donor with discordant occurrence of DGF (i.e., one kidney of the pair had DGF). Results. A total of 5382 recipient pairs were analyzed. Recipients with DGF were more likely to be male (67% vs. 59%, P<0.01), African American (36% vs. 27%, P<0.01), obese (30% vs. 19%, P<0.01), diabetic (28% vs. 22%, P<0.01), on maintenance dialysis (92% vs. 83%, P<0.01), and to have longer wait-time (571 vs. 471 days, P<0.01), longer cold ischemia time (22 vs. 20 hr, P<0.01), and donor and recipient size mismatch (32% vs. 24%, P<0.01). Multivariable analyses confirmed these associations and identified panel reactive antibody more than 10% and low center volume as additional risk factors for DGF (odds ratio for panel reactive antibody >10%: 1.17, confidence interval 1.05–1.29, P<0.01; and odds ratio for <83 transplants/year: 1.29, confidence interval 1.17–1.44, P<0.01). Conclusions. After fully matching for donor factors, many recipient characteristics were noted to be associated with DGF. Better management of modifiable recipient and transplant risk factors such as obesity, wait time, and cold time may help to reduce the occurrence of DGF.

Preliminary experience with renal transplantation in HIV+ recipients: low acute rejection and infection rates.

Background. Only four centers have reported their results with renal transplantation in human immunodeficiency virus (HIV)+ recipients on highly active antiretroviral therapy, and acute rejection (AR) rates have consistently ranged from 43% to 67%. Methods. We examined the outcomes of eight adult HIV+ primary renal allograft recipients with median 15 (range 8–47) months follow-up with multiple other high-risk factors, including African American ethnicity, hepatitis C virus (HCV) positivity, long waiting times, prior sensitization, paucity of live donors, and delayed graft function. Our immunosuppressive protocol consisted of an anti-interleukin-2 receptor antibody for induction, and mycophenolate mofetil, cyclosporin A, and prednisone for maintenance. Initial and 3- to 6-month cyclosporin A trough level targets were 250 to 300 and 225 to 275 ng/mL, respectively, and mycophenolate mofetil dose was adjusted according to 2 to 4 week surveillance and subsequent as needed mycophenolic acid predose concentrations during the first 6 months. Results. Patient and graft survival were 100% and 88%, respectively, with an AR rate of 13% and excellent renal function. No patients developed new-onset diabetes, opportunistic or other serious infections, malignancy, or progression of hepatitis C virus-related liver disease. Excellent suppression of HIV replication with maintenance of CD4 counts was noted in all cases. Conclusions. Our findings suggest that HIV+ patients on highly active antiretroviral therapy can undergo successful renal transplantation with a low incidence of both AR and AIDS-associated and non-AIDS associated infections, despite associated risk factors for poorer outcome. Our encouraging but preliminary results with this protocol will need to be verified in larger numbers of HIV+ renal allograft recipients with longer follow-up.

Is Delayed Graft Function Causally Associated with Long-Term Outcomes after Kidney Transplantation? Instrumental Variable Analysis

Background Although some studies have found an association between delayed graft function (DGF) after kidney transplantation and worse long-term outcomes, a causal relationship remains controversial. We investigated this relationship using an instrumental variables model (IVM), a quasi-randomization technique for drawing causal inferences. Methods We identified 80,690 adult, deceased-donor, kidney-only transplant recipients from the Scientific Registry of Transplant Recipients between 1997 and 2010. We used cold ischemia time (CIT) as an instrument to test the hypothesis that DGF causes death-censored graft failure and mortality at 1 and 5 years after transplantation, controlling for an array of characteristics known to affect patient and graft survival. We compared our IVM results with a multivariable linear probability model. Results DGF occurred in 27% of our sample. Graft failure rates at 1 and 5 years were 6% and 22%, respectively, and 1-year and 5-year mortality rates were 5% and 20%, respectively. In the linear probability model, DGF was associated with increased risk of both graft failure and mortality at 1 and 5 years (P<0.001). In the IVM, we found evidence suggesting a causal relationship between DGF and death-censored graft failure at both 1 year (13.5% increase; P<0.001) and 5 years (16.2% increase; P<0.001) and between DGF and mortality at both 1 year (7.1% increase; P<0.001) and 5 years (11.0% increase; P<0.01). Results were robust to exclusion of lower quality as well as pumped kidneys and use of a creatinine-based definition for DGF. Conclusion Instrumental variables analysis supports a causal relationship between DGF and both graft failure and mortality.

Health insurance status of US living kidney donors

BACKGROUND AND OBJECTIVES Ensuring follow-up of living kidney donors (LKDs) is essential to long-term preventive care. We sought information on health insurance status of US LKDs, with particular attention to age, gender, and ethnicity. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS The United Network for Organ Sharing/Organ Procurement Transplantation Network database was queried for associations among age at donation, race, gender, and health insurance status. We studied all US LKDs between July 2004 and September 2006. RESULTS A total of 10,021 LKDs with known health insurance status were studied, 1765 (18%) of whom lacked health insurance at donation. There were 4852 donors without health insurance information. Younger kidney donors had higher rates of being uninsured (age 18 to 34: 26.2%; age 35 to 49: 15.2%; age 50 to 64: 11.2%; age >65: 3.8%; P < 0.0001), as did men (19.5 versus 16.3% for women; P < 0.0001), and ethnic minorities (white 13.4%, black 21%, Hispanic 35.6%, Asian 26.7%; P < 0.0001). CONCLUSIONS This study confirms that younger patients, ethnic minorities, and men are less likely to have health insurance when donating a kidney, which could negatively affect adherence to long-term follow-up.

Short‐Term Experience with Early Steroid Withdrawal in African‐American Renal Transplant Recipients

There are limited data on the results of early steroid withdrawal (ESW) in African‐American (AA) renal allograft recipients. We examined short‐term transplant outcomes in a retrospective, non‐concurrent cohort study of 40 AAs who did not (ESW group), and 33 who did [steroid maintenance (SM) group] receive maintenance steroids after day 4 post‐transplant. Patients received thymoglobulin (ATG) induction, mycophenolate mofetil, and tacrolimus or sirolimus. Data were analyzed using survival analysis methods and regression models. Patients in the ESW group were older, had lower current panel reactive antibody and fewer re‐transplants, and received fewer doses of ATG. One‐year graft survival and acute rejection (AR) rates were 100% and 13% in the ESW group and 97% and 15% in the SM group. After controlling for confounders, at 1 year, ESW was not associated with higher risk of graft loss, AR, or worse graft function, but was associated with less weight gain. The SM group had higher cholesterol levels at 3 months and higher risk of post‐transplant diabetes mellitus. We did not observe any cases of subclinical rejection. This study suggests that ESW under modern immunosuppression is safe over the short term in at least a subset of AA recipients with risk profiles similar to those studied herein, and could be associated with improved outcomes.