Incidence, etiology, and significance of acute kidney injury in the early post-kidney transplant period.

Little is known about the incidence, causes, and significance of acute kidney injury (AKI) in the early transplant period. This study used a definition as >26 µmol/L increase in creatinine within 48 h or >50% increase over a period >48 h. In 326 adult consecutive recipients of a solitary kidney transplant from 2006 to 2014 followed at this center, 21% developed AKI within the first six months. Most etiologies were CNI toxicity (33%) or unknown (26%), whereas acute rejection accounted for 17% and urinary tract obstruction for 10%. Those with AKI had a significantly lower glomerular filtration rate (GFR) at one-yr post-transplant (adjusted beta coefficient -5.5 mL/min/1.73 m(2) , 95% CI: -10.4, -0.7, p = 0.025) in a multivariable linear regression model. However, the AKI definition missed 6 of 19 episodes of acute rejection and 4 of 10 episodes of urinary tract obstruction. When acute rejection (including those that did not satisfy AKI criteria) was included in the model, other causes of AKI were not significantly associated with GFR at year 1. Although AKI, using current criteria, is likely to be a significant predictor of later outcomes, important causes are missed and the criteria are not sensitive for clinical decision-making.

Contraindications to kidney transplantation: uneven grounds?

BACKGROUND: Determining eligibility for a kidney transplant is an important decision. Practice guidelines define contraindications to transplantation; however many are not evidence based. Canadian guidelines recommend that patients unlikely to survive the wait period not be evaluated. The purpose of this study was to evaluate what proportion of patients with a contraindication would survive the wait time. METHODS: Consecutive incident dialysis patients (January 2006 to December 2012) with a contraindication, defined using Canadian guidelines, were studied. Mortality rates were determined for each individual contraindication. Theoretical survival to the median wait time to transplantation was calculated. RESULTS: Of 746 incident patients, 435 (58 %) were deemed to have a contraindication at dialysis start. Nearly 80 % had a contraindication with a high mortality rate (dementia, multisystem disease, etc.). Patients with high mortality rates were less likely to survive the wait list than be transplanted. Patients with non-adherence, obesity, and potentially reversible disease had relatively low mortality rates, were more likely to survive, and possibly be transplanted at a time with the prospect of a better outcome. CONCLUSIONS: This study gives some credence that many patients with a contraindication are not likely to benefit. A better framework of defining contraindications is needed to allow better decision-making.

Gastrointestinal stromal tumour in a recipient with kidney transplantation.

Immunosuppression is associated with an increased risk of post-transplant malignancies. Gastrointestinal stromal tumours are the most common mesenchymal tumours of the gastrointestinal tract. However, they have seldom been reported recipient with transplantation. In this report, a 46-year-old woman, a recipient with kidney transplantation, who developed a gastric tumour is presented. Removal of this tumour required a partial gastrectomy. Histopathology and immunohistochemistry examinations revealed a high-risk gastric stromal tumour. Adjuvant imatinib mesylate treatment was initiated. There was no evidence of tumour recurrence at 12-month follow-up.

Access to kidney transplantation: outcomes of the non-referred.

BACKGROUND: There is a concern that some, especially older people, are not referred and could benefit from transplantation. METHODS: We retrospectively examined consecutive incident end stage renal disease (ESRD) patients at our center from January 2006 to December 2009. At ESRD start, patients were classified into those with or without contraindications using Canadian eligibility criteria. Based on referral for transplantation, patients were grouped as CANDIDATE (no contraindication and referred), NEITHER (no contraindication and not referred) and CONTRAINDICATION. The Charlson Comorbidity Index (CCI) was used to assess comorbidity burden. RESULTS: Of the 437 patients, 133 (30.4%) were CANDIDATE (mean age 50 and CCI 3.0), 59 (13.5%) were NEITHER (age 76 and CCI 4.4), and 245 (56.1%) were CONTRAINDICATION (age 65 and CCI 5.5). Age was the best discriminator between NEITHER and CANDIDATES (c-statistic 0.96, P <0.0001) with CCI being less discriminative (0.692, P <0.001). CANDIDATES had excellent survival whereas those patients designated NEITHER and CONTRAINDICATION had high mortality rates. NEITHER patients died or developed a contraindication at very high rates. By 1.5 years 50% of the NEITHER patients were no longer eligible for a transplant. CONCLUSIONS: There exists a relatively small population of incident patients not referred who have no contraindications. These are older patients with significant comorbidity who have a small window of opportunity for kidney transplantation.

Screening for proteinuria in kidney transplant recipients.

BACKGROUND: Proteinuria is a predictor of graft loss and death in kidney transplant recipients. This study examines the clinical significance of albumin-to-creatinine (ACR) and protein-to-creatinine (PCR) ratios compared with conventional dipstick measures of proteinuria. METHODS: At this single centre, 500 adult patients with a functioning kidney transplant > 4 months provided a urine sample for dipstick, ACR and PCR. The primary end point was defined as death-censored graft loss. Associations between proteinuria and graft loss were examined by concordance statistics and multivariate Cox models. RESULTS: There were 32 graft losses over a mean 2.98 years follow-up. PCR (c = 0.82, P < 0.001) and ACR (c = 0.83, P < 0.001) demonstrated similar concordance with events, and both scored higher than dipstick (c = 0.76, P < 0.001). ACR cut points of 30 and 300 mg/g for grading albuminuria were equivalent to 130 and 490 mg/g for PCR. Moderate grades of proteinuria by ACR and PCR were predicted of adverse events in a multivariate analysis. CONCLUSIONS: ACR and PCR are probably equivalent in predicting adverse events. Conventional dipstick is also predictive but does not appear to be as sensitive.

Cardiovascular outcomes in the outpatient kidney transplant clinic: the Framingham risk score revisited.

BACKGROUND AND OBJECTIVES: Cardiovascular disease is an important cause of morbidity and death in kidney transplant recipients. This study examines the Framingham risk score's ability to predict cardiac and stroke events. Because cyclosporine and tacrolimus have different cardiovascular risk profiles, these agents were also examined. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A prospective cohort evaluation of 540 patients were followed for a median of 4.7 yr in an outpatient kidney transplant clinic. Baseline Framingham risk scores were calculated and all cardiovascular outcomes were collected. RESULTS: Rates per 100 patient-years were 1.79 for cardiac and 0.78 for stroke events. The ratio of observed-to-predicted cardiac events was 1.64-fold higher [95% confidence interval (CI) 1.19 to 2.94] for the cohort, 2.74-fold higher (95% CI 1.70 to 4.24) in patients age 45 to 60 with prior cardiac disease or diabetes mellitus, but not higher in other age subgroups. Stroke was not increased above predicted. Risk scores for cardiac (c = 0.65, P = 0.003) and stroke (c = 0.71, P = 0.004) events were modest predictors. 10-yr event scores for cardiac (9.3 versus 13.5%, P < 0.001) and stroke (7.1 versus 10.0%, P = 0.002) were lower for tacrolimus compared with cyclosporine-treated patients. However observed cardiac events were higher in tacrolimus recipients (2.50, 95% CI 1.09 to 5.90) in an adjusted Cox model. CONCLUSIONS: Although risk scores are only modest predictors, patients with the highest event rates are easily identified. Treating high-risk patients with cardioprotective medications should remain a priority.