The CARI guidelines. Donors at risk: hypertension

No difference in follow-up estimated glomerular filtration rate between hypertensive and matched nonhypertensive kidney donors

BACKGROUND

According to current guidelines, kidney donor candidates with controlled hypertension using 1 or 2 antihypertensive drugs may be considered as donor. However, this recommendation is based on the study that antihypertensive drug was initiated in mainly "after donor registration" and this may be white-coat hypertension because of donation-related anxiety. We compared the follow-up eGFR between kidney donors with preexisting hypertension and matched nonhypertensive donors.

METHODS

This single-center retrospective study classified 97 living hypertensive donors previously receiving antihypertensive drugs into two groups: 1 drug group (61 donors) and 2 drugs group (36 donors). We compared the follow-up eGFR between each donor previously receiving antihypertensive drugs and three matched nonhypertensive donors in terms of age, sex, and follow-up duration.

RESULTS

At a mean (range) of 51 months (12-214) in the 1 drug group, and 54 months (12-175) in the 2 drugs group after donation, there was no significant difference in follow-up eGFR between hypertensive donors previously receiving antihypertensive drugs and matched controls in each group and in total donors. There was no difference in the incidence of the patients with follow-up eGFR<45mL/min/m2 in each group and their matched controls. Multiple linear regression analysis showed that baseline eGFR was the only independent predictor for the final follow-up eGFR in the total donors.

CONCLUSION

Our results support the current guidelines that donor candidates with controlled hypertension using 1 or 2 antihypertensive drugs may be considered as donors, and may increase the strength of this recommendation.

Respecting living kidney donor autonomy: an argument for liberalising living kidney donor acceptance criteria

Doctors routinely refuse donation offers from prospective living kidney donors with certain comorbidities such as diabetes or obesity out of concern for donor wellbeing. This refusal occurs despite the ongoing shortage of kidney transplants and the superior performance of living donor kidney transplants compared to those from deceased donors. In this paper, we argue that this paternalistic refusal by doctors is unjustified and that, within limits, there should be greater acceptance of such donations. We begin by describing possible weak and strong paternalistic justifications of current conservative donor acceptance guidelines and practices. We then justify our position by outlining the frequently under-recognised benefits and the routinely overestimated harms of such donation, before discussing the need to respect the autonomy of willing donors with certain comorbidities. Finally, we respond to a number of possible objections to our proposal for more liberal kidney donor acceptance criteria. We use the situation in Australia as our case study, but our argument is applicable to comparable situations around the world.

Practice Patterns in the Acceptance of Medically Complex Living Kidney Donors with Obesity, Hypertension, Family History of Kidney Disease, or Donor-Recipient Age Discrepancy

Background  To assess the practice patterns of the acceptance of medically complex living kidney donors (MCLKDs). Methods  We distributed a survey to nephrologists and transplant surgeons (TS) across the world through major international transplant societies. The survey contained questions regarding obesity, abnormal blood glucose profile, mild hypertension, donor-recipient age discrepancy, or family history of kidney disease of unknown etiology. Results  In total, 239 respondents from 29 countries (42% were nephrologists and 58% were TS). Most respondents would allow donations from obese donors, especially if they intended to lose weight but would be cautious if these donors had abnormal blood glucose or family history of diabetes mellitus. In hypertensive donors, future pregnancy plans mattered in decisions regarding the acceptance of female donors. Most respondents would allow young donors but would be more cautious if they had a future risk of hypertension or a family history of kidney disease of unknown etiology. They would also allow donations from an older person if prolonged waiting time was anticipated. We found multiple areas of consensus of practice among the diverse members of international transplant societies, with some interesting variations among nephrologists and TS. Conclusions  This survey highlights the practice patterns of the acceptance of MCLKDs among the international community. In the absence of clear guidelines, this survey provides additional information to counsel kidney donors with these conditions.

Long-Term Outcome of Live Kidney Donation in South Korea

Background

Kidney donors may be at increased risk for end-stage renal disease (ESRD) as well as cardiovascular and all-cause mortality. In particular, data on long-term safety after kidney donation in Asian populations are lacking. We aimed to assess the safety of live kidney donation in Korean donors by using a matched control group.

Material/Methods

We conducted a retrospective cohort study using a hospital-based database (Asan Medical Center, Seoul, Korea) and a control group from the national health insurance claims database in South Korea. We analyzed the health status of 1608 kidney donors who underwent donation between September 1990 and December 2015, and we compared their characteristics with those of matched 6426 non-donors (1: 4 ratio). We also measured the glomerular filtration rate (GFR) with ⁵¹Cr EDTA and urinary albumin excretion and assessed the prevalence of hypertension, diabetes, and general health status in 200 volunteer donors.

Results

Mortality was significantly lower in kidney donors compared with the matched controls (130.2 vs. 185.4 per 100,000 person-years, P=0.02). There was no significant difference in mortality if a donor had hypertension or was a current smoker at the time of donation. There was also no significant difference in ESRD (43.1 vs. 35.2 per 100,000 person-years, P=0.07) between the 2 groups regardless of hypertension and smoking status. Among the 200 donors with measured GFR, 11.5% had GFR values <60 ml/min/1.73 m² at 9.4±5.3 years after donation. Older age (P=0.001) and female sex (P=0.021) were significantly associated with GFR values <60 mL/min/1.73 m².

Conclusions

Mortality and ESRD were uncommon in carefully selected kidney donors. However, donors with pre-existing risk factors should be followed up more closely to ensure long-term safety.

Critical Appraisal of International Clinical Practice Guidelines in Kidney Transplantation Using the Appraisal of Guidelines for Research and Education II Tool: A Systematic Review

BACKGROUND

Although clinical practice guidelines (CPGs) are used for the development of local protocols in kidney transplantation (Ktx), the quality of their methodology is variable. This systematic review aimed to critically appraise international CPGs in all aspects of Ktx using the Appraisal of Guidelines for Research and Evaluation II tool.

METHODS

Clinical Practice Guidelines in Ktx and donation published between 2010 and 2017 were identified from MEDLINE, Embase, National Guideline Clearinghouse, National Health Service and National Institute for Health and Care Excellence Evidence Searches, and the websites of transplant societies. Using Appraisal of Guidelines for Research and Evaluation II, 3 appraisers assessed the quality of CPGs. Interrater reliability was measured using the intraclass correlation coefficient (ICC).

RESULTS

Searches identified 3168 records, and 115 CPGs were included. The highest scoring Appraisal of Guidelines for Research and Evaluation II domain was "scope and purpose" (80%; range, 30%-100%), followed by "clarity of presentation" (77%; range, 43%-98%), "editorial independence" (52%; range, 0%-94%), "rigor of development" (47%; range 6%-97%) and "stakeholder involvement" (41%; range, 11%-85%). The poorest scoring domain was "applicability" (31%; range, 3%-74%). Most CPGs were recommended for future use either with (63%) or without (18%) modifications. A small number (14%) were not recommended for future use or reviewers (5%) did not agree on recommending the CPG. The overall mean CPG quality score was 4 of 7 (range, 2-7). The mean ICC of 0.74 indicated substantial agreement between reviewers.

CONCLUSIONS

The quality of international CPGs in Ktx was variable, and most CPGs lacked key aspects of methodological robustness and transparency. Improvements in methodology, patient involvement, and strategies for implementation are required.

To Study the Impact of Donor Nephrectomy on Blood Pressure as Measured by Ambulatory Blood Pressure Monitoring and Renal Function

Prospective living kidney donors need meticulous evaluation prior to kidney donation. Ambulatory blood pressure monitoring (ABPM) is considered the reference standard for diagnosing hypertension. With no prior study available in India in this context, we undertook this study to evaluate the utility of ABPM in kidney donors and effect of donor nephrectomy on renal function. This was a prospective observational study involving healthy prospective kidney donors between 18 and 70 years with normal office blood pressure measurements (OBPM). Detailed clinical and biochemical parameters were recorded. OBPM and 24-hour ABPM was done preoperatively and 3 months following donor nephrectomy. There were 51 donors with a mean age of 46.1 ± 11.3 years, of which 40 (78.4%) were females. Preoperatively, three (5.8%) donors were hypertensive on ABPM but normal on OBPM (P = 0.08). Three months post nephrectomy, hypertension was present in seven (13.7%) donors by ABPM, while only two (3.9%) donors were diagnosed as hypertensive by OBPM (P = 0.02). Median pre-nephrectomy proteinuria was 70 mg (10 mg-180 mg) with a mean estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease (MDRD) formula of 86.86 ± 19.1 ml/min. Six donors developed >300 mg/day proteinuria, and 17 (33.3%) had a 24-hour urinary protein excretion greater than 150 mg/day. Mean serum creatinine (0.79 ± 0.11 vs 1.03 ± 0.16 mg/dl) significantly increased post donation, more so in donors >55 years of age (1.14 ± 0.25 mg/dl). Our study shows that in transplant donors, ABPM is better for diagnosing hypertension, which otherwise remains masked in 10% of the donors on routine OBPM. Significance of post-nephrectomy hypertension and increasing proteinuria needs further evaluation.

Optimizing Live Kidney Donor Workup: A Decision Analysis Approach

BACKGROUND

Screening potential live kidney donors is an intense process for both candidates and the healthcare system. It is conventionally implemented using a standard generic protocol. Efficiencies in this process could potentially be achieved using personalized protocols that are optimized for a given candidate. Aim: To create personalized protocols (by age, sex, and paired exchange status) and evaluate them relative to the standard generic protocol.

METHODS

Two personalized protocols were created. One sequenced tests according to probability (high to low) of excluding a given candidate. The other sequenced tests according to the expected cost (low to high) per exclusion. Test costs and exclusion probabilities were extracted predominantly from Australian sources. These were integrated into a decision analysis incorporating Markov processes. This estimated the expected financial cost and expected number of tests performed to exclude an ineligible candidate in the standard generic and personalized protocols.

RESULTS

The standard generic protocol consistently ranked poorest in terms of expected costs and expected tests per exclusion across all ages, sexes, and paired exchange status. Compared with the most efficient personalized protocol, the standard generic protocol was on average A$1767.49 more expensive and required 3.53 more tests.

CONCLUSIONS

Personalized protocols enhance the ability of a kidney transplant unit to effectively exclude live kidney donor candidates more quickly and cost effectively compared with the conventional standard generic protocol.

KDIGO Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors

The 2017 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors is intended to assist medical professionals who evaluate living kidney donor candidates and provide care before, during and after donation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach and guideline recommendations are based on systematic reviews of relevant studies that included critical appraisal of the quality of the evidence and the strength of recommendations. However, many recommendations, for which there was no evidence or no systematic search for evidence was undertaken by the Evidence Review Team, were issued as ungraded expert opinion recommendations. The guideline work group concluded that a comprehensive approach to risk assessment should replace decisions based on assessments of single risk factors in isolation. Original data analyses were undertaken to produce a "proof-in-concept" risk-prediction model for kidney failure to support a framework for quantitative risk assessment in the donor candidate evaluation and defensible shared decision making. This framework is grounded in the simultaneous consideration of each candidate's profile of demographic and health characteristics. The processes and framework for the donor candidate evaluation are presented, along with recommendations for optimal care before, during, and after donation. Limitations of the evidence are discussed, especially regarding the lack of definitive prospective studies and clinical outcome trials. Suggestions for future research, including the need for continued refinement of long-term risk prediction and novel approaches to estimating donation-attributable risks, are also provided.In citing this document, the following format should be used: Kidney Disease: Improving Global Outcomes (KDIGO) Living Kidney Donor Work Group. KDIGO Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors. Transplantation. 2017;101(Suppl 8S):S1-S109.

Risk-Factor Profile of Living Kidney Donors: The Australia and New Zealand Dialysis and Transplant Living Kidney Donor Registry 2004-2012

BACKGROUND

Recent literature suggests that living kidney donation may be associated with an excess risk of end-stage kidney disease and death. Efforts to maximize access to transplantation may result in acceptance of donors who do not fit within current guidelines, potentially placing them at risk of adverse long-term outcomes.

METHODS

We studied the risk profile of Australian and New Zealand living kidney donors using data from the Australia and New Zealand Dialysis and Transplant Living Kidney Donor Registry over 2004 to 2012. We compared their predonation profile against national guidelines for donor acceptance.

RESULTS

The analysis included 2,932 donors (mean age 48.8 ± 11.2 years, range 18-81), 58% female and 87% Caucasian. Forty (1%) had measured glomerular filtration rate less than 80 mL/min; 32 (1%) had proteinuria >300 mg/day; 589 (20%) were hypertensive; 495 (18%) obese; 9 (0.3%) were diabetic while a further 55 (2%) had impaired glucose tolerance; and 218 (7%) were current smokers. Overall 767 donors (26%) had at least one relative contraindication to donation and 268 (9%) had at least one absolute contraindication according to national guidelines.

CONCLUSIONS

Divergence of current clinical practice from national guidelines has occurred. In the context of recent evidence demonstrating elevated long-term donor risk, rigorous follow-up and reporting of outcomes are now mandated to ensure safety and document any change in risk associated with such a divergence.

Development of a Donor-Centered Approach to Risk Assessment: Rebalancing Nonmaleficence and Autonomy

Living kidney donors are often excluded from the shared decision making and patient-centered models that are advocated in medical practice. Thresholds for acceptable risk vary between transplant centers, and between clinicians and donors. Although donor selection committees commonly focus on medical risks, potential donors also consider nonmedical risks and burdens, which may alter their assessment of an acceptable level of medical risk. Thus, transplant centers may encounter ethical tensions between nonmaleficence and respect for donor autonomy. A donor-centered model of risk assessment and risk reconciliation would integrate the donor's values and preferences in a shared decision about their eligibility to donate. This paper argues for shifting to a donor-centered model of risk assessment, and presents a research agenda to facilitate the greater participation of donors in their own evaluation and approval processes.

Shifting paradigms in eligibility criteria for live kidney donation: a systematic review

As the organ shortage increases, inherently the demand for donor kidneys continues to rise. Thus, live kidney donation is essential for increasing the donor pool. In order to create successful expansion, extended criteria live kidney donors should be considered. This review combines current guidelines with all available literature in this field, trying to seek and establish the optimal extended criteria. Comprehensive searches were carried out in major databases until November 2013 to search for articles regarding older age, overweight and obesity, hypertension, vascular anomalies/multiplicity, nulliparous women, and minors as donors. Of the 2079 articles found, 152 fell within the scope of the review. Five major guidelines were included and reviewed. Based on the literature search, live kidney donation in older donors (up to 70 years of age) seems to be safe as outcome is comparable to younger donors. Obese donors have comparable outcome to lean donors, in short- and mid-term follow-up. Since little literature is available proving the safety of donation of hypertensive donors, caution is advised. Vascular multiplicity poses no direct danger to the donor and women of childbearing age can be safely included as donors. Although outcome after donation in minors is shown to be comparable to adult donors, they should only be considered if no other options exist. We conclude that the analyzed factors above should not be considered as absolute contraindications for donation.

Do multiple renal arteries in the remnant kidney have a negative influence on kidney donors after kidney donation?

AIM

To investigate whether the presence of multiple renal arteries in the remnant kidney has implications for lower renal function or increased incidence of hypertension.

METHODS

We reviewed the intraoperative and follow-up data of 101 live kidney donors who underwent nephrectomies at our institution. Sixty-nine donors (68.3%) had single artery in the remnant kidney (Group A), while 32 donors (31.7%) had multiple renal arteries in the remnant kidney (Group B). We compared the demographic and intraoperative data between the two groups. The follow-up data of donors in each group were divided into three subgroups based on the length of the follow-up period (12-24 months, 24-48 months and ≥48 months). Subgroups were created based on blood pressure and serum creatinine level. The δblood pressure (follow-up blood pressure minus preoperative blood pressure) and δserum creatinine (follow-up serum creatinine minus preoperative serum creatinine) in each subgroup in Group A were compared with the counterparts in Group B.

RESULTS

Renal arterial stenosis and calcification of renal arterial wall were not observed in all donors. There were no significant differences in the intraoperative characteristics (e.g. age, body mass index, operative duration and estimated blood loss) between the two groups. In addition, the blood pressure and serum creatinine level among subgroups within each group were similar. Furthermore, significant differences in δblood pressure and δserum creatinine were not observed between subgroups within the same follow-up period. Recipient survival rate and serum creatinine level were similar and acceptable in both groups.

CONCLUSIONS

The presence of multiple renal arteries in the remnant kidney does not have additional negative influence on kidney donors after kidney donation.