OPTN/SRTR 2020 Annual Data Report: Living Donor Collective

Abstract

The first successful solid organ transplant was a living donor kidney transplant in 1954. Since then, living donation has been an important source of organs for kidney and liver transplants in the United States. Unfortunately, the demand for organs has not kept pace with the supply, and unlike deceased donor transplant, there has been little growth in the number of living donor transplants over the past decade. To better understand possible barriers to living donation and long-term risks attributable to donation, the Health Resources and Services Administration (HRSA) directed the Scientific Registry of Transplant Recipients (SRTR) to establish a national registry of all living donor candidates and donors evaluated at US transplant programs to acquire lifetime follow-up information. Other goals include understanding the factors associated with candidate approval and variation in approval practices across centers. A pilot program was conducted from June 2018 through September 2020 to inform baseline data collection and registration processes. In September 2020, the registry began recruiting additional sites evaluating candidates for living donation. Here, we describe candidates registered at participating living donor kidney and liver programs, from June 2018 through the end of 2020. Not all programs submitted data throughout the whole period. Data for kidney and liver living donor candidates are presented separately.

Introduction

The Living Donor Collective (LDC) was established by the Scientific Registry of Transplant Recipients (SRTR) under the direction of the Health Resources and Services Administration (HRSA). The primary goals of the LDC are to better understand barriers to living donation and long-term outcomes of living donors. This chapter includes previously reported data from 2107 consecutive kidney donor candidates and 398 consecutive liver donor candidates from June 2018 to March 12, 2020^1,2 and extends data collection through December 31, 2020, adding 348 new kidney donor candidates and 163 new liver donor candidates.

Living Kidney Donor Candidate Reasons for Not Donating

Among 2455 kidney donor candidates, 1874 (76%) completed evaluations and were classified as approved or not approved. Of these, 970 (52%) were approved for donation (Figure LD 1). For 581 (24%), the outcome of the evaluation was undetermined at the time of analysis. One of the objectives of the LDC is to examine why some candidates who are evaluated do not proceed to donation. Programs can list multiple reasons for not donating.

The most common reason for not donating was medical risk, reported among 549 (47.5%) of those with one or more reasons for non-donation (Figure LD 2). The most common medical reason for not proceeding with donation was concern that the living donor candidate would develop chronic kidney disease based on the presence of kidney stones or low kidney function. Among those who declined to donate, concern for chronic kidney disease was reported in 141 (25.7%) (Figure LD 3). Concern about chronic kidney disease was followed in frequency by medical concerns such as hypertension in 134 (24.4%), obesity in 56 (10.2%), cardiovascular disease risk in 30 (5.5%), concerns about diabetes risk in 48 (8.7%), and other concerns in 140 (25.5%).

Psychosocial issues were listed as the reason for not donating in 163 (14.1%) of cases with one or more reasons (Figure LD 2). Psychosocial reasons for non-donation in those with one or more reasons for non-donation included psychosocial stressors in 54 (33.1%), psychiatric illness in 35 (21.5%), substance use disorder in 24 (14.7%), and other in 29 (17.8%) (Figure LD 4).

Decline by the living donor was reported by 148 (12.8%) of cases with one or more reasons for non-donation (Figure LD 2). Among those with candidate reasons for non-donation, candidate concerns included “undisclosed” reasons in 75 (50.7%), missed appointments in 53 (35.8%), concern about risk in 12 (8.1%), and family opposition in 8 (5.4%) (Figure LD 5).

Increased risk to the intended recipient was the reason for not donating in 114 (9.9%) of cases with one or more reasons for non-donation (Figure LD 2). Among those who declined based on concern about risk to the recipient, the reported concerns included anatomical reasons such as kidney cysts in 23 (20.2%), multiple renal arteries or veins in 23 (20.2%), and other in 68 (59.6%) (Figure LD 6).

A contraindication in the intended recipient was the reason for not donating in 108 (9.3%) of cases with one or more reasons for non-donation (Figure LD 2). Among those who did not proceed due to lack of sustained recipient need, the intended recipient received a deceased donor transplant in 53 (49.1%), became too ill or died in 30 (27.8%), or had other recipient-related reasons in 25 (23.1%) (Figure LD 7).

Living Kidney Donor Candidate Characteristics Associated with Donation Approval

Relationships of candidate characteristics with donation approval may suggest potential barriers to donation. Figures LD 10 - LD 28 display the distributions of candidate disposition (registered, approved, not approved) according to candidate characteristics.

Compared to registration levels across relationship categories, related people and spouses appeared somewhat more likely to be approved for donation (Figure LD 10). Distantly related people were approved less often than related ones.

• Registered donor candidates were most often ages 35 to 49 (36%) and 50 to 64 (32%), while 22% were 18 to 34, and 10% were 65 and older.

• Compared with registration levels across age-groups, those ages 18 to 34 were less likely than those 50 to 64 to be approved (Figure LD 11).

• Women were evaluated substantially more often than men (61% vs 39%). Women were also more likely than men to be approved for donation, relative to their evaluation rates (Figure LD 12).

• White individuals comprised 72% of evaluated candidates, while 28% were of other racial/ethnic groups. Compared with frequencies of evaluation, White candidates were more often approved than Black, Asian, and other race (Figure LD 13).

• Thirty-seven percent of evaluated candidates were single, while 62% were partnered. Compared with frequencies of evaluation, partnered candidates more often approved than singles (Figure LD 14).

• Fifty-eight percent of candidates had a college education, 19% had a graduate education, and 19% had a high school education or less. Candidates with college or postgraduate education were more often approved for donation than those with lower levels of education (Figure LD 15).

• Most candidates (88%) had health insurance at evaluation. Candidates with health insurance were slightly more likely to be approved than uninsured candidates (Figure LD 16).

• Most candidates (80%) were employed at evaluation, which was associated with slightly higher donation approval rates than unemployment (Figure LD 17).

• Less than a third (31%) of candidates reported having ever smoked cigarettes. Candidates who smoked cigarettes were less likely to be approved than non-smokers (Figure LD 18).

• Most candidates had an estimated glomerular filtration rate (eGFR) of 90 or higher (59%) or 60 to 90 mL/min/1.73m² (39%). Compared with registration rates, approval was more common in those with an eGFR of 60 to 90 than those with an eGFR of 90 mL/min/1.73m² or higher (Figure LD 19).

• Approval for donation was slightly lower in candidates with elevated total cholesterol, elevated LDL, low HDL and/or high triglycerides (Figure LD 20, Figure LD 21, Figure LD 22, and Figure LD 23).

• Most candidates (74%) had fasting glucose of less than 100 mg/dl, and these candidates were more likely to be approved for donation that those with higher fasting glucose levels (Figure LD 24).

• A minority of candidates (7%) had hypertension. While having a diagnosis of hypertension was not associated with relative frequency of approval (Figure LD 25), lower systolic (Figure LD 26) and diastolic blood pressure (Figure LD 27) were associated with approval for donation.

• Twenty-one percent of candidates had a BMI in the World Health Organization (WHO) obese range (30 to <35 kg/m²), and 4% were morbidly obese (BMI ≥35 mg/m²). Approval for donation was slightly less common among candidates with an obesity or morbid obesity (Figure LD 28).

Living Liver Donor Candidate Reasons for Not Donating

Among 561 liver donor candidates, 498 (89%) completed evaluations, and 254 (51%) of them were approved for donation (Figure LD 29). For 11% of candidates, the outcome of the evaluations was undetermined at the time of analysis.

The most common reason for not donating was medical risk to the donor, reported in 73 (24.2%) of those with one or more reasons for non-donation (Figure LD 30). Among potential donors who declined due to medical risk, liver steatosis was reported in 12 (16.4%), and concern about liver disease was reported in 14 (19.2%) (Figure LD 31). Other medical concerns included obesity in 14 (19.2%), diabetes or diabetes risk in 11 (15.1%), malignancy in 9 (12.3%), and other in 13 (17.8%).

Psychosocial issues were reported as the reason for not donating in 49 (16.2%) of cases with one or more reasons for not donating (Figure LD 30), including availability of another living donor candidate in 19 (38.8%), multiple psychosocial stressors in 6 (12.2%), psychiatric illness in 7 (14.3%), feeling conflicted or coerced in 11 (22.4%), or other reasons in 6 (12.2%), respectively (Figure LD 32).

Candidate-related reasons for not donating were indicated in 28 (9.2%) of those with one or more reasons for not donating (Figure LD 30), including undisclosed reasons in 21 (75.0%), missed appointments in 4 (14.3%), and other in 3 (10.7%) (Figure LD 33).

Increased risk to the recipient for not donating was reported in 62 (20.5%) of cases with one or more reasons for non-donation (Figure LD 30). Among those who declined based on concern about risk to the recipient, concerns included inadequate liver volume in 26 (41.9%), anatomic abnormalities in 16 (25.8%), and other reasons in 20 (32.3%) (Figure LD 34).

In the end the intended recipient did not need a living liver donor in 71 (23.5%) with one or more reasons for non-donation (Figure LD 30). Among those who did not proceed due to lack of sustained recipient need, the intended recipient received a deceased donor transplant in 42 (59.2%), died or became too ill for a transplant in 18 (25.4%), or other reasons in 11 (15.5%) (Figure LD 35).

Economic barriers were reported as the reason for not donating in 5 (1.7%) of cases with one or more reasons for not donating (Figure LD 30). Other reasons were reported in 14 (4.6%) (Figure LD 30).

Living Liver Donor Candidate Characteristics Associated with Donation Approval

The following candidate characteristics can provide clues to potential barriers to donation:

• Trends of the relationship between donor candidates and their intended recipients (Figures LD 36 and LD 37) were similar to those of all living liver donors in the United States in 2019 (Figure LI 54). Compared with registration levels across relationship categories, related and distantly related pairs appeared more likely to be approved for donation (Figure LD 38).

• Candidates were most often ages 18 to 34 (35%) and 35 to 49 (44%), while 21% were aged 50 and older. Relative to registration levels across age-groups, those age 18 to 34 were slightly less likely to be approved than those aged 35 to 49 (Figure LD 39).

• Women were evaluated more often than men (54% vs 46%) and were also more likely to be approved for donation, compared with their rates of evaluation (Figure LD 40).

• White individuals comprised 89% of evaluated candidates, while only 11% were of other racial/ethnic groups. Compared with their frequencies of evaluation, White candidates were more likely to be approved than Black and other race candidates (Figure LD 41).

• Forty percent of evaluated candidates were single, while 58% were partnered. There was no difference in approval proportions across marital status categories (Figure LD 42).

• Sixty-four percent of candidates had a college education, 18% had a graduate education, and 16% had a high school education or less. Candidates with a college education were more likely to be approved for donation than those less education (Figure LD 43).

• Most candidates (94%) had health insurance at evaluation. Approval did not vary appreciably by insurance status (Figure LD 44).

• Most candidates (85%) were employed at evaluation. Approval did not vary appreciably by employment status (Figure LD 45).

• Twenty-seven percent of candidates had ever smoked cigarettes. Compared with registration levels, nonsmokers had a modestly higher approval rate (Figure LD 46).

• Most candidates (91%) had a serum bilirubin level of 1.0 mg/dl or less. Those with higher levels of bilirubin were slightly less likely to be approved for donation (Figure LD 47)

• Most candidates with a serum glutamic-oxaloacetic transaminase (SGOT) (AST) level of 40 U/L or lower and a serum glutamic pyruvic transaminase (SGPT) (ALT) level of 56 U/L or lower were likely to be approved for donation (Figures LD 48 and 49).

• Most candidates (86%) reported an average alcohol intake of 0 to 6 drinks per week, which was associated with approval for donation more often that those with higher intake levels (Figure LD 50).

• Eighteen percent of candidates had a BMI in the World Health Organization obese range (30 to <35 kg/m²), and 3% were morbidly obese (≥35 mg/m²). Approval for donation was slightly less common among obese or morbidly obese candidates (Figure LD 51).

References

1. Kasiske BL, Ahn Y-S, Conboy M, Dew MA, Folken C, Levan M, Israni AK, Lentine K, Matas AJ, Newell KA, Lapointe Rudow D, Massie AB, Musgrove D, Snyder J, Taler S, Wang J, Waterman AD, on behalf of the Living Donor Collective participants. Outcomes of living kidney donor candidate evaluations in the Living Donor Collective pilot registry. Transplantation Direct 2021 May;7(5):e689. doi: 10.1097/TXD.0000000000001143.

2. Kasiske BL, Ahn Y-S, Conboy M, Dew MA, Folken C, Levan ML, Humar A, Israni AK, Lapointe Rudow D, Trotter, JF, Massie AB, Musgrove D, and the Living Donor Collective participants, Outcomes of living liver donor candidate evaluations in the Living Donor Collective pilot registry. Clinical Transplantation. 2021 Aug 3. https://doi.org/10.1111/ctr.14394.

Figure List

LDC

Figure LD 1. Overall kidney donor candidate registrations and decisions
Figure LD 2. Reasons for not donating among potential kidney donors registered with LDC
Figure LD 3. Detailed reasons for not donating among potential kidney donors who declined due to high medical risk
Figure LD 4. Detailed reasons for not donating among potential kidney donors who declined due to psychosocial reasons
Figure LD 5. Detailed reasons for not donating among potential kidney donors who declined due to candidate reasons
Figure LD 6. Detailed reasons for not donating among potential kidney donors who declined due to anatomical reasons
Figure LD 7. Detailed reasons for not donating among potential kidney donors who declined due to recipient reasons
Figure LD 8. Count of registered kidney donor candidates by relationship to recipient
Figure LD 9. Percent of registered kidney donor candidates by relationship to recipient
Figure LD 10. Proportion of kidney donor candidates approved by relationship to recipient
Figure LD 11. Living donor kidney candidates by age group and donation status
Figure LD 12. Living donor kidney candidates by sex and donation status
Figure LD 13. Living donor kidney candidates by race/ethnicity group and donation status
Figure LD 14. Living donor kidney candidates by maritial status and donation status
Figure LD 15. Living donor kidney candidates by education and donation status
Figure LD 16. Living donor kidney candidates by insurance and donation status
Figure LD 17. Living donor kidney candidates by employment and donation status
Figure LD 18. Living donor kidney candidates by cigarette use and donation status
Figure LD 19. Living donor kidney candidates by eGFR and donation status
Figure LD 20. Living donor kidney candidates by total cholesterol level and donation status
Figure LD 21. Living donor kidney candidates by LDL cholesterol level and donation status
Figure LD 22. Living donor kidney candidates by HDL cholesterol level and donation status
Figure LD 23. Living donor kidney candidates by triglyceride level and donation status
Figure LD 24. Living donor kidney candidates by fasting glucose level and donation status
Figure LD 25. Living donor kidney candidates by hypertension and donation status
Figure LD 26. Living donor kidney candidates by systolic blood pressure level and donation status
Figure LD 27. Living donor kidney candidates by diastolic blood pressure level and donation status
Figure LD 28. Living donor kidney candidates by BMI and donation status
Figure LD 29. Overall liver donor candidate registrations and decisions
Figure LD 30. Reasons for not donating among potential liver donors registered with LDC
Figure LD 31. Detailed reasons for not donating among potential liver donors who declined due to high medical risk
Figure LD 32. Detailed reasons for not donating among potential liver donors who declined due to psychosocial reasons
Figure LD 33. Detailed reasons for not donating among potential liver donors who declined due to candidate reasons
Figure LD 34. Detailed reasons for not donating among potential liver donors who declined due to anatomical reasons
Figure LD 35. Detailed reasons for not donating among potential liver donors who declined due to recipient reasons
Figure LD 36. Count of registered liver donor candidates by relationship to recipient
Figure LD 37. Percent of registered liver donor candidates by relationship to recipient
Figure LD 38. Proportion of liver donor candidates approved by relationship to recipient
Figure LD 39. Living donor liver candidates by age group and donation status
Figure LD 40. Living donor liver candidates by sex and donation status
Figure LD 41. Living donor liver candidates by race/ethnicity group and donation status
Figure LD 42. Living donor liver candidates by maritial status and donation status
Figure LD 43. Living donor liver candidates by education and donation status
Figure LD 44. Living donor liver candidates by insurance and donation status
Figure LD 45. Living donor liver candidates by employment and donation status
Figure LD 46. Living donor liver candidates by cigarette use and donation status
Figure LD 47. Living donor liver candidates by bilirubin level and donation status
Figure LD 48. Living donor liver candidates by SGOT (AST) level and donation status
Figure LD 49. Living donor liver candidates by SGPT (ALT) level and donation status
Figure LD 50. Living donor liver candidates by average alcohol drinks per week and donation status
Figure LD 51. Living donor liver candidates by BMI and donation status