Abstract
This cohort study investigates kidney transplant outcomes among undocumented immigrants at a single US center.
Whether undocumented immigrants should or should not be systematically granted access to the benefits of kidney transplant generates significant debate.1,2,3,4,5 Yet, little is known about undocumented immigrants’ actual transplant outcomes.1,5 Our study’s aim was to perform a granular single-center analysis of our program’s considerable long-term experience with a large cohort of predominantly adult undocumented immigrants to provide much needed data for public debate and policy making.
Methods
We identified 75 undocumented immigrants who underwent kidney transplant at our institution from January 2003 to July 2019. We excluded 2 recipients who never achieved graft function (1 graft with thrombosis and 1 with primary nonfunction). The study cohort thus included 73 recipients (68 adults, 5 adolescents). We assessed long-term outcomes and compared observed graft survival with the risk-adjusted expected individual graft survival (available for the 1-year mark) obtained from the Scientific Registry for Transplant Recipients. This study was approved by the UC Davis Institutional Review Board, and the study was considered exempt from informed consent.
Results
Of 73 included participants, 43 (59%) were male, and the median (range) age was 38.2 (13.6-69.9) years. All recipients were from Mexico, Central America, or South America; most had received a deceased donor graft (Table 1). Overall, with a median follow-up of 5.5 (1.1-17.3) years, we observed 7 graft losses (10%) (Table 2). Seven recipients (10%) were lost to follow-up (all with good graft function at last known contact). Graft survival at 8 years was 85.9% for deceased donor recipients and 100% for live donor recipients (Table 2). One-year observed graft survival was higher than the expected risk-adjusted 1-year Scientific Registry for Transplant Recipients graft survival for both deceased and live donor grafts (Table 2).
Table 1. Recipient Characteristics According to Donor Type.
| Characteristic | Kidney recipient group, No. (%) | |
|---|---|---|
| Deceased donor (n = 65) | Living donor (n = 8) | |
| Male | 38 (59) | 5 (63) |
| Female | 27 (41) | 3 (37) |
| Age, median (range), y | 38.4 (13.6-69.9) | 32.0 (20.5-50.5) |
| Pediatric recipient (<18 y) | 5 (8) | 0 |
| Age, median (range), y | 17 (13-17) | NA |
| Patient-reported country of origin | ||
| Mexico | 64 (98) | 6 (75) |
| Guatemala | 0 | 2 (25) |
| Ecuador | 1 (2) | 0 |
| Primary kidney disease | ||
| Diabetes | 14 (22) | 1 (13) |
| Hypertension | 10 (15) | 0 |
| IgA nephropathy | 4 (6) | 0 |
| Polycystic kidney disease | 3 (5) | 0 |
| FSGS | 6 (9) | 0 |
| Unknown | 22 (34) | 5 (63) |
| Other | 6 (9) | 2 (25) |
| Primary insurance | ||
| Public | 43 (66) | 8 (100) |
| Private | 21 (32) | 0 |
| Unknown | 1 (2) | 0 |
Abbreviations: FSGS, focal-segmental glomerulosclerosis; NA, not applicable.
Table 2. Posttransplant Outcomes According to Donor Type.
| Outcome | Kidney recipient group, No. (%) | |
|---|---|---|
| Deceased donor (n = 65) | Living donor (n = 8) | |
| Delayed graft function (dialysis within the first week posttransplant) | 20 (31) | 1 (13) |
| Follow-up time, median (range), y | 5.4 (1.1-3.7) | 9.7 (3.5-17.3) |
| Last known recipient status | ||
| Currently observed by our program | 53 (81) | 6 (75) |
| Lost graft | 7 (11) | 0 |
| Lost to follow-up | 5 (8) | 2 (25) |
| Time to loss to follow-up, median (range), y | 5.3 (1.5-10.7) | 7.1 (5.8-8.4) |
| Serum creatinine level at loss to follow-up, median (range), mg/dL | 1.0 (0.8-1.7) | 1.4 (1.2-1.7) |
| Graft losses | 7 (11) | 0 |
| Chronic rejection | 2 (26) | 0 |
| BK nephropathy | 2 (26) | 0 |
| Hyperfiltration injury | 1 (14) | 0 |
| Medication noncompliance | 1 (14) | 0 |
| Died with a functioning graft | 1 (14) | 0 |
| Time to graft failure, median (range), y | 4 (1-8) | NA |
| Observed graft survival (Kaplan-Meier), % | ||
| 1 y | 98.5 | 100 |
| 3 y | 95.1 | 100 |
| 5 y | 90.5 | 100 |
| 8 y | 85.9 | 100 |
| Expected SRTR risk-adjusted graft survival at 1 y, % | 95.7 | 97.2 |
Abbreviations: NA, not applicable; SRTR, Scientific Registry of Transplant Recipients.
SI conversion factor: To convert serum creatinine level to micromoles per liter, multiply by 88.4.
Discussion
Access to kidney transplant remains extremely limited for undocumented immigrants with end-stage kidney disease in the US owing to (1) limited or nonexistent financial coverage in many states, (2) concerns that the patients’ potential socioeconomic instability may impede follow-up care, and (3) allocation of a scarce resource to undocumented immigrants.2,3,4,5 But kidney transplant may be beneficial—both medically for the patients and socioeconomically for society—as a large proportion of undocumented immigrants currently rely on life-long emergency-only hemodialysis to treat their end-stage kidney disease.3,4,5
Therefore, little is known about transplant outcomes in undocumented immigrants.1,5 To our knowledge, this analysis constitutes the largest-published single-center experience (allowing for a more granular outcome analysis) and the only single-center analysis that includes adult recipients. Our cohort was younger (median age 38.2 years [13.6-69.9] ) than our center’s current overall recipient cohort (mean [SD] age, 50.3 [15.3] years)—consistent with the younger age of the immigrant population.6 None of the graft losses appeared to be directly attributable to documentation status or insurance coverage. Observed graft survival at the end of the critical first year posttransplant was higher than risk-adjusted expected survival. For the deceased donor recipients in our study, the 3-year graft survival (Kaplan-Meier) compared favorably with the 88.2% observed 3-year survival for our center’s overall adult deceased donor recipient cohort, and with the 87.5% deceased donor 3-year graft survival in the US.6 Our study recipients’ longer-term outcomes were excellent as well (Table 2).6 These excellent outcomes suggest that the undocumented status did not confer an increased graft loss risk. Yet, the fact that 10% of recipients were lost to follow-up warrants future—prospective—exploration.
The study’s limitations include its retrospective nature, the study population’s homogeneous geographic origin (potentially limiting applicability of our findings to other immigrant populations of differing ethnic and racial composition), and the overall lack of adequate controls for the unique socioeconomic-linguistic and access-to-care barriers faced by undocumented immigrants. Nonetheless, the highly encouraging outcomes—using standard selection and posttransplant care protocols—in this challenged recipient population strongly suggest that undocumented immigrant patients with end-stage kidney disease should not be precluded from consideration for kidney transplant based on immigration status alone. Additional studies are necessary to identify those at risk of dropout during follow-up and whether specialized protocols would benefit this unique population to further optimize posttransplant care and outcomes.
References
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