FC002: Humoral and Cellular Immune Responses After a Three-Dose Course of Mrna-1273 Covid-19 Vaccine in Kidney Transplant Recipients: A Prospective Cohort Study

BACKGROUND AND AIMS

Seroconversion after a two-dose course of mRNA COVID-19 vaccination in kidney transplant recipients ranges between 30% and 50% in different series. We previously demonstrated that a substantial proportion of patients (35%) without a humoral response, develop a cellular response after the second dose assessed by the ELISpot technique. We aim to study the evolution of both humoral and cellular responses in the same cohort before and 1 month after the administration of the third dose of 100 mcg of mRNA-1273 COVID-19 vaccine.

METHOD

Final population included 129 KTRs studied at four time-points: at baseline before the first dose, after the second dose (median 42 days) and before (203 days) and after (232 days) the third dose. At all the time-points, IgG and IgM were assessed as well as N- and S-protein specific ELISpot. The main outcome was seroconversion after the third dose.

RESULTS

After the second dose, 26.7% of naïve cases experienced seroconversion. Before the third dose and in the absence of clinically evident COVID-19, this percentage increased to 61.9%. After the third dose, seroconversion was observed in 80.0% of patients. S-ELISpot positivity after the second dose was significantly associated with final seroconversion [OR (95% CI) 3.14 (1.10–8.96); P = .032], while transplantation < 1 year and previous kidney transplant were negatively associated with [OR (95% CI) 0.23 (0.07–0.80); P = .021 and OR (95% CI) 0.22 (0.06–0.78); P = .020, respectively). IgG after third dose were significantly higher (P < .001) in patients who maintained S-ELISpot positivity throughout the study (34.3%) and were correlated with S-spots after the second dose (r = 0.344, P < .001).

CONCLUSION

A substantial proportion of KTRs vaccinated with mRNA-1273 develops a late seroconversion after two doses and only a fifth remained seronegative after a third. Cellular immunity seems to play a major role in the development of a final strong humoral response.

FC 110: Survival Benefit of Preemptive Simultaneous Pancreas-Kidney Transplantation

BACKGROUND AND AIMS

The evidence regarding the benefits of performing preemptive SPK (pSPK) is controversial. The aim of the present study was to evaluate the impact of pSPK on long-term patient and grafts outcomes when compared with npSPK and pKTA through a national registry study with recipients reported to the Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) registry, and to analyse the potential benefits associated with pSPK not only in patients with T1D but also in patients with T2D.

METHOD

To explore the survival advantage of performing a pSPK, we compared the outcomes in pSPK with nonpreemptive SPK (npSPK) recipients between 2000 and 2017 from the OPTN/UNOS registry. To account for the potential benefit provided solely by the kidney transplant, we further compared to recipients of preemptive Kidney Transplantation Alone (pKTA) with diabetes. A propensity score analysis was applied.

RESULTS

A total of 1522 patients received a pSPK, 7894 an npSPK and 3343 a pKTA. Overall recipient survival was superior for the pSPK group when compared with the pKTA (97.7%, and 80.9% versus 97.7% and 72.9% at 1 and 10 years, respectively, P < 0.001), with pKTA being associated with an increased risk of patient death [HR 1.34, 95% confidence interval (95% CI) 1.10–1.63; P = 0.003]. Estimated kidney graft survival was similar in both groups. After IPTW adjustment, pKTA was significantly associated with an increased risk of death-censored kidney graft failure (HR 1.31, 95% CI 1.09–1.56; P = 0.002). The npSPK patients presented both worse patient and kidney graft survival when compared with pSPK.

CONCLUSION

In conclusion, the observed survival benefit of performing an SPK preemptively reinforces the need for early referral for transplantation in patients with insulin-dependent diabetes and advanced chronic kidney disease.

MO929KIDNEY TRANSPLANTATION IN MONOCLONAL IMMUNOGLOBULIN DEPOSITION DISEASE: A REPORT OF 6 CASES

Background and Aims

Monoclonal immunoglobulin deposition disease (MIDD) is a systemic rare condition that usually leads to end stage renal disease. Treatment of patients with a bortezomib-based regimen followed by autologous stem cell transplantation (ASCT) has been increasingly used, with improvements in the response rates and the renal graft outcomes in kidney transplant recipients

Method

Retrospective study of 6 patients diagnosed of MIDD with complete response but not renal response after hematologic treatment that underwent kidney transplant in our institution between 2010 and 2019.

Results

A total of 6 patients (5 women) were analyzed, with mean age at diagnosis of 47 years (range 40-53). At presentation their mean eGFR was 18 mL/minute (range 9-25) and mean proteinuria of 5.5 g (range 0.290-12.5). The deposit was kappa type except in 1 case (heavy and light lambda type chains). In all of them there was an absence of monoclonal component in blood and urine but positive immunofixation in 5 cases (2 only in urine). 3 started chronic hemodialysis during admission and the others at 3, 5 and 44 months after diagnosis. As hematological treatment, all received bortezomib followed by ASCT, being under complete hematological response at the time of kidney transplant. It was performed at 28 months on average from ASCT (range 11-42), with mean kappa/lambda ratio of 2.6 (range 1.33-3.75). 3 patients received induction with thymoglobulin and 3 with basiliximab, followed by triple therapy with tacrolimus + prednisone + mTOR inhibitor (4 patients) or mycophenolate (2 patients). During a median follow-up of 20,5 months from kidney transplant and 54 months from ASCT, 1 patient experienced hematologic relapse and 2 had hematologic progression (one of them with MIDD relapse in the allograft) requiring treatment. The patient with organ relapse received Daratumumab monotherapy achieving complete hematologic response but graft failure. The other 5 patients had functional graft with median serum creatinine 1.68 mg/dl.

Conclusion

In patients with MIDD and sustained complete hematologic response, a kidney transplant can be considered. The optimal approach to treatment of hematologic relapse or recurrence of MIDD after kidney transplant remains to be determined