Polyomavirus and cytomegalovirus infections are risk factors for grafts loss in simultaneous pancreas and kidney transplant

Risk of cytomegalovirus infection and subsequent allograft failure after pancreas transplantation

Cytomegalovirus (CMV) is a common cause of infection after transplantation, but few studies have evaluated its epidemiology, risk factors, and outcomes among pancreas transplant recipients. We performed a retrospective cohort study of adults who underwent pancreas transplantation from January 1, 2010, through December 31, 2020, at 3 sites in Arizona, Florida, and Minnesota. The primary outcome was clinically significant CMV infection (csCMVi), defined as CMV disease or infection requiring antiviral therapy. The secondary outcome was pancreas allograft failure. Among 471 pancreas transplant recipients, 117 (24.8%) developed csCMVi after a median of 226 (interquartile range 154-289) days. CMV donor (D)+/R- patients had a significantly higher incidence of csCMVi (hazard ratio [HR] 4.01, 95% confidence interval [CI] 2.10-7.64; P < .001). In adjusted analysis, a lower absolute lymphocyte count (ALC) was associated with a greater risk of csCMVi among seropositive recipients (HR 1.39 per 50% decrease, 95% CI 1.13-1.73; P = .002) but not among D+/R- patients (HR 1.04 per 50% decrease, 95% CI 0.89-1.23; P = .595). csCMVi, lower ALC, and acute rejection (P < .001) were independently associated with pancreas allograft failure. In conclusion, CMV D+/R- was associated with csCMVi in pancreas recipients, although ALC was associated with csCMVi only among seropositive patients. The development of csCMVi in pancreas recipients was associated with poor pancreas allograft outcomes.

Real world experience with conversion from valganciclovir to letermovir for cytomegalovirus prophylaxis: Letermovir reverses leukopenia and avoids mycophenolate dose reduction

PURPOSE

Valganciclovir (VGC) is the gold-standard for cytomegalovirus (CMV) prophylaxis (PPX) after solid organ transplant (SOT). Letermovir (LTV) was recently approved in high-risk kidney transplant and has reduced myelosuppressive toxicity. Conversion from VGC to LTV may be pursued in the setting of leukopenia. It is unknown if this strategy is effective.

METHODS

Adult patients receiving abdominal SOT were included if converted from VGC to LTV between January 1, 2018 and January 31, 2023. Primary objective was to describe the impact of LTV conversion as measured by WBC recovery, mycophenolate modification, and use of GCSF, and prophylaxis efficacy assessed by course completion and breakthrough DNAemia. Secondary objective was to evaluate rates of post-prophylaxis CMV.

RESULTS

Seventy five SOT recipients met inclusion criteria. Mean change in WBC in response to LTV conversion by day 14 was +2.02 ± 2.52 k/uL. 75%(56/75) of the population did not require mycophenolate adjustment or had their dose increased after conversion. GCSF was required in 38.7%(29/75) prior to conversion; only 21.3%(16/75) of patients required GCSF after conversion. Early termination was uncommon, 14.7%(11/75) stopped due to lack of ongoing insurance approval, only one patient stopped due to adverse effects (1.3%). One patient had clinically significant breakthrough (1.3%) that was successfully managed with VGC. Incidence of post prophylaxis CMV was 40%.

CONCLUSION

Withholding of VGC with LTV conversion may improve leukopenia without need for additional supportive measures. Most importantly, this strategy avoided additional mycophenolate modifications. In our study, LTV was associated with low rates of breakthrough. Post-prophylaxis CMV was similar to VGC prophylaxis.

A comprehensive update of the metabolic and toxicological considerations for immunosuppressive drugs used during pancreas transplantation

INTRODUCTION

Despite significant advancements in immunosuppressive regimens and surgical techniques, the prevalence of adverse events related to immunosuppression remains a major challenge affecting the long-term survival rates of pancreas and kidney allografts.

AREAS COVERED

This article presents a comprehensive review of the literature and knowledge (Jan/2012-Feb/2023) concerning glucose metabolism disorders and nephrotoxicity associated with tacrolimus and mammalian target of rapamycin inhibitors (mTORi). Novel signaling pathways potentially implicated in these adverse events are discussed. Furthermore, we extensively examine the findings from clinical trials evaluating the efficacy and safety of tacrolimus, mTORi, and steroid minimization.

EXPERT OPINION

Tacrolimus-based regimens continue to be the standard treatment following pancreas transplants. However, prolonged use of tacrolimus and mTORi may lead to hyperglycemia and nephrotoxicity. Understanding and interpreting experimental data, particularly concerning novel signaling pathways beyond calcineurin-NFAT and mTOR pathways, can offer valuable insights for therapeutic interventions to mitigate hyperglycemia and nephrotoxicity. Additionally, critically analyzing clinical trial results can identify opportunities for personalized safety-based approaches to minimize side effects. It is imperative to conduct randomized-controlled studies to assess the impact of mTORi use and steroid-free protocols on pancreatic allograft survival. Such studies will aid in tailoring treatment strategies for improved transplant outcomes.

Impact of Cytomegalovirus Infection and Disease on Graft Loss After Pancreas Transplantation: A Single-Institution Study in Japan

BACKGROUND

Cytomegalovirus (CMV) is one of the most frequent infections after pancreas transplantation (PTx), and it is unclear whether CMV infection is associated with pancreas graft loss. A limited number of studies about the relationship between CMV infection and pancreas graft loss have been reported from Western countries, but there have been no reports from Japan. This study investigated the relationship between CMV infection and pancreas graft loss after PTx in a single Japanese institution.

METHODS

This study included 58 patients who underwent PTx from deceased donors from April 2000 to March 2021 in our institution. We assessed pancreas graft loss based on CMV infection and disease and investigated the causes of graft loss, the time of onset of CMV disease, and the time of graft loss for each case.

RESULTS

The numbers of patients in the 4 categories of donor (D) and recipient (R) pretransplant anti-CMV antibody status were as follows: 4 (6.9%) in the D-/R- group, 6 (10.3%) in the D-/R+ group, 34 (58.6%) in the D+/R+ group, and 14 (24.1%) in the D+/R- group. Of the 58 patients, 74.1% and 44.1% received diagnoses of CMV infection and disease after PTx, respectively. There were no significant differences in the survival rates of pancreas graft loss stratified by CMV infection (P = .1809) or disease (P = .6241).

CONCLUSIONS

This study suggests that CMV infection and disease had no significant influence on pancreas graft loss in this Japanese institution.

Letermovir conversion after valganciclovir treatment in cytomegalovirus high-risk abdominal solid organ transplant recipients may promote development of cytomegalovirus-specific cell mediated immunity

PURPOSE

To evaluate the association of conversion from valganciclovir to letermovir on cytomegalovirus-specific cellular immunity.

METHODS

Adult patients were included if they received a kidney or liver transplant between 8/1/2018-12/31/20, developed symptomatic, high-level CMV viremia and were converted to letermovir 480 mg daily as monotherapy after treatment with ganciclovir-derivatives for a minimum of 4 weeks and had subsequent CMV cell-mediated immunity (CMI) testing via ICS assay by flow cytometry (Viracor Eurofins T Cell Immunity Panel).

RESULTS

Seven patients met inclusion criteria; 87.5% were male and recipients of a kidney transplant. All patients were CMV high risk (D+/R-). Mean time from transplant to CMV disease was 200 ± 91 days. Peak viral load (VL) during CMV treatment was 540,341 ± 391,211 IU/mL. Patients received a mean of 30 ± 24 weeks (range: 4-78 weeks) of therapy with ganciclovir-derivatives at induction doses prior to letermovir introduction. The median absolute lymphocyte count (ALC) at letermovir initiation was 400/μL (IQR 575) and the median VL was 51.6 (range: ND-490) IU/mL. Most patients (n = 5/7, 71.4%) experienced an increase in VL 1 and/or 2 weeks after conversion to letermovir. All patients had positive CMI per ICS assay after conversion. Patients received a mean of 10.3 ± 6.9 weeks of letermovir prior to having a positive result. Median ALC at positivity was 900/μL. Immunosuppression was not further reduced from initiation of letermovir to demonstration of CMV CMI. No patient had progressive replication or breakthrough disease while maintained on letermovir and three patients (42.9%) underwent antiviral withdrawal without recurrence at the last follow-up.

CONCLUSION

In this case series of abdominal transplant recipients with severe or persistent CMV infection, patients developed CMV-specific CMI after conversion to letermovir monotherapy. These data suggest that using letermovir in place of valganciclovir for secondary prophylaxis may address the lack of efficacy previously seen with this approach, as well as the issues that plague antiviral withdrawal with systematic monitoring. Future prospective studies are needed to evaluate this effect in a more controlled research environment with serial CMI testing to elucidate the optimal duration of letermovir when used in this way.