Use of mTOR inhibitor as prophylaxis for cytomegalovirus disease after kidney transplantation: A natural experiment

Evolving trends in immunosuppression use and cytomegalovirus infection risk over the past decade in kidney transplantation

BACKGROUND

The goal was to determine trends in immunosuppression use and its impact on cytomegalovirus (CMV) outcomes over the past 10 years.

METHODS

This was a single-center longitudinal cohort study of adult kidney recipients transplanted between Jan 2012 and June 2021. Baseline and follow-up data were gathered via chart abstraction and analyzed using univariate and multivariate analyses.

RESULTS

Of 2392 kidney transplants conducted, 131 patients did not meet inclusion criteria. The mean age was 52 years, 41% were female, 57% were black, and 19% were CMV high-risk. The use of rabbit anti-thymocyte globulin (RATG) induction (odds ratio [OR] 1.6, 1.3-2.1), tacrolimus (FK) level >8 ng/mL (OR 1.1, 1.09-1.11), CMV D+/R- rates (OR 1.06, 1.02-1.10), white blood cell count <3000 (OR 1.22, 1.18-1.26) and valganciclovir prophylaxis (OR 1.7, 1.6-1.9) have significantly increased over the past 10 years.  Rejection rates (OR 0.86, 0.82-0.91) and BK viremia >2000 (OR 0.91, 0.91-0.98) have decreased. RATG induction (adjusted hazard ratio [aHR] 1.35, 1.2-1.5), FK >8 ng/mL (aHR 3.5, 3.2-3.9), Belatacept conversion (aHR 2.5, 2.1-3.1), and rejection (aHR 1.8, 1.6-2.0) were significant risk factors for developing CMV infection, while mycophenolate mofetil <1500 mg (aHR 0.52, 0.47-0.59), mammalian target of rapamycin inhibitor (mTORi) conversion (0.77, 0.56-0.89), cyclosporine-A conversion (aHR 0.68, 0.56-0.84) were associated with lower risk of CMV infection.

CONCLUSION

Increasing use of potent immunosuppression coupled with higher CMV D+/R- F rates may be driving higher rates of CMV infection. Cyclosporine and mTORi conversion appears to be protective against CMV.  A more individualized immunosuppression regimen based on infection risk merits consideration.

Anti-CMV therapy, what next? A systematic review

Human cytomegalovirus (HCMV) is one of the main causes of serious complications in immunocompromised patients and after congenital infection. There are currently drugs available to treat HCMV infection, targeting viral polymerase, whose use is complicated by toxicity and the emergence of resistance. Maribavir and letermovir are the latest antivirals to have been developed with other targets. The approval of letermovir represents an important innovation for CMV prevention in hematopoietic stem cell transplant recipients, whereas maribavir allowed improving the management of refractory or resistant infections in transplant recipients. However, in case of multidrug resistance or for the prevention and treatment of congenital CMV infection, finding new antivirals or molecules able to inhibit CMV replication with the lowest toxicity remains a critical need. This review presents a range of molecules known to be effective against HCMV. Molecules with a direct action against HCMV include brincidofovir, cyclopropavir and anti-terminase benzimidazole analogs. Artemisinin derivatives, quercetin and baicalein, and anti-cyclooxygenase-2 are derived from natural molecules and are generally used for different indications. Although they have demonstrated indirect anti-CMV activity, few clinical studies were performed with these compounds. Immunomodulating molecules such as leflunomide and everolimus have also demonstrated indirect antiviral activity against HCMV and could be an interesting complement to antiviral therapy. The efficacy of anti-CMV immunoglobulins are discussed in CMV congenital infection and in association with direct antiviral therapy in heart transplanted patients. All molecules are described, with their mode of action against HCMV, preclinical tests, clinical studies and possible resistance. All these molecules have shown anti-HCMV potential as monotherapy or in combination with others. These new approaches could be interesting to validate in clinical trials.

Conversion to mTOR Inhibitor to Reduce the Incidence of Cytomegalovirus Recurrence in Kidney Transplant Recipients Receiving Preemptive Treatment: A Prospective, Randomized Trial

BACKGROUND

Although mammalian target of rapamycin inhibitors (mTORi) are associated with a lower incidence of the first episode of cytomegalovirus (CMV) infection/disease in kidney transplant recipients receiving calcineurin inhibitors (CNIs), the efficacy and safety of the conversion from the antimetabolite to an mTORi for the prevention of CMV recurrence are unknown.

METHODS

In this single-center prospective randomized trial, low-immunological-risk, CMV-positive kidney transplant recipients receiving preemptive therapy were randomized to be converted (sirolimus [SRL]) or not (control [CTR]) immediately after the treatment of the first episode of CMV infection/disease and were followed for 12 mo. A sample size of 72 patients was calculated to demonstrate a 75% reduction in the incidence of CMV recurrence (80% power, 95% confidence level).

RESULTS

Of 3247 adult kidney transplants performed between September 13, 2015, and May 7, 2019, 1309 (40%) were treated for the first CMV infection/disease, and 72 were randomized (35 SRL and 37 CTR). In the SRL group, there were no episodes of CMV recurrence, compared with 16 patients in the CTR group (0% versus 43%; P  < 0.0001). Four patients had a second and 1 a third recurrent CMV event. Three of them were converted to SRL and did not develop any further CMV events. There were no differences in the incidence of acute rejection, drug discontinuation, kidney function, and patient and graft survival at 12 mo.

CONCLUSIONS

These data suggest that, in CMV-positive kidney transplant recipients, the conversion from an antiproliferative drug to SRL after the first CMV episode is an effective and safe strategy for recurrent episodes.

Decreased incidence of acute rejection without increased incidence of cytomegalovirus (CMV) infection in kidney transplant recipients receiving rabbit anti-thymocyte globulin without CMV prophylaxis - a cohort single-center study

Induction therapy with rabbit anti-thymocyte globulin (rATG) in low-risk kidney transplant recipients (KTR) remains controversial, given the associated increased risk of cytomegalovirus (CMV) infection. This natural experiment compared 12-month clinical outcomes in low-risk KTR without CMV prophylaxis (January/3/13-September/16/15) receiving no induction or a single 3 mg/kg dose of rATG. We used logistic regression to characterize delayed graft function (DGF), negative binomial to characterize length of hospital stay (LOS), and Cox regression to characterize acute rejection (AR), CMV infection, graft loss, death, and hospital readmissions. Recipients receiving 3 mg/kg rATG had an 81% lower risk of AR (aHR 0.14 0.190.25 , P < 0.001) but no increased rate of hospital readmissions because of infections (0.68 0.911.21 , P = 0.5). There was no association between 3 mg/kg rATG and CMV infection/disease (aHR 0.86 1.101.40 , P = 0.5), even when the analysis was stratified according to recipient CMV serostatus positive (aHR 0.94 1.251.65 , P = 0.1) and negative (aHR 0.28 0.571.16 , P = 0.1). There was no association between 3 mg/kg rATG and mortality (aHR 0.51 1.253.08 , P = 0.6), and graft loss (aHR 0.34 0.731.55 , P = 0.4). Among low-risk KTR receiving no CMV pharmacological prophylaxis, 3 mg/kg rATG induction was associated with a significant reduction in the incidence of AR without an increased risk of CMV infection, regardless of recipient pretransplant CMV serostatus.

Longitudinal study on oral shedding of human betaherpesviruses 6 and 7 in renal transplant recipients reveals active replication

BACKGROUNG

Roseolovirus latency and persistence in salivary glands that are frequently reactivated after renal transplantation to cause infection have been reported. However, limited information is available on the persistence and excretion of HHV-6 and HHV-7 during and after transplant.

METHODS

32 renal transplant recipients were followed up before (T1) and after transplant (T2 and T3) and viral replication (via assessment of mRNA) in oral fluid samples investigated. Roseolovirus DNA was detected and quantified via multiplex qPCR. For evaluation of mRNA replication, positive samples were subjected to nested RT-PCR.

RESULTS

Viral replication of HHV-7 was significantly increased during T3 (72.9%), compared to the pre-transplant period T1 (25%; McNemar Test, p= 0.001). Analysis of the viral replicative to quantitative ratio disclosed ahigher number of DNA copies (>106) in positive cases of replication (p < 0.001). Astrong positive correlation (Spearman correlation coefficient = 0.781; p< 0.001) was evident between viral quantities of Roseoloviruses.

CONCLUSION

Our findings consistently suggest that the salivary gland is an important site of active and persistent infection by roseoloviruses. In view of the increasing problem of Roseoloviruses, pre- and post-transplantation, viral surveillance and monitoring of active replication are pivotal steps for effective screening and treatment of renal transplant patients.

Herpesviruses oral shedding and viremia in renal transplant recipients: A longitudinal study

BACKGROUND

The objective was to assess the oral shedding and viremia of human herpesviruses in renal transplant recipients.

METHODS

This is a cohort study in which the participants were examined in three different periods: the first within 24 hours before renal transplantation and the second and third ones 15-20 and 45-60 days after the transplantation. Mouthwash and blood samples were collected in each period and then submitted to screening for the presence of eight types of human herpesviruses by using multiplex PCR.

RESULTS

HSV-1 and EBV were more frequent in the saliva after renal transplantation, 15- to 20-day period after the transplant. EBV was found in the saliva of 26 (35.6%) patients before renal transplantation and in 56.2% and 46.6% of them, in the 15- to 20-day and 45- to 60-day periods after the transplant, respectively. High detection rates (75.3%-78.1%) were found for HHV-7 despite the lack of significant variations between the study periods. There was no concordance between herpesviruses oral shedding and viremia.

CONCLUSION

We concluded that the pattern of excretion of HSV-1 and EBV in saliva is changed immediately after renal transplantation, increasing in the 15- to 20-day period after the transplant surgery. No concordance between herpesviruses oral shedding and viremia was observed.