Incidence and outcomes of fever of unknown origin after kidney transplant in the modern era.

BACKGROUND: While presumably less common with modern molecular diagnostic and imaging techniques, fever of unknown origin (FUO) remains a challenge in kidney transplant recipients (KTRs). Additionally, the impact of FUO on patient and graft survival is poorly described. METHODS: A cohort of adult KTRs between January 1, 1995 and December 31, 2018 was followed at the University of Wisconsin Hospital. Patients transplanted from January 1, 1995 to December 31, 2005 were included in the "early era"; patients transplanted from January 1, 2006 to December 31, 2018 were included in the "modern era". The primary objective was to describe the epidemiology and etiology of FUO diagnoses over time. Secondary outcomes included rejection, graft and patient survival. RESULTS: There were 5590 kidney transplants at our center during the study window. FUO was identified in 323 patients with an overall incidence rate of .8/100 person-years. Considering only the first 3 years after transplant, the incidence of FUO was significantly lower in the modern era than in the early era, with an Incidence Rate Ratio (IRR) per 100 person-years of .48; 95% CI: .35-.63; p < .001. A total of 102 (31.9%) of 323 patients had an etiology determined within 90 days after FUO diagnosis: 100 were infectious, and two were malignancies. In the modern era, FUO remained significantly associated with rejection (HR = 44.1; 95% CI: 16.6-102; p < .001) but not graft failure (HR = 1.21; 95% CI: .68-2.18; p = .52) total graft loss (HR = 1.17; 95% CI: .85-1.62; p = .34), or death (HR = 1.17; 95% CI: .79-1.76; p = .43. CONCLUSIONS: FUO is less common in KTRs during the modern era. Our study suggests infection remains the most common etiology. FUO remains associated with significant increases in risk of rejection, warranting further inquiry into the management of immunosuppressive medications in SOT recipients in the setting of FUO.

Cytomegalovirus Post-Prophylaxis Surveillance in High-Risk Kidney and Liver Recipients Prevents CMV End-Organ Disease and Ganciclovir-Resistance.

PURPOSE: Evaluate cytomegalovirus (CMV) post-prophylaxis surveillance in high-risk (D+/R-) kidney and liver transplant recipients. METHODS: Adult D+/R- patients were included if transplanted between 6/1/15 and 11/30/22 and divided into a pre-CMV-stewardship-era (6/1/15-5/31/18), CMV-stewardship-era (6/1/18-6/30/20), and a surveillance-era (7/1/2020-11/30/2022) then followed through 12 months. The primary objective was to evaluate CMV-related outcomes. The secondary objective was to assess graft and patient survival by era. RESULTS: There were 328 patients in the study period; 133 in the pre-stewardship-era, 103 in the stewardship-era, and 92 in the surveillance-era. Replication rates in the surveillance-era were significantly higher, as anticipated due to increased sampling (pre 38.4%, stewardship 33.0%, surveillance 52.2%, p = 0.02). Time from transplant to first replication was similar (pre 214.0 ± 79.0 days, stewardship 231.1 ± 65.5, surveillance 234.9 ± 61.4, p = 0.29). CMV viral load (VL) at first detection, maximum-VL, and incidence of VL > 100 000 IU/mL were numerically lower in the surveillance era, although not statistically significant. CMV end-organ disease (p < 0.0001) and ganciclovir-resistance (p = 0.002) were significantly lower in the surveillance era than in both previous eras. Rejection was not different between eras (p = 0.4). Graft (p = 0.0007) and patient survival (p = 0.008) were significantly improved in the surveillance era. CONCLUSIONS: Post-prophylaxis surveillance significantly reduced CMV end-organ disease and resistance. Despite observing increased replication rates in the surveillance era, rejection was not significantly different and there was no graft loss or patient mortality at 12 months.

The next frontier: cytomegalovirus antiviral stewardship programs in solid organ transplant.

PURPOSE OF REVIEW: Cytomegalovirus (CMV) is a driver of negative patient and allograft outcomes after solid organ transplantation (SOT) and new tools are needed to circumvent these outcomes. We will review key elements of CMV antiviral stewardship in SOT, discuss the available evidence for CMV antiviral stewardship programs and feature areas for expansion in the current landscape of CMV management. RECENT FINDINGS: CMV remains a common complication after SOT. While consensus guidelines provide recommendations for the prevention and treatment of CMV, a one-size-fits-all approach is not necessarily appropriate for all unique patients and posttransplant courses, types of SOT recipients and transplant centers. Additionally, consensus guidelines have not been updated since the approval of two new antiviral therapies for the treatment of CMV after SOT or emerging evidence for the incorporation of immune functional assays into clinical practice.From the models provided in recent literature, CMV antiviral stewardship programs have demonstrated efficacy by increasing successful treatment of viremia, optimizing and reducing unnecessary use of (val)ganciclovir for both prophylaxis and treatment, and preventing development of ganciclovir-resistant CMV infections. These models highlight the multidisciplinary approach required of CMV antiviral stewardship programs to provide standardization of management, including incorporation of new therapies and diagnostic tools. SUMMARY: CMV antiviral stewardship programs represent a promising avenue to considerably improve the management of CMV after SOT. Future studies are needed to evaluate a potential positive impact on graft outcomes and patient survival.

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.

Discordance in cytomegalovirus viremia in kidney recipients from the same donor is associated with the worst outcomes.

BACKGROUND: Cytomegalovirus (CMV) is a common viral infection in kidney transplant recipients (KTR) that has been associated with negative outcomes. The effect on outcomes of concordance versus discordance in CMV between two different recipients of kidneys from the same donor is largely unknown. METHODS: We reviewed all adult deceased donor kidney transplant recipients (DDKTs) for which both kidneys were transplanted to two different recipients at our center between 2014 and 2019. Recipient pairs from each donor were divided into groups based on concordance or discordance for the development of CMV viremia between the pair; concordant no CMV (cc-no-CMV) if neither KTR developed CMV, concordant CMV (cc-CMV) if both KTRs developed CMV. The discordant group was then further divided based on the individual development of CMV (dc-CMV) or lack of development of CMV (dc-no-CMV). Patient mortality and death-censored graft failure (DCGF) were outcomes of interest. RESULTS: Of 578 KTRs, 67% were cc-no-CMV, 5% were cc-CMV, 14% were dc-no-CMV, and 14% dc-CMV. Some of the baseline characteristics differ among the groups including a higher prevalence of high-risk serostatus (D+/R-) in cc-CMV (32%) and dc-CMV (32%). In multivariate analysis, with reference to cc-no-CMV, dc-CMV was associated with increased risk for DCGF (HR 3.13, 95% CI 1.58-6.19), and so was delayed graft function. Factors associated with increased risk of mortality were advanced recipient age and DGF. cc-CMV was neither associated with mortality nor DCGF. CONCLUSIONS: These findings support that in certain contexts, CMV viremia has adverse allograft outcomes, and this is highlighted when illustrated via discordance in CMV between pair kidneys from the same deceased donor.

Seasonal variation of cytomegalovirus disease in kidney transplant recipients.

PURPOSE: Studies conducted in the northern United States found cytomegalovirus (CMV) disease after liver transplantation follows a seasonal pattern, with increased incidence in fall and winter. This has not been evaluated in kidney transplant recipients. Improved understanding of CMV seasonality may help guide use of preventative therapies. METHODS: We evaluated adult patients receiving a kidney transplant at our center in Wisconsin from January 1, 1995 to December 31, 2018. CMV event was defined as quantifiable viral replication with clinical signs or symptoms suspicious for CMV per current consensus recommendations. Seasons were divided as follows: winter (December-February), spring (March-May), summer (June-August), and fall (September-November). The primary objective was to evaluate the annual distribution of CMV disease and determine whether this differed by season. RESULTS: There were 6151 kidney transplants in the study period. A total of 913 patients had 1492 episodes of CMV. Median time from transplant to first detection was 5.51 months (interquartile range [IQR] 2.87-11.7). The observed overall incidence exceeded the expected incidence in winter (+.7%), spring (+5.5%), and fall (+3.4%) and was less than expected in summer (-9.5%) (p = .18). The incidence of CMV during summer, however, was 21% less than expected (p = .001) in recipients who were CMV positive (R+) at the time of transplantation. No such difference was observed in CMV negative recipients (R-; p = .58). CONCLUSION: CMV after kidney transplant appears to be less common during the summer season in patients who were R+ at transplant but does not follow seasonal variation in R-. Reasons for this are unclear but are likely related to CMV-specific cell-mediated immunity. These findings may have clinical implications, particularly the use of non-pharmacologic strategies to improve response to antiviral therapy.

Real-World Experience With CMV inSIGHT T Cell Immunity Testing in High-Risk Kidney and Pancreas Transplant Recipients.

BACKGROUND: Cytomegalovirus (CMV)-specific cell-mediated immunity is important for control of CMV after transplant. Assays exist to measure this, but their place in therapy is unclear, particularly in CMV high-risk recipients, without pretransplant exposure. OBJECTIVE: The objective of this study was to evaluate predictive potential of a positive assay to determine freedom from DNAemia and describe subsequent 3-month CMV outcomes. METHODS: Adult CMV high-risk kidney and/or pancreas transplant recipients were included if a CMV inSIGHT T Cell Immunity Panel (TCIP, Eurofins Viracor) was ordered and resulted between 1 August, 2019 and 30 July, 2022. RESULTS: Seventy-six patients were included in our study; 49 tested during prophylaxis and 27 during treatment. Most TCIP assays obtained in the prophylaxis cohort were negative (n = 46, 93.9%). Rate of post-TCIP CMV infection was 10.2%. In those tested during treatment, 33.3% were positive and rate of post-TCIP CMV recurrence was 22.2%. The positive predictive value of the assay to successfully predict immunity was 66.7% during both prophylaxis and treatment. There were 4 cases of TCIP predictive failure with progressive CMV replication. At time of replication, 2 patients had concomitant clinical confounders thought to influence immune control of viral replication. All patients had intensification of immunosuppression prior to recurrent replication, but after TCIP was collected. CONCLUSION AND RELEVANCE: The data obtained from the TCIP are not static, immune control of CMV in latency can change and must be evaluated in clinical context. Timing of TCIP after transplant is significant, and patient-specific factors remain important to assess the likelihood of CMV in each unique patient-specific scenario. A CMV stewardship program can aid in application and interpretation of results.

Maribavir for the Management of Cytomegalovirus in Adult Transplant Recipients: A Review of the Literature and Practical Considerations.

OBJECTIVE: To review the efficacy and safety of maribavir for management of cytomegalovirus (CMV) in solid organ transplant recipients. DATA SOURCES: A literature search of PubMed and the Cochrane Controlled Trials Register (1960 to early July 2022) was performed using the following search terms: maribavir, 1263W94, and cytomegalovirus. STUDY SELECTION AND DATA EXTRACTION: All relevant English-language studies were reviewed and considered, with a focus on phase 3 trials. DATA SYNTHESIS: Maribavir, an orally available benzimidazole riboside with minimal adverse effects, was originally studied for universal prophylaxis in phase 3 trials but failed to demonstrate noninferiority over placebo and oral ganciclovir. It was effective for preemptive treatment in a dose-finding Phase 2 study. Maribavir is FDA approved for treatment of refractory/resistant CMV infection based on improved response rate at 8 weeks compared with investigator-assigned therapy (IAT) when initiated at median viral loads less than approximately 10 000 IU/mL (55.7% vs 23.9%, P < 0.001). Recurrence after 8-week treatment for refractory/resistant CMV was high (maribavir 50% vs IAT 39%). Significant drug interactions exist and must be managed by a pharmacotherapy expert to prevent harm. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: The addition of maribavir to the antiviral armamentarium should improve the management of refractory/resistant CMV, allowing early transition from toxic, high-cost, intravenous agents such as foscarnet and outpatient management. Optimal timing of initiation, duration, and potential alternative uses are unclear. CONCLUSION: Future studies are needed to fully elucidate the role of maribavir in the management of CMV after transplant.

CMV antiviral stewardship: navigating obstacles to facilitate target attainment.

PURPOSE OF REVIEW: Despite the availability of potent antivirals, consensus guidelines and decades of research, cytomegalovirus (CMV) continues to be associated with negative outcomes after solid organ transplant. This has been attributed to postprophylaxis CMV infection and a lack of development of CMV-specific cell mediated immunity (CMI). A shift from a focus on antiviral prevention to a focus on CMI target attainment is needed to improve CMV outcomes after transplantation. RECENT FINDINGS: There are many obstacles to CMI target attainment. Antiviral stewardship programs (AVS) have been employed to improve patient outcomes through appropriate antiviral use, reduction of unnecessary exposure and resistance mitigation. By focusing on the patient's unique substrate of conglomerate risk factors and addressing these factors specifically with evidenced based methodology, the AVS can address these obstacles, increasing rates of CMI and subsequently reducing risk of future CMV infection and negative outcomes. SUMMARY: With its multidisciplinary composition utilizing decades of experience from antimicrobial stewardship principles and practices, the AVS is uniquely poised to facilitate the shift from a focus on prevention to CMI target attainment and be the supporting pillar for the frontline transplant clinician caring for transplant patients with CMV.

Risk factors for high level cytomegalovirus viremia in liver transplant recipients and associated outcomes.

PURPOSE: To evaluate epidemiology, risk-factors, and outcomes of high-level (HL) cytomegalovirus (CMV) viremia in liver transplant recipients. METHODS: Adult patients receiving a liver transplant between 1/1/2017 and 9/30/2020 were evaluated. Viral loads at University of Wisconsin Health Clinical Laboratories were required to allow for numerical comparison. Primary objective was incidence and outcomes of HL CMV viremia (viral-load > 100 000 IU/ml). Secondary objective was to elucidate risk factors to allow targeted interventions. RESULTS: Two hundred nine patients met inclusion criteria; 175 kept their graft for at least 240 days. Of these nine patients developed HL CMV, 28 developed low-level (LL CMV, viral-load 250-100 000 IU/ml), and 138 did not develop CMV viremia. When comparing these three groups via classic statistical methods time from transplant to viremia was similar (HL 158 ± 77 days, LL 150 ± 76 days). Clinical factors were also similar with the exception of donor seropositivity (HL 87.5%, LL 70.4%, No CMV 49.6%, p = 0.025). HL CMV was significantly associated with graft loss (p < 0.0001) on Kaplan-Meier analysis; graft loss in the LL CMV group did not differ from the no CMV group (p = 0.96). To allow valid assessment of risk factors in the total study population (n = 209), models of time-varying covariates were used, and Cox proportional hazards ratios were calculated. In this analysis, HL CMV was associated with a significantly increased risk of graft loss (HR 5.6, p = 0.0016). When investigating risk factors associated with HL CMV, donor seropositivity significantly increased risk (HR 8.85, 95% CI 1.13-71.43, p = 0.038). Pretransplant total bilirubin (HR 1.04, 95% CI 0.998-1.07, p = 0.06) trended toward significance. Recipient seronegativity, liver disease, clinical and allocation model for end-stage liver disease (MELD), transplant surgery duration, age, sex, induction immunosuppression, and maintenance immunosuppression were not significantly associated with development of HL CMV. CONCLUSION: HL CMV after liver transplant is uncommon but is associated with a significantly increased risk of graft loss that is not present in those patients who develop LL CMV or do not develop CMV viremia. Given these negative graft effects, CMV stewardship interventions targeting recipients of CMV seropositive allografts are warranted. Future larger scale studies evaluating the potential role of other factors in risk stratification are needed.

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.

Cytomegalovirus antiviral stewardship in solid organ transplant recipients: A new gold standard.

PURPOSE: Antimicrobial stewardship programs (ASPs) are essential entities that promote the appropriate use of antimicrobials, leading to improved patient outcomes and reduced resistance. Application to the immunocompromised host is a natural progression for expansion. Cytomegalovirus (CMV) infection is a common complication following solid organ transplant with significant implications on graft survival, making it an attractive ASP target. The aim of this piece is to review our center-specific experience with the development, implementation, and maintenance of a CMV stewardship initiative at a large transplant center. METHODS: Our CMV stewardship initiative began in 2018. Herein, we review 3 years' experience and quality-related improvement that occurred from initiation to present state and share our stewardship algorithms. Special attention is paid to the impact of the program as well as our increased understanding of the complex interplay between prevention, treatment, and host development of CMV-specific cell-mediated immunity (CMI). RESULTS: We found our stewardship initiative not only reduced the incidence of ganciclovir resistance but also streamlined care via a centralized and structured approach. This objective, protocolized program has resulted in a significant shift away from a reactive to a proactive state and in turn, reduced CMV treatment rates (26% at initiation to 12% in the current state, p = .012). CONCLUSION: A dedicated multidisciplinary team focused on CMV stewardship is imperative in providing a patient-centered approach focused on development of CMV-specific CMI, and as a result prevention of CMV disease. We believe these programs will be the new gold standard for CMV management.

A pilot study of an intensified ganciclovir dosing strategy for treatment of cytomegalovirus disease in kidney and/or pancreas transplant recipients.

PROBLEM: Mathematical modeling suggests aggressive ganciclovir dosing in the first week of cytomegalovirus disease (CMV) treatment may improve response. This has not been evaluated clinically. METHODS: Adult kidney and/or pancreas transplant recipients admitted with CMV (4/29/19-7/15/20) received IV ganciclovir(10 mg/kg Q12 h × 7 days) with step-down to standard-of-care (SOC) dosing thereafter (5 mg/kg Q12). A SOC cohort admitted before implementation of the dosing strategy (10/20/16-3/2/19) served as a comparator. PRIMARY OBJECTIVE: rate of viral clearance (delta log CMV) at therapy day 7. SECONDARY OBJECTIVE: safety/short term efficacy. RESULTS: Fifty-four patients met inclusion criteria; 22 high-dose, 32 SOC. Demographics were similar with the exception of more women (45.4% vs. 15.6%,P = .03) and higher presenting viral-load in the high-dose group (log 6.0±.7 vs. log 5.2±1.2, P = .02). High-dose resulted in significantly greater response to therapy at day 7 (log -.92±.51 vs. log -.56±.79, P = .04). Change in WBC at day 7 was not different (-.49±1.92 vs. -.45±5.1, P = .97). Short-term clinical outcomes were similar between groups including mean hospital length-of-stay (P = .52), readmission rates (30 d: P = .38; 90 d: P = .5) and achievement of CMV viral-load less-than-lower-limit-of-quantification by day 90 (73% vs. 84%, P = .06). Rejection after CMV as well as graft/patient survival were similar between groups (P = .56, P > .99, P > .99). CONCLUSION: A high-dose IV ganciclovir strategy results in improved viral clearance kinetics without safety concerns and similar short term clinical outcomes.

Conversion from cytomegalovirus universal prophylaxis with valganciclovir to the preemptive monitoring approach to manage leukopenia after kidney or pancreas transplantation.

PURPOSE: In clinical practice, conversion from universal cytomegalovirus prophylaxis (CMV PPX) with valganciclovir (VGC) to targeted therapy (preemptive monitoring, PEM) is often pursued in the setting of leukopenia. It is unknown if this is an effective strategy. METHODS: Adult patients receiving a kidney and/or pancreas transplant were included if converted from PPX to PEM between 9/1/19 and 3/1/20 due to leukopenia. A positive CMV viral load (VL) was defined as CMV PCR greater than the lower limit of quantification (LLOQ) based on local lab testing. A CMV VL of >500 IU/mL was chosen as the preemptive treatment (PET) threshold. Primary objective was to describe the impact of conversion on resolution of leukopenia. Secondary objectives were to assess PEM associated outcomes. RESULTS: There were 49 patients converted from PPX to PEM due to leukopenia in the study period; 88% were KTRs and 96% received lymphocyte-depleting induction; 84% were seropositive at transplant (R+) and 16% were high-risk (D+/R-). Mean WBC at time of enrollment was 1.4 ± 0.4. After PEM conversion, WBC recovered to >3 in 87.8% of the population in a mean of 26.8 ± 24.5 days. Immunosuppression was modified in 96% of the population and GCSF was required in 46.9% of patients. CMV viremia occurred in 36.7% of the population; 78% were KTRs and 94% were R+. Time from PEM enrollment to PET was 64 ± 34 days. Median VL at first detection was 587 IU/mL, median peak was 1920 IU/mL. Five patients (27.8%) presented with symptoms consistent with CMV syndrome, none had end organ disease. Six patients (33%) presented with a VL <500 IU/mL at first detection, but all subsequently surpassed the threshold and required PET. Mean duration of PET was 25 ± 11 days. Mean change in WBC in response to PET was -0.4 ± 1.3. Immunosuppression required further adjustment in 61% of patients. There were no deaths or graft loss due to CMV at last follow-up. CONCLUSION: In kidney and pancreas transplant recipients who undergo PEM conversion due to leukopenia, withholding of VGC can improve leukopenia, but other concomitant measures are necessary. This population should be considered fairly high risk, with a threshold of treatment of first quantifiable replication. Our findings suggest lack of harm from this approach but highlight the importance of close monitoring to prevent symptomatic replication. Larger studies with longer follow-up are needed to better evaluate the impact of PEM conversion on late-onset CMV and patient and graft outcomes.

The addition of adjunctive letermovir to valganciclovir for refractory cytomegalovirus viremia in kidney transplant recipients.

PURPOSE: Persistent viral replication resulting in ongoing cytomegalovirus (CMV) viremia despite adequate therapy is difficult to manage and associated with negative outcomes. We report a case series of kidney transplant recipients receiving adjunctive letermovir in combination with valganciclovir for refractory CMV. METHODS: Adult patients receiving a kidney or kidney-pancreas transplant were included if they developed CMV viremia and initiated letermovir 480 mg daily as part of a dual therapy regimen with valganciclovir 900 mg twice daily between 1/9/2020 and 31/12/2020. Included patients received ≥90 days of valganciclovir and had a detectable viral load less than 1000 Iu/ml (log10  < 3) at the time of letermovir initiation. The primary objective was to evaluate the impact of adjunctive letermovir on viral clearance to negativity. We also evaluated effect of letermovir on tacrolimus levels. RESULTS: Eight patients were included. Letermovir was added 223 ± 105 days after initiation of CMV treatment with ganciclovir derivatives. Median viral load at initiation was 139.7 (range: 73-355) IU/ml and did not clear or change significantly after 2, 4 and 12 weeks of adjunctive letermovir (132.5 [range: 34.5-513] IU/ml vs. 68.7 [range: 34.5-574] IU/ml vs. 78.3 [range: 34.5-347] IU/ml, p > 0.05). Tacrolimus was reduced by ∼30% in anticipation of a letermovir-tacrolimus drug interaction. Despite this reduction, mean tacrolimus serum levels two weeks after adjunctive letermovir increased by 43% (5.6 ± 1.6 ng/ml vs 8.0 ± 4.6 ng/ml). CONCLUSION: In kidney and kidney-pancreas recipients with refractory CMV, the use of adjunctive letermovir did not result in viral clearance. Additionally, despite a mean tacrolimus dose reduction of 30% at letermovir initiation, serum concentrations increased by over 40%. Further investigation into the optimal approach to refractory CMV is needed.

Cytomegalovirus antiviral stewardship in the COVID-19 Era: Increasing complexity of prophylaxis and treatment and potential mitigation strategies.

Cytomegalovirus (CMV) infection is one of the most common and significant complications after solid organ transplant (SOT). Severe acute respiratory coronavirus 2 (SARS-CoV-2), which causes the novel betacoronavirus 2019 disease (COVID-19), has become the first global pandemic in 100 years. The world's attention has turned to address this unanticipated development; however, the viral infection that has long plagued outcomes after solid organ transplantation still requires vigilance. With physical distancing as the key intervention to reduce the healthcare burden, and the unease related to healthcare contact within the transplant population given the associated morbidity and mortality of COVID-19 in transplant recipients, providers have struggled to evaluate and streamline essential in-person healthcare contact, including laboratory visits. Owing to this, the COVID-19 pandemic has placed a significant strain on the delivery of CMV prophylaxis and treatment after solid organ transplantation. In this piece, we will describe issues our CMV antiviral stewardship service has encountered in the care of the transplant recipient with CMV during the this unprecedented time and share our expert opinion to approaches to providing optimal, evidenced based care during a pandemic associated with a seemingly unrelated viral infection.

Management of BK viremia is associated with a lower risk of subsequent cytomegalovirus infection in kidney transplant recipients.

The risk of subsequent cytomegalovirus infection (CMV) in kidney transplant recipients (KTR) after diagnosis of BK polyomavirus viremia (BKV) is unclear, and current evidence is conflicting. We reviewed all KTR transplanted at our institution between 1/1/2005 and 12/31/2015. Follow-up began 3 months after transplantation to avoid confounding effects of prophylaxis. Clinically significant BKV, defined as detectable BK viremia >1000 copies/mL via molecular diagnostic testing (PCR), was treated as a time-varying exposure with 1-year follow-up. This viral load cutoff was chosen to ensure a more homogenous population that would be considered to have clinically significant BK viremia that necessitated management via immunosuppressive modification. Patients were then screened for subsequent CMV infection. 2435 RTX recipients met inclusion criteria; of these, 314 developed BKV during follow-up (BK+). Lymphocyte depletion, tacrolimus maintenance, and biopsy-proven rejection were significantly higher in the BK+ group. BK+ was associated with lower risk of subsequent CMV infection (BK+ HR 0.45, 95% CI 0.22-0.94, P = .03, relative risk reduction 55%). When adjusted for significant confounding factors, CMV incidence remained reduced in the BK+ population (HR 0.47, 95% CI 0.22-0.98, P = .04). This large series of KTR demonstrates that BKV is associated with lower risk of subsequent CMV infection.

Prediction of cytomegalovirus infection: A single-center experience utilizing a newly available cell-mediated immunity assay by flow cytometry, a risk factor screening tool, and serologically demonstrated immunity.

PURPOSE: Describe use and predictive potential of an intracellular cytokine staining (ICS) cytomegalovirus cell-mediated immunity (CMV CMI) assay and a risk factor screening tool on CMV reactivation in a real-world clinical setting and compare this to serologically demonstrated immunity by CMV IGG. METHODS: Adult transplant patients at our center with the ICS assay resulted between 10/1/2018 and 9/1/2019 were included. Assays were considered positive per manufacturer specifications. RESULTS: Twenty-five patients underwent ICS CMV CMI testing at our institution during the study period. The majority were kidney transplant recipients, 76% were D+/R-, and 76% were receiving CMV treatment. The positive predictive value (PPV) of the assay to predict lack of CMV was 87%; 93% when patients with antiviral resistance were excluded and 91% in only those receiving treatment. The presence of ≤2 clinical risk factors on the screening tool had a PPV of 92% in predicting lack of recurrence. In comparison, serologically demonstrated immunity by CMV IGG had a PPV of 62%. CONCLUSIONS: In our study representing real-world clinical use, the ICS CMV CMI assay and the risk factor screening tool had predictive potential that was superior to serologically demonstrated immunity. The reliability of the assay seemed to decrease with higher degrees of clinical risk suggesting a multimodal screening approach is warranted.

Epidemiology, Risk Factors, and Outcomes After Early Posttransplant Clostridiodes difficile Infection in Renal Transplant Recipients.

BACKGROUND: Modifiable risk-factors associated with Clostridioides difficile infection (CDI) in renal-transplant (RTX) have not been clearly established and peri-transplant risk has not been described. OBJECTIVE: Evaluate epidemiology, risk-factors and outcomes after CDI occurring in the first 90 days after RTX (CDI-90).Methods: Observational cohort study/survival analysis of adult RTX recipients from 1/1/2012-12/31/2015. Primary outcome was CDI-90 incidence/risk-factors. Secondary outcome was evaluation of post-90 day transplant outcomes. RESULTS: 982 patients met inclusion criteria; 46 with CDI-90 and 936 without (comparator). CDI incidence in the total population was 4.7% at 90 days, 6.3% at 1 year, and 6.4% at 3 years. Incidence of CDI-90 was 5%; time to diagnosis was 19.4±25 days (median 7). Risk-factors for CDI-90 were alemtuzumab induction (Hazard ratio [HR] 1.5, 95% CI(1.1-2.0), p = 0.005) and age at transplant (HR 1.007/year, 95% CI (1.002-1.012), p= 0.007). However, risk-factors for CDI at any time were different; donation-after-circulatory-death (DCD) donor (HR 2.5 95% CI (1.3-4.9), p = 0.008) and female gender (HR 1.6 95% CI (1.0-2.7), p = 0.049). On Kaplan-Meier, CDI-90 appeared to have an impact on patient/graft survival, however when analyzed in a multivariable stepwise Cox proportional hazards model, only age was significantly associated with survival (p = 0.002). CONCLUSION AND RELEVANCE: Incidence of CDI-90 is low, mostly occurring in the first post-operative month. Risk-factors vary temporally based on time from transplant. In the early post-op period induction agent and age at transplant are significant, but not after. Associations between CDI and negative graft outcomes appear to be largely driven by age. Future studies validating these risk-factors as well as targeted prophylaxis strategies and their effect on long term graft outcomes and the host microbiome are needed.

Bordetella pertussis in a four-time kidney transplant recipient: A call for immunization programs at transplant centers.

Pertussis, or whooping cough, is a highly contagious respiratory illness caused most frequently by Bordetella pertussis. Clinical presentation ranges in severity, but life-threatening illness disproportionately affects children and immunocompromised individuals. Acellular vaccines for pertussis have been available for decades, and they are recommended throughout the lifespan. A patient who had received a kidney transplant presented with respiratory distress and dry cough as manifestations of co-infection with B pertussis and Bordetella parapertussis/bronchiseptica. The goal of this case report was to highlight the importance of immunization programs at transplant centers, which are in the unique position to care for patients both with end-stage organ disease and in the post-transplant setting.