A Randomized Trial of Valganciclovir Prophylaxis Versus Preemptive Therapy in Kidney Transplant Recipients

Pre-emptive treatment for cytomegalovirus viraemia to prevent cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is a significant cause of morbidity and death in solid organ transplant recipients. Pre-emptive treatment of patients with CMV viraemia using antiviral agents has been suggested as an alternative to routine prophylaxis to prevent CMV disease. This is an update of a Cochrane review first published in 2006 and updated in 2013.

OBJECTIVES

To determine the benefits and harms of pre-emptive treatment of CMV viraemia to prevent CMV disease and death (any cause) and the indirect effects of CMV infection (acute rejection, graft loss, opportunistic infections) in solid organ transplant recipients.

SEARCH METHODS

The Cochrane Kidney and Transplant Register of Studies was searched up to 17 December 2024 using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing pre-emptive treatment with placebo, no specific treatment, or antiviral prophylaxis in solid organ transplant recipients.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the eligibility of the identified studies, assessed the risk of bias, and extracted all data. Results were expressed as risk ratio (RR) and 95% confidence intervals (CI) for dichotomous outcomes. Statistical analyses were performed using a random-effects model. The certainty of evidence was assessed per outcome using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

In this update, we have included seven new studies, bringing the total number of included studies to 22 (1883 participants). Of these, seven investigated pre-emptive treatment versus placebo or standard care, 12 looked at pre-emptive treatment versus antiviral prophylaxis, one study investigated oral versus intravenous pre-emptive treatment, one investigated pre-emptive valganciclovir versus pre-emptive ganciclovir, and one investigated letermovir 40 mg twice/day versus 80 mg once/day. Studies were conducted in Australia, Brazil, the Czech Republic, Germany, Italy, Japan, Norway, Spain, South Korea, and the USA. Organ transplant recipients included kidney, liver, heart, lung, and kidney-pancreas. Thirteen studies were single-centre studies, six were multicentre, and three were unknown. The number of participants ranged from 12 to 296. Overall, selection bias was unclear (55%); performance, detection and attrition bias were high (91%, 63% and 95%, respectively), and reporting bias was low (55%). Compared with placebo or standard care, pre-emptive treatment probably reduces the risk of CMV disease (7 studies, 315 participants: RR 0.29, 95% CI 0.11 to 0.80; I2 = 54%; moderate-certainty evidence) but may result in little or no difference in death (any cause) (3 studies, 176 participants: RR 1.23, 95% CI 0.35 to 4.30; I2 = 0%; low-certainty evidence). Pre-emptive treatment may result in little or no difference in CMV organ involvement, CMV-associated symptoms, acute rejection, graft loss, other infections or leucopenia. Compared to prophylaxis, pre-emptive treatment may make little or no difference to the risk of developing CMV disease (11 studies, 1322 participants: RR 0.97, 95% CI 0.47 to 2.01; I2 = 54%; low-certainty evidence) and probably makes little or no difference to death (any cause) (9 studies, 1098 participants: RR 0.95, 95% CI 0.60 to 1.52; I2 = 0%; moderate-certainty evidence). Pre-emptive treatment may increase the risk of CMV infection (8 studies, 867 participants: RR 1.97, 95% CI 1.48 to 2.61; I2 = 66%; low-certainty evidence). The risk of leucopenia (7 studies, 869 participants: RR 0.57, 95% CI 0.38 to 0.87; I2 = 33%; moderate-certainty evidence) and neutropenia (5 studies, 859 participants: RR 0.63, 95% CI 0.44 to 0.90; I2 = 0% moderate certainty evidence) probably decreases with pre-emptive therapy. There may be little or no difference in the risks of acute rejection, graft loss, and infections other than CMV. Single studies were identified for comparisons between different pre-emptive treatments: 1) oral ganciclovir versus IV ganciclovir; 2) valganciclovir versus ganciclovir; 3) 40 mg twice/day versus 80 mg once/day. No differences between these treatment modalities in terms of CMV disease, death (any cause), or adverse events were identified.

AUTHORS' CONCLUSIONS

In this review, we have included seven new studies, yet the available evidence is overall of low certainty and the conclusions remain similar to the previous version of this review. Pre-emptive treatment probably reduces the risk of CMV disease compared with placebo or standard care. There were no clear differences between pre-emptive treatment and prophylaxis to prevent CMV disease or reduce the risk of death (any cause). The risk of CMV infection may be higher for patients receiving pre-emptive therapy, but the risk of adverse events, such as leucopenia, is probably lower.

Management of cytomegalovirus in adult solid organ transplant patients: GESITRA-IC-SEIMC, CIBERINFEC, and SET recommendations update

Cytomegalovirus (CMV) infection remains a significant challenge in solid organ transplantation (SOT). The last international consensus guidelines on the management of CMV in SOT were published in 2018, highlighting the need for revision to incorporate recent advances, notably in cell-mediated immunity monitoring, which could alter the current standard of care. A working group including members from the Group for the Study of Infection in Transplantation and the Immunocompromised Host (GESITRA-IC) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and the Spanish Society of Transplantation (SET), developed consensus-based recommendations for managing CMV infection in SOT recipients. Recommendations were classified based on evidence strength and quality using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The final recommendations were endorsed through a consensus meeting and approved by the expert panel.

Terminally differentiated effector memory T cells in kidney transplant recipients: New crossroads

Immunosenescence, the age-related dysregulation of innate and adaptive immunity, impairs immune response and increases inflammation, leading to higher infection and cardiovascular risks, particularly outside the field of transplantation. In kidney transplant recipients (KTRs), conditions like cytomegalovirus infection, old age, uremia, smoking, and diabetes, linked to poor outcomes, are associated with enhanced immunosenescence. Recent studies highlight the pathogenic role of cytotoxic T cells, particularly terminally differentiated effector memory T cells that reexpress CD45RA (TEMRA), in graft dysfunction. A higher proportion of circulating CD8+ TEMRA cells is observed in KTRs with chronic rejection. In antibody-mediated rejection, they invade the graft by superior chemotactic properties and binding to human leukocyte antigen (HLA) antibodies through FcγRIIIa (CD16). Also in microvascular inflammation without donor-specific antibodies, and even in patients without rejection but faster decline of kidney function, intragraft CD8+ TEMRA cells were instrumental. CD8+ TEMRA cells may explain the unresolved dismal graft outcomes associated with donor age and cytomegalovirus-serostatus mismatching and could become a novel therapeutic target in KTRs.

Valacyclovir or valganciclovir for cytomegalovirus prophylaxis: A randomized controlled trial in adult and pediatric kidney transplant recipients

BACKGROUND

Valganciclovir (valG), a cytomegalovirus (CMV) prophylactic agent, has dose-limiting side effects. The tolerability and effectiveness of valacyclovir (valA) as CMV prophylaxis is unknown.

METHODS

We conducted a randomized, open-label, single-center trial of valA versus valG for all posttransplant CMV prophylaxis in adult and pediatric kidney recipients. Participants were randomly assigned to receive valA or valG. Primary endpoints were the incidence of CMV viremia and side-effect related drug reduction with secondary assessment of incidence of EBV viremia.

RESULTS

Of the 137 sequential kidney transplant recipients enrolled, 26 % were positive and negative for CMV antibody in donor and recipient respectively. The incidence of CMV viremia (4 of 71 [6 %]; 8 of 67 [12 %] P = 0.23), time to viremia (P = 0.16) and area under CMV viral load time curve (P = 0.19) were not significantly different. ValG participants were significantly more likely to require side-effect related dose reduction (15/71 [21 %] versus 1/66 [2 %] P = 0.0003). Leukopenia was the most common reason for valG dose reduction and granulocyte-colony stimulating factor was utilized for leukopenia recovery more frequently (25 % in valG vs 5 % in valA: P = 0.0007). Incidence of EBV viremia was not significantly different.

CONCLUSIONS

ValA has significantly less dose-limiting side effects than valG. In our study population, a significant increase in CMV viremia was not observed, in adults and children after kidney transplant, compared to valG.

TRIAL REGISTRATION NUMBER

NCT01329185.

Pre-Transplant Frequencies of FoxP3+CD25+ in CD3+CD8+ T Cells as Potential Predictors for CMV in CMV-Intermediate Risk Kidney Transplant Recipients

Cytomegalovirus (CMV) infection detrimentally influences graft survival in kidney transplant recipients, with the risk primarily determined by recipient and donor serostatus. However, recipient CD8+ T cells play a crucial role in CMV control. The optimal preventive strategy (prophylaxis vs. pre-emptive treatment), particularly for seropositive (intermediate risk) recipients, remains uncertain. We investigated CD8+ T cell subpopulation dynamics and CMV occurrence (DNAemia ≥ 100 IU/mL) in 65 kidney transplant recipients, collecting peripheral blood mononuclear cells before (T1) and 1 year after transplantation (T2). Comparing the two timepoints, we found an increase in granulocyte, monocyte and CD3+CD8+ T cells numbers, while FoxP3+CD25+, LAG-3+ and PD-1+ frequencies were reduced at T2. CMV DNAemia occurred in 33 recipients (55.8%) during the first year. Intermediate risk patients were disproportionally affected by posttransplant CMV (N = 29/45, 64.4%). Intermediate risk recipients developing CMV after transplantation exhibited lower leukocyte, monocyte, and granulocyte counts and higher FoxP3+CD25+ frequencies in CD3+CD8+ T cells pre-transplantation compared to patients staying CMV negative. Pre-transplant FoxP3+CD25+ in CD3+CD8+ T cells had the best discriminatory potential for CMV infection prediction within the first year after transplantation (AUC: 0.746). The FoxP3+CD25+ CD3+CD8+ T cell subset may aid in selecting intermediate risk kidney transplant recipients for CMV prophylaxis.

Bridging the gap: assessing CMV DNAemia in kidney transplant recipients with previous solid organ transplants

Cytomegalovirus (CMV) infection poses a significant threat to solid organ transplant (SOT) recipients and can lead to various complications and adverse outcomes. In an effort to prevent CMV infection, it is common to utilize prophylactic strategies, including antiviral medications such as valganciclovir, especially for high-risk patients. Risk factors for CMV infection in kidney transplant recipients (KTRs) include CMV mismatch between donor and recipient (i.e., donor positive, recipient negative), and intensity of immunosuppression, such as the use of T-cell depleting agents. However, little attention has been given to KTRs with a history of prior SOTs, despite their prolonged exposure to immunosuppressive regimens. The aim of this retrospective single-center study was to investigate the incidence and implications of CMV DNAemia in KTRs with prior SOTs. The study included 97 KTRs with prior SOTs and 154 KTRs with no prior transplants as a control group. In the study group, the most common SOT before the current kidney transplantation (KT), was a previous KT. Patients in the KTR group with prior SOTs were more sensitized than those in the control group [calculated panel-reactive antibody > 30%: 49 (50.5%) vs. 30 (19.45%) patients, p = 0.001]. There was a 39.2% incidence of CMV DNAemia in the previous SOT group compared to 48.7% in the control group [non-significant (NS)]. Patients with prior SOTs demonstrated a shorter post-transplant time to CMV DNAemia [median time 1.6 months (interquartile range, IQR 0.7-5.8) in the KTRs with prior SOTs vs. 2.6 months (IQR 1.5-8.1) in the control group (p = 0.001)]. Although the study highlights the need for tailored prophylaxis strategies and vigilant monitoring in KTRs with prior SOTs, its limitations, such as its retrospective nature and single-center design, call for further multicenter research to establish comprehensive guidelines for managing CMV DNAemia in this unique patient population. Despite these limitations, this study underscores the importance of recognizing the heightened risk of CMV infection or reactivation in KTRs overall and the potential benefits of proactive intervention to mitigate associated morbidity and mortality.

Adverse Drug Events after Kidney Transplantation

Introduction: Kidney transplantation stands out as the optimal treatment for patients with end-stage kidney disease, provided they meet specific criteria for a secure outcome. With the exception of identical twin donor-recipient pairs, lifelong immunosuppression becomes imperative. Unfortunately, immunosuppressant drugs, particularly calcineurin inhibitors like tacrolimus, bring about adverse effects, including nephrotoxicity, diabetes mellitus, hypertension, infections, malignancy, leukopenia, anemia, thrombocytopenia, mouth ulcers, dyslipidemia, and wound complications. Since achieving tolerance is not feasible, patients are compelled to adhere to lifelong immunosuppressive therapies, often involving calcineurin inhibitors, alongside mycophenolic acid or mTOR inhibitors, with or without steroids. Area covered: Notably, these drugs, especially calcineurin inhibitors, possess narrow therapeutic windows, resulting in numerous drug-related side effects. This review focuses on the prevalent immunosuppressive drug-related side effects encountered in kidney transplant recipients, namely nephrotoxicity, post-transplant diabetes mellitus, leukopenia, anemia, dyslipidemia, mouth ulcers, hypertension, and viral reactivations (cytomegalovirus and BK virus). Additionally, other post-kidney-transplantation drugs such as valganciclovir may also contribute to adverse events such as leukopenia. For each side effect, we propose preventive measures and outline appropriate treatment strategies.