Cytomegalovirus infection in kidney transplant patients: Prevalence, risk factors, and impact on outcome - A local multicentre experience

Accurate Multiplex qPCR Detection of Epstein-Barr Virus/Cytomegalovirus/BK Virus in Kidney Transplant Patients: Pilot Study

Chronic kidney disease is a really important heath issue, and transplantation is an intervention that can greatly increase patient quality of life and survival. The aim of this study was to perform a comprehensive evaluation of the BK virus, CMV, and EBV in kidney transplant recipients (KTRs); to assess the prevalence of infections; and to test if our detection method would be feasible for use in follow-ups with KTRs. A total of 157 KTRs registered at the Clinical Hospital "Dr. C. I. Parhon", Iași, Romania, were selected using specific inclusion/exclusion criteria. We tested the blood samples from each patient for BK, EBV, and CMV using a multiplex real-time PCR (qPCR) assay and the TaqMan PCR principle. The highest prevalence was detected for BKV (11/157, 7%), followed by CMV (9/157, 5.7%) and EBV (5/157, 3.2%). By simultaneously detecting three possible nephropathic viruses and oncogenes in KTRs using multiplex real-time PCR, we aimed to optimize their monitoring and follow-up. The prevalence of the tested nephropathogenic viruses-BKV, CMV, and EBV-was comparable to that analyzed in other studies. We demonstrate that the use of qPCR for viral detection in KTRs is a robust, cost-effective method for case monitoring.

Deciphering the pathogen heterogeneity for precise diagnosis and personalized therapeutics of infections after kidney transplantation: insights from metagenomic next-generation sequencing

Introduction

The aim of this study was to compare the detection performance of mNGS against that of conventional tests (CT) in patients suffering from infection after kidney transplantation.

Methods

A total of 138 samples from 85 kidney transplant patients with acute or chronic infections were simultaneously analyzed using mNGS and CT from July 2021 to August 2023.

Results

Compared with CT, mNGS demonstrated a higher sensitivity (95.96% vs. 27.27%) but lower specificity (48.72% vs. 84.62%) in pathogen detection. Moreover, mNGS exhibited significant advantages in detecting mixed and rare infections. The pathogens commonly identified in kidney transplant patients were severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), followed by Pneumocystis jirovecii and Cytomegalovirus (CMV). mNGS guided the precise clinical diagnosis in 89.13% of cases and assisted in altering therapeutics from empirical antibiotic approaches to personalized plans in 56.10% of cases, including treatment escalation (40.65%), initiation (11.38%), drug adjustment (3.25%), and de-escalation (0.81%).

Discussion

Our study demonstrated the superior detection performance of mNGS and its significant clinical value. This reflected the great potential of mNGS as a complementary clinical detection technology for kidney transplant patients.

Hospitalizations for opportunistic infections following transplantation and associated risk factors: A national cohort study of Medicare beneficiaries

BACKGROUND

Opportunistic infections (OIs) are a significant cause of morbidity and mortality after organ transplantation, though data in the liver transplant (LT) population are limited.

METHODS

We performed a retrospective cohort study of LT recipients between January 1, 2007 and Deceber 31, 2016 using Medicare claims data linked to the Organ Procurement and Transplantation Network database. Multivariable Cox regression models evaluated factors independently associated with hospitalizations for early (≤1 year post transplant) and late (>1 year) OIs, with a particular focus on immunosuppression.

RESULTS

There were 11 320 LT recipients included in the study, of which 13.2% had at least one OI hospitalization during follow-up. Of the 2638 OI hospitalizations, 61.9% were early post-LT. Cytomegalovirus was the most common OI (45.4% overall), although relative frequency decreased after the first year (25.3%). Neither induction or maintenance immunosuppression were associated with early OI hospitalization (all p > .05). The highest risk of early OI was seen with primary sclerosing cholangitis (aHR 1.74; p = .003 overall). Steroid-based and mechanistic target of rapamycin inhibitor-based immunosuppression at 1 year post LT were independently associated with increased late OI (p < .001 overall).

CONCLUSION

This study found OI hospitalizations to be relatively common among LT recipients and frequently occur later than previously reported. Immunosuppression regimen may be an important modifiable risk factor for late OIs.

A Systematic Review and Meta-analysis of Optimized CMV Preemptive Therapy and Antiviral Prophylaxis for CMV Disease Prevention in CMV High-Risk (D+R-) Kidney Transplant Recipients

The optimal strategy for cytomegalovirus (CMV) disease prevention in CMV donor/recipient kidney transplant recipients remains uncertain. Conclusions of prior meta-analyses that CMV disease rates with preemptive therapy (PET) and universal prophylaxis (UP) were comparable may have been affected by inclusion of studies lacking key determinants of efficacy of the respective strategies.

Methods

We conducted a systematic review and meta-analysis of PET with weekly CMV polymerase chain reaction monitoring for ≥3 mo and UP with 6 mo of valganciclovir. PubMed and Embase databases were reviewed from January 1, 2010, to April 1, 2022. Risk of bias was assessed with 3 instruments (Cochrane RoB, Cochrane RoBINS-I, and an instrument for assessing risk in observational studies). The primary outcome was CMV disease incidence by 1-y posttransplant. Secondary outcomes by 1-y were graft loss, acute allograft rejection, and mortality. Results were synthesized using generalized linear mixed model meta-analysis. PET studies were stratified into low-threshold (LT) and high-threshold (HT) PET based on the viral load threshold for initiation of antiviral therapy.

Results

Twenty-five studies met inclusion criteria (6 PET, 19 UP). CMV disease incidence was significantly higher in HT (0.30 [95% confidence interval (CI), 0.22-0.39]) versus LT PET (0.06 [95% CI, 0.03-0.12]). LT PET was associated with a significantly lower CMV disease incidence (0.06 [95% CI, 0.03-0.12]) versus UP (0.21 [95% CI, 0.17-0.27]). Incidence of graft loss, acute allograft rejection, or mortality was not significantly different between LT PET and UP (P > 0.05 for all comparisons). Receipt of lymphocyte-depleting antibodies was not associated with a significant difference in CMV disease incidence (odds ratio = 1.34 [95% CI, 0.80-2.25]).

Conclusions

LT PET is associated with a significantly lower incidence of CMV disease compared to UP with similar rates of other clinical outcomes. These findings provide rationale and preliminary data for a randomized superiority trial of optimized LT-PET versus UP in donor seropositive recipient seronegative kidney transplant recipients.

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.

The impact of induction therapy in low-immunological risk kidney transplant recipients regardless of HLA matching

BACKGROUND

Induction agents have proved to reduce the rate of acute rejection (AR) in kidney transplant recipients (KTRs) without improving long-term graft and patient survival (PS).

OBJECTIVE

This study evaluates the utility of induction therapy in low immunological risk KTRs regardless of donor-to-recipient HLA matching.

METHODS

We retrospectively reviewed the records of 218 patients undergoing kidney transplantation (KT). These patients were divided into two groups according to the usage of induction therapy: 82 did not receive any induction therapy (Group I), and 136 patients received either Anti-IL2 receptor antibodies or anti-thymocyte globulin (Group II). All patients had panel reactive antibody (PRA) < 20% and absence of donor-specific antibodies (DSA). The difference in outcomes were assessed at different intervals following KT.

RESULTS

The rate of bacterial infections at one year (p-value = 0.032) and the frequency of CMV disease (p-value = 0.044) were significantly higher in Group II (with induction therapy). The duration of hospital stay, the rate and severity of acute rejection, the occurrence of delayed graft function, the rate and type of surgical complications at one year, and the graft function and survival at one and three years were similar between the two groups (p-value = NS). In addition, the financial burden is much less in Group I (without induction therapy), reducing the total cost of the transplant procedure.

CONCLUSION

We conclude that induction therapy in low-immunological risk kidney transplant patients is not a must regardless of donor-to-recipient HLA matching. Therefore, induction therapy did not yield significant health results, but had negative financial consequences.

Risk factors for cytomegalovirus infection and disease after kidney transplantation: A meta-analysis

OBJECTIVE

To investigate the risk factors for cytomegalovirus (CMV) infection and disease in kidney transplantation recipient, and provide references for the prevention and control of CMV infection and disease in kidney transplantation patients.

METHODS

Chinese and international literature related to risk factors for CMV infection and disease in renal transplant recipients was searched using databases, including China National Knowledge Infrastructure; WanFang Data; Wiper; Chinese Biomedical Literature database; PubMed; Embase; Web of Science, and the Cochrane Register of Controlled Trials. Two researchers independently screened the literature, extracted the data, and evaluated the quality of the literature according to published standards. A meta-analysis was performed using RevMan 5.4 software to extract the risk factors for CMV infection and disease in renal transplant recipients.

RESULTS

A total of 59,847 subjects were included in 24 studies. The risk factors for CMV infection were ATG [OR = 2.76, 95% CI (2.10, 3.63), P < 0.00001], Donor (D) CMV-IgG(+) Receptor (R)(-): (D+/R-) [OR = 2.97, 95% CI (1.63, 5.44), P = 0.004 < 0.05], recipient age [OR = 1.96, 95% CI (1.50, 2.54), P < 0.00001], lymphocytopenia [OR = 3.26, 95% CI (1.46, 7.31), P < 0.00001], and mycophenolate [OR = 3.22, 95% CI (2.02, 5.46), P < 0.00001]. The protective factor for CMV infection was glomerular filtration rate (GFR) [OR = 0.98, 95% CI (0.97, 0.99), P < 0.00001], and the uncertain factors were the use of tacrolimus [OR = 0.91, 95% CI (0.64, 1.28), P = 0.58 > 0.05], rejection [OR = 1.32, 95% CI (0.49, 3.53), P = 0.58 > 0.05], donor age [OR = 1.00, 95% CI (0.99, 1.01), P = 0.67 > 0.5], and preemptive therapy [OR = 0.51, 95% CI (0.11, 2.36), P = 0.86 > 0.05]. The risk factors for CMV disease were D+/R- [OR = 4.78, 95% CI (3.76, 6.07), P < 0.00001], ATG [OR = 1.83, 95% CI (1.25, 2.67), P < 0.00001], rejection [OR = 1.42, 95% CI (1.26, 1.59), P < 0.00001], mycophenolate [OR = 1.67, 95% CI (1.38, 2.02), P < 0.00001], recipient age [OR = 1.03, 95% CI (1.02, 1.03), P < 0.00001], donor age [OR = 1.01, 95% CI (1.00, 1.01), P = 0.001 < 0.05], Donor (D) CMV-IgG(+) Receptor(R)(+): (D+/R+) [OR = 1.92, 95% CI (1.49, 2.46), P < 0.00001], the use of prednisolone [OR = 1.59, 95% CI (1.32, 1.92), P < 0.00001], and diabetes mellitus[OR = 1.18, 95% CI (1.01, 1.37), P = 0.03 < 0.05], and the uncertain factors were donor type [OR = 4.10, 95% CI (0.28, 59.79), P = 0.30 > 0.05], time of transplantation [OR = 0.95, 95% CI (0.78, 1.16), P = 0.64 > 0.05], and the use of cyclosporine [OR = 1.50, 95% CI (0.62, 3.64), P = 0.37 > 0.05].

CONCLUSION

There are many factors influencing CMV infection and disease in kidney transplant patients. Risk factors should be carefully monitored, protective factors strengthened, and more attention paid to uncertain factors.