Negative Impact of CMV and BKV Infections on Kidney-Allograft Function at 1-Year Post-Transplantation: Can it Be Changed by Modifying Immunosuppression?

Viral load kinetics and the clinical consequences of cytomegalovirus in kidney transplantation

Background

Despite advances in clinical management, cytomegalovirus (CMV) infection remains a serious complication and an important cause of morbidity and mortality following kidney transplantation. Here, we explore the importance of viral load kinetics as predictors of risk and potential guides to therapy to reduce transplant failure in a large longitudinal Genome Canada Transplant Consortium (GCTC) kidney transplant cohort.

Methods

We examined the relationship between CMV infection rates and clinical characteristics, CMV viral load kinetics, and graft and patient outcomes in 2510 sequential kidney transplant recipients in the British Columbia Transplant Program. Transplants were performed between January 1, 2008, and December 31, 2018, were managed according to a standard protocol, and were followed until December 31, 2019, representing over 3.4 million days of care.

Results

Longitudinal CMV testing was performed in 2464 patients, of whom 434 (17.6%) developed a first episode of CMV viremia at a median of 120 (range: 9-3906) days post-transplant. Of these patients, 93 (21.4%) had CMV viremia only and 341 (78.6%) had CMV viremia with clinical complications, of whom 21 (4.8%) had resulting hospitalization. A total of 279 (11.3%) patients died and 177 (7.2%) patients lost their graft during the 12 years of follow-up. Patients with CMV infection were at significantly greater risk of graft loss (p=0.0041) and death (p=0.0056) than those without. Peak viral load ranged from 2.9 to 7.0 (median: 3.5) log10 IU/mL, the duration of viremia from 2 to 100 (15) days, and the viral load area under the curve from 9.4 to 579.8 (59.7) log10 IU/mL × days. All three parameters were closely inter-related and were significantly increased in patients with more severe clinical disease or with graft loss (p=0.001). Duration of the first CMV viremic episode greater than 15 days or a peak viral load ≥4.0 log10 IU/mL offered simple predictors of clinical risk with a 3-fold risk of transplant failure.

Conclusion

Viral load kinetics are closely related to CMV severity and to graft loss following kidney transplantation and provide a simple index of risk which may be valuable in guiding trials and treatment to prevent transplant failure.

Low-Dose vs Standard-Dose Valganciclovir for Cytomegalovirus Prophylaxis After Kidney Transplantation: A Single-Center Retrospective Analysis

BACKGROUND

Prophylactic administration of valganciclovir (VG) is an accepted method for the prevention of cytomegalovirus (CMV) infection after kidney transplantation (KTx). The standard dosage of oral VG is 900 mg/day, adjusted to renal function. There is growing evidence that low-dose 450 mg/day VG might be safe and effective. We compared low-dose vs standard-dose prophylaxis after KTx in a single-center follow-up study.

METHODS

Data from 603 renal transplantations at a single center were retrospectively analyzed (2011-2014, 12-month follow-up). Recipients with donor IgG positive-recipient IgG positive (D+/R+), (D+/R-), and (D-/R+) CMV serostatus were routinely treated with 450 mg/day VG for 3 months. Based on the same prophylactic dose, patients could be categorized into two groups according to their postoperative renal function: those receiving standard-dose VG due to a lower estimated glomerular filtration rate (eGFR) (average eGFR<60 mL/min/1.73 m2) and those receiving low-dose VG due to higher eGFR (average eGFR>60 mL/min/1.73 m2).

RESULTS

Estimated glomerular filtration rate-based VG serum alterations significantly affected the risk of CMV infection with a higher incidence in higher VG levels (standard-dose: 357 patients, CMV: 33 cases (9.2 %); low-dose: 246 patients, CMV: 10 cases (4.1%). The occurrence of known risk factors: serologic risk distribution and rate of induction therapy were not statistically different between the 2 groups. Treatment of an acute rejection episode influenced the infection rate significantly in the standard-dose group. As a side effect of prophylaxis, leucopenia (<3G/L) was 2.46 times higher in standard-dose vs low-dose group.

CONCLUSION

Low-dose VG administration is safe and non-inferior to the standard dose in the prophylaxis of CMV infection after KTx.

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.

Impact of antimetabolite discontinuation following cytomegalovirus or BK polyoma virus infection in kidney transplant recipients

BACKGROUND

Cytomegalovirus (CMV) and BK polyoma virus (BKV) infection following kidney transplantation have been associated with allograft dysfunction and allograft loss. Reduction in immunosuppression is a mainstay of management yet has been associated with increased risk of rejection. According to international consensus guidelines, one approach to management of these viral infections is to discontinue the antimetabolite. Little is known surrounding long-term outcomes in these patients, and it remains unclear if consideration should be given to resuming the antimetabolite as variable re-escalation strategies have been reported. The objective was to describe episodes of rejection and identify risk factors for rejection following antimetabolite withdrawal after CMV or BKV DNAemia in kidney transplant recipients.

METHODS

This single-center, retrospective review evaluated adult kidney transplant recipients with a serum CMV or BKV DNA PCR ≥500 copies/ml who underwent antimetabolite discontinuation. The primary outcome assessed was the incidence of biopsy-proven acute rejection (BPAR).

RESULTS

One hundred fifty-nine patients were included. Overall, 14 patients (8.8%) experienced BPAR at a median of 1.6 years after antimetabolite discontinuation. Compared to CMV, discontinuation after BKV DNAemia was associated with a higher incidence of BPAR. Characteristics observed more frequently in patients with BPAR included younger age, female sex, higher initial viral load, and development of de novo donor-specific antibody (DSA).

CONCLUSION

These findings suggest that antimetabolite discontinuation after CMV or BKV DNAemia in kidney transplant recipients is a reasonable and safe approach. Further prospective studies investigating optimal immunosuppression management following CMV or BKV DNAemia in kidney transplant recipients are warranted.

Integrated Analysis of ceRNA Regulatory Network Associated With Tumor Stage in Cervical Cancer

Objective

To analyze the abnormally expressed genes involved in cervical cancer occurrence and development.

Materials and Methods

Integrated bioinformatics methods were used to analyze differentially expressed (DE) RNAs, including mRNAs, microRNAs (miRNAs), and long non-coding RNAs (lncRNAs), in stage I, II, III, and IV cervical cancer patients from the TCGA database to fully reveal the dynamic changes caused by cervical cancer.

Results

First, DE RNAs in cervical cancer tissues from stage I, II, III, and IV patients and normal cervical tissues were identified and divided into different profiles. Several DE RNA profiles were down-regulated or up-regulated in stage I, III, and IV patients. GO and KEGG analysis of DE mRNA profile 1, 2, 4, 5, 6 and 22 which were significantly down-regulated or up-regulated showed that DE mRNAs are involved in cell division, DNA replication, cell adhesion, the positive and negative regulation of RNA polymerase ll promoter transcription. Besides, DE RNA profiles with significant differences in patient stages were analyzed to perform a competing endogenous RNA (ceRNA) regulatory network of lncRNA, miRNA, and mRNA. The protein-protein interaction (PPI) network of DE mRNAs in the ceRNA regulatory network was also constructed. The network had nine central genes (up-regulated genes: CDKN2A, GSK3B, BIRC5, CYCS, MAD2L1; down-regulated genes: PTEN, FOXO3, CCND2, TGFBR2). Survival analysis found that 5 lncRNAs, 9 mRNAs, and 4 miRNAs can be used as prognostic indicators of cervical cancer. Finally, combined with cluster analysis results, we further screened 2 DE RNAs (AMZ2P1 and HDAC5) using clinical samples, suggesting that AMZ2P1, and HDAC5 may act as diagnostic biomarkers for the development of cervical cancer.

Conclusion

This research provides new effective targets and reliable biological markers for the diagnosis and prognosis of cervical cancer.

Withdrawing mycophenolate mofetil in treating a young kidney transplant recipient with COVID-19: A case report

RATIONALE

Coronavirus disease 2019 (COVID-19) is a novel infectious disease and became a global issue. Treatment of COVID-19 especially in solid organ transplant recipients is empirical and controversial, especially the adjustment of the immunosuppressants.

PATIENT CONCERNS

A 29-year-old kidney transplant recipient with the symptoms of COVID-19 pneumonia.

DIAGNOSES

COVID-19 pneumonia after kidney transplantation.

INTERVENTIONS

He was treated with modified immunosuppressants (unchanged dose of tacrolimus and oral corticosteroids while discontinuing mycophenolate mofetil (MMF)), antibiotics, interferon α-2b inhalation and traditional Chinese medicine.

OUTCOMES

He recovered from COVID-19 pneumonia after 29 days of hospitalization. And the renal function (measured as blood urea nitrogen, serum creatinine, and urine protein) returned to normal.

LESSONS

In certain group of COVID-19 (e.g., mild to moderate cases, young patients without comorbidities), a reduction instead of an overall withdrawal of immunosuppressant in kidney transplant recipients is feasible.