Absolute Lymphocyte Count: A Predictor of Recurrent Cytomegalovirus Disease in Solid Organ Transplant Recipients

Efficacy of valganciclovir prophylaxis in kidney transplant recipients following low-dose rituximab induction therapy: a multicenter retrospective study

BACKGROUND

Rituximab (RIT) induction therapy is widely used for desensitization against ABO-incompatible living-donor kidney transplants (KT). However, the efficacy of valganciclovir (VGCV) prophylaxis against cytomegalovirus (CMV) disease and infection in KT recipients (KTRs) following RIT induction remains unclear.

METHODS

The current multicenter retrospective study included 213 KTRs who received low-dose RIT induction between 1998 and 2021, across 6 facilities included in the Michinoku Renal Transplant Network (MRTN). VGCV dosage varied from 450 mg/day (twice weekly) to 900 mg/day (daily), with treatment durations of 3-12 months. The primary and secondary endpoints were the incidence of CMV disease and infection, respectively.

RESULTS

The incidence of CMV disease was significantly higher in the VGCV group (23.5%; 16 patients) than in the non-VGCV group (5.5%; 8 patients) (p < 0.01). The incidence of CMV infection was 54.5% (79 patients) in the non-VGCV group and 48.5% (33 patients) in the VGCV group, with no significant difference (p = 0.42). In the subgroup of CMV-seronegative KTRs receiving allografts from CMV-seropositive donors (CMV IgG (D + /R-)), 18 out of 24 KTRs received VGCV prophylaxis, of whom 10 (55.6%) developed CMV disease. Within this subgroup, only 4 KTRs received VGCV with the standard protocol (900 mg daily for 6 months), and none developed CMV disease.

CONCLUSION

Insufficient VGCV prophylaxis does not reduce the incidence of CMV disease in KTRs following low-dose RIT induction. Despite concerns about leukopenia due to RIT and VGCV, in KTRs with CMV IgG (D + /R-) serostatus, VGCV prophylaxis with a standard protocol may be advisable.

Pulmonary Immunocompromise in Solid Organ Transplantation

This article reviews the multitude of factors contributing to immune dysfunction and pulmonary infection risk in solid organ transplant recipients and references relevant clinical scientific reports. The mechanisms of action of individual immunosuppressive agents are explained, and the clinical effects of these drugs are compared. In addition, specialized methods to assess the net state of immunosuppression in individual transplant recipients and their limitations are discussed.

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.

Current and emerging tools for simultaneous assessment of infection and rejection risk in transplantation

Infection and rejection are major complications that impact transplant longevity and recipient survival. Balancing their risks is a significant challenge for clinicians. Current strategies aimed at interrogating the degree of immune deficiency or activation and their attendant risks of infection and rejection are imprecise. These include immune (cell counts, function and subsets, immunoglobulin levels) and non-immune (drug levels, viral loads) markers. The shared risk factors between infection and rejection and the bidirectional and intricate relationship between both entities further complicate transplant recipient care and decision-making. Understanding the dynamic changes in the underlying net state of immunity and the overall risk of both complications in parallel is key to optimizing outcomes. The allograft biopsy is the current gold standard for the diagnosis of rejection but is associated with inherent risks that warrant careful consideration. Several biomarkers, in particular, donor derived cell-free-DNA and urinary chemokines (CXCL9 and CXCL10), show significant promise in improving subclinical and clinical rejection risk prediction, which may reduce the need for allograft biopsies in some situations. Integrating conventional and emerging risk assessment tools can help stratify the individual's short- and longer-term infection and rejection risks in parallel. Individuals identified as having a low risk of rejection may tolerate immunosuppression wean to reduce medication-related toxicity. Serial monitoring following immunosuppression reduction or escalation with minimally invasive tools can help mitigate infection and rejection risks and allow for timely diagnosis and treatment of these complications, ultimately improving allograft and patient outcomes.

Pathogen-specific cell-mediated immunity to guide the management of cytomegalovirus in solid organ transplantation: state of the art clinical review

INTRODUCTION

Cytomegalovirus (CMV) is a common opportunistic infection after solid organ transplantation, with significant impact on morbidity and long-term survival. Despite advances in diagnostics and therapeutics, the management of CMV remains very challenging.

AREAS COVERED

This article reviews emerging data on the clinical utility of laboratory assays that quantify cell-mediated immune responses to CMV. Observational studies have consistently demonstrated that a deficiency in pathogen-specific cell-mediated immunity is correlated with a heightened risk of primary, reactivation or recurrent CMV after transplantation. A limited number of interventional studies have recently investigated cell-mediated immune assays in guiding the prevention and treatment of CMV infection after solid organ transplantation.

EXPERT OPINION

The pathogenesis and outcome of CMV after solid organ transplantion reflect the interplay between viral replication and CMV-specific immune reconstitution. Research in CMV-specific cell-mediated immunity paved way for the development of several laboratory assays that may assist clinicians in predicting the risk of CMV after transplantation, individualize the approach to CMV disease prevention, guide the need and duration of treatment of CMV infection, and predict the risk of relapse after treatment. More interventional studies are needed to further solidify the role of cell-mediated immune assays in various clinical situations after transplantation.

Performance of a Global Functional Assay Based on Interferon-γ Release to Predict Infectious Complications and Cancer After Kidney Transplantation

The QuantiFERON-Monitor assay (QTF-Monitor) is intended to assess innate and adaptive immune responses by quantifying interferon (IFN)-γ release upon whole blood stimulation with a TLR7/8 agonist and an anti-CD3 antibody. We performed the QTF-Monitor in 126 kidney transplant recipients (KTRs) at different points during the first 6 post-transplant months. The primary outcome was overall infection, whereas secondary outcomes included bacterial infection, opportunistic infection and de novo cancer. The association between IFN-γ production and outcomes was analyzed as "low" immune responses (<15 IU/mL) and as a continuous variable to explore alternative thresholds. There were no significant differences in the occurrence of overall infection according to the QTF-Monitor at any monitoring point. Regarding secondary outcomes, KTRs with a low response at week 2 experienced a higher incidence of bacterial infection (50.8% versus 24.4%; P-value = 0.006). Low response at month 1 was also associated with opportunistic infection (31.6% versus 14.3%; P-value = 0.033). The discriminative capacity of IFN-γ levels was poor (areas under the ROC curve: 0.677 and 0.659, respectively). No differences were observed for the remaining points or post-transplant cancer. In conclusion, the QTF-Monitor may have a role to predict bacterial and opportunistic infection in KTRs when performed early after transplantation.

Management of cytomegalovirus infection after liver transplantation

Cytomegalovirus (CMV) infection is one of the primary causes of morbidity and mortality following liver transplantation (LT). Based on current worldwide guidelines, the most effective strategies for avoiding post-transplant CMV infection are antiviral prophylaxis and pre-emptive treatment. CMV- IgG serology is the established technique for pretransplant screening of both donors and recipients. The clinical presentation of CMV infection and disease exhibits variability, prompting clinicians to consistently consider this possibility, particularly within the first year post-transplantation or subsequent to heightened immunosuppression. At annual symposia to discuss CMV prevention and how treatment outcomes can be improved, evidence on the incorporation of immune functional tests into clinical practice is presented, and the results of studies with new antiviral treatments are evaluated. Although there are ongoing studies on the use of letermovir and maribavir in solid organ transplantation, a consensus reflected in the guidelines has not been formed. Determining the most appropriate strategy at the individual level appears to be the key to enhancing outcomes. Although prevention strategies reduce the risk of CMV disease, the disease can still occur in up to 50% of high-risk patients. A balance between the risk of infection and disease development and the use of immunosuppressants must be considered when talking about the proper management of CMV in solid organ transplant recipients. The objective of this study was to establish a comprehensive framework for the management of CMV in patients who have had LT.

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.

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Absolute Lymphocyte Count: a Predictor of Positive Serum PCR for Trypanosoma cruzi in Patients with Chagas Disease Undergoing Heart Transplantation

BACKGROUND

It is unknown whether lymphopenia is a risk factor for the reactivation of Chagas disease in heart transplantation (HTx), as recently described in the reactivation of cytomegalovirus in transplant patients.

OBJECTIVE

To evaluate whether lymphopenia in the perioperative period of heart transplantation is related to early Trypanosoma cruzi parasitemia.

METHODS

This observational, retrospective study analyzed a sample from January 2014 to January 2023). Parasitemia was evaluated in the first 3 months after HTx using serum polymerase chain reaction (PCR) and compared with the total lymphocyte count in the perioperative period of HTx using receiver operating characteristic curves. Baseline characteristics were compared with PCR for Chagas using independent Cox proportional hazards models. A significance level of 5% was adopted.

RESULTS

The sample (n = 35) had a mean age of 52.5 ± 8.1 years, and 22 patients (62.8%) had positive PCR for Chagas. The mean lowest lymphocyte values in the first 14 days after HTx were 398 ± 189 and 755 ± 303 cells/mm3 in patients with and without parasitemia, respectively, within 3 months after HTx (area under the curve = 0.857; 95% confidence interval: 0.996 to 0.718, sensitivity and specificity of 83.3% and 86.4%). A cutoff value of less than 550 lymphocytes/mm3 was determined as a risk factor for the presence of parasitemia. Patients with lymphocytes < 550 units/mm3 in the first 14 days after HTx presented positive PCR in 80% of cases. For every increase of 100 lymphocytes/mm3, the risk of PCR positivity was reduced by 26% (hazard rate ratio = 0.74; 95% confidence interval: 0.59 to 0.93, p = 0.009).

CONCLUSION

There was an association between lymphopenia in the perioperative period of HTx and early T. cruzi parasitemia detected by PCR.

Cytomegalovirus infection in heart transplant recipients: Epidemiology, risk factors, and long-term outcomes from a major transplant center in the United States

Background

Despite the use of antiviral prophylaxis, cytomegalovirus (CMV) remains a common opportunistic infection following heart transplantation. This study analyzes the rates, risk factors, and outcomes of CMV among heart transplant recipients.

Methods

A retrospective cohort study was conducted of adults who underwent heart transplantation between January 1, 2011, and March 31, 2019. The primary outcome was clinically significant CMV infection (csCMVi), defined as CMV disease or asymptomatic infection requiring pre-emptive therapy. The secondary outcome was all-cause mortality. Patients received valganciclovir prophylaxis up to 6 months, depending on CMV donor/recipient serostatus. Kaplan-Meier curve and multivariable Cox regression were used for outcome analysis.

Results

Among 553 heart transplant recipients, 101 (18.3%) experienced csCMVi, including 35 (6.3%) with CMV disease. csCMVi was uncommon during prophylaxis. In multivariable analysis, CMV D+/R- status hazard ratio (HR 12.88, 95% CI 6.76-24.56; p < 0.001) and lower absolute lymphocyte counts in seropositive recipients (HR 1.48, 95% CI 1.23-1.79; p < 0.001), but not CMV D+/R- patients (HR 1.18, 95% CI 0.94-1.47; p = 0.162), were significantly associated with csCMVi. Sixty patients died during follow-up, and csCMVi was associated with increased mortality (HR 2.84, 95% CI 1.62-4.98; p < 0.001).

Conclusions

In this large cohort of heart transplant recipients, csCMVi was linked to higher mortality. CMV D+/R- serostatus was associated with an increased risk of csCMVi, with lower absolute lymphocyte counts increasing risk only in CMV seropositive recipients. Strategies for optimizing CMV prevention in serodiscordant heart recipients are warranted.

What's New: Updates on Cytomegalovirus in Solid Organ Transplantation

Cytomegalovirus (CMV) is one of the most common infections occurring after solid organ transplantation. This high burden of disease, which incurs sizeable morbidity, may be worsening with the proportion of high-risk D+/R- solid organ transplantation recipients increasing in some regions globally. Cohort studies continue to support either universal prophylaxis or preemptive therapy as effective prevention strategies. Letermovir prophylaxis was noninferior to valganciclovir in adult high-risk D+/R- kidney transplant recipients with fewer drug-related adverse events in a recent clinical trial and has now been approved for such use in some regions. Maribavir preemptive therapy failed to demonstrate noninferiority when compared with valganciclovir in hematopoietic stem cell transplant recipients but looked promising for safety. Donor matching could be useful in prevention CMV disease with a survival advantage demonstrated in seronegative recipients waiting up to 30 mo for a seronegative kidney. Immune-guided prophylaxis resulted in fewer CMV infection episodes in lung transplant recipients when compared with fixed-duration prophylaxis in a recent clinical trial. For treatment of refractory or resistant CMV infection, maribavir was more efficacious and better tolerated when compared with investigator-initiated therapy in its registration trial for this condition. Further research regarding best treatment and prophylaxis of resistant or refractory CMV infection is needed to reflect best clinical practice choices. Optimal use of immune globulin or CMV-specific T cells for prevention or treatment of CMV disease remains undefined. Standardized definitions for the design of CMV clinical trials have been developed. In this review, we highlight recent updates in the field from data published since 2018.

Case report: CMV retinitis following local and systemic immunosuppression

We report the case of a 71-year-old man who presented 2 years following renal transplantation with diffuse, unilateral cytomegalovirus retinitis five weeks after receiving an intravitreal dexamethasone implant device for the management of central retinal vein occlusion. Examination of the left eye showed diffuse retinal hemorrhages, attenuated and tortuous retinal vessels, and superior retinal whitening. The patient was successfully treated with serial intravitreal foscarnet injections and oral valganciclovir with disease regression observed by 12 weeks after presentation. The patient's visual acuity and examination remained stable at 9-months follow-up.

Clinical features and prognosis of systemic lupus erythematosus complicated by active cytomegalovirus infection: a retrospective cohort study

Objective

The aim of this study was to investigate the clinical traits and consequences of systemic lupus erythematosus (SLE) complicated by active cytomegalovirus (CMV) infection.

Methods

This retrospective review involved the examination of medical records for patients diagnosed with SLE who had an active CMV infection at the time of their discharge from Peking Union Medical College Hospital between June 2016 and December 2022. The consistency between plasma CMV deoxyribonucleic acid (DNA) viral load and pp65 antigenemia was analyzed using the chi-square test. Related factors for CMV disease in SLE complicated by active CMV infection patients were analyzed by univariate analysis and multivariable stepwise logistic regression. Cox hazards regression analysis was used to determine predictors for all-cause mortality and CMV recurrence within 3 months.

Results

A total of 206 patients were enrolled in this study. Of the 123 patients who were detected with both plasma CMV DNA viral load and pp65 antigenemia within an interval not exceeding 72 h, the consistency between plasma CMV DNA viral load and pp65 antigenemia was not good (Kappa = -0.304, p < 0.001). Plasma CMV DNA viral load ≥ 1,600 copies/mL [odds ratio (OR) 4.411, 95% CI 1.871-10.402, p = 0.001], current glucocorticoids dose (equivalent to prednisolone) ≥60 mg/d (OR 2.155, 95% CI 1.071-4.334, p = 0.031), and elevated alanine transaminase (OR 3.409, 95% CI 1.563-7.435, p = 0.002) were significant clinical clues indicating CMV disease in SLE. Multivariable Cox hazards regression analysis showed that CMV organ involvement [hazard ratio (HR) 47.222, 95% CI 5.621-396.689, p < 0.001], SLE multi-system involvement (HR 1.794, 95% CI 1.029-3.128, p = 0.039), and elevated hypersensitive C-reactive protein (hsCRP) (HR 5.767, 95% CI 1.190-27.943, p = 0.030) were independent risk factors for 3-month all-cause mortality. CMV organ involvement (HR 3.404, 95% CI 1.074-10.793, p = 0.037) was an independent risk factor for CMV recurrence within 3 months.

Conclusion

In SLE patients, plasma CMV DNA viral load seemed to have a higher value in the diagnosis of CMV disease; patients with CMV organ involvement, SLE multi-system involvement, and elevated hsCRP might have a higher risk of 3-month all-cause mortality; and patients with CMV organ involvement might have a higher risk of CMV recurrence within 3 months.

Cytomegalovirus Cell-mediated Immunity Assays in Pediatric Transplantation

Cytomegalovirus (CMV) is a significant cause of morbidity and mortality in pediatric transplantation. However, currently utilized CMV prevention paradigms have limitations, leading to research aimed at novel strategies for mitigation of CMV infection. Cell-mediated immunity (CMI) is crucial in controlling CMV infection and the use of CMV-specific CMI assays to guide prevention and treatment of CMV infection in both solid organ transplant and hematopoietic cell transplant recipients shows great promise. In this article, we review the immune response to CMV infection to highlight the rationale for CMI assays, describe available commercial assays and strategies for their use, and summarize relevant literature regarding the use of CMI assays in transplant recipients.

Slaying the "Troll of Transplantation"-new frontiers in cytomegalovirus management: A report from the CMV International Symposium 2023

The 2023 International CMV Symposium took place in Barcelona in May 2023. During the 2-day meeting, delegates and faculty discussed the ongoing challenge of managing the risk of cytomegalovirus infection (the Troll of Transplantation) after solid organ or hematopoietic cell transplantation. Opportunities to improve outcomes of transplant recipients by applying advances in antiviral prophylaxis or pre-emptive therapy, immunotherapy, and monitoring of cell-mediated immunity to routine clinical practice were debated and relevant educational clinical cases presented. This review summarizes the presentations, cases, and discussions from the meeting and describes how further advances are needed before the Troll of Transplantation is slain.

Clinical utility of a cytomegalovirus-specific T cell assay in assessing the risk of post-prophylaxis cytomegalovirus infection and post-treatment relapse

INTRODUCTION

Cytomegalovirus (CMV) causes significant morbidity in solid organ transplant recipients (SOTR). Measuring cell-mediated immunity (CMI) may inform the risk of CMV infection after antiviral prophylaxis and predict relapse after CMV treatment.

METHODS

We serially assessed CMV CMI using the QuantiFERON-CMV assay (QF-CMV; Qiagen, Germantown, MD) in two cohorts of SOTRs: during valganciclovir prophylaxis and during treatment of CMV viremia. Results of CMI were correlated with post-prophylaxis CMV infection and post-treatment relapse, respectively.

RESULTS

Only one (4.2%) of 24 CMV D+/R- patients demonstrated positive QF-CMV by the end of valganciclovir prophylaxis. Four (16.6%) patients developed post-prophylaxis CMV infection; all four had undetectable QF-CMV at end of prophylaxis. Among 20 patients treated for CMV infection, 18 (90%) developed QF-CMV levels >.2 IU/mL by end of antiviral treatment and none developed CMV relapse. In contrast, the single patient who relapsed after completing treatment had a CMV CMI <.2 IU/ml (p = .0036).

CONCLUSION

Since CMV D+/R- SOTRs are unlikely to develop adequate CMV CMI while receiving valganciclovir prophylaxis, the utility of CMV CMI monitoring for risk stratification during time of prophylaxis had limited value. Conversely, CMV CMI testing may be a useful marker of the risk of CMV relapse after antiviral treatment.

A Clinical Model to Predict the Occurrence of Select High-risk Infections in the First Year Following Heart Transplantation

Background

Invasive infection remains a dangerous complication of heart transplantation (HT). No objectively defined set of clinical risk factors has been established to reliably predict infection in HT. The aim of this study was to develop a clinical prediction model for use at 1 mo post-HT to predict serious infection by 1 y.

Methods

A retrospective cohort study of HT recipients (2000-2018) was performed. The composite endpoint included cytomegalovirus (CMV), herpes simplex or varicella zoster virus infection, blood stream infection, invasive fungal, or nocardial infection occurring 1 mo to 1 y post-HT. A least absolute shrinkage and selection operator regression model was constructed using 10 candidate variables. A concordance statistic, calibration curve, and mean calibration error were calculated. A scoring system was derived for ease of clinical application.

Results

Three hundred seventy-five patients were analyzed; 93 patients experienced an outcome event. All variables remained in the final model: aged 55 y or above, history of diabetes, need for renal replacement therapy in first month, CMV risk derived from donor and recipient serology, use of induction and/or early lymphodepleting therapy in the first month, use of trimethoprim-sulfamethoxazole prophylaxis at 1 mo, lymphocyte count under 0.75 × 103cells/µL at 1 mo, and inpatient status at 1 mo. Good discrimination (C-index 0.80) and calibration (mean absolute calibration error 3.6%) were demonstrated.

Conclusion

This model synthesizes multiple highly relevant clinical parameters, available at 1 mo post-HT, into a unified, objective, and clinically useful prediction tool for occurrence of serious infection by 1 y post-HT.

Cytomegalovirus Cell-Mediated Immunity: Ready for Routine Use?

Utilizing assays that assess specific T-cell-mediated immunity against cytomegalovirus (CMV) holds the potential to enhance personalized strategies aimed at preventing and treating CMV in organ transplantation. This includes improved risk stratification during transplantation compared to relying solely on CMV serostatus, as well as determining the optimal duration of antiviral prophylaxis, deciding on antiviral therapy when asymptomatic replication occurs, and estimating the risk of recurrence. In this review, we initially provide an overlook of the current concepts into the immune control of CMV after transplantation. We then summarize the existent literature on the clinical experience of the use of immune monitoring in organ transplantation, with a particular interest on the outcomes of interventional trials. Current evidence indicates that cell-mediated immune assays are helpful in identifying patients at low risk for replication for whom preventive measures against CMV can be safely withheld. As more data accumulates from these and other clinical scenarios, it is foreseeable that these assays will likely become part of the routine clinical practice in organ transplantation.

BK polyomavirus DNAemia in pancreas transplant recipients compared to pancreas-kidney recipients

BACKGROUND

BK polyomavirus (BKV) infection is a common complication of kidney transplantation. While BKV has been described in non-kidney transplant recipients, data are limited regarding its epidemiology and outcomes in pancreas transplant recipients.

METHODS

We conducted a retrospective cohort study of adults who underwent pancreas transplantation from 2010-2020. The primary outcome was BKV DNAemia. Secondary outcomes were estimated glomerular filtration rate (eGFR) reduction by 30%, eGFR < 30 mL/min/1.73 m2 , endstage kidney disease, and pancreas allograft failure. Cox regression with time-dependent variables was utilized.

RESULTS

Four hundred and sixty-six patients were analyzed, including 74, 46, and 346 with pancreas transplant alone (PTA), pancreas-after-kidney, or simultaneous pancreas-kidney transplants, respectively. PTA recipients experienced a lower incidence of BKV DNAemia (8.8% vs. 32.9%; p < .001) and shorter duration of DNAemia (median 28.0 vs. 84.5 days). No PTA recipients with BKV DNAemia underwent kidney biopsy or developed endstage kidney disease. Lymphopenia, non-PTA transplantation, and older age were associated with BKV DNAemia, which itself was associated with pancreas allograft failure (adjusted hazard ratio 2.14, 95% confidence interval 1.27-3.60; p = .004). Among PTA recipients, BKV DNAemia was not associated with eGFR reduction or eGFR < 30 mL/min/1.73 m2 .

CONCLUSIONS

BKV DNAemia was common among PTA recipients, though lower than a comparable group of pancreas-kidney recipients. However, BKV DNAemia was not associated with adverse native kidney outcomes and no PTA recipients developed endstage kidney disease. Conversely, BKV DNAemia was associated with pancreas allograft failure. Further studies are needed to estimate the rate of BKV nephropathy in this population, and further evaluate long-term kidney outcomes.

Oral antiviral drugs for treatment of cytomegalovirus in transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is an opportunistic pathogen responsible for substantial morbidity after solid organ transplantation and haematopoietic stem cell transplantation. Treatment of CMV disease involves a two-pronged approach with antiviral drug treatment coupled with strategies to minimize the intensity of immune suppression.

OBJECTIVES

This narrative review examines the evidence for the current treatment of CMV disease in transplant recipients, including the use of oral antiviral drugs.

SOURCES

Literature search was performed on PubMed with keywords cytomegalovirus, transplantation, ganciclovir, valganciclovir, maribavir, letermovir, cidofovir, and foscarnet.

CONTENT

Intravenous and oral valganciclovir are the standard first-line treatment of cytomegalovirus disease after transplantation. Oral maribavir has demonstrated superior efficacy and safety over CMV DNA polymerase inhibitors for the treatment of refractory or resistant CMV infection. Transplant patients with severe and life-threatening CMV disease, those with very high viral load, and patients with impaired gastrointestinal absorption should still be treated initially with intravenous antiviral drugs, including ganciclovir and foscarnet. Criteria for the safe transition from intravenous therapies to oral antiviral drugs include achieving clinical improvement and satisfactory decline in viral load. Recurrence of CMV viremia and disease is common, particularly among transplant patients who are lymphopenic and have impaired CMV-specific immunity.

IMPLICATIONS

Oral antiviral drugs for the treatment of CMV infection and disease in transplant recipients have improved the CMV landscape, because they reduce the cost and mitigate the inconvenience and risks related to prolonged hospitalization and the need for long-term intravascular access. However, their antiviral efficacy should be complemented by an intentional strategy of reducing the degree of immune suppression to allow for immunologic recovery that ensures durable control of CMV infection.

Diagnosis, Prevention, and Treatment of Infections in Kidney Transplantation

Kidney transplant often is complicated by infections in the recipient from therapy-related and patient-related risk factors. Infections in kidney transplant recipients are associated with increased morbidity, mortality, and allograft dysfunction. There is a predictable timeline after kidney transplant regarding the types of pathogens causing infections, reflecting the net state of immunosuppression. In the early post-transplant period, bacterial infections comprise two thirds of all infections, followed by viral and fungal infections. Infections occurring early after kidney transplantation are generally the result of postoperative complications. In most cases, opportunistic infections occur within 6 months after kidney transplantation. They may be caused by a new infection, a donor-derived infection, or reactivation of a latent infection. Community-acquired pneumonia, upper respiratory tract infections, urinary tract infections, and gastrointestinal infections are the most common infections in the late period after transplantation when the net immunosuppression is minimal. It is crucial to seek information on the time after transplant, reflecting the net state of immunosuppression, previous history of exposure/infections, geography, and seasonal outbreaks. It is imperative that we develop regionally specific guidelines on screening, prevention, and management of infections after kidney transplantation.

Absolute Lymphocyte Count as a Marker for Cytomegalovirus Infection After Heart Transplantation

BACKGROUND

Previous studies indicate an association between reduced absolute lymphocyte count (ALC) and cytomegalovirus (CMV) infection after solid organ transplantation and have therefore highlighted the potential of ALC as a simple tool to predict CMV infection in transplant patients. This study aimed to examine the utility of ALC as a valuable marker for CMV infection in heart transplant patients.

METHODS

Clinical information and ALC data of all adult patients who received orthotopic heart transplantation at the Medical University of Vienna between January 2004 and May 2019 were collected. We performed a multivariable Cox regression model that incorporates repeated measurements of ALC as a time-varying continuous factor in 2 ways, first as continuous logarithmic factor considering a 50% decrease of ALC levels and second as binary factor using a threshold of 610 cells/μL.

RESULTS

One hundred fifty-eight (39%) patients developed CMV infection over the course of 2 y. Patients with lymphopenia were shown to be at higher risk of developing CMV infection both in the continuous approach (HR [per 50% reduction] 1.29; confidence interval [CI], 1.09-1.53; P = 0.003) and the binary approach with a cutoff of 610 cells/μL (HR 1.74; CI, 1.20-2.51; P = 0.003).

CONCLUSIONS

This study demonstrated a strong association between reduced ALC and the development of CMV infection after heart transplantation. ALC value monitoring could provide an additional tool to assess individualized CMV risk after solid organ transplantation.

Female sex and advanced age are associated with invasive cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

Limited data exist to describe sex-based differences in the severity of cytomegalovirus (CMV) infection after solid organ transplant (SOT). We sought to identify if a difference exists in likelihood of tissue-invasive disease between male and female SOT recipients and to understand how age affects this relationship.

METHODS

A retrospective cohort of 180 heart, liver, and kidney recipients treated for CMV was examined. A logistic regression model was developed to assess the relationship between female sex and CMV type (noninvasive vs. invasive). A secondary regression analysis looked at the relationship of invasive CMV with a variable combining sex with age above or below 50.

RESULTS

There were 37 cases of proven or probable invasive CMV, occurring in 30% of females versus 16% of males. After adjustment for potential confounders, females with CMV infection were significantly more likely to have invasive disease (odds ratio (OR) 2.69, 95% confidence interval (CI) 1.25-5.90, p = .01). Females 50 years or older were at particular risk compared with males under 50 years (adjusted OR 4.54, 95% CI 1.33-18.83, p = .02).

CONCLUSION

Female SOT recipients with CMV in our cohort were more likely than males to have tissue-invasive disease, with the highest risk among older females. Further prospective studies are warranted to explore underlying immunologic mechanisms.

Cytomegalovirus in the transplant setting: Where are we now and what happens next? A report from the International CMV Symposium 2021

The CMV Symposium in September 2021 was an international conference dedicated to cytomegalovirus (CMV) infection after solid organ or hematopoietic stem cell transplantation. This review provides an overview of the presentations given by the expert faculty, supplemented with educational clinical cases. Topics discussed include CMV epidemiology and diagnosis, the burden of CMV infection and disease, CMV-specific immunity and management of CMV in transplant settings. Major advances in the prevention and treatment of CMV in the past decade and increased understanding of CMV immunity have led to improved patient outcomes. In the future, management algorithms may be individualized based on the transplant recipient's immune profile, which will mark the start of a new era for patients with CMV.

Risk factors for mortality in kidney transplant recipients with COVID-19: a single centre experience and case-control study

BACKGROUND

COVID-19 infection is considered to cause high mortality in kidney transplant recipients (KTR). Old age, comorbidities and acute kidney injury are known risk factors for increased mortality in KTR. Nevertheless, mortality rates have varied across different regions. Differences in age, comorbidities and varying standards of care across geographies may explain some variations. However, it is still unclear whether post-transplant duration, induction therapy, antirejection therapy and co-infections contribute to increased mortality in KTR with COVID-19. The present study assessed risk factors in a large cohort from India.

METHODS

A matched case-control study was performed to analyze risk factors for death in KTR (N = 218) diagnosed with COVID-19 between April 2020 to July 2021 at the study centre. Cases were KTR who died (non-survivors, N = 30), whereas those who survived were taken as controls (survivors, N = 188).

RESULTS

A high death-to-case ratio of 13.8% was observed amongst study group KTR infected with COVID-19. There was a high incidence (12.4%) of co-infections, with cytomegalovirus being the most common co-infection among non-survivors. Diarrhea, co-infection, high oxygen requirement, and need for mechanical ventilation were significantly associated with mortality on regression analyses. Antirejection therapy, lymphopenia and requirement for renal replacement therapy were associated with worse outcomes.

CONCLUSIONS

The mortality was much higher in KTR who required mechanical ventilation and had co-infections. Mortality did not vary with the type of transplant, post-transplant duration and usage of depletion induction therapy. An aggressive approach has to be taken for an early diagnosis and therapeutic intervention of associated infections.

GS. A Case of Cytomegalovirus Colitis in an Immunocompetent COVID-19 Patient

Cytomegalovirus (CMV) is a double-stranded DNA virus that belongs to the herpesvirus family. In the immunocompetent host, CMV infection is usually mild and goes unnoticed. Patients become prone to CMV infection as a result of immunosuppressive drugs or disorders that weaken cellular immunity. In severe COVID-19 infection, the patient experiences a drop in his T lymphocytes and becomes prone to opportunistic infections such as CMV colitis. In this paper, we presented a rare case of CMV colitis in a 54-year-old female with a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) polymerase chain reaction. The patient was admitted to the intensive care unit and intubated due to the severity of her presentation. The patient received high-dose dexamethasone followed by a tapering dose of prednisolone. Fifteen days post-admission, the patient started to have melena with a drop in her hemoglobin. Sigmoidoscopy revealed ulcerated lesions that extended 5 cm proximally, and multiple biopsies confirmed the diagnosis of CMV colitis. The patient was started on ganciclovir 5 mg/kg intravenously for 21 days. The patient's symptoms improved to the point where she no longer complained of melena, and her hemoglobin level normalized. The patient was discharged home in stable condition, to be followed later in the outpatient clinic.

Risk constellations, viral infections, and prophylaxis in uterine transplantation

PURPOSE OF REVIEW

Uterine transplantation (UTx) is a burgeoning new category of solid organ transplantation (SOT) that is practiced at several centers worldwide (first transplantation in 2013). Although there are still relatively low numbers of transplants (<75 published in literature), they are increasing in frequency and thus we attempt to discuss the current documented infections in this population as well as theoretical infectious risks and summarize prophylaxis and treatment strategies of centers current performing these procedures.

RECENT FINDINGS

The most reported posttransplantation infection is not surprisingly urinary tract infections, with other documented infections including bacterial infections at site of graft (Enterococcus), herpes simplex virus, cytomegalovirus (CMV), human papillomavirus, Candida, and reportedly posttransplant lymphoproliferative disorder. The net state of immunosuppression and host factors (host colonization and serologic status of viral exposures) plays a significant role in infectious risk and with low numbers of infections documented, much of our guidance surrounding prophylaxis is inferred from SOT literature.

SUMMARY

In this review, we give an overview of described infections in UTx and theoretical infectious risks, detailing how to tailor prophylaxis base on host risk, with specific focus that the goal of transplantation is completion of a successful pregnancy as the desired outcome. Special considerations should be given to pregnant recipients when managing infectious complications and further data collection and reporting regarding infectious complications is crucial to advance this field as numbers of transplantation continue to increase.

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.

Evaluation of Cytomegalovirus Infections in Liver Transplant Recipients Under Universal Prophylaxis: A Single Centre Experience

Background: Cytomegalovirus (CMV) is one of the leading viral agents that can pave the way for serious complications and organ damage in solid organ transplant (SOT) recipients after transplantation. Strategies have been developed to protect at-risk patients from CMV infection following transplantation. Since more than 90% of adults in Turkey were positive for CMV IgG, universal CMV prophylaxis was applied, and the results were evaluated. Objectives: This study aimed to evaluate the results of universal CMV prophylaxis after liver transplantation in the long term. Methods: A total of 1,090 liver transplant patients were evaluated in terms of CMV infection in the Organ Transplantation Institute of Inonu University, Malatya, Turkey, from October 2014 to December 2019. In order to identify the CMV infections, quantitative nucleic acid amplification (QNAT) was used to detect potential CMV DNA. The cut-off value of CMV DNA was determined to be 1000 copies/mL after transplantation. Results: According to the clinical and laboratory assessments, 33 (3%) patients were diagnosed with CMV infection, and 25 (2.3%) patients were evaluated as possibly having CMV syndrome. Also, eight of the 33 patients were assessed as having end-organ CMV disease and 25 as probable CMV syndrome. In the late period following prophylaxis, CMV infection was observed in 10 (0.9%) cases. The infection rate after prophylaxis (0.9%) was lower than the infection rate (2.1%) seen during prophylaxis. Conclusions: Close clinical follow-up with CMV prophylaxis and strict monitoring of CMV DNA by determining a specific cut-off point are important in the follow-up of liver transplant patients.

CMV viral load kinetics as surrogate endpoints after allogeneic transplantation

BACKGROUNDViral load (VL) surrogate endpoints transformed development of HIV and hepatitis C therapeutics. Surrogate endpoints for CMV-related morbidity and mortality could advance development of antiviral treatments. Although observational data support using CMV VL as a trial endpoint, randomized controlled trials (RCTs) demonstrating direct associations between virological markers and clinical endpoints are lacking.METHODSWe performed CMV DNA PCR on frozen serum samples from the only placebo-controlled RCT of ganciclovir for early treatment of CMV after hematopoietic cell transplantation (HCT). We used established criteria to assess VL kinetics as surrogates for CMV disease or death by weeks 8, 24, and 48 after randomization and quantified antiviral effects captured by each marker. We used ensemble-based machine learning to assess the predictive ability of VL kinetics and performed this analysis on a ganciclovir prophylaxis RCT for validation.RESULTSVL suppression with ganciclovir reduced cumulative incidence of CMV disease and death for 20 years after HCT. Mean VL, peak VL, and change in VL during the first 5 weeks of treatment fulfilled the Prentice definition for surrogacy, capturing more than 95% of ganciclovir's effect, and yielded highly sensitive and specific predictions by week 48. In the prophylaxis trial, the viral shedding rate satisfied the Prentice definition for CMV disease by week 24.CONCLUSIONSOur results support using CMV VL kinetics as surrogates for CMV disease, provide a framework for developing CMV preventative and therapeutic agents, and support reductions in VL as the mechanism through which antivirals reduce CMV disease.FUNDINGMerck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc.

Difference in absolute lymphocyte count among male and female heart transplant recipients

The impact of sex on immune composition in the setting of solid organ transplantation is unknown. Immunocompetent men and women have quantitative differences in multiple markers of immunity, including lymphocyte subsets. Lymphocytes are of particular interest given the routine use of medications targeted at cell-mediated immunity. The objective of this retrospective cohort study was to compare absolute lymphocyte count (ALC) measurements of male and female heart recipients immediately before, and 1 month after, transplantation. Data was collected on 375 adult recipients (104 female and 271 male) from 2000 to 2018 at a single center. Mean ALC was compared using Student's t-test. Women had higher mean ALC both at baseline (female 1.6 × 10³ cells/μl vs. male 1.3 × 10³ cells/μl; P < .001) and at 1 month post-transplantation (mean 1.2 × 10³ cells/μl vs. .8 × 10³ cells/μl; P < .001). This finding could have important implications for sex-based differences in predisposition to rejection or response to infection or vaccination.

Posttreatment Lymphopenia Is Associated With an Increased Risk of Redeveloping Nontuberculous Lung Disease in Patients With Mycobacterium avium Complex Lung Disease

BACKGROUND

Lymphopenia has been reported as a risk factor for poor prognosis in various infectious diseases, including Mycobacterium avium complex lung disease (MAC-LD), and recurrence in several infectious diseases. However, the association between lymphopenia and the risk of redeveloping nontuberculous lung disease (NTM-LD) after completed treatment for MAC-LD is unknown.

METHODS

We performed a retrospective cohort study with 147 patients with MAC-LD who successfully completed guideline-based therapy. Lymphopenia was defined as an absolute lymphocyte count (ALC) <1000 cells/μL based on commonly accepted reference values.

RESULTS

During the median follow-up period of 41.9 months after treatment completion, 59 (40.1%) patients redeveloped NTM-LD. Patients with NTM-LD redevelopment had significantly lower posttreatment ALCs (median, 1260 vs 1420 cells/μL) than those without, and the univariate Cox proportional hazard analysis identified posttreatment ALC as a predictive factor for redevelopment (hazard ratio, .94 [95% confidence interval, .89-.99] for every increase of 100 cells/μL; P = .04). In the multivariate analysis, posttreatment ALC and the extent of bronchiectasis were independently associated with NTM-LD redevelopment. The cumulative rate of NTM-LD redevelopment was significantly higher in patients with posttreatment lymphopenia than in those without (P = .008).

CONCLUSIONS

Posttreatment lymphopenia could predict an increased risk of NTM-LD redevelopment after completed treatment for MAC-LD.

Risk Factors for Cytomegalovirus Reactivation and Association With Outcomes in Critically Ill Adults With Sepsis: A Pooled Analysis of Prospective Studies

We performed multivariable analysis of potential risk factors (including cytomegalovirus [CMV] reactivation) for clinical outcomes by day 28 (death or continued hospitalization, ventilator-free days, intensive care unit (ICU)-free days, hospital-free days) from pooled cohorts of 2 previous prospective studies of CMV-seropositive adults with sepsis. CMV reactivation at any level, >100 IU/mL, >1000 IU/mL, peak viral load, and area under the curve were independently associated with the clinical outcomes. We identified the potential effect size of CMV on outcomes that could be used as end points for future interventional trials of CMV prevention using antiviral prophylaxis in ICU patients with sepsis.

Reactivation of Cytomegalovirus Following Left Ventricular Assist Device Implantation: A Case-Control Study

While cytomegalovirus (CMV) reactivation occurs in immunocompetent patients who are critically ill and has been associated with worse outcomes, very few cases of CMV reactivation have been reported following left ventricular assist device (LVAD) implantation. We aimed to evaluate the incidence and risk factors for CMV reactivation following LVAD implantation. Retrospective chart review of patients who had undergone LVAD implantation between July 2004 and December 2018 was performed. Cases with CMV reactivation post-LVAD were randomly matched (1:2) by sex, LVAD type, and implant year with controls utilizing SAS macros. Fisher's exact and paired sample t-tests were performed to evaluate for differences between categorical and continuous variables, respectively. Days to reactivation post-LVAD implantation were calculated in cases, and the corresponding times post-LVAD implantation were determined in control patients for variable comparisons. Survival analysis was performed using the Kaplan-Meier method. Of the 349 patients reviewed, 208 (59.6%) patients were seropositive for CMV before LVAD implantation. Of these 208 patients, eight (3.8%) had CMV reactivation following LVAD implantation. The median time to CMV reactivation following LVAD implantation was 21.5 days (range, 6-177). Six (75%) patients had CMV viremia, and the other two had colitis and pneumonia without viremia. In comparison to controls, patients with CMV had higher creatinine levels (p = 0.039) and higher RDW (p = 0.05) and were more likely to have received steroids within the previous week (p = 0.028) and to have concurrent bacterial infection (p = 0.001). CMV reactivation following LVAD implantation is more frequent than expected. Early testing, diagnosis, and treatment in at-risk patients (i.e., renal failure, steroid use, elevated RDW) might improve clinical outcomes.

Factors associated with neutropenia post heart transplantation

BACKGROUND

Neutropenia is a serious complication following heart transplantation (OHT); however, risk factors for its development and its association with outcomes is not well described. We sought to study the prevalence of neutropenia, risk factors associated with its development, and its impact on infection, rejection, and survival.

METHODS

A retrospective single-center analysis of adult OHT recipients from July 2004 to December 2017 was performed. Demographic, laboratory, medication, infection, rejection, and survival data were collected for 1 year post-OHT. Baseline laboratory measurements were collected within the 24 hours before OHT. Neutropenia was defined as absolute neutrophil count ≤1000 cells/mm3. Cox proportional hazards models explored associations with time to first neutropenia. Associations between neutropenia, analyzed as a time-dependent covariate, with secondary outcomes of time to infection, rejection, or death were also examined.

RESULTS

Of 278 OHT recipients, 84 (30%) developed neutropenia at a median of 142 days (range 81-228) after transplant. Factors independently associated with increased risk of neutropenia included lower baseline WBC (HR 1.12; 95% CI 1.11-1.24), pre-OHT ventricular assist device (1.63; 1.00-2.66), high-risk CMV serostatus [donor positive, recipient negative] (1.86; 1.19-2.88), and having a previous CMV infection (4.07; 3.92-13.7).

CONCLUSIONS

Neutropenia is a fairly common occurrence after adult OHT. CMV infection was associated with subsequent neutropenia, however, no statistically significant differences in outcomes were found between neutropenic and non-neutropenic patients in this small study. It remains to be determined in future studies if medication changes in response to neutropenia would impact patient outcomes.

Evaluation of cytomegalovirus prophylaxis in low and intermediate risk kidney transplant recipients receiving lymphocyte-depleting induction

Cytomegalovirus (CMV) is a significant cause of morbidity in kidney transplant recipients (KTR). Historically at our institution, KTR with low and intermediate CMV risk received 6 months of valganciclovir if they received lymphocyte depleting induction therapy. This study evaluates choice and duration of CMV prophylaxis based on donor (D) and recipient (R) CMV serostatus and the incidence of post-transplant CMV viremia in low (D-/R-) and intermediate (R+) risk KTR receiving lymphocyte-depleting induction therapy. A protocol utilizing valacyclovir for 3 months for D-/R- and valganciclovir for 3 months for R+ was evaluated. Adult D-/R- and R+ KTR receiving anti-thymocyte globulin, rabbit or alemtuzumab induction from 8/20/2016 to 9/30/2018 were evaluated through 1 year post-transplant. Patients were excluded if their CMV serostatus was D+/R-, received a multi-organ transplant, or received basiliximab. Seventy-seven subjects met the inclusion criteria: 25 D-/R- (4 historic group, 21 experimental group) and 52 R+ (31 historic, 21 experimental). No D-/R- patients experienced CMV viremia. Among the R+ historic and experimental groups, there was no significant difference in viremia incidence (35.5% vs 52.4%; P = .573). Of these cases, the peak viral load was similar between the groups (median [IQR], 67 [<200-444] vs <50 [<50-217]; P = .711), and there was no difference in the incidence of CMV syndrome (16.1% vs 14.3%; P = 1.000) or CMV related hospitalization (12.9% vs 14.3%; P = 1.000). No patient experienced tissue invasive disease. These results suggest limiting valganciclovir exposure may be possible in low and intermediate risk KTR receiving lymphocyte-depleting induction therapy with no apparent impact on CMV-related outcomes.

Post-transplant absolute lymphocyte count predicts early cytomegalovirus infection after heart transplantation

Immunosuppressive therapy can decrease rejection episodes and increase the risk of severe and fatal infections in heart transplantation (HT) recipients. Immunosuppressive therapy can also decrease the absolute lymphocyte count (ALC), but the relationship between early post-transplant ALC and early cytomegalovirus (CMV) infection is largely unknown, especially in HT. We retrospectively analyzed 58 HT recipients who tested positive for CMV IgG antibody and received basiliximab induction therapy. We collected preoperative and 2-month postoperative data on ALC and CMV load. The CMV load > 1200 IU/mL was used as the cutoff value to define early CMV infection. Post-transplant lymphopenia was defined as an ALC of < 500 cells/μL at postoperative day (POD) #7. On POD #7, 29 (50.0%) patients had post-transplant lymphopenia and 29 (50.0%) patients did not. The incidence of CMV infection within 1 or 2 months of HT was higher in the post-transplant lymphopenia group than in the non-lymphopenia group (82.8% vs. 48.3%, P = 0.013; 89.7% vs. 65.5%, P = 0.028, respectively). ALC < 500 cells/μL on POD #7 was an independent risk factor for early CMV infection within 1 month of HT (odds ratio, 4.14; 95% confidence interval, 1.16-14.77; P = 0.029). A low ALC after HT was associated with a high risk of early CMV infection. Post-transplant ALC monitoring is simple and inexpensive and can help identify patients at high risk of early CMV infection.

Progress and Challenges in the Prevention, Diagnosis, and Management of Cytomegalovirus Infection in Transplantation

Hosts with compromised or naive immune systems, such as individuals living with HIV/AIDS, transplant recipients, and fetuses, are at the highest risk for complications from cytomegalovirus (CMV) infection. Despite substantial progress in prevention, diagnostics, and treatment, CMV continues to negatively impact both solid-organ transplant (SOT) and hematologic cell transplant (HCT) recipients. In this article, we summarize important developments in the field over the past 10 years and highlight new approaches and remaining challenges to the optimal control of CMV infection and disease in transplant settings.

Association between lymphopenia at one month post-transplant and infectious outcomes or death in heart transplant recipients

BACKGROUND

Cell-mediated immunity is a specific target of several medications used to prevent or treat rejection in orthotopic heart transplantation. Low absolute lymphocyte count (ALC) has potential to be a useful and accessible clinical indicator of overall infection risk. Though some studies have demonstrated this association in other transplant populations, it has not been assessed in heart transplant recipients.

METHODS

A single-center retrospective cohort study examined adult heart transplant recipients transplanted between 2000 and 2018. The exposure of interest was ALC less than 0.75 x10 3cells/µL at one month post-transplant and the primary endpoint was a composite outcome of infection (including cytomegalovirus [CMV], herpes simplex I/II or varicella zoster virus [HSV/VZV], blood stream infection [BSI], invasive fungal infection [IFI]) or death occurring after one month and before one year post-transplant. A multivariable Cox proportional hazards model was created to control for confounders identified using clinical judgment and statistical criteria.

RESULTS

Of 375 subjects analyzed, 101 (27%) developed the composite outcome (61 CMV, 3 HSV/VZV, 19 BSI, 10 IFI, 8 deaths). Lymphopenia (ALC<0.75 x10 3cells/µL) at one month was associated with a greater than two fold higher rate of the composite outcome (hazard ratio 2.26, 95% confidence interval 1.47-3.46, p-value <0.001) compared to patients without lymphopenia at one month. After adjustment for confounding variables, the presence of lymphopenia remained statistically significantly associated with the composite outcome (HR 1.72 95% CI 1.08-2.75, p=0.02). Conclusion: ALC measured at one month post-heart transplant is associated with an increased risk of infectious outcomes or death in the ensuing 11months. This is a simple, accessible laboratory measure.

Absolute lymphocyte count as marker of cytomegalovirus and allograft rejection: Is there a "Safe Corridor" after kidney transplantation?

The contrasting outcomes of lymphocyte manipulation after solid organ transplantation are allograft rejection and infections, commonly with cytomegalovirus (CMV). Peripheral blood absolute lymphocyte count (ALC) may serve as a predictive marker for these outcomes. Using a retrospective review of clinical and laboratory dataset, we aimed to determine whether a range of ALC (termed "safe ALC corridor") exists where CMV infection and rejection outcomes are minimal in a cohort of 381 kidney transplant recipients. In an extended Cox model using a time-dependent covariate for peripheral blood ALC, a value below the cut-off of 610 cells/uL was associated with the development of CMV infection both in the overall cohort (Hazard Ratio [HR] 2.25 (95% confidence internal [CI] 1.02-4.96; P = .043) and the subgroup of high-risk CMV D+/R- mismatch patients (HR 2.91 [95% CI 1.09-7.77]; P = .033). In contrast, a time-dependent Cox analysis did not show any significant association between ALC and rejection (per IQR decrease, HR 1.2 [95% CI: 0.76-1.9]; P = .434). Accordingly, a "safe ALC corridor" could not be defined. In conclusion, a low peripheral blood ALC (ie, threshold of 610 cells/uL) can be used to stratify the risk of CMV disease after kidney transplantation.