Cytomegalovirus infection in solid organ transplant recipients

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.

Area-Level Social Deprivation and Cytomegalovirus Seropositivity at the Time of Solid Organ Transplant

Importance

Cytomegalovirus (CMV) is associated with significant morbidity and mortality in solid organ transplant (SOT) recipients. The risk factors for CMV seropositivity in SOT recipients, including area-level social deprivation in the US, have not been fully characterized.

Objective

To (1) evaluate CMV seroprevalence, (2) assess the recipient characteristics associated with CMV seropositivity, and (3) assess the association of area-level social deprivation index (SDI) scores with pretransplant CMV serostatus.

Design, Setting, and Participants

This retrospective cross-sectional analysis of the Scientific Registry of Transplant Recipients database included all adult (aged ≥18 years) SOT recipients from January 1, 2008, to May 31, 2022. Data were analyzed from April 10 to October 25, 2023.

Exposure

Recipient characteristics and area-level SDI.

Main Outcomes and Measures

Multivariable generalized linear models were used to evaluate the association between (1) patient characteristics and CMV and (2) social deprivation (measured by SDI scores, which were assessed in quintiles, from lowest to highest) and CMV seropositivity. In addition, differences based on patient demographics and the transplanted organ(s) were evaluated.

Results

Among the 389 288 SOT recipients included in the analysis, mean (SD) age was 53.3 (13.0) years; 63.0% were male, 21.4% were Black, 15.2% were Hispanic White, 56.2% were non-Hispanic White, and 62.7% were CMV seropositive. The mean (SD) age was higher among CMV seropositive (54.0 [12.7] years) compared with CMV seronegative (52.0 [13.5] years) patients. Seropositivity for CMV was higher among women (69.9%) than men (58.5%) and among Black (74.8%) and Hispanic White (80.2%) patients compared with non-Hispanic White patients (50.4%). Seropositivity for CMV was highest among kidney (64.5%), liver (63.6%), and kidney and liver (66.2%) recipients. Greater SDI scores were associated with greater CMV seropositivity, ranging from 51.7% for the least deprived to 75.5% for the most deprived quintiles (P < .001), independent of age, sex, or race.

Conclusions and Relevance

In this cross-sectional study, an association between SDI and CMV seropositivity was observed among SOT recipients, independent of age, sex, or race and ethnicity. To optimize posttransplant outcomes in CMV seropositive recipients, efforts targeting prevention of CMV reactivation need to be prioritized in these higher-risk populations.

Dynamics and Evolution of Donor-derived Cytomegalovirus Infection in 3 Solid Organ Transplant Recipients With the Same Multiorgan Donor

BACKGROUND

Cytomegalovirus (CMV) infection poses a significant risk to immunosuppressed transplant recipients, manifesting through primary infection, reinfection, or reactivation.

METHODS

We analyzed the emergence of drug resistance in CMV infection in 3 patients who were later found to have received an allograft from a shared, deceased donor. The seronegative transplant recipients developed symptomatic CMV infections after bowel/pancreas, kidney, or lung transplantation. Prospective Sanger sequencing was used to identify mutations in the viral DNA polymerase (DP) and protein kinase (PK). DP and PK variants were retrospectively quantified by targeted next-generation sequencing. The impact of the novel DP-A505G substitution on drug susceptibility was assessed using a recombinant virus. Whole-genome sequencing of clinical CMV samples was enabled through target DNA enrichment.

RESULTS

The DP-A505G substitution was found in all patient samples and could be associated with a natural polymorphism. A subsequent review of the patients' clinical histories revealed that they had all received organs from a single donor. The CMV infection exhibited divergent evolution among the patients: patient 1 developed resistance to ganciclovir and foscarnet because of 2 DP mutations (V715M and V781I), patient 2 showed no genotypic resistance, and patient 3 developed ganciclovir (PK-L595S) and maribavir resistance (PK-T409M). Interpatient variation across the entire CMV genome was minimal, with viral samples clustering in phylogenetic analysis.

CONCLUSIONS

All 3 transplant recipients were infected with the same donor-derived CMV strain and readily developed different drug susceptibility profiles. This underscores the importance of judicious antiviral drug use and surveillance in preventing antiviral resistance emergence.

Torque Teno Virus: A Promising Biomarker in Kidney Transplant Recipients

Torque Teno Virus (TTV) is a ubiquitous component of the human virome, not associated with any disease. As its load increases when the immune system is compromised, such as in kidney transplant (KT) recipients, TTV load monitoring has been proposed as a method to assess immunosuppression. In this prospective study, TTV load was measured in plasma and urine samples from 42 KT recipients, immediately before KT and in the first 150 days after it. Data obtained suggest that TTV could be a relevant marker for evaluating immune status and could be used as a guide to predict the onset of infectious complications in the follow-up of KT recipients. Since we observed no differences considering distance from transplantation, while we found a changing trend in days before viral infections, we suggest to consider changes over time in the same subjects, irrespective of time distance from transplantation.

Five-year single-center analysis of cytomegalovirus viremia in kidney transplant recipients and possible implication for novel prophylactic therapy approaches

BACKGROUND

Cytomegalovirus (CMV) infections are a common complication after kidney transplantation (KTx) and negatively affecting patient outcome. Valganciclovir (VGC) prophylaxis is often limited by drug-induced side effects and dose reduction due to decline in kidney function.

METHOD

In the present study, episodes of CMV viremia in the first year after KTx in a cohort of 316 recipients were analyzed retrospectively to identify risk factors linked to persistent infections.

RESULTS

In the studied cohort, 18.7% of patients showed a high-risk (HR) constellation (D+/R-) for CMV infections. CMV viremia affected 22% of our cohort, with HR patients being the most affected cohort (44.1%). Within this group, most viremic events (65.3%) occurred while patients were still on prophylactic therapy, showing significantly higher viral loads and a longer duration compared to seropositive recipients.

CONCLUSION

The analysis at hand revealed that detection of viremia under ongoing antiviral prophylaxis bears an increased risk for sustained viral replication and antiviral drug resistance in HR patients. We identified low estimated glomerular filtration rate (eGFR) and lower dose VGC prophylaxis post-KTx as a risk factor for breakthrough infections in HR patients in our single center cohort. These patients might benefit from a closer CMV monitoring or novel prophylactic agents as letermovir.

Herpes Virus Infection in Lung Transplantation: Diagnosis, Treatment and Prevention Strategies

Lung transplantation is an ultimate treatment option for some end-stage lung diseases; due to the intense immunosuppression needed to reduce the risk of developing acute and chronic allograft failure, infectious complications are highly incident. Viral infections represent nearly 30% of all infectious complications, with herpes viruses playing an important role in the development of acute and chronic diseases. Among them, cytomegalovirus (CMV) is a major cause of morbidity and mortality, being associated with an increased risk of chronic lung allograft failure. Epstein-Barr virus (EBV) is associated with transformation of infected B cells with the development of post-transplantation lymphoproliferative disorders (PTLDs). Similarly, herpes simplex virus (HSV), varicella zoster virus and human herpesviruses 6 and 7 can also be responsible for acute manifestations in lung transplant patients. During these last years, new, highly sensitive and specific diagnostic tests have been developed, and preventive and prophylactic strategies have been studied aiming to reduce and prevent the incidence of these viral infections. In this narrative review, we explore epidemiology, diagnosis and treatment options for more frequent herpes virus infections in lung transplant patients.

De Novo Cytomegalovirus Colitis in a Donor-Seronegative/Recipient-Seronegative Kidney Transplant Recipient

Cytomegalovirus (CMV) is one of the most frequent microbes linked with kidney transplant recipients. CMV infection is typically classified as CMV virus isolation in any body fluid or specimen. We present a 43-year-old man who underwent a deceased donor kidney transplant with CMV donor-seronegative and recipient-seronegative (CMV D-/R-) status and completed three months of CMV prophylaxis with high-dose acyclovir given his low-risk status. He was admitted for complaints of profuse watery diarrhea and persistent fevers lasting one week in duration. His infectious workup led to a CMV quantitative nucleic acid amplification test (QNAT) polymerase chain reaction (PCR) of 239,977 IU/mL with a biopsy-proven diagnosis of invasive CMV colitis. He was treated inpatient with intravenous ganciclovir for two weeks and then de-escalated to oral valganciclovir until achieving viremia resolution with undetectable CMV QNAT PCR as an outpatient. This case illustrates the importance of the changing epidemiology and clinical presentation of CMV disease in solid organ transplant (SOT) recipients in an era of new immunosuppression regimens and improved CMV disease detection in the early post-transplant period.

Prediction of herpes virus infections after solid organ transplantation: a prospective study of immune function

Introduction

Herpes virus infections are a major concern after solid organ transplantation and linked to the immune function of the recipient. We aimed to determine the incidence of positive herpes virus (cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus type 1/2 (HSV-1/2), and varicella zoster virus (VZV)) PCR tests during the first year post-transplantation and assess whether a model including immune function pre-transplantation and three months post-transplantation could predict a subsequent positive herpes virus PCR.

Methods

All participants were preemptively screened for CMV, and EBV IgG-negative participants were screened for EBV during the first year post-transplantation. Herpes virus PCR tests for all included herpes viruses (CMV, EBV, HSV-1/2, and VZV) were retrieved from the Danish Microbiology database containing nationwide PCR results from both hospitals and outpatient clinics. Immune function was assessed by whole blood stimulation with A) LPS, B) R848, C) Poly I:C, and D) a blank control. Cytokine concentrations (TNF-α, IL-1β, IL-6, IL-8, IL-10, IL-12p40, IL-17A, IFN-α, and IFN-γ) were measured using Luminex.

Results

We included 123 liver (54%), kidney (26%), and lung (20%) transplant recipients. The cumulative incidence of positive herpes virus PCR tests was 36.6% (95% CI: 28.1-45.1) during the first year post-transplantation. The final prediction model included recipient age, type of transplantation, CMV serostatus, and change in Poly I:C-induced IL-12p40 from pre-transplantation to three months post-transplantation. The prediction model had an AUC of 77% (95% CI: 61-92). Risk scores were extracted from the prediction model, and the participants were divided into three risk groups. Participants with a risk score <5 (28% of the cohort), 5-10 (45% of the cohort), and >10 (27% of the cohort) had a cumulative incidence of having a positive herpes virus PCR test at 5.8%, 25%, and 73%, respectively (p < 0.001).

Conclusion

In conclusion, the incidence of positive herpes virus PCR tests was high, and a risk model including immune function allowed the prediction of positive herpes virus PCR and may be used to identify recipients at higher risk.

Diagnostic stewardship to limit repeat plasma cytomegalovirus viral load testing

BACKGROUND

Frequent serial monitoring of plasma cytomegalovirus (CMV) viral load caused unnecessary budgets for laboratory testing without changes in treatment. We aimed to implement diagnostic stewardship to limit CMV viral load testing at appropriate intervals.

METHODS

A quasi-experimental study was performed. To avoid unnecessary plasma CMV viral load testing, the inpatient electronic pop-up reminder was launched in 2021. In cases with plasma CMV viral load testing was ordered in intervals of less than five days, telephone interview and feedback were performed. Pre-post intervention data was compared in terms of clinical and monetary outcomes. The rate of plasma CMV viral load testing performed in intervals of less than five days was compared between 2021 and 2019 using the Poisson regression model.

RESULTS

After the protocol implementation, there was a significant decrease in the rate of plasma CMV viral load test orders in intervals of less than five days from 17.5% to 8.0% [incidence rate ratio 0.40, p < 0.001]. There was no statistically significant difference in the incidence of CMV DNAemia and CMV disease (p = 0.407 and 0.602, respectively). As a result, the hospital could save the costs of plasma CMV viral load testing per 1,000 patients performed with intervals of less than five days from 2,646,048.11 to 1,360,062.89 Thai Baht.

CONCLUSIONS

The diagnostic stewardship program is safe and helpful in reducing unnecessary plasma CMV viral load testing and costs.

Effective Letermovir Prophylaxis of CMV infection post allogeneic hematopoietic cell transplantation: Results from the French temporary authorization of use compassionate program

We report the results of the French Temporary Authorization of Use (ATU) compassionate program of letermovir for primary prophylaxis conducted in 21 transplant centers. Patients were CMV seropositive allogeneic hematopoietic cell transplantation recipients and at high risk for CMV infection. Primary prophylaxis was defined as initiation of letermovir between day 0 and day +28 post-transplant. Between November 2017 and January 2019, 96 patients with a median age of 56 years received letermovir and follow-up data were available for 78 patients. The median time from transplant to letermovir initiation was 4 days, and the median duration of exposure to letermovir was 78 days, with 57 patients still on treatment at the cutoff date. Letermovir was temporarily discontinued in 4 patients (5.1%) and stopped in 39 patients (50.0%), in most cases due to planned end of treatment (n = 16, 20.5%). Fifteen patients (19.2%) each presented one positive CMV PCR, in median 13 days after letermovir initiation. Clinically significant CMV infection was reported in 5 patients (6.4%). No CMV disease was reported. At least one adverse drug reaction was reported for 12 patients (15.4%). In this early access program, letermovir was effective with comparable results of the phase 3 study with a low rate of clinically significant CMV infection, including in patients who were at high-risk for CMV infection.

Cytomegalovirus and other herpesviruses after hematopoietic cell and solid organ transplantation: From antiviral drugs to virus-specific T cells

Herpesviruses can either cause primary infection or may get reactivated after both hematopoietic cell and solid organ transplantations. In general, viral infections increase post-transplant morbidity and mortality. Prophylactic, preemptive, or therapeutically administered antiviral drugs may be associated with serious side effects and may induce viral resistance. Virus-specific T cells represent a valuable addition to antiviral treatment, with high rates of response and minimal side effects. Even low numbers of virus-specific T cells manufactured by direct selection methods can reconstitute virus-specific immunity after transplantation and control viral replication. Virus-specific T cells belong to the advanced therapy medicinal products, and their production is regulated by appropriate legislation; also, strict safety regulations are required to minimize their side effects.

Evaluation of treatment patterns, healthcare resource utilization, and costs among patients receiving treatment for cytomegalovirus following allogeneic hematopoietic cell or solid organ transplantation

AIM

Management of cytomegalovirus (CMV) infection/disease in transplant recipients may be complicated by toxicities and resistance to conventional antivirals, adding to the overall healthcare burden. We characterized treatment patterns, healthcare resource utilization (HCRU), and costs to elucidate the healthcare burden associated with CMV therapies post-transplant.

MATERIALS AND METHODS

A retrospective, longitudinal cohort study of transplant recipients using data from a US commercial insurance claims database (2013-2017) was conducted. Patients with a claim for post-transplant CMV diagnosis and anti-CMV treatment (ganciclovir, valganciclovir, foscarnet, or cidofovir) were identified (Treated CMV cohort) and compared with patients with neither a claim for CMV diagnosis nor anti-CMV treatment (No CMV cohort) for outcomes including HCRU and associated costs. Allogeneic hematopoietic cell transplantation (HCT) or solid organ transplantation (SOT) recipients were analyzed separately. Anti-CMV treatment patterns were assessed in the Treated CMV cohort. Costs were evaluated among subgroups with myelosuppression or nephrotoxicity.

RESULTS

Overall, 412 allogeneic HCT and 899 SOT patients were included in the Treated CMV cohorts, of which 41.7% and 52.5%, respectively, received multiple antiviral courses. Treated CMV cohorts compared with No CMV cohorts had higher mean monthly healthcare visits per patient (allogeneic HCT: 8.83 vs 6.61, SOT: 5.61 vs 4.45) and had an incremental adjusted mean monthly cost per patient differences of $8,157 (allogeneic HCT, p < .004) and $2,182 (SOT, p < .004). Among Treated CMV cohorts, HCRU and costs increased with additional CMV antiviral treatment courses. Mean monthly costs were higher for patients with than without myelosuppression or nephrotoxicity.

LIMITATIONS

Results may not be generalizable to patients covered by government insurance or outside the USA.

CONCLUSIONS

CMV post-transplant managed with conventional treatment is associated with substantial HCRU and costs. The burden remains particularly high for patients requiring multiple treatment courses for post-transplant CMV or for transplant recipients who develop myelosuppression or nephrotoxicity.

Cost-effectiveness of Preemptive Therapy Versus Prophylaxis in a Randomized Clinical Trial for the Prevention of Cytomegalovirus Disease in Seronegative Liver Transplant Recipients With Seropositive Donors

BACKGROUND

The relative costs of preemptive therapy (PET) or prophylaxis for the prevention of cytomegalovirus (CMV) disease in high-risk donor CMV-seropositive/recipient-seronegative (D+/R-) liver transplant recipients have not been assessed in the context of a randomized trial.

METHODS

A decision tree model was constructed based on the probability of outcomes in a randomized controlled trial that compared valganciclovir as PET or prophylaxis for 100 days in 205 D+/R- liver transplant recipients. Itemized costs for each site were obtained from a federal cost transparency database. Total costs included costs of implementation of the strategy and CMV disease treatment-related costs. Net cost per patient was estimated from the decision tree for each strategy.

RESULTS

PET was associated with a 10% lower absolute rate of CMV disease (9% vs 19%). The cost of treating a case of CMV disease in our patients was $88 190. Considering cost of implementation of strategy and treatment-related cost for CMV disease, the net cost-savings per patient associated with PET was $8707 compared to prophylaxis. PET remained cost-effective across a range of assumptions (varying costs of monitoring and treatment, and rates of disease).

CONCLUSIONS

PET is the dominant CMV prevention strategy in that it was associated with lower rates of CMV disease and lower overall costs compared to prophylaxis in D+/R- liver transplant recipients. Costs were driven primarily by more hospitalizations and higher CMV disease-associated costs due to delayed onset postprophylaxis disease in the prophylaxis group.

Development of a Vaccine against Human Cytomegalovirus: Advances, Barriers, and Implications for the Clinical Practice

Human cytomegalovirus (hCMV) is one of the most common causes of congenital infection in the post-rubella era, representing a major public health concern. Although most cases are asymptomatic in the neonatal period, congenital CMV (cCMV) disease can result in permanent impairment of cognitive development and represents the leading cause of non-genetic sensorineural hearing loss. Moreover, even if hCMV mostly causes asymptomatic or pauci-symptomatic infections in immunocompetent hosts, it may lead to severe and life-threatening disease in immunocompromised patients. Since immunity reduces the severity of disease, in the last years, the development of an effective and safe hCMV vaccine has been of great interest to pharmacologic researchers. Both hCMV live vaccines-e.g., live-attenuated, chimeric, viral-based-and non-living ones-subunit, RNA-based, virus-like particles, plasmid-based DNA-have been investigated. Encouraging data are emerging from clinical trials, but a hCMV vaccine has not been licensed yet. Major difficulties in the development of a satisfactory vaccine include hCMV's capacity to evade the immune response, unclear immune correlates for protection, low number of available animal models, and insufficient general awareness. Moreover, there is a need to determine which may be the best target populations for vaccine administration. The aim of the present paper is to examine the status of hCMV vaccines undergoing clinical trials and understand barriers limiting their development.

A Novel Case of Cytomegalovirus Pneumonia in an Acquired Thrombotic Thrombocytopenic Purpura Patient Treated With Rituximab

Thrombotic thrombocytopenic purpura (TTP) is thrombotic microangiopathy that is universally fatal if not promptly recognized and treated. Standard treatment includes plasma exchange (PLEX) therapy and immunosuppression. We present a case of an 80 years old African American male with a past medical history significant for essential hypertension, chronic obstructive pulmonary disease, and a recent TTP diagnosis for which he was treated with PLEX, glucocorticoids, and rituximab. The patient presented with complaints of shortness of breath of four days duration. He was hypoxemic on presentation; other vital signs were within normal limits. The basic metabolic panel and complete blood count were unremarkable. A computed tomography (CT) of the chest with contrast showed right lower lobe segmental and subsegmental pulmonary emboli. He was initiated on intravenous heparin therapy. During hospitalization, he had progressive clinical deterioration with progressive hypoxemia. A repeat CT scan demonstrated bilateral pulmonary infiltrates. The patient underwent bronchoscopy due to concerns of opportunistic infections in view of his recent immunosuppressive treatment. Bronchoalveolar lavage revealed cytomegalovirus (CMV), and the patient was initiated on ganciclovir. CMV pneumonia has been reported after rituximab therapy in patients with lymphomas and lymphoproliferative disorders. To our knowledge, this is the first case of CMV pneumonia after rituximab therapy in a patient with TTP.

Preventing Infection by Human Cytomegalovirus

The way to a successful vaccine against human cytomegalovirus is hampered by the peculiar biology of this infection. However, some candidate vaccines have been shown to protect seronegative women and transplant recipients, and we should know soon whether they can prevent congenital infection.

The risk factor analysis and treatment experience in pneumocystis jirovecii pneumonia after kidney transplantation

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection among solid organ transplantation. The occurrence of PJP is dangerous and fatal if there is no early identification and sufficient treatment.

OBJECTIVE

The aim of this study was to evaluate the risk factors and provide appropriate strategies of prophylaxis and treatment for PJP after kidney transplantation in our centre.

PATIENTS/METHODS

From January 2009 to December 2018, a total of 167 kidney transplantation recipients with pneumonia were enrolled, including 47 PJP patients as PJP group and 120 non-PJP patients as control group. The clinical characteristics of the two groups were analysed retrospectively.

RESULTS

Multivariate analysis showed that high total dosage of ATG [OR, 2.03; 95% CI, 1.12-3.68] and cytomegalovirus (CMV) infection were independent risk factors for PJP. Trimethoprim-sulfamethoxazole (TMP-SMX) (1.44 g q6h)-based treatment was used for 2 weeks, and its dosage and course were adjusted according to the therapeutic effect and side effects. Forty-five cases were recovered after 3 months of follow-up, and two patients died of respiratory failure. TMP-SMX (0.48 g/day) prophylaxis was used for 3-6 months and prolonged to 7-8 months after treatment for acute rejection, which reduced the incidence of PJP compared with those without prophylaxis.

CONCLUSION

Our study suggests that the high total dosage of ATG and CMV infection indicate the increased risk of PJP. The strategies of prophylaxis and treatment for PJP after kidney transplantation in our centre were effective.

Human Cytomegalovirus-Encoded microRNAs Can Be Found in Saliva Samples from Renal Transplant Recipients

Human cytomegalovirus (HCMV) infections are common following renal transplantation and may have long-lasting effects. HCMV can be measured directly by viral DNA or indirectly via host immune responses. HCMV-encoded microRNA (miRNA) may alter the pathobiology of HCMV infections and contribute to the progression of HCMV disease. HCMV-encoded miRNAs can be detected in blood but have not been sought in saliva. We investigated saliva samples from 32 renal transplant recipients (RTR) and 12 seropositive healthy controls for whom immunological data was available. Five HCMV-encoded miRNAs (miR-UL112-5p, miR-US5-2-3p, miR-UL36, miR-US25-2-3p and miR-UL22A) were sought using primer probe assays. HCMV miRNA species were detected in saliva from 15 RTR and 3 healthy controls, with miR-US5-2-3p most commonly detected. The presence of HCMV miRNAs associated with increased T-cell responses to HCMV IE-1 in RTR, suggesting a link with frequent reactivations of HCMV.

Pretransplant Cytomegalovirus-Specific Cellular Immunity and Risk of Viral Reactivation Following Lung Transplantation: A Prospective Cohort Study

Cytomegalovirus (CMV) remains a significant burden in lung transplant recipients. Deficiencies in T-cell immunity posttransplant increase the risk of CMV-associated complications. However, it is not clear if underlying poor pretransplant immunity increases risk. To assess this, we recruited 39 prospective lung transplant patients and performed QuantiFERON-CMV on their peripheral blood. More than a third of prospective CMV-seropositive transplant recipients were CMV non-immune reactive (CMV-NIR) pretransplant. CMV-NIR status was associated with a significantly higher incidence of CMV reactivation posttransplant, demonstrating that dysfunctional CMV immunity in prospective lung transplant recipients is associated with an increased risk of viral reactivation posttransplant.

Epidemiology, risk factors, and outcomes associated with cytomegalovirus in adult kidney transplant recipients: A systematic literature review of real-world evidence

Kidney transplant recipients (KTRs) have increased risk for cytomegalovirus (CMV) infection/disease given the necessity of drug-induced immunosuppression. A comprehensive review of published literature reporting real-world data on prevention strategies utilized and associated CMV burden outcomes is limited. Such data could help inform future clinical practice and identify unmet needs in CMV management. We conducted a systematic review of observational studies published in Medline or EMBASE from January 2008 to November 2018 to identify current real-world CMV management approaches, CMV infection/disease risk factors, and outcomes associated with CMV infection. Descriptive statistics and pooled quantitative analyses were conducted. From 1608 records screened, 86 citations, including 69 803 adult KTR, were included. Prophylaxis and preemptive therapy (PET) were predominant approaches among D+/R- and R + CMV serostatus transplants, respectively. Valganciclovir and ganciclovir were frequently utilized across CMV risk strata. Despite prevention approaches, approximately one-fourth of KTR developed CMV infection. Age and D+/R- CMV serostatus were consistent risk factors for CMV infection/disease. CMV infection/disease was associated with increased mortality and graft loss. CMV was similarly associated with acute rejection (AR) risk, but with high heterogeneity among studies. Limited data were available on CMV and opportunistic infections (OIs) risk. CMV remains a significant issue. New strategies may be needed to optimize CMV management.

Using blood donors and solid organ transplant donors and recipients to estimate the seroprevalence of cytomegalovirus and Epstein-Barr virus in Canada: A cross-sectional study

BACKGROUND

Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections are common, causing significant morbidity in pregnancy (congenital CMV) and transplant recipients (CMV, EBV). Canadian prevalence data are needed to model disease burden and develop strategies for future vaccines. We estimated prevalence using screening data from blood donors and solid organ transplant (SOT) donors and recipients.

METHODS

We retrospectively analyzed CMV and EBV serology from Alberta SOT donors (n = 3,016) and recipients (n = 4,614) (1984-2013) and Canadian Blood Services blood donors (n = 1,253,350) (2005-2014), studying associations with age, sex, organ, year, and geographic region.

RESULTS

CMV seroprevalence rises gradually with age. By age 70, CMV seropositivity ranged from 67% (blood donors) to 73% (SOT recipients). Significant proportions of women of child-bearing age were CMV-seronegative (organ donors, 44%; SOT recipients, 43%; blood donors, 61%). Blood donor CMV seroprevalence decreased from 48% in Western Canada to 30% in Eastern Canada. Women were more likely to be CMV-seropositive (ORs = 1.58, 1.45, and 1.11 for organ donors, SOT recipients, and blood donors, respectively) and EBV-seropositive (ORs = 1.87 and 1.46 for organ donors and SOT recipients, respectively). EBV prevalence rises rapidly, and by age 17-29 years, 81% of SOT recipients and 90% of organ donors were seropositive.

CONCLUSIONS

Canada has relatively low and perhaps decreasing age-specific EBV and CMV prevalence, making Canadians vulnerable to primary infection-associated morbidity and suggesting benefit from future vaccines. Collection and analysis of routine serology screening data are useful for observing trends.

Risk Factors for Cytomegalovirus Reactivation in Lung Transplant Recipients

PURPOSE

We examined risk factors that may have contributed to Cytomegalovirus (CMV) reactivation among patients who underwent lung transplantation (LTx).

METHODS

We reviewed medical records of patients who underwent LTx at a tertiary healthcare hospital in South Korea between January 2013 and May 2017. We excluded patients who died within the first year after LTx and those lost to follow-up. CMV reactivation was defined as the detection of CMV titers above 3000 copies/ml regardless of specific symptoms after prophylaxis cessation.

RESULTS

Of 89 patients included, 39 (43.8%) developed CMV reactivation. Of those 39 patients, 16 (41.0%) experienced additional CMV reactivation. Multivariate analysis identified lymphocyte counts below 1.0 × 10³/μl (hazard ratio [HR] 49.33, p < 0.001) and use of steroids at more than twice the standard dose (HR 8.07, p < 0.001) as risk factors for CMV reactivation. The multivariate model also identified chronic kidney disease (CKD; HR 5.19, p = 0.016) and pneumonia (HR 17.22, p = 0.013) as risk factors for repetitive CMV reactivation.

CONCLUSION

This study suggests that lymphopenia and high doses of steroids may be important risk factors for CMV reactivation in LTx patients. Our results also suggest that repetitive CMV reactivation may be associated with CKD and pneumonia.

Human Cytomegalovirus Mediates Unique Monocyte-to-Macrophage Differentiation through the PI3K/SHIP1/Akt Signaling Network

Blood monocytes mediate the hematogenous dissemination of human cytomegalovirus (HCMV) in the host. However, monocytes have a short 48-hour (h) lifespan and are not permissive for viral replication. We previously established that HCMV infection drives differentiation of monocytes into long-lived macrophages to mediate viral dissemination, though the mechanism was unclear. Here, we found that HCMV infection promoted monocyte polarization into distinct macrophages by inducing select M1 and M2 differentiation markers and that Akt played a central role in driving differentiation. Akt's upstream positive regulators, PI3K and SHIP1, facilitated the expression of the M1/M2 differentiation markers with p110δ being the predominant PI3K isoform inducing differentiation. Downstream of Akt, M1/M2 differentiation was mediated by caspase 3, whose activity was tightly regulated by Akt in a temporal manner. Overall, this study highlights that HCMV employs the PI3K/SHIP1/Akt pathway to regulate caspase 3 activity and drive monocyte differentiation into unique macrophages, which is critical for viral dissemination.

Efficacy and Safety of a Weight-based Dosing Regimen of Valganciclovir for Cytomegalovirus Prophylaxis in Pediatric Solid-organ Transplant Recipients

BACKGROUND

Valganciclovir has been widely used for cytomegalovirus (CMV) prophylaxis in solid-organ transplant recipients. However, the optimal dosing protocol and target exposure in children are still unclear. Specific data as to the efficacy and safety of low-dose/low-exposure regimens are lacking and urgently needed.

METHODS

During 2010 to 2015, the clinical efficacy and safety of a weight-based regimen of valganciclovir of 17 mg/kg/day, with a stratified dose reduction for impaired creatinine clearance, given as a CMV prophylaxis for 3 to 6 months, was retrospectively evaluated among pediatric kidney and liver transplant recipients, 12 months posttransplantation. Incidence of CMV infection was assessed by periodic measurements of viral load; adverse events were evaluated.

RESULTS

Eighty-three children who had undergone 86 transplantations and were treated with 17 mg/kg of valganciclovir were included. Median age was 9.77 years (range, 0.6 to 18.9). Twelve (14%) developed CMV infection: 1 during prophylaxis and 11 during follow-up. These events comprised 6 cases of asymptomatic viremia and 6 cases of a clinically significant disease without occurrences of tissue-invasive disease. Treatment-related adverse effects occurred in 7 patients (8%), mostly hematological, resulting in premature drug cessation.

CONCLUSIONS

Our results support the use of 17 mg/kg of valganciclovir for CMV prophylaxis in liver and kidney transplanted children as it showed satisfactory long-term efficacy and a good safety profile.

Small bowel perforation secondary to CMV-positive terminal ileitis postrenal transplant

Cytomegalovirus (CMV) infection of the gastrointestinal tract is common in immunosuppressed patients; however, small bowel perforation from tissue-invasive CMV disease after many years of immunosuppressive therapy is a rare complication requiring timely medical and surgical intervention. We report a case of a postrenal transplant patient who presented to the emergency department with severe lower abdominal pain with CT of the abdomen/pelvis revealing a small bowel perforation. He underwent an emergent laparoscopic right hemicolectomy, and his histopathology of the terminal ileum was positive for CMV disease. He was successfully treated with intravenous ganciclovir postoperatively. We discuss the pathophysiology, histopathological features and treatment of CMV infection.

CMV infection management in transplant patients in Italy

Transplant represents an effective strategy in the management of chronic organ dysfunction. Nonetheless, life threatening risks remain, especially in the post-transplant; among them, human cytomegalovirus (CMV) is a major concern, currently causing active infections in at least one-third of transplant recipients. Microbiologist and transplant scientific societies redefined guidance on CMV disease prevention and the best use for universal prophylaxis and pre-emptive virological monitoring. Developments in molecular diagnostic supported the spread of the pre-emptive strategy, and quantitative Real Time-PCR assays has unravelled the potential of viral load measurement as a predictor of the infection development in CMV post-transplant management. However, despite the WHO 1st CMV International Standard, the standardization of diagnostic and clinical practice has been limited by the absence of algorithms for calculating conversion factor to International Units and the lack of shared monitoring procedure, both at national and international level. At a regional level, the Italian scientific societies, AMCLI (Italian Clinical Microbiologist Association), SITO (Organ Transplant Italian Society), GITMO (Italian Group for Bone Marrow Transplant), recently tried to define a consensus for post-transplant monitoring. The concerted practice encompasses molecular quantitative PCR assays technical aspects and endorses the relevance of immunologic monitoring for improvement in patient risk stratification and prognosis. Here, we provide an overview of the state of the art of CMV management strategies, with a specific focus on the clinical practices and on the scientific societies' initiatives that aim to implement international standardization guidelines at a national level.

Impact of standardized protocols for cytomegalovirus disease prevention in pediatric solid organ transplant recipients

End-organ disease caused by CMV is a significant cause of morbidity and mortality in pediatric SOT recipients. Pediatric transplant centers have adopted various approaches for CMV disease prevention in this patient population. We observed significant practice variation in CMV testing, prophylaxis, and surveillance across SOT groups in our center. To address this, we implemented evidence-based standardized protocols and measured outcomes pre- and post-implementation of these protocols. We performed retrospective chart review for SOT recipients from 2009 to 2014 at Boston Children's Hospital. Using descriptive statistics, we measured practice improvement in provision of appropriate prophylaxis, occurrence of neutropenia and associated complications, and occurrence of CMV DNAemia and CMV disease pre- and post-intervention. The pre- and post-intervention periods included 141 and 109 patients, respectively. With the exception of kidney transplant recipients, provision of appropriate valganciclovir prophylaxis improved across SOT groups post-intervention (P < .01). Occurrence of >1 episode of neutropenia was greater in the preintervention period (30% vs 10%, P < .001). In both periods, neutropenia was associated with few episodes of invasive infections. The occurrence of CMV disease did not differ and was overall low. However, due to routine surveillance a significantly greater number of asymptomatic CMV DNAemia episodes were identified and treated in the post-intervention period. Implementation of standardized prevention protocols helped to improve the provision of appropriate prophylaxis to patients at risk for CMV acquisition, increased the diagnosis and treatment of asymptomatic CMV DNAemia, and decreased episodes of recurrent neutropenia in patients receiving prophylaxis.

A Practical Review of Cytomegalovirus in Gastroenterology and Hepatology

Human cytomegalovirus (CMV) is a ubiquitous Herpesviridae virus with a wide spectrum of pathology in humans. Host immunity is a major determinant of the clinical manifestation of CMV and can vary widely in the gastroenterology and hepatology practice setting. Immunocompetent patients generally develop a benign, self-limited mononucleosis-like syndrome whereas gastrointestinal tissue-invasive disease is more frequently seen in immunocompromised and inflammatory bowel disease patients. Additionally, liver allograft dysfunction is a significant consequence of CMV infection in liver transplant patients. While polymerase chain reaction and immunohistochemistry techniques allow for the reliable and accurate detection of CMV in the human host, the diagnostic value of different serologic, endoscopic, and histologic tests depends on a variety of factors. Similarly, latent CMV, CMV infection, and CMV disease carry different significance depending on the patient population, and the decision to initiate antiviral therapy can be complex and patient-specific. This review will focus on the pathophysiology, diagnosis, and management of CMV in patient populations relevant to the practice of gastroenterology and hepatology-liver transplant recipients, inflammatory bowel disease patients, and otherwise immunocompetent patients.

The Expanding Field of Secondary Antibody Deficiency: Causes, Diagnosis, and Management

Antibody deficiency or hypogammaglobulinemia can have primary or secondary etiologies. Primary antibody deficiency (PAD) is the result of intrinsic genetic defects, whereas secondary antibody deficiency may arise as a consequence of underlying conditions or medication use. On a global level, malnutrition, HIV, and malaria are major causes of secondary immunodeficiency. In this review we consider secondary antibody deficiency, for which common causes include hematological malignancies, such as chronic lymphocytic leukemia or multiple myeloma, and their treatment, protein-losing states, and side effects of a number of immunosuppressive agents and procedures involved in solid organ transplantation. Secondary antibody deficiency is not only much more common than PAD, but is also being increasingly recognized with the wider and more prolonged use of a growing list of agents targeting B cells. SAD may thus present to a broad range of specialties and is associated with an increased risk of infection. Early diagnosis and intervention is key to avoiding morbidity and mortality. Optimizing treatment requires careful clinical and laboratory assessment and may involve close monitoring of risk parameters, vaccination, antibiotic strategies, and in some patients, immunoglobulin replacement therapy (IgRT). This review discusses the rapidly evolving list of underlying causes of secondary antibody deficiency, specifically focusing on therapies targeting B cells, alongside recent advances in screening, biomarkers of risk for the development of secondary antibody deficiency, diagnosis, monitoring, and management.

Management of Infection in Patients With Kidney Transplant

With the pervasive nature of chronic kidney disease, kidney transplantation is likely to continue to increase in the coming years. There are many infectious risks related to kidney transplant, including reactivation of latent infections, surgical complications, infectious risks related to immunosuppression, and nosocomial and community-acquired infections. These are described classically via timeline with early infections (first month), middle (1 to 6 months), and late (after 6 months). Kidney transplant patients may suffer from infections secondary to a vast array of organisms, including bacteria, fungi, and viruses. Certain infections, particularly viral infections such as cytomegalovirus, Epstein-Barr virus, and BK virus, may portend acute and chronic implications of the infection and its subsequent impact on graft function. Critical care physicians and nephrologists caring for patients with a renal transplant must understand the broad array of possible infections, atypical presentations, and nuanced implications for appropriate evaluation and subsequent therapy, combined with the need for possible prophylaxis and/or suppression. Multidisciplinary teams, including transplant physicians and infectious diseases physicians, are encouraged strongly.

Human Cytomegalovirus UL135 Interacts with Host Adaptor Proteins To Regulate Epidermal Growth Factor Receptor and Reactivation from Latency

Human cytomegalovirus, HCMV, is a betaherpesvirus that establishes a lifelong latent infection in its host that is marked by recurrent episodes of reactivation. The molecular mechanisms by which the virus and host regulate entry into and exit from latency remain poorly understood. We have previously reported that UL135 is critical for reactivation, functioning in part by overcoming suppressive effects of the latency determinant UL138 We have demonstrated a role for UL135 in diminishing cell surface levels and targeting epidermal growth factor receptor (EGFR) for turnover. The attenuation of EGFR signaling promotes HCMV reactivation in combination with cellular differentiation. In this study, we sought to define the mechanisms by which UL135 functions in regulating EGFR turnover and viral reactivation. Screens to identify proteins interacting with pUL135 identified two host adaptor proteins, CIN85 and Abi-1, with overlapping activities in regulating EGFR levels in the cell. We mapped the amino acids in pUL135 necessary for interaction with Abi-1 and CIN85 and generated recombinant viruses expressing variants of pUL135 that do not interact with CIN85 or Abi-1. These recombinant viruses replicate in fibroblasts but are defective for reactivation in an experimental model for latency using primary CD34+ hematopoietic progenitor cells (HPCs). These UL135 variants have altered trafficking of EGFR and are defective in targeting EGFR for turnover. These studies demonstrate a requirement for pUL135 interactions with Abi-1 and CIN85 for regulation of EGFR and mechanistically link the regulation of EGFR to reactivation.IMPORTANCE Human cytomegalovirus (HCMV) establishes a lifelong latent infection in the human host. While the infection is typically asymptomatic in healthy individuals, HCMV infection poses life-threatening disease risk in immunocompromised individuals and is the leading cause of birth defects. Understanding how HCMV controls the lifelong latent infection and reactivation of replication from latency is critical to developing strategies to control HCMV disease. Here, we identify the host factors targeted by a viral protein that is required for reactivation. We define the importance of this virus-host interaction in reactivation from latency, providing new insights into the molecular underpinnings of HCMV latency and reactivation.

Vaccination against the human cytomegalovirus

The human cytomegalovirus (HCMV) is the most important infectious cause of congenital abnormalities and also of infectious complications of transplantation. The biology of the infection is complex and acquired immunity does not always prevent reinfection. Nevertheless, vaccine development is far advanced, with numerous candidate vaccines being tested, both live and inactivated. This article summarizes the status of the candidate vaccines.

The convergent epidemiology of tuberculosis and human cytomegalovirus infection

Although several factors are known to increase the risk of tuberculosis, the occurrence of tuberculosis disease in an infected individual is difficult to predict. We hypothesize that active human cytomegalovirus infection due to recent infection, reinfection or reactivation plays an epidemiologically relevant role in the aetiology of tuberculosis by precipitating the progression from latent tuberculosis infection to disease. The most compelling support for this hypothesis comes from the striking similarity in age-sex distribution between the two infections, important because the age-sex pattern of tuberculosis disease progression has not been convincingly explained. Cytomegalovirus infection and tuberculosis have other overlapping risk factors, including poor socio-economic status, solid organ transplantation and, possibly, sexual contact and whole blood transfusion. Although each of these overlaps could be explained by shared underlying risk factors, none of the epidemiological observations refute the hypothesis. If this interaction would play an epidemiologically important role, important opportunities would arise for novel approaches to controlling tuberculosis.

The convergent epidemiology of tuberculosis and human cytomegalovirus infection

Although several factors are known to increase the risk of tuberculosis, the occurrence of tuberculosis disease in an infected individual is difficult to predict. We hypothesize that active human cytomegalovirus infection due to recent infection, reinfection or reactivation plays an epidemiologically relevant role in the aetiology of tuberculosis by precipitating the progression from latent tuberculosis infection to disease. The most compelling support for this hypothesis comes from the striking similarity in age-sex distribution between the two infections, important because the age-sex pattern of tuberculosis disease progression has not been convincingly explained. Cytomegalovirus infection and tuberculosis have other overlapping risk factors, including poor socio-economic status, sexual contact, whole blood transfusion and solid organ transplantation. Although each of these overlaps could be explained by shared underlying risk factors, none of the epidemiological observations refute the hypothesis. If this interaction would play an epidemiologically important role, important opportunities would arise for novel approaches to controlling tuberculosis.

Human cytomegalovirus triggers the assembly of AIM2 inflammasome in THP-1-derived macrophages

Absent in melanoma 2 (AIM2) inflammasome is a multiprotein complex which plays a pivotal role in the host immune response to multiple pathogens. The role of AIM2 in human cytomegalovirus (HCMV) infection is poorly studied. Thus, using a small inference RNA (siRNA) approach and THP-1 derived macrophage cells infected with HCMV AD169 strain, we investigated the impact of HCMV infection on AIM2-mediated molecular events. Compared to wild-type cells, AIM2-defiecient macrophages showed a limited ability to activate caspase-1, process IL-1β, and induce cell death. In addition, AIM2-defiecient cells were unable to efficiently control HCMV infection, as the transcription of virus DNA polymerase gene UL54 and major tegument protein gene UL83 were higher compared to wild-type cells. In conclusion, HCMV infection induces an AIM2 inflammasome response, which negatively influences viral life cycle.

Burden of cytomegalovirus disease in solid organ transplant recipients: a national matched cohort study in an inpatient setting

BACKGROUND

We investigated the impact of early- (E-CMV) and late onset (L-CMV) cytomegalovirus disease on the probability of graft rejection, graft failure, mortality, and healthcare resource use, following solid organ transplantation (SOT) in France.

METHODS

A retrospective analysis of data from the French 'Programme de Médicalisation des Systèmes d'Information' database (2007-2011) was conducted to identify SOT recipients who developed CMV disease in an inpatient setting. Recipients were stratified by time to CMV disease onset: E-CMV (≤3 months), L-CMV-3M (>3-24 months), and L-CMV-6M (>6-24 months). Data were analyzed by comparing recipients with CMV disease or without (controls) in a 1:2 ratio, matched according to age, gender, target organ, and previous/simultaneous occurrence of graft rejection. Graft failure, graft rejection, all-cause in-hospital mortality, and resource utilization (including hospitalization costs) were assessed over 12 months following CMV disease diagnosis.

RESULTS

Among 20 473 SOT recipients, 2430 (11.86%) were reported to have CMV disease within 24 months after transplantation. CMV disease was significantly associated with an increased risk of graft rejection and mortality, as indicated by logistic regression analysis. Odd ratios (ORs) for the risk of graft rejection were E-CMV=1.43, L-CMV-3M=1.50, and L-CMV-6M=1.61 (all P<.05), while ORs for mortality were E-CMV=2.85, L-CMV-3M=4.22, and L-CMV-6M=4.77 (all P<.0001). Only L-CMV was significantly correlated with a higher risk of graft failure: E-CMV=1.18 (P=.1906), L-CMV-3M=1.77 (P=.0013), and L-CMV-6M=3.12 (P<.0001). Hospitalization costs increased by €7078 (range €6270-€22 111), €6523 (range €5328-€10 295), and €6311 (range €5295-€9184) in recipients with E-CMV, L-CMV-3M, and L-CMV-6-M, respectively.

CONCLUSION

This study, based on French national data, demonstrates the considerable burden of CMV disease in SOT recipients and highlights the importance of developing new strategies to prevent and manage CMV disease and improve clinical outcomes for SOT patients.

Practical Recommendations for Long-term Management of Modifiable Risks in Kidney and Liver Transplant Recipients: A Guidance Report and Clinical Checklist by the Consensus on Managing Modifiable Risk in Transplantation (COMMIT) Group

Short-term patient and graft outcomes continue to improve after kidney and liver transplantation, with 1-year survival rates over 80%; however, improving longer-term outcomes remains a challenge. Improving the function of grafts and health of recipients would not only enhance quality and length of life, but would also reduce the need for retransplantation, and thus increase the number of organs available for transplant. The clinical transplant community needs to identify and manage those patient modifiable factors, to decrease the risk of graft failure, and improve longer-term outcomes.COMMIT was formed in 2015 and is composed of 20 leading kidney and liver transplant specialists from 9 countries across Europe. The group's remit is to provide expert guidance for the long-term management of kidney and liver transplant patients, with the aim of improving outcomes by minimizing modifiable risks associated with poor graft and patient survival posttransplant.The objective of this supplement is to provide specific, practical recommendations, through the discussion of current evidence and best practice, for the management of modifiable risks in those kidney and liver transplant patients who have survived the first postoperative year. In addition, the provision of a checklist increases the clinical utility and accessibility of these recommendations, by offering a systematic and efficient way to implement screening and monitoring of modifiable risks in the clinical setting.

Cytomegalovirus infection in lung transplant recipients

INTRODUCTION

Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality in solid organ transplant (SOT) patients. Lung transplant recipients are particularly at risk given the intense immunosuppression required. Areas covered: The Detailed review of the literature related to CMV infection, its direct and indirect effect on lung allograft function, as well as diagnosis, immune monitoring, treatment options and prevention strategies. Expert commentary: In lung transplant recipients, CMV infection is associated with pro-inflammatory and immune inhibitory effects that increase the risk of graft dysfunction and loss. Diagnosis of CMV infection remains challenging. Treatment options remain relatively limited.

Immunological Prediction of Cytomegalovirus (CMV) Replication Risk in Solid Organ Transplantation Recipients: Approaches for Regulating the Targeted Anti-CMV Prevention Strategies

The current cytomegalovirus (CMV) prevention strategies in solid organ transplantation (SOT) recipients have contributed towards overcoming the detrimental effects caused by CMV lytic infection, and improving the long-term success rate of graft survival. Although the quantification of CMV in peripheral blood is the standard method, and an excellent end-point for diagnosing CMV replication and modulating the anti-CMV prevention strategies in SOT recipients, a novel biomarker mimicking the CMV control mechanism is required. CMV-specific immune monitoring can be employed as a basic tool predicting CMV infection or disease after SOT, since uncontrolled CMV replication mostly originates from the impairment of immune responses against CMV under immunosuppressive conditions in SOT recipients. Several studies conducted during the past few decades have indicated the possibility of measuring the CMV-specific cell-mediated immune response in clinical situations. Among several analytical assays, the most advancing standardized tool is the QuantiFERON®-CMV assay. The T-Track® CMV kit that uses the standardized enzyme-linked immunospot assay is also widely employed. In addition to these assays, immunophenotyping and intracellular cytokine analysis using flow cytometry (with fluorescence-labeled monoclonal antibodies or peptide-major histocompatibility complex multimers) needs to be adequately standardized and validated for potential clinical applications.

The Etiology, Incidence, and Impact of Preservation Fluid Contamination during Liver Transplantation

The role of contaminated preservation fluid in the development of infection after liver transplantation has not been fully elucidated. To assess the incidence and etiology of contaminated preservation fluid and determine its impact on the subsequent development of infection after liver transplantation, we prospectively studied 50 consecutive liver transplants, and cultured the following samples in each instance: preservation fluid (immediately before and at the end of the back-table procedure, and just before implantation), blood, and bile from the donor, and ascitic fluid from the recipient. When any culture was positive, blood cultures were obtained and targeted antimicrobial therapy was started. We found that the incidence of contaminated preservation fluid was 92% (46 of 50 cases of liver transplantation per year), but only 28% (14/50) were contaminated by recognized pathogens. Blood and bile cultures from the donor were positive in 28% and 6% respectively, whereas ascitic fluid was positive in 22%. The most frequently isolated microorganisms were coagulase-negative staphylococci. In nine cases, the microorganisms isolated from the preservation fluid concurred with those grown from the donor blood cultures, and in one case, the isolate matched with the one obtained from bile culture. No liver transplant recipient developed an infection due to the transmission of an organism isolated from the preservation fluid. Our findings indicate that contamination of the preservation fluid is frequent in liver transplantation, and it is mainly caused by saprophytic skin flora. Transmission of infection is low, particularly among those recipients given targeted antimicrobial treatment for organisms isolated in the preservation fluid.

Siglec-H protects from virus-triggered severe systemic autoimmunity

Siglec-H is a key negative regulator of the type I interferon pathway, reducing the incidence of autoimmunity after viral infection.

It is controversial whether virus infections can contribute to the development of autoimmune diseases. Type I interferons (IFNs) are critical antiviral cytokines during virus infections and have also been implicated in the pathogenesis of systemic lupus erythematosus. Type I IFN is mainly produced by plasmacytoid dendritic cells (pDCs). The secretion of type I IFN of pDCs is modulated by Siglec-H, a DAP12-associated receptor on pDCs. In this study, we show that Siglec-H–deficient pDCs produce more of the type I IFN, IFN-α, in vitro and that Siglec-H knockout (KO) mice produce more IFN-α after murine cytomegalovirus (mCMV) infection in vivo. This did not impact control of viral replication. Remarkably, several weeks after a single mCMV infection, Siglec-H KO mice developed a severe form of systemic lupus–like autoimmune disease with strong kidney nephritis. In contrast, uninfected aging Siglec-H KO mice developed a mild form of systemic autoimmunity. The induction of systemic autoimmune disease after virus infection in Siglec-H KO mice was accompanied by a type I IFN signature and fully dependent on type I IFN signaling. These results show that Siglec-H normally serves as a modulator of type I IFN responses after infection with a persistent virus and thereby prevents induction of autoimmune disease.

Effect of artemether-lumefantrine (Coartem) on cytomegalovirus urine viral load during and following treatment for malaria in children

BACKGROUND

Artemisinins, commonly used to treat malaria, have shown activity against cytomegalovirus (CMV) in vitro, in an animal model, and in case reports; however, the in vivo anti-CMV activity has not been well investigated.

OBJECTIVES

To evaluate whether artemisinins affect CMV shedding among subjects co-infected with CMV and malaria.

STUDY DESIGN

A prospective observational study of children in Mali (6 month-10 year) presenting with fever. Urine samples were collected at day 0, 3, and 14 from children treated with artemether-lumefantrine (Coartem(®)) for malaria and those who had other illnesses not treated with Coartem. CMV DNA was quantified using a real-time PCR. Resulting urine viral loads were compared between the groups at three time points.

RESULTS

164 malaria cases and 143 non-malaria comparisons were enrolled. Eighty-one (49%) cases and 88 (62%) comparisons shed CMV at day 0. Day 0 and day 3 viral loads were similar, but at day 14 the median viral load of cases was lower than that of comparisons (360 vs 720 copies/mL or 2.56 vs 2.86 log10), p=0.059. A stratified analysis of day 0 high viral shedders (defined as >1000 copies/mL) showed significantly lower median viral load at day 14 among cases (490 copies/mL, 2.69 log10) vs comparisons (1200 copies/mL, 3.08 log10), p=0.045.

CONCLUSION

A high rate of urinary CMV shedding was found in a malaria-endemic area. Among high virus shedders artemether-lumefantrine decreased urine viral load, but the effect was not observed when analysis of both high and low shedders was performed. These results support additional studies of artemisinin dosing and duration in CMV infection.

Risks and Epidemiology of Infections After Lung or Heart–Lung Transplantation

Nowadays, lung transplantation is an established treatment option of end-stage pulmonary parenchymal and vascular disease. Post-transplant infections are a significant contributor to overall morbidity and mortality in the lung transplant recipient that, in turn, are higher than in other solid organ transplant recipients. This is likely due to several specific factors such as the constant exposure to the outside environment and the colonized native airway, and the disruption of usual mechanisms of defense including the cough reflex, bronchial circulation, and lymphatic drainage. This chapter will review the common infections that develop in the lung or heart–lung transplant recipient, including the general risk factors for infection in this population, and specific features of prophylaxis and treatment for the most frequent bacterial, viral, and fungal infections. The effects of infection on lung transplant rejection will also be discussed.

Factors influencing mortality in solid organ transplant recipients with bloodstream infection

Although bloodstream infection (BSI) is a major cause of mortality after solid organ transplantation, information regarding its prognostic factors is scarce. To identify risk factors for 30-day mortality in solid organ transplant (SOT) recipients with BSI, we prospectively recorded all episodes of BSI occurring in adult SOT recipients from January 2007 to October 2014 at a university hospital. We identified 361 consecutive episodes of BSI involving 246 patients. The 30-day case-fatality rate from the onset of BSI was 11.4%. Factors independently associated with 30-day mortality in a logistic regression analysis were shock at presentation (OR 13.658; 95% CI 5.985-31.168), acute graft rejection in the previous 6 months (OR 3.681; 95% CI 1.059-12.795), and a platelet count of <50,000 × 10(9)/L (OR 3.070; 95% CI 1.173-8.038). Kidney recipients were the patients with the best prognosis (OR 0.375; 95% CI 0.156-0.900). Our findings may help to identify SOT recipients with BSI who are at the highest risk of death.