Who among cytomegalovirus-seropositive liver transplant recipients is at risk for cytomegalovirus infection?

Epidemiology and Management of Infections in Liver Transplant Recipients

Background: Improvements in liver transplant (LT) outcomes are attributed to advances in surgical techniques, use of potent immunosuppressants, and rigorous pre-LT testing. Despite these improvements, post-LT infections remain the most common complication in this population. Bacteria constitute the most common infectious agents, while fungal and viral infections are also frequently encountered. Multi-drug-resistant bacterial infections develop because of polymicrobial overuse and prolonged hospital stays. Immediate post-LT infections are commonly caused by viruses. Conclusions: Appropriate vaccination, screening of both donor and recipients before LT and antiviral prophylaxis in high-risk individuals are recommended. Antimicrobial drug resistance is common in high-risk LT and associated with poor outcomes; epidemiology and management of these cases is discussed. Additionally, we also discuss the effect of coronavirus disease 2019 (COVID-19) infection and monkeypox in the LT population.

Cytomegalovirus Disease as a Risk Factor for Invasive Fungal Infections in Liver Transplant Recipients under Targeted Antiviral and Antimycotic Prophylaxis

Cytomegalovirus (CMV) infection is the most common opportunistic infection that occurs following orthotopic liver transplantation (OLT). In addition to the direct infection-related symptoms, it also triggers an immunological response that may contribute to adverse clinical outcomes. CMV disease has been described as a predictor of invasive fungal infections (IFIs) but its role under an antiviral prophylaxis regimen is unclear.

METHODS

We retrospectively analyzed the medical records of 214 adult liver transplant recipients (LTRs). Universal antiviral prophylaxis was utilized in recipients with CMV mismatch; intermediate- and low-risk patients received pre-emptive treatment.

RESULTS

Six percent of patients developed CMV disease independent of their serostatus. The occurrence of CMV disease was associated with elevated virus load and increased incidence of leucopenia and IFIs. Furthermore, CMV disease was associated with higher one-year mortality and increased relapse rates within the first year of OLT.

CONCLUSIONS

CMV disease causes significant morbidity and mortality in LTRs, directly affecting transplant outcomes. Due to the increased risk of IFIs, antifungal prophylaxis for CMV disease may be appropriate. Postoperative CMV monitoring should be considered after massive transfusion, even in low-risk serostatus constellations. In case of biliary complications, biliary CMV monitoring may be appropriate in the case of CMV-DNA blood-negative patients.

Cytomegalovirus Hepatitis in Immunocompetent and Immunocompromised Hosts

Human cytomegalovirus (HCMV) infection is common and affects between 40-100% of the worldwide population. However, the majority of cases are asymptomatic and when severe disease occurs, it is usually restricted to immunocompromised patients. Liver involvement by HCMV differs significantly, accordingly to the immune status of the host. In immunocompromised patients, particularly liver transplant patients, it often causes clinically significant hepatitis. On the other hand, in immunocompetent patients, HCMV hepatitis requiring hospitalization is extremely rare. This review aims to appraise studies regarding the pathophysiology of HCMV hepatitis, including mechanisms of latency and reactivation and its contribution to disease development, clinical presentation, diagnostic modalities and treatment, with a focus on comparing different aspects between immunocompromised and immunocompetent hosts.

Primary sclerosing cholangitis as an independent risk factor for cytomegalovirus infection after liver transplant

BACKGROUND

Cytomegalovirus (CMV) infection is one of the most common infectious complications after solid organ transplant; it is associated with morbidity and mortality and with many direct and indirect effects. However, monitoring and therapeutic procedures are very heterogeneous across treatment centers. Additionally, factors that place patients at risk of CMV infection are poorly defined.

METHODS

Clinical and demographic data from 833 LT recipients and their donors were retrospectively analyzed. Univariate and multivariate analysis were applied. CMV infection was detected by quantitative nucleic acid testing with a lower limit of detection of 40 IU/mL.

RESULTS

In total, 192 of 833 patients (23%) experienced at least one episode of CMV infection after LT; CMV infection occurred to a large extent during the first year after transplant (70%). Multivariate analysis demonstrated that CMV donor-recipient risk constellation (OR 2.05, 95% CI) and primary sclerosing cholangitis (PSC) before LT (OR 3.76, 95% CI) are independent risk factors for CMV infection after LT.

CONCLUSION

Patients with high-risk serostatus, PSC, or both should be monitored more thoroughly and should receive prolonged prophylaxis against CMV infection.

The Incidence and Effect of Cytomegalovirus Disease on Mortality in Transplant Recipients and General Population: Real-world Nationwide Cohort Data

Background: In addition to the conventional opportunistic infections in solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) recipients, cytomegalovirus (CMV) infection is associated with various chronic inflammatory diseases or poor outcomes in non-immunocompromised critically ill patients. To evaluate the burden or outcome of CMV replication in non-transplant individuals, we compared the incidence rates (IRs) for CMV disease and all-cause mortality between SOT recipients, HSCT recipients, and non-transplant population. Methods: The SOT (N=16,368) and HSCT (N=10,206) cohorts between 2010 and 2015 were established using the WHO ICD-10 from the whole population-based large database of the Health Insurance Review & Assessment Service (HIRA). CMV cases, defined as symptomatic disease with isolation of virus, DNA, pp65 antigen, and pathology except CMV syndrome, were extracted with the unique codes for relief of medical costs of HIRA in the same dataset. Cox's proportional hazard regression analyses and log-rank test in the Kaplan-Meier curves were performed to compare all-cause mortality between the three groups. Results: The CMV IRs adjusted by age and sex were significantly higher in the SOT (adjusted IR [95% confidence intervals], 33.1 [28.8-38.0] per 1,000 person-years) and HSCT recipients (5.1 [4.6-6.1] per 1,000 person-years) than in the whole population (0.58 [0.49-0.67] per 100,000 person-years). However, SOT recipients with CMV (18/283, 6.4%) had significantly lower all-cause mortality than non-transplant individuals with CMV (207/1,258, 16.5%) (adjusted hazard ratio [95% CI], 0.42 [0.25-0.67], log-rank P < 0.001). Conclusion: These data suggest that CMV disease in patients without transplants is associated with poor outcomes.

Cytomegalovirus infection after liver transplantation

Human cytomegalovirus (CMV) represents the most common opportunistic infection in liver transplant recipients. CMV infections in post liver transplant patients cause significant morbidity and mortality, directly affecting post-transplant outcomes. This review will provide the framework for the surveillance, diagnosis, prophylaxis and treatment of CMV in the liver transplant population.

Post liver transplant recurrent and de novo viral infections

Survival following liver transplantation has changed dramatically owing to improvement in surgical techniques, peri-operative care and optimal immunosuppressive therapy. Post-Liver transplant (LT) de novo or recurrent viral infection continues to cause major allograft dysfunction, leading to poor graft and patient survival in untreated patients. Availability of highly effective antiviral drugs has significantly improved post-LT survival. Patients transplanted for chronic hepatitis B infection should receive life-long nucleos(t)ide analogues, with or without HBIg for effective viral control. Patients with chronic hepatitis C should be commenced on directly acting antiviral (DAA) drugs prior to transplantation. DAA therapy for post-LT recurrent hepatitis C infection is associated with close to 100% sustained virological response (SVR), irrespective of genotype. De novo chronic Hepatitis E infection is an increasingly recognised cause of allograft dysfunction in LT recipients. Untreated chronic HEV infection of the graft may lead to liver fibrosis and allograft failure. CMV and EBV can reactivate leading to systemic illness following liver transplantation. With COVID-19 pandemic, post-transplant patients are at risk of SARS-Co-V2 infection. Majority of the LT recipients require hospitalization, and the mortality in this population is around 20%. Early recognition of allograft dysfunction and identification of viral aetiology is essential in the management of post-LT de novo or recurrent infections. Optimising immunosuppression is an important step in reducing the severity of allograft damage in the treatment of post-transplant viral infections. Viral clearance or control can be achieved by early initiation of high potency antiviral therapy.

Infections in Liver Transplantation

Liver transplantation has become an important treatment modality for patients with end-stage liver disease/cirrhosis, acute liver failure, and hepatocellular carcinoma. Although surgical techniques and immunosuppressive regimens for liver transplantation have improved significantly over the past 20 years, infectious complications continue to contribute to the morbidity and mortality in this patient population. The use of standardized screening protocols for both donors and recipients, coupled with targeted prophylaxis against specific pathogens, has helped to mitigate the risk of infection in liver transplant recipients. Patients with chronic liver disease and cirrhosis have immunological deficits that place them at increased risk for infection while awaiting liver transplantation. The patient undergoing liver transplantation is prone to develop healthcare-acquired infections due to multidrug-resistant organisms that could potentially affect patient outcomes after transplantation. The complex nature of liver transplant surgery that involves multiple vascular and hepatobiliary anastomoses further increases the risk of infection after liver transplantation. During the early post-transplantation period, healthcare-acquired bacterial and fungal infections are the most common types of infection encountered in liver transplant recipients. The period of maximal immunosuppression that occurs at 1–6 months after transplantation can be complicated by opportunistic infections due to both primary infection and reactivation of latent infection. Severe community-acquired infections can complicate the course of liver transplantation beyond 12 months after transplant surgery. This chapter provides an overview of liver transplantation including indications, donor-recipient selection criteria, surgical procedures, and immunosuppressive therapies. A focus on infections in patients with chronic liver disease/cirrhosis and an overview of the specific infectious complications in liver transplant recipients are presented.

Cytomegalovirus infection in living donor liver transplant recipients significantly impacts the early post-transplant outcome: A single center experience

BACKGROUND

Cytomegalovirus (CMV) is the most common viral infection in liver transplant recipients that influences the outcomes of liver transplantation. However, its impact on early outcomes following living donor liver transplantation (LDLT) is not fully defined in the Indian subcontinent. This study was done to assess the impact of CMV infection on early post-transplant outcomes in LDLT recipients.

METHODS

Out of 272 LDLTs performed from January 2012 to April 2013, 151 recipients underwent CMV viral load analysis in plasma within 90 days post LDLT based on clinical suspicion. Patients with CMV infection (n = 55) were compared with those without CMV infection (n = 96).

RESULTS

The median time interval of CMV infection from LDLT was 25 days (range 2-90 days). The mean age of study population was 48.92 years. About 116 (76.8%) of the patients were male. Hepatitis C virus (HCV) (39.1%)-related chronic liver disease (CLD) was most common indication for liver transplant. No statistically significant difference was observed in etiology of liver disease (P = .38), Chid-Turcotte-Pugh (CTP) (P = .41), and Model for End-stage Liver Disease (MELD) (P = .12) scores between the groups. Patients with CMV infection had significantly higher incidence of acute cellular rejection (16.1% vs 5.4%, P = .02); longer ICU stay (P = .01); and a higher overall 90-day mortality (24.2% vs 6.7%, P = .001). Bacteremia and fungemia were significantly more common in the CMV infection group.

CONCLUSION

Cytomegalovirus infection significantly influences the early post LDLT outcomes and contributes to increased overall mortality.

Seroprevalence of cytomegalovirus in donors & opportunistic viral infections in liver transplant recipients

Background & objectives:

Opportunistic virus infections are common in liver transplant (LT) recipients. There is a risk of developing infection with cytomegalovirus (CMV) and herpes-related viruses such as herpes simplex virus-1 and 2 (HSV-1 & 2), Epstein-Barr virus (EBV) and Varicella Zoster virus (VZV), reactivation of infection and recurrent infection. This study was conducted to determine CMV seropositivity in donors and its influence on LT recipients and seropositivity of CMV, HSV-1 and 2, EB viral capsid antigen (EBVCA) and VZV in LT recipients and their reactivation.

Methods:

Pre-transplant data for IgG and IgM for CMV (and donor), HSV-1 and -2, EB viral capsid antigen (VCA) and VZV were available for 153 recipients. All recipients were on ganciclovir or valganciclovir prophylaxis for three months after LT. For reactivation rates, findings of post-transplant CMV quantitative reverse transcription polymerase chain reaction (CMV qRT-PCR) assay were associated with pre-transplant serological profile.

Results:

Of the 153 LT recipients, 131 were men (85.6%). The median age of LT was 46 yr (range 9 months-71 yr). Overall exposure to CMV was 71.8 per cent followed by EB VCA (61.4%) and VZV (49.6%). Susceptibility to both HSV-1 and -2 was high across all decades (P<0.001). Seropositivity of CMV in donor was 90.9 per cent (100 out of 110). Post-transplant CMV qRT- PCR was positive in 17 (26.6%; 3 in recipient negative) of 64 samples tested. qRT-PCR assay was positive in one out of four (25%) tested for HSV-1 and nine out of 19 (47.4%) tested for EBV. Two recipients tested for HSV-2 and one for VZV were negative. There were three deaths in recipients (D+ R+) who were also positive for CMV qRT PCR. There was one death due to HSV-1 pneumonia. One patient with EBV reactivation developed post-transplant lymphoproliferative disorder two years after transplant.

Interpretation & conclusions:

Transplant recipient were at highest risk of acquiring HSV-1 and -2 more so for HSV-2. CMV exposure in transplant recipients and donors were very high and at greatest risk for recipient reactivation rate. Despite this, death related to CMV reactivation was low.

High-Dose Acyclovir for Cytomegalovirus Prophylaxis in Seropositive Abdominal Transplant Recipients

Background: Following abdominal solid organ transplant (aSOT), valganciclovir (VGC) is recommended for cytomegalovirus (CMV) prophylaxis. This agent is associated with efficacy concerns, toxicity, and emergence of ganciclovir resistance. Objective: To evaluate the incidence of high-dose acyclovir (HD-A) prophylaxis failure in seropositive aSOT recipients (R+). Methods: This was a retrospective, single-center study of R+ transplanted without lymphocyte-depleting induction between January 1, 2000, and June 30, 2013, discharged with 3 months of HD-A prophylaxis (800 mg 4 times daily). The primary outcome was incidence of prophylaxis failure. Secondary outcomes were incidence of biopsy-proven tissue-invasive disease and prophylaxis failure for each allograft subgroup. Results: A total of 1525 patients met inclusion criteria: 944 renal (RTX), 108 simultaneous pancreas-kidneys (SPK), 462 liver (LTX), and 11 pancreas (PTX) transplant recipients. The composite rate of HD-A prophylaxis failure was 7%; incidence of tissue-invasive disease was 0.4%. Failure rates were 4.5%, 6.1%, 11%, and 20% in the RTX, SPK, LTX, and PTX populations, respectively; tissue-invasive disease rates were 0.2%, 0%, 0.7%, and 10%. Failure occurred more frequently in the LTX and PTX populations ( P < 0.0001, HR = 2.6; P = 0.04 HR = 4.4). Incidence of tissue-invasive disease was minimal and not different in the RTX, LTX and SPK populations ( P = 0.34). When evaluating recipients of seronegative allografts (D−), the composite failure rate was 3.4% with no significant difference between allograft subgroups ( P = 0.45). Conclusion: HD-A may be a reasonable prophylaxis alternative for D−/R+ recipients, in the absence of lymphocyte-depleting induction, if low incidence viremia is tolerable. Future studies are needed to determine the long-term impact of CMV viremia in the setting of this prophylaxis approach.

Cytomegalovirus Infection in Liver Transplant Recipients: Current Approach to Diagnosis and Management

Cytomegalovirus (CMV) infection is the most common viral infection in liver transplant recipients, affecting post-transplant patients and graft survival. Recent advances in diagnosis and management of CMV have led to marked reduction in incidence, severity, and its associated morbidity and mortality. CMV DNA assay is the most commonly used laboratory parameter to diagnose and monitor CMV infection. Current evidence suggests that both pre-emptive and universal prophylaxis approaches are equally justified in liver transplant recipients. Intravenous ganciclovir and oral valganciclovir are the most commonly used drugs for treatment of CMV disease. Most of the centre use valganciclovir prophylaxis for prevention of CMV disease in liver trasplant recipient. The aim of this article is to review the current standard of care for diagnosis and management of CMV disease in liver transplant recipients.

Two strategies for prevention of cytomegalovirus infections after liver transplantation

AIM: To analyze differences in patients’ clinical course, we compared two regimes of either preemptive therapy or prophylaxis after liver transplantation.

METHODS: This retrospective study was reviewed and approved by the institutional review board of the University of Leipzig. Cytomegalovirus (CMV) prophylaxis with valganciclovir hydrochloride for liver transplant recipients was replaced by a preemptive strategy in October 2009. We retrospectively compared liver transplant recipients 2 years before and after October 2009. During the first period, all patients received valganciclovir daily. During the second period all patients included in the analysis were treated following a preemptive strategy. Outcomes included one year survival and therapeutic intervention due to CMV viremia or infection.

RESULTS: Between 2007 and 2010 n = 226 patients underwent liver transplantation in our center. n = 55 patients were D⁺/R^- high risk recipients and were excluded from further analysis. A further 43 patients had to be excluded since CMV prophylaxis/preemptive strategy was not followed although there was no clinical reason for the deviation. Of the remaining 128 patients whose data were analyzed, 60 received prophylaxis and 68 were treated following a preemptive strategy. The difference in overall mortality was not significant, nor was it significant for one-year mortality where it was 10% (95%CI: 8%-28%, P = 0.31) higher for the preemptive group. No significant differences in blood count abnormalities or the incidence of sepsis and infections were observed other than CMV. In total, 19 patients (14.7%) received ganciclovir due to CMV viremia and/or infections. Patients who were treated according to the preemptive algorithm had a significantly higher rate risk of therapeutic intervention with ganciclovir [n = 16 (23.5%) vs n = 3 (4.9%), P = 0.003)].

CONCLUSION: These data suggest that CMV prophylaxis is superior to a preemptive strategy in patients undergoing liver transplantation.

Risk factors for cytomegalovirus reactivation after liver transplantation: can pre-transplant cytomegalovirus antibody titers predict outcome?

Despite preexisting cytomegalovirus (CMV) immunity, CMV-seropositive liver transplantation (LT) patients remain at risk of CMV infection. We hypothesized that the pre-transplant CMV antibody titer correlates with the risk of CMV reactivation. We conducted a retrospective study of CMV-seropositive LT recipients who did not receive anti-CMV prophylaxis from 2007 to 2013. The pre-transplant CMV immunoglobulin G (IgG) titer, which was measured with an enzyme-linked fluorescent immunoassay, was assessed as a risk factor for CMV reactivation with multivariate Cox proportional hazards models. The population consisted of 225 CMV-seropositive LT patients with a median age of 57 years (interquartile range, 47-62 years). The CMV titer distributions were as follows: <60 (40%) and ≥60 AU/mL (60%). The Kaplan-Meier estimates for CMV infection were 17% at 3 months, 18% at 6 months, and 19% at 12 months after transplantation. In a univariate analysis, a marginally significant increased risk of CMV infection was seen in LT recipients with a pre-transplant CMV IgG titer<60 AU/mL versus ≥60 AU/mL [hazard ratio (HR), 1.79; 95% confidence interval (CI), 0.98-3.28 (P=0.06)]. This risk was statistically significant in the subgroup of recipients who received allografts from CMV-seropositive donors [HR, 2.21; 95% CI, 1.15-4.26 (P=0.02)]. In a multivariate analysis, a pre-transplant CMV IgG titer<60 AU/mL was significantly associated with CMV infection [HR, 3.11; 95% CI, 1.60-6.03 (P<0.001)]. The other risk factors were high body mass index, donor CMV seropositivity, prolonged cold ischemic time, use of an interleukin-2 receptor antagonist for induction therapy, and high numbers of post-transplant infections. A lower pre-transplant CMV antibody titer is significantly associated with CMV infection after LT. Quantitative measurement of CMV-specific humoral immunity may have a potential role in improving the CMV prevention strategy in CMV-seropositive LT recipients.

Acyclovir versus Valganciclovir for Preventing Cytomegalovirus Infection in Intermediate-Risk Liver Transplant Recipients

Context

Cytomegalovirus (CMV) is an opportunistic infection that causes profound morbidity and mortality after orthotopic liver transplant (OLT). The CMV immunoglobulin G serostatuses of donors and recipients are the main factors influencing risk for development of CMV infection after transplant.

Objective

To compare acyclovir and valganciclovir for preventing CMV infection after OLT.

Design, Setting, and Patients

Retrospective assessment of adult OLT recipients at intermediate risk for CMV infection at New York Presbyterian Hospital.

Intervention

All patients received ganciclovir 5 mg/kg intravenously every 12 hours or valganciclovir 900 mg orally every 12 hours for 7 days after transplant. On postoperative day 8, patients received antiviral prophylaxis according to risk stratification: acyclovir 800 mg orally 3 times daily in donor seronegative/recipient seropositive (D-/R+) patients or valganciclovir 900 mg orally once daily in donor seropositive/recipient seropositive (D+/R+) patients.

Main Outcome Measure

Composite incidence of CMV infection, syndrome, or tissue-invasive disease.

Results

Of 275 OLT recipients, 89 were at intermediate risk for CMV infection (29 D−/R+, 60 D+/R+). CMV infection, syndrome, or tissue-invasive disease occurred in 1 patient (3%) in the D−/R+ group and 5 patients (8%) in the D+/R+ group ( P=.66). One patient (3%) in the D−/R+ group had a CMV infection develop. Five D+/R+ recipients (8%) had CMV infection; 3 of them had CMV syndrome (5%), 1 had CMV hepatitis (1.6%), and the other had CMV esophagitis (1.6%); all events occurred after prophylaxis was discontinued. The rates of CMV infection were similar in D−/R+ patients treated with acyclovir and D+/R+ patients receiving valganciclovir. This risk-stratified approach to viral prophylaxis after OLT resulted in an acceptable rate of CMV infection in D−/R+ recipients and may avoid the costs and adverse effects associated with valganciclovir therapy.

Prophylaxis versus pre-emptive treatment for prevention of cytomegalovirus infection in CMV-seropositive orthotopic liver-transplant recipients

This study compared the pre-emptive and the prophylactic strategies used to prevent cytomegalovirus (CMV) infection and disease in CMV-seropositive orthotopic liver-transplant recipients and searched for associated predictive factors. Seventy-three orthotopic liver-transplant recipients who had received a transplant before November 2005 were given ganciclovir IV pre-emptively (group I) and 56 recipients who had received a transplant after November 2005 were given prophylactic valganciclovir for 3 months (group II). Demographic and biochemical parameters did not statistically vary between the groups at baseline. Monitoring of CMV DNAemia was similar in both groups. Forty-two (57.5%) patients presented with CMV infection in group I and 18 (32.1%) in group II (P < 0.004). CMV DNAemia was first detected at a median of 33 days post-transplant in group I and at 98.5 days in group II (P < 0.003), but viral loads were not significantly different. The overall incidence of CMV disease was 9.6% in group I versus 7.1% in group II (ns). Thirty-five (47.9%) patients presented with biopsy-proven acute rejection in group I and 13 (23.2%) in group II (P = 0.004). Forty (55%) patients in group I and 25 (44.6%) in group II presented with de novo post-transplant diabetes (P = 0.057). At 1-year post-transplant, global survival curves were not significantly different. Independent factors associated with CMV reactivation were an absence of CMV prophylaxis, CMV serological status of the donor, cold ischemia time, and HLA A + B + DR compatibility. CMV prophylaxis is efficacious and can prevent safely the direct and indirect effects of CMV infection in CMV-seropositive orthotopic liver-transplant recipients.

Universal prophylaxis or preemptive strategy for cytomegalovirus disease after liver transplantation: a systematic review and meta-analysis

We systematically reviewed and meta-analyze the efficacy of universal prophylaxis (UP) and preemptive (PE) strategies (using ganciclovir or valganciclovir) in preventing cytomegalovirus (CMV) disease (CMD) among liver transplant recipients (LTRs). We performed an electronic search of MEDLINE, EMBASE and the Cochrane Database till December 2013. Studies that assessed UP or PE for preventing CMD in LTRs were included. The risk of bias was assessed using the Newcastle-Ottawa scale. The primary outcome was CMD, secondary outcomes being acute cellular rejection (ACR), graft loss (GL) and mortality. Due to the heterogeneity of comparative studies, an indirect comparison was performed. Pooled incidence rates with 95% confidence interval (CI) are calculated for each outcome using a random-effects model. Thirty-two studies involving 2456 LTRs were included. The majority of the studies were of low risk of bias. Irrespective of donor/recipient CMV sero-status, CMD was 10% with UP (95% CI: 6-14; I(2)  = 87%; 16 studies, n = 1581) and 7% with PE (95% CI: 3-10; I(2)  = 84%; 16 studies, n = 875) (mean difference 2.6; 95% CI: -3.25 to 8.45, p = 0.34). Likewise, ACR and mortality were similar with the two strategies. However, GL was significantly lower in the UP group, regardless of donor/recipient sero-status. In indirect comparison, the incidence of CMD, ACR and mortality in LTRs were similar with two strategies. Trials comparing the two strategies directly are needed.

Management of cytomegalovirus infection and disease in liver transplant recipients

Cytomegalovirus (CMV) is one of the most common viral pathogens causing clinical disease in liver transplant recipients, and contributing to substantial morbidity and occasional mortality. CMV causes febrile illness often accompanied by bone marrow suppression, and in some cases, invades tissues including the transplanted liver allograft. In addition, CMV has been significantly associated with an increased predisposition to acute and chronic allograft rejection, accelerated hepatitis C recurrence, and other opportunistic infections, as well as reduced overall patient and allograft survival. To negate the adverse effects of CMV infection on transplant outcome, its prevention, whether through antiviral prophylaxis or preemptive therapy, is an essential component to the management of liver transplant recipients. Two recently updated guidelines have suggested that antiviral prophylaxis or preemptive therapy are similarly effective in preventing CMV disease in modest-risk CMV-seropositive liver transplant recipients, while antiviral prophylaxis is the preferred strategy over preemptive therapy for the prevention of CMV disease in high-risk recipients [CMV-seronegative recipients of liver allografts from CMV-seropositive donors (D+/R-)]. However, antiviral prophylaxis has only delayed the onset of CMV disease in many CMV D+/R- liver transplant recipients, and such occurrence of late-onset CMV disease was significantly associated with increased all-cause and infection-related mortality after liver transplantation. Therefore, a search for better strategies for prevention, such as prolonged duration of antiviral prophylaxis, a hybrid approach (antiviral prophylaxis followed by preemptive therapy), or the use of immunologic measures to guide antiviral prophylaxis has been suggested to prevent late-onset CMV disease. The standard treatment of CMV disease consists of intravenous ganciclovir or oral valganciclovir, and if feasible, reduction in pharmacologic immunosuppression. In one clinical trial, oral valganciclovir was as effective as intravenous ganciclovir for the treatment of mild to moderate CMV disease in solid organ (including liver) transplant recipients. The aim of this article is to provide a state-of-the art review of the epidemiology, diagnosis, prevention, and treatment of CMV infection and disease after liver transplantation.

Cytomegalovirus infection: its incidence and management in cytomegalovirus-seropositive living related liver transplant recipients: a single-center experience

It is believed that antiviral prophylaxis decreases the incidence of cytomegalovirus (CMV) reactivation and disease. There are few data regarding weekly assays for CMV DNA after transplantation and the subsequent management of CMV. Here we report a cohort of living related liver transplantation (LRLT) patients who were treated for invasive CMV disease or for CMV infections if they were receiving steroids for rejection. Patients who underwent liver transplantation at our center between September 2006 and August 2010 and were recipient-positive/donor-positive (R(+) /D(+) ) were prospectively included. Patients were tested for CMV DNA 3 weeks after transplantation. CMV DNA-positive patients underwent weekly DNA monitoring until there were 2 consecutive negative reports. Those who developed CMV disease or had rising DNA titers while they were on treatment for rejection were treated. A Cox regression analysis was performed for factors predicting survival. Two hundred sixty-six of the 306 R(+) /D(+) patients were CMV DNA-negative 3 weeks after transplantation, and 40 had detectable DNA. One of the DNA-negative patients developed CMV disease after treatment for rejection with methylprednisolone. Thirty patients had <500 copies/mL, and 10 had ≥500 copies/mL. Two of the 30 patients with DNA levels < 500 copies/mL developed CMV disease. Six of the 10 patients with DNA levels ≥500 copies/mL developed disease. CMV disease occurred in 9 of the 306 patients (2.9%). One patient received treatment for a rise in DNA titers while he was receiving steroids. There was a significant correlation between steroid administration for acute cellular rejection (ACR) and CMV reactivation (P = 0.003) and disease (P = 0.002). A multivariate analysis showed that CMV reactivation/disease did not predict survival. There was no difference in survival between CMV DNA-positive patients and CMV DNA-negative patients (P = 0.68). In conclusion, CMV reactivation is common after LRLT (13%), but the disease is rare (2.9%) without prophylaxis in CMV immunoglobulin G-positive recipients. The administration of steroids for ACR strongly correlates with CMV reactivation and disease. CMV reactivation and disease did not affect survival in our patient cohort.

Cytomegalovirus ileitis in a patient after liver transplantation-differentiating from de novo IBD

Cytomegalovirus (CMV) infection of the gastrointestinal (GI) tract has been reported in immunocompromised patients and is seen following liver transplantation. Although CMV infection can affect any part of the GI tract, involvement of the terminal ileum is rarely encountered after liver transplantation. We report a case of a 32-year-old male who developed CMV infection of the terminal ileum while receiving immunosuppression for liver transplantation. Initial ganciclovir treatment did not improve the patient's symptoms and therapy was then switched to foscarnet which ultimately resulted in resolution of infection. However the patient continued to have symptoms because of intermittent small bowel obstruction because of ulcerations and fibrosis ultimately requiring surgical resection. CMV DNA polymerase chain reaction (PCR) was negative throughout the course of infection. Surgical resected specimen revealed no evidence of inflammatory bowel disease (IBD). Follow up colonoscopy up to a year after infection also did not reveal any evidence of IBD. Compartmentalization in the clinical presentation of CMV involving GI tract can be seen with a negative blood DNA PCR. Histological diagnosis thus forms an important part in the clinical follow-up of liver transplant patients undergoing intense immunosuppression and should be aggressively pursued in patients with GI symptoms. De novo IBD should be considered in the differential diagnosis in these patients who do not improve with anti-viral treatment.

Current concepts on cytomegalovirus infection after liver transplantation

Cytomegalovirus (CMV) is the most common viral pathogen that negatively impacts on the outcome of liver transplantation. CMV cause febrile illness often accompanied by bone marrow suppression, and in some cases, invades tissues including the transplanted allograft. In addition, CMV has been significantly associated with an increased predisposition to allograft rejection, accelerated hepatitis C recurrence, and other opportunistic infections, as well as reduced overall patient and allograft survival. To negate the adverse effects of CMV on outcome, its prevention, whether through antiviral prophylaxis or preemptive therapy, is regarded as an essential component to the medical management of liver transplant patients. Two recent guidelines have suggested that antiviral prophylaxis or preemptive therapy are similarly effective in preventing CMV disease in modest-risk CMV-seropositive liver transplant recipients, while antiviral prophylaxis is the preferred strategy over preemptive therapy for the prevention of CMV disease in high-risk recipients [CMV-seronegative recipients of liver allografts from CMV-seropositive donors (D+/R-)]. However, antiviral prophylaxis has only delayed the onset of CMV disease in many CMV D+/R- liver transplant recipients, and at least in one study, such occurrence of late-onset primary CMV disease was significantly associated with increased mortality after liver transplantation. Therefore, optimized strategies for prevention are needed, and aggressive treatment of CMV infection and disease should be pursued. The standard treatment of CMV disease consists of intravenous ganciclovir or oral valganciclovir, and if feasible, one should also reduce the degree of immunosuppression. In one recent controlled clinical trial, valganciclovir was found to be as effective and safe as intravenous ganciclovir for the treatment of mild to moderate CMV disease in solid organ (including liver) transplant recipients. In this article, the authors review the current state and the future perspectives of prevention and treatment of CMV disease after liver transplantation.

Recommendations for the assessment and reporting of multivariable logistic regression in transplantation literature

Multivariable logistic regression is an important method to evaluate risk factors and prognosis in solid organ transplant literature. We aimed to assess the quality of this method in six major transplantation journals. Eleven analytical criteria and four documentation criteria were analyzed for each selected article that used logistic regression. A total of 106 studies (6%) out of 1,701 original articles used logistic regression analyses from January 1, 2005 to January 1, 2006. The analytical criteria and their respective reporting percentage among the six journals were: Linearity (25%); Beta coefficient (48%); Interaction tests (19%); Main estimates (98%); Ovefitting prevention (84%); Goodness-of-fit (3.8%); Multicolinearity (4.7%); Internal validation (3.8%); External validation (8.5%). The documentation criteria were reported as follows: Selection of independent variables (73%); Coding of variables (9%); Fitting procedures (49%); Statistical program (65%). No significant differences were found among different journals or between general versus subspecialty journals with respect to reporting quality. We found that the report of logistic regression is unsatisfactory in transplantation journals. Because our findings may have major consequences for the care of transplant patients and for the design of transplant clinical trials, we recommend a practical solution for the use and reporting of logistic regression in transplantation journals.

Race and ethnicity in access to and outcomes of liver transplantation: a critical literature review

Racial/ethnic disparities in access to and outcomes of liver transplantation are an important topic given the increasing diversity in the United States. Most reports on this topic predate the advent of allocation based on the model for end-stage liver disease (MELD). For many patients with a variety of lethal conditions, liver transplantation is the only effective therapy, signifying the importance of equitable access to care. Racial/ethnic disparities have been described at various steps of the liver transplant process, including liver disease prevalence and treatment, access to a transplant center and its waitlist, receipt of a liver transplant and posttransplant outcomes. The purpose of this minireview is to critically evaluate the published literature on racial/ethnicity-based disparities in liver disease prevalence and treatment, transplant center referral, transplant rates and posttransplant outcomes. We identify the shortcomings of previous reports and detail the barriers to completing properly constructed analyses, particularly emphasizing deficits in requisite data and the need for improved study design. Understanding the nature of race/ethnicity-based disparities in liver transplantation is necessary to improve research initiatives, policy design and serves the broader responsibility of providing the highest quality care to all patients with liver disease.

Postoperative infectious complications of abdominal solid organ transplantation

There is a rapidly growing population of immunocompromised organ transplant recipients. These patients are at risk of a large variety of infections that have significant consequences on mortality, graft dysfunction, and graft loss. The diagnosis and treatment of these infections are facilitated by an understanding of the preoperative, perioperative, and postoperative risk factors; the typical pathogens; and their characteristic time of presentation. On the basis of these factors, we put forth an algorithm for diagnosing and treating suspected infections in solid organ transplant recipients.

Cytomegalovirus infection after liver transplantation: Current concepts and challenges

Cytomegalovirus (CMV) is a common viral pathogen that influences the outcome of liver transplantation. In addition to the direct effects of CMV syndrome and tissue-invasive diseases, CMV is associated with an increased predisposition to acute and chronic allograft rejection, accelerated hepatitis C recurrence, and other opportunistic infections, as well as reduced overall patient and allograft survival. Risk factors for CMV disease are often interrelated, and include CMV D+/R- serostatus, acute rejection, female gender, age, use of high-dose mycophenolate mofetil and prednisone, and the overall state of immunity. In addition to the role of CMV-specific CD4+ and CD8+ T lymphocytes, there are data to suggest that functionality of the innate immune system contributes to CMV disease pathogenesis. In one study, liver transplant recipients with a specific polymorphism in innate immune molecules known as Toll-like receptors were more likely to develop higher levels of CMV replication and clinical disease. Because of the direct and indirect adverse effects of CMV disease, its prevention, whether through antiviral prophylaxis or preemptive therapy, is an essential component in improving the outcome of liver transplantation. In the majority of transplant centers, antiviral prophylaxis is the preferred strategy over preemptive therapy for the prevention of CMV disease in CMV-seronegative recipients of liver allografts from CMV-seropositive donors (D+/R-). However, the major drawback of antiviral prophylaxis is the occurrence of delayed-onset primary CMV disease. In several prospective and retrospective studies, the incidence of delayed-onset primary CMV disease ranged from 16% to 47% of CMV D+/R- liver transplant recipients. Current data suggests that delayed-onset CMV disease is associated with increased mortality after liver transplantation. Therefore, optimized strategies for prevention and novel drugs with unique modes of action are needed. Currently, a randomized controlled clinical trial is being performed comparing the efficacy and safety of maribavir, a novel benzimidazole riboside, and oral ganciclovir as prophylaxis against primary CMV disease in liver transplant recipients. The treatment of CMV disease consists mainly of intravenous (IV) ganciclovir, and if feasible, a reduction in the degree of immunosuppression. A recent controlled clinical trial demonstrated that valganciclovir is as effective and safe as IV ganciclovir for the treatment of CMV disease in solid organ (including liver) transplant recipients. In this article, the author reviews the current state and the future perspectives of prevention and treatment of CMV disease after liver transplantation.

Evaluation and management of end-stage liver disease in children

End-stage liver disease in children presents a challenging array of medical and psychosocial problems for the health care delivery team. Many of these problems are similar to those encountered by caregivers of adults with end-stage liver disease, such as the development of complications of cirrhosis, including ascites, spontaneous bacterial peritonitis, and esophageal variceal hemorrhage. However, the natural history of disease progression in children and their responses to medical therapy can differ significantly from that of their adult counterparts. Children with end-stage liver disease are especially vulnerable to nutritional compromise; if not effectively managed, this can seriously impact long-term outcomes and survival both before and after liver transplantation. Moreover, close attention must be given to vaccination status and the clinical setting at which health care is delivered to optimize outcomes and the delivery of high-quality pediatric health care. In this review, we address important components of the evaluation and management of children with chronic end-stage liver disease.

Valganciclovir preemptive therapy for the prevention of cytomegalovirus disease in high-risk seropositive solid-organ transplant recipients

BACKGROUND

The role of valganciclovir in the prevention of cytomegalovirus (CMV) disease in high-risk seropositive transplant patients is not known.

METHODS

We prospectively followed 301 seropositive solid organ transplant recipients to assess the efficacy and safety of valganciclovir (VGCV) in the prevention of CMV disease in high-risk patients. Asymptomatic patients with an antigenemia test >or=25 positive cells/2x10(5) polymorphonuclear cells received valganciclovir 900 mg twice a day as preemptive therapy until resolution of antigenemia (minimum 14 days). Additionally, patients treated with antilymphocytic drugs for more than 6 days received prophylaxis with VGCV 900 mg once a day during 90 days. Mean follow-up was 14 months (range 6-20 months).

RESULTS

Thirty-eight patients received VGCV; 24 as preemptive therapy and 14 due to the use of antilymphocytic drugs. No patient developed CMV disease during the follow-up. Viral load (antigenemia) decreased a mean of 78% from baseline after 7 days of VGCV therapy (P=0.024) and 98% at day 14 (P=0.029). Two patients showed a relapse of the antigenemia test >or=25 positive cells and were successfully treated with a repeated course of VGCV. Leukopenia (<2500/mm3) developed in 3/24 (12.5%) recipients in the preemptive therapy group and required to discontinuing the drug in one of them.

CONCLUSIONS

VGCV is safe and highly efficacious in the prevention of CMV disease in high-risk seropositive organ transplant recipients.

Mixed infection with multiple strains of murine cytomegalovirus occurs following simultaneous or sequential infection of immunocompetent mice

As with human cytomegalovirus (HCMV) infection of humans, murine CMV (MCMV) infection is widespread in its natural host, the house mouse Mus domesticus, and may consist of mixed infection with different CMV isolates. The incidence and mechanisms by which mixed infection occurs in free-living mice are unknown. This study used two approaches to determine whether mixed infection with MCMV could be established in laboratory mice. The first utilized two naturally occurring MCMV strains, N1 and G4, into which the lacZ gene was inserted by homologous recombination. The lacZ gene was used to track recombinant and parental viruses in simultaneously coinfected mice. In the second approach, a real-time quantitative PCR (qPCR) assay was used to detect viral immediate-early 1 (ie1) gene sequences in mice successively coinfected with G4 and then with the K181 MCMV strain. In both systems, mixed infection was detected in the salivary glands and lungs of experimentally infected mice. MCMV-specific antibody in sera and G4 IE1-specific cytotoxic lymphocyte responses in the spleens of twice-infected mice did not prevent reinfection. Finally, the prevalence of mixed infection in free-living mice trapped in four Australian locations was investigated using real-time qPCR to detect ie1 DNA sequences of N1, G4 and K181. Mixed infection with MCMVs containing the G4 and K181 ie1 sequences was detected in the salivary glands of 34·2 % of trapped mice. The observations that mixed infections are common in free-living M. domesticus and are acquired by immunocompetent mice through simultaneous or successive infections are important for vaccine development.