Cytomegalovirus viremia in lung transplant recipients receiving ganciclovir and immune globulin

Predictors of Cytomegalovirus Recurrence Following Cessation of Posttransplant Prophylaxis

INTRODUCTION

Cytomegalovirus (CMV) infection is associated with a poor prognosis after lung transplantation, and donor and recipient CMV serostatus is a risk factor for reactivation. CMV prophylaxis is commonly administered in the first year following transplantation to reduce CMV infection; however, the risk factors for long-term reactivation remain unclear. We investigated the timing and risk factors of CMV infection after prophylactic administration.

METHODS

This study was a retrospective review of the institutional lung transplantation database from June 2014 to June 2022. Data on patient characteristics, pretransplantation laboratory values, postoperative outcomes, and CMV infection were collected. Donor CMV-IgG-positive and recipient CMV-IgG-negative groups were defined as the CMV mismatch group.

RESULTS

During the study period, 257 patients underwent lung transplantation and received a prophylactic dose of valganciclovir hydrochloride for up to 1 y. CMV infection was detected in 69 patients (26.8%): 40 of 203 (19.7%) in the non-CMV mismatch group and 29 of 54 (53.7%) in the CMV mismatch group (P < 0.001). CMV infection after prophylaxis occurred at a median of 425 and 455 d in the CMV mismatch and non-CMV mismatch groups, respectively (P = 0.07). Multivariate logistic regression analysis revealed that preoperative albumin level (odds ratio [OR] = 0.39, P = 0.04), CMV mismatch (OR = 15.7, P < 0.001), and donor age (OR = 1.05, P = 0.009) were significantly associated with CMV infection.

CONCLUSIONS

CMV mismatch may have increased the risk of CMV infection after lung transplantation, which decreased after prophylaxis. In addition to CMV mismatch, low preoperative albumin level and donor age were independent predictors of CMV infection.

Association between cytomegalovirus viremia and long-term outcomes in lung transplant recipients

Although cytomegalovirus (CMV) viremia/DNAemia has been associated with reduced survival after lung transplantation, its association with chronic lung allograft dysfunction (CLAD) and its phenotypes is unclear. We hypothesized that, in a modern era of CMV prophylaxis, CMV DNAemia would still remain associated with death, but also represent a risk factor for CLAD and specifically restrictive allograft syndrome (RAS)/mixed phenotype. This was a single-center retrospective cohort study of all consecutive adult, first, bilateral-/single-lung transplants done between 2010-2016, consisting of 668 patients. Risks for death/retransplantation, CLAD, or RAS/mixed, were assessed by adjusted cause-specific Cox proportional-hazards models. CMV viral load (VL) was primarily modeled as a categorical variable: undetectable, detectable to 999, 1000 to 9999, and ≥10 000 IU/mL. In multivariable models, CMV VL was significantly associated with death/retransplantation (≥10 000 IU/mL: HR = 2.65 [1.78-3.94]; P < .01), but was not associated with CLAD, whereas CMV serostatus mismatch was (D+R-: HR = 2.04 [1.30-3.21]; P < .01). CMV VL was not associated with RAS/mixed in univariable analysis. Secondary analyses with a 7-level categorical or 4-level ordinal CMV VL confirmed similar results. In conclusion, CMV DNAemia is a significant risk factor for death/retransplantation, but not for CLAD or RAS/mixed. CMV serostatus mismatch may have an impact on CLAD through a pathway independent of DNAemia.

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.

Long-Term Impact of Cytomegalovirus Serologic Status on Lung Transplantation in the United States

BACKGROUND

Cytomegalovirus (CMV) infection has been associated with poor outcomes after solid organ transplantation. The long-term impact of donor and recipient CMV serological status on lung transplant outcomes remains unclear. Accordingly, we evaluated the impact of donor and recipient CMV status on long-term patients as well as allograft survival after single (SLT) and double lung transplantation (BLT).

METHODS

The Scientific Registry of Transplant Recipients was used to track all adult lung transplants in United States from May 2005 to June 2016. Patient mortality and bronchiolitis obliterans syndrome were determined up to 5 years using Cox proportional hazards modeling. Additionally, landmark analysis was performed conditional on survival at 1 year.

RESULTS

Compared with donor negative-recipient CMV-IgG negative (D-R-), donor positive-recipient negative (D+R-) and donor positive-recipient positive (D+R+) groups had increased mortality at 1 and 5 years after BLT, with the former demonstrating highest risk. Although mortality was not increased with CMV seropositive donors after SLT at 1 year, both D+R- and D+R+ groups demonstrated greater mortality at 5 years. Risk of bronchiolitis obliterans syndrome was not affected by CMV serological status. Conditional landmark analysis confirmed that lungs from CMV seropositive donors conferred highest risk for long-term mortality.

CONCLUSIONS

CMV seronegative recipients undergoing either BLT or SLT from CMV seropositive donors have the highest risk of long-term mortality that extends beyond the first year. Further studies are needed to determine the causes of higher mortality observed in the CMV seronegative recipients and risks and benefits of extension of CMV prophylaxis, particularly in the high-risk group.

Ganciclovir

Ganciclovir is synthetic nucleoside analog of guanine closely related to acyclovir but has greater activity against cytomegalovirus. This comprehensive profile on ganciclovir starts with a description of the drug: nomenclature, formulae, chemical structure, elemental composition, and appearance. The uses and application of the drug are explained. The methods that were used for the preparation of ganciclovir are described and their respective schemes are outlined. The methods which were used for the physical characterization of the dug are: ionization constant, solubility, X-ray powder diffraction pattern, crystal structure, melting point, and differential scanning calorimetry. The chapter contains the spectra of the drug: ultraviolet spectrum, vibrational spectrum, nuclear magnetic resonance spectra, and the mass spectrum. The compendial methods of analysis of ganciclovir include the United States Pharmacopeia methods. Other methods of analysis that were reported in the literature include: high-performance liquid chromatography alone or with mass spectrometry, electrophoresis, spectrophotometry, voltammetry, chemiluminescence, and radioimmunoassay. Biological investigation on the drug includes: pharmacokinetics, metabolism, bioavailability, and biological analysis. Reviews on the methods used for preparation or for analysis of the drug are provided. The stability of the drug in various media and storage conditions is reported. More than 240 references are listed at the end of the chapter.

The Role of Infections in BOS

Background: Infectious agents, particularly cytomegalovirus (CMV), have long been considered to be potential triggers for BOS, although the exact magnitude of the role of infections and the mechanisms thereof remain an area of active research. Methods: This chapter will review previous literature and newer results concerning the possible roles of CMV, other herpesviruses, community-acquired respiratory viruses, bacteria (including Pseudomonas, other gram-negative, gram-positive, and atypical organisms), and fungi, including colonization as well as invasive infection. Results: The text reviews and evaluates the body of literature supporting a role for these infectious agents as risk factors for BOS and time to BOS. Changing patterns of infection over time are taken into account, and studies that have shown an association between BOS (or lack thereof) and CMV are reviewed. Strategies for prevention or early treatment of infections are discussed as potential means of preserving allograft function long term. Immunizations, stringent infection-control practices, and antimicrobial treatment including newer therapies will be discussed. Conclusion: In addition to the classic literature that has focused on CMV, an expanding spectrum of infectious organisms has been implicated as possible risk factors for BOS. Increasing knowledge of the impact of long-term antiviral suppression, prophylaxis, and outcomes of early therapy will help guide future recipient management.

Cytomegalovirus immunoglobulin decreases the risk of cytomegalovirus infection but not disease after pediatric lung transplantation

BACKGROUND

Cytomegalovirus (CMV) has been associated with morbidity, including chronic allograft rejection, in transplant recipients. Data from adult centers suggests that CMV hyperimmune globulin (CMVIG) and ganciclovir together are superior in preventing CMV viremia than ganciclovir alone.

METHODS

A retrospective review of pediatric lung transplant recipients at 14 sites in North America and Europe was conducted to evaluate the effect of adding cytomegalovirus immunoglobulin (CMVIG) prophylaxis to at least 3 weeks of intravenous ganciclovir therapy in pediatric lung transplant recipients. Data were recorded for the first year after transplantation. Associations between time to CMV and risk factors, including CMVIG use, were assessed by multivariable Cox proportional hazards models.

RESULTS

Of 599 patients whose records were reviewed, 329 received at least 3 weeks of ganciclovir, with 62 (19%) receiving CMVIG. CMVIG was administered more frequently with CMV donor-positive/recipient-negative serostatus (p < 0.05). In multivariable models, patients who did not receive CMVIG as part of their prophylaxis were 3 times more likely to develop CMV infection (hazard ratio, 3.4; 95% confidence interval, 1.2-9.5) independent of CMV serostatus. However, CMVIG administration was not associated with decreased risk of episodes of CMV disease. Receipt of CMVIG was not associated with decreased risks of post-transplant morbidities (acute rejection, respiratory viral infection or early bronchiolitis obliterans) or morbidity within the first year after pediatric lung transplantation.

CONCLUSION

The use of CMVIG in addition to antiviral prophylaxis in pediatric lung transplantation requires further evaluation.

Postlung Transplant Survival is Equivalent Regardless of Cytomegalovirus Match Status

BACKGROUND

The purpose of this study was to assess (1) the relationship between donor-recipient cytomegalovirus (CMV) serologic status and posttransplant survival in the current era and (2) temporal changes in posttransplant survival by CMV matching status.

METHODS

De-identified data were obtained from the United Network for Organ Sharing. Based on pretransplant CMV serologic status (+ or -) of recipients (R) and donors (D), posttransplant survival was compared among three groups: D+ /R-, D+/- /R+, and D- /R-. Primary analysis focused on transplants performed January 1, 2000 to December 31, 2004, in recipients 18 years of age or older. To assess temporal trends in survival among groups, all lung transplants occurring between January 1, 1990, and December 31, 2004, were considered and divided into three periods based on transplant year: 1990 through 1994, 1995 through 1999, and 2000 through 2004. The primary outcome measure was survival, reported as rate of death per 100 patient-years. Kaplan-Meier analysis with log-rank test was used for time-to-event analysis.

RESULTS

During the current era (2000 through 2004), D+ /R- (n = 951), D+/- /R+ (n = 2,676), and D- /R- (n = 772) exhibited no differences in survival (p = 0.561), with rates of death per 100 patient-years of 16.6 (95% confidence interval, 14.9 to 18.5), 15.0 (95% confidence interval, 14.0 to 16.0), and 14.7 (95% confidence interval, 13.0 to 16.6), respectively. However, survival was significantly different for groups in the earlier eras of 1990 through 1994 (p < 0.001) and 1995 through 1999 (p < 0.001). During the three periods, survival improved significantly in D+ /R- (p < 0.001) and D+/- /R+ (p < 0.001), but survival in D- /R- (p = 0.351) did not change significantly with time.

CONCLUSIONS

In the current era, survival after lung transplantation is statistically equivalent regardless of CMV match status. Although in previous eras survival was worse among the D+/- /R+ and D+ /R- groups, in this era of aggressive CMV prophylaxis, CMV mismatch should not be sufficient grounds to decline a lung allograft offer.

CMV-specific CD8 T-cell dynamics in the blood and the lung allograft reflect viral reactivation following lung transplantation

Despite the potentially high burden of cytomegalovirus (CMV)-related disease following lung transplantation, the role of the cytotoxic T-lymphocyte (CTL) response to CMV in this patient group is ill-defined. We assessed the CMV-specific T-cell response in the blood and lung allograft of immunosuppressed lung transplant recipients receiving antiviral prophylaxis and following their withdrawal. While the proportion of CMV-specific CTL varied between patients, in the absence of CMV reactivation the level of CMV-specific CD8+ T cells in the blood remained stable over time. In the majority of patients CMV-specific cells could be detected in the lung allograft, often in the absence of viral DNA. Additionally, following primary CMV lung infection, CMV-specific CD8+ T cells were detected no earlier than 100 days post-transplantation but still prior to the detection of viral DNA in the lung allograft. Together these findings suggest that very low levels of CMV replication are sufficient to both prime and recruit CMV-specific CD8+ T cells to the MHC-mismatched lung allograft. The direct detection of CMV-specific T cells with an effector phenotype in the lung allograft suggests a protective antiviral function. This study provides a framework upon which the association between CMV and chronic allograft rejection can be further studied.

Management of cytomegalovirus infection in lung transplant recipients: evidence-based recommendations

Cytomegalovirus (CMV) continues to cause significant morbidity and mortality in lung transplant recipients. This article presents recommendations based on available evidence for the optimal management of CMV in lung transplant recipients, which have been developed by an expert committee of transplant physicians-surgeons and infectious disease specialists.

Comparing cytomegalovirus prophylaxis in renal transplantation: single center experience

BACKGROUND

Cytomegalovirus (CMV) presents a serious threat to CMV-seronegative recipients (R-), who have received an organ from a seropositive donor (D+).

OBJECTIVES

We compared the effectiveness of three different prophylactic protocols in CMV D+/R- patients and reviewed data on patients who received no prophylaxis.

PATIENTS AND METHODS

We reviewed 1137 kidney transplantations from 1995 to 2004. Of these, 147 recipients were CMV negative (D+/R-); 125 patients received CMV prophylaxis. Group I received CMV hyperimmune gammaglobulin only, group II received CMV hyperimmune gammaglobulin plus oral ganciclovir, and group III received prophylaxis with oral ganciclovir only.

RESULTS

In group I, CMV infection was observed in 31 of 53 patients (59%), and CMV disease was diagnosed in 9 (17%) during the prophylaxis. In the first year post transplant, a total of 41 of 53 patients (77.5%) had primary CMV infection. In group II, CMV infection occurred in 7 of 30 patients (23%), and CMV disease was diagnosed in only 2 (7%) during prophylaxis. In the first year post transplant, a total of 9 of 30 patients (30%) had primary CMV infection. In group III, 9 of 42 patients (21%) developed CMV infection during prophylaxis, and CMV disease was not observed. In the first year post transplant, a total of 13 of 42 patients (30%) had primary CMV infection. In contrast, all 22 CMV D+/R- patients without prophylaxis developed CMV infection (100%); CMV disease was diagnosed in 10 (45%), and 1 patient died.

CONCLUSIONS

Prophylaxis with hyperimmune gammaglobulin and/or oral ganciclovir significantly reduces CMV infection and disease. Prophylaxis with ganciclovir was significantly more effective than hyperimmune gammaglobulin monoprophylaxis, and more cost effective than combined prophylaxis.

Viral prophylaxis in organ transplant patients

Viral pathogens have emerged as the most important microbial agents having deleterious effects on solid organ transplant (SOT) recipients. Antiviral chemoprophylaxis involves the administration of medications to abort transmission of, avoid reactivation of, or prevent progression to disease from, active viral infection. Cytomegalovirus (CMV) is the major microbial pathogen having a negative effect on SOT recipients. CMV causes infectious disease syndromes, augments iatrogenic immunosuppression and is commonly associated with opportunistic superinfection. CMV has also been implicated in the pathogenesis of rejection. Chemoprophylactic regimens for CMV have included oral aciclovir (acyclovir) at medium and high doses, intravenous and oral ganciclovir, and the prodrugs valaciclovir (valacyclovir) and valganciclovir. CMV prophylactic strategies should be stratified, with the highest-risk patients receiving the most 'potent' prophylactic regimens. Herpes simplex virus (HSV) reactivation in SOT recipients is more frequent, may become more invasive, takes longer to heal, and has greater potential for dissemination to visceral organs than it does in the immunocompetent host. Prophylactic regimens for CMV are also effective chemoprophylaxis against HSV; in the absence of CMV prophylaxis, aciclovir, valaciclovir or famciclovir should be used as HSV prophylaxis in seropositive recipients. Primary varicella-zoster virus (VZV) after SOT is rare and most commonly seen in the paediatric transplant population because of VZV epidemiology. Zoster occurs in 5-15% of patients, usually after the sixth post-transplant month. Prophylactic regimens for zoster are neither practical nor cost effective after SOT because of the late onset of disease and low proportion of affected individuals. All SOT recipients should receive VZV immune globulin after contact with either varicella or zoster. Epstein-Barr virus has its most significant effect in SOT as the precipitating factor in the development of post-transplant lymphoproliferative disorders. Antiviral agents that could be effective are the same as those used for CMV, but indications for and effectiveness of prophylaxis are poorly established. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are important pathogens in the SOT population as indications for transplantation. So-called 'prophylaxis' for recurrent HBV and HCV after liver transplantation is controversial, suppressive rather than preventive, and potentially lifelong. Influenza infection after SOT is acquired by person-to-person contact. During epidemic periods of influenza, transplant populations experience a relatively high frequency of infection, and influenza may affect immunosuppressed SOT recipients more adversely than immunocompetent individuals. Antiviral medications for prevention of influenza are administered as post-exposure prophylaxis to SOT recipients, in addition to yearly vaccine, in circumstances such as influenza epidemics and nosocomial outbreaks, and after exposure to a symptomatic individual during 'flu season'.

Time-dependent bias was common in survival analyses published in leading clinical journals

OBJECTIVE

In survival analysis, "baseline immeasurable" time-dependent factors cannot be recorded at baseline, and change value after patient observation starts. Time-dependent bias can occur if such variables are not analyzed appropriately. This study sought to determine the prevalence of such time-dependent bias in highly-cited medical journals.

STUDY DESIGN AND SETTING

We searched Medline databases to identify all observational studies that used a survival analysis in American Journal of Medicine, Annals of Internal Medicine, Archives of Internal Medicine, British Medical Journal, Chest, Circulation, Journal of the American Medical Association, Lancet, and New England Journal of Medicine between 1998 and 2002. Studies with "baseline immeasurable" time-dependent factors were susceptible to time-dependent bias if a time-dependent covariate analysis was not used.

RESULTS

Of 682 eligible studies, 127 (18.6%, 95% CI 15.8-21.8%) contained a "baseline immeasurable" time-dependent factor and 52 (7.6% [5.8-9.9%] of all survival analyses/40.9% [32.3-50.0%] of studies with a time-dependent factor) were susceptible to time-dependent bias. In 35 studies (5.1% [3.7-7.1%]/27.6% [20.5-35.9%]), the bias affected a variable highlighted in the study abstract and correction of the bias could have qualitatively changed the study's conclusion in over half of studies.

CONCLUSION

In medical journals, time-dependent bias is concerningly common and frequently affects key factors and the study's conclusion.

Following universal prophylaxis with intravenous ganciclovir and cytomegalovirus immune globulin, valganciclovir is safe and effective for prevention of CMV infection following lung transplantation

We prospectively determined the safety and efficacy of valganciclovir for prevention of cytomegalovirus (CMV) in at-risk (donor positive/recipient negative [D+/R-] or R+) lung transplant recipients. We also determined the length of prophylaxis required to significantly decrease both CMV infection and disease. Consecutive lung transplant recipients surviving >30 days (n = 90) received combination prophylaxis with intravenous (i.v.) ganciclovir (GCV) 5 mg/kg/day and cytomegalovirus immune globulin (CMV-IVIG) followed by valganciclovir (450 mg twice-daily) to complete 180, 270 or 365 days of prophylaxis. This group was compared to a historical group (n = 140) who received high-dose oral acyclovir following i.v. GCV and CMV-IVIG. CMV disease was significantly lower in patients receiving valganciclovir compared to acyclovir (2.2% vs. 20%; p < 0.0001). Freedom from CMV infection and disease was significantly greater (p < 0.02) in patients receiving 180, 270 or 365 days of prophylaxis (90%, 95% and 90%, respectively) compared to those receiving 100-179 days (64%) or < 100 days (59%). No patient receiving valganciclovir died during the study. Following prophylaxis with i.v. GCV and CMV-IVIG, valganciclovir is safe and effective for prevention of CMV infection and disease in at-risk lung transplant recipients. The required length of prophylaxis was at least 180 days.

Impact of Cytomegalovirus Match on Survival after Cardiac and Lung Transplantation

Acute cytomegalovirus (CMV) disease and indirect effects caused by the virus alter the outcome after solid organ transplantation. Long-term results after 54 lung and 139 cardiac transplants at a single center have been retrospectively analyzed with regard to CMV status. Standard CMV prophylaxis consisted of ganciclovir for 100 days. Lung recipients were pretransplant CMV negative in 32 per cent as compared to heart recipients with 23 per cent. Patient survival after mismatch transplants (donor positive, recipient negative) was significantly reduced as compared to the other match groups (42% vs 76% at five years, P = 0.01). In heart recipients, CMV positive patients receiving a CMV negative graft showed best survival, whereas in the group of lung recipients negative/negative matched transplants produced best results. In both groups, CMV negative grafts had a better outcome than CMV positive grafts, and a survival difference between heart and lung recipients was only observed in recipients of a CMV positive grafts. Despite ganciclovir prophylaxis, CMV match remains an important factor for survival follwing heart and, even more profoundly, lung transplantation. Because survival was least favorable in the mismatched group, prophylactic regimens warrant improvement. For CMV negative lung recipients, CMV matching might be considered.

Critical care aspects of lung transplantation

Lung transplantation currently is the preferred treatment option for a variety of end-stage pulmonary diseases. Remarkable progress has occurred through refinements in technique and improved understanding of transplant immunology and microbiology. As a result, recipients are surviving longer after their transplant. Despite improvements in short- and intermediate-term survival, long-term success with lung transplantation remains limited by chronic allograft rejection, also known as bronchiolitis obliterans syndrome. Despite its long-term limitations, lung transplantation remains the only hope for many with end-stage pulmonary disease, and during the past 20 years, it has become increasingly accepted and used. As a result, clinicians working in an intensive care unit (ICU) are more likely to be exposed to these patients both in the immediate postoperative period as well as throughout their remaining lives. It is thus important that the ICU team have a working knowledge of the common complications, when these complications are most likely to occur, and how best to treat them when they do arise. The main focus of this review is to address the variety of potential graft and life-threatening problems that may occur in lung transplant recipients. Because the ICU is also the most common setting where a potential donor is identified, donor issues will briefly be addressed.

Delay of CMV infection in high-risk CMV mismatch lung transplant recipients due to prophylaxis with oral ganciclovir

Cytomegalovirus (CMV) is a common opportunistic infection in lung transplant recipients. Despite the use of early post-operative intravenous ganciclovir, most high-risk patients develop CMV infection. We conducted this retrospective study to determine the efficacy of extended CMV prophylaxis with oral ganciclovir in high-risk, donor-positive-recipient-negative, lung recipients. All patients initially received 3 months of intravenous ganciclovir and CMV hyperimmune globulin. Clinical outcomes in all CMV mismatch patients undergoing lung transplant surviving at least 3 months were included (n = 42). Since 1998, 14 patients received no oral ganciclovir prophylaxis (group 1) and 28 patients received indefinite oral ganciclovir after completion of intravenous therapy (group 2). In those patients receiving oral ganciclovir, the prevalence of post-transplant CMV infection was significantly reduced over the first 180 d post-transplant (50% in group 1 vs. 4% in group 2; p < 0.001). Although some CMV events were observed with additional follow-up in group 2, there remained a significantly greater freedom from CMV infection by Kaplan-Meier analysis in group 2 as compared with group 1, with over 30 months follow-up time in each group (log-rank, p = 0.02). A moderate rate of drug discontinuation was observed in group 2, and no severe drug-related events occurred. In high-risk lung transplant recipients, CMV prophylaxis with intravenous ganciclovir, followed by indefinite oral ganciclovir, significantly delays and reduces post-transplant CMV infections. A larger prospective randomized study is needed to confirm the benefits of oral ganciclovir on CMV prevention.

Variability in standard care for cytomegalovirus prevention and detection in pediatric lung transplantation: survey of eight pediatric lung transplant programs

Cytomegalovirus (CMV) infection after pediatric lung transplantation is a significant risk factor for morbidity and mortality in the first year after transplantation. Multiple strategies have been reported for CMV prevention among adult lung transplant programs. In contrast, little information has been reported regarding protocols for prevention and detection of CMV from pediatric programs. We conducted a survey to better understand the range of practice patterns for CMV prevention and detection at pediatric lung transplant centers. A self-administered questionnaire was distributed to 11 pediatric lung transplant centers identified through the International Pediatric Lung Transplant Collaborative in September 2002. A member of the lung transplant team from each institution was asked to provide the methods of CMV prevention and surveillance. Eight of 11 centers surveyed responded to the questionnaire accounting for 45.6% (26 of 57) and 100% (three of three) of the pediatric lung transplants performed in the US and UK in 2001, respectively. All centers used prophylactic therapy against CMV with either ganciclovir or valganciclovir with duration ranging from 3.5 wk to indefinitely. Most centers (six of eight) prescribed a prophylactic regimen based on donor and recipient CMV serostatus. Half (four of eight) of the centers report using CMV hyperimmune globulin in addition to an antiviral agent. Method for CMV detection varied widely, including use of conventional viral culture (n = 1), antigenemia (n = 7), and polymerase chain reaction (n = 2). A wide range of strategies is used to prevent and detect CMV in pediatric lung transplant recipients with little empiric evidence demonstrating the optimal approach. A retrospective analysis among these centers is being conducted to evaluate the efficacy of these approaches.

Impact of prophylaxis with cytogam alone on the incidence of CMV viremia in CMV-seropositive lung transplant recipients

BACKGROUND

Cytomegalovirus (CMV) infection remains a serious problem after lung transplantation. The purpose of this study was to evaluate the efficacy of CytoGam, a CMV hyperimmune globulin (CMV-IGIV), as CMV prophylaxis after lung transplantation.

METHODS

This prospective, randomized, open-label study compared prophylaxis with CMV-IGIV and no prophylaxis in 44 CMV-seropositive lung transplant recipients. The primary end-point was development of CMV viremia during the first year after transplantation.

RESULTS

Cytomegalovirus viremia was detected in 13 of 22 recipients without prophylaxis and in 16 of 22 recipients with CMV-IGIV prophylaxis (p = 0.19). Cytomegalovirus pneumonitis developed in 8 controls vs in 11 CMV-IGIV recipients (p = 0.54). We found no significant difference between the groups in the incidence of positive shell vial assays (6.8% +/- 6.5% without vs 11.2% +/- 10.1% with prophylaxis, p = 0.09) or in the attack rate of CMV pneumonitis (0.41 +/- 0.59 episodes/patient without vs 0.86 +/- 0.99 episodes/patient with prophylaxis, p = 0.07). Similarly, no difference was apparent in the time to onset of CMV viremia, to detection of CMV DNA in peripheral blood leukocytes by polymerase chain reaction, or to development of CMV pneumonitis. The incidence of acute rejection and bronchiolitis obliterans syndrome and the survival rate during the first post-transplant year did not differ between the groups.

CONCLUSIONS

Prophylaxis with CMV-IGIV alone did not decrease CMV viremia or pneumonitis, did not decrease the incidence of acute rejection or bronchiolitis obliterans syndrome, and did not affect 1-year survival of CMV-seropositive lung transplant recipients at our center.

Bronchiolitis obliterans syndrome and early human cytomegalovirus DNAaemia dynamics after lung transplantation

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) remains a major cause of morbidity and mortality after lung transplantation. The major identified risk factors for BOS are acute rejection and human cytomegalovirus (HCMV) infection, the latter despite the use of relatively insensitive and nonspecific measures such as HCMV pneumonitis and HCMV serostatus, respectively. We hypothesized that a more accurate prospective analysis of HCMV reactivation in lung transplant recipients (LTRs) would improve our understanding of the association between HCMV and BOS development.

METHODS

In 26 LTRs, HCMV DNAaemia was measured using quantitative polymerase chain reaction at monthly intervals during the initial 6 months posttransplantation. BOS was defined as a sustained irreversible 20% decrease in FEV1 compared with the best baseline FEV1 posttransplantation in the absence of any other cause.

RESULTS

Of the 26 LTRs, 23 were assessable with regard to the BOS outcome variable. At a median follow-up of 37 months, 10 patients had developed BOS. During the first 6-month monitoring period, HCMV DNAaemia was detected in 15 of the 23 patients on at least one occasion, and there were 12 episodes of HCMV pneumonitis in eight patients. Episodes of grade A3 or greater acute rejection occurred in eight LTRs, six of whom had been HCMV DNAaemia positive at least once and four of whom also demonstrated HCMV pneumonitis. Our results revealed a strong association between BOS and early HCMV DNAaemia detection (univariate analysis [P=0.002] and freedom from BOS analysis [P=0.006]).

CONCLUSION

Early HCMV DNAaemia in LTRs is associated with the development of BOS despite routine ganciclovir prophylaxis.

Cytomegalovirus viremia associated with death or retransplantation in pediatric lung-transplant recipients

BACKGROUND

Cytomegalovirus (CMV) infection is a frequent complication of lung transplantation. However, there is limited information regarding the incidence and sequelae of CMV infections in pediatric lung-transplant recipients. On the basis of case series suggesting that CMV infection was associated with excess morbidity and mortality in lung-transplant recipients, we hypothesize that CMV viremia increases the risk of bronchiolitis obliterans (BOS) or death and retransplantation in the first year following transplantation.

METHODS

A case-cohort study of pediatric primary lung-transplant recipients was performed. Univariate analysis was used to assess whether CMV viremia was associated with BOS or death and retransplantation within 1 year after transplantation. Patients at high risk for CMV infection received ganciclovir prophylaxis for 42 days posttransplantation.

RESULTS

From July 1990 to November 2000, 194 pediatric patients received primary lung transplants. Twenty-three percent of patients developed CMV viremia. Eighty percent of CMV viremia episodes occurred before 120 days posttransplant. A first episode of CMV viremia was associated with retransplantation or death between days 90 and 365 (RR=4.1, 95% confidence interval [CI] 1.1-14.5) and was not associated with BOS (RR=1.3, 95% CI 0.5-3.3).

CONCLUSIONS

CMV viremia in the first year after pediatric primary lung transplantation is associated with increased risk of death or retransplantation between 90 and 365 days posttransplant, when CMV prophylaxis has stopped. A phase II pilot trial is warranted to assess safety and short-term efficacy of increasing the duration of CMV prophylaxis from 42 to 120 days.

Prevention of cytomegalovirus infection and disease after lung transplantation: results using a unique regimen employing delayed ganciclovir

BACKGROUND

Many lung transplant programs employ lengthy regimens of IV ganciclovir therapy to prevent disease due to cytomegalovirus (CMV). In 1994, we introduced a regimen of delayed ganciclovir prophylaxis for CMV infection. This consisted of 2 weeks of IV ganciclovir therapy, initiated 3 to 4 weeks after transplantation, with subsequent viral monitoring and preemptive therapy as needed. When not receiving ganciclovir, patients received oral acyclovir, 800 mg tid, for 6 months. CMV-seronegative patients with seropositive donors also received four doses of CMV hyperimmune globulin. This study analyzes the CMV outcomes of 54 patients who received the delayed regimen compared to 33 historical control subjects who received only acyclovir prophylaxis (n = 28) or oral acyclovir and 2 to 4 weeks of ganciclovir early after transplantation (n = 5).

METHODS

CMV detection was by shell vial culture or IgG seroconversion; after 1996, CMV detection was by blood antigenemia. The diagnosis of CMV disease also required a typical clinical syndrome or pathologic evidence of CMV. The main outcome was the actuarial incidence of CMV infection and disease. In order to account for the effect of other important risk factors for CMV infection, the time to CMV infection and disease was also studied as dependeant variables in a Cox proportional-hazard analysis, with the delayed regimen and other important risk factors as independent variables.

RESULTS

The delayed regimen reduced the actuarial incidence of CMV infection from 80 to 48% (p < 0.001) and CMV disease from 31 to 10% (p < 0.01). No seropositive patient receiving the delayed regimen developed CMV disease. Twelve of the 54 patients in the study group required additional IV antiviral treatment, but the total use of ganciclovir averaged only 18 days per patient. In a Cox proportional-hazards model, the use of delayed ganciclovir was the only factor that showed a significant association with freedom from CMV infection (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.24 to 0.75; p = 0.003) and CMV disease (HR, 0.29; 95% CI, 0.10 to 0.86; p = 0.03).

CONCLUSION

A regimen of CMV prophylaxis employing 2 weeks of IV ganciclovir initiated 3 to 4 weeks after lung transplantation followed by virologic monitoring and preemptive therapy as needed provides good protection against CMV disease.

Provision of laboratory services for heart and lung transplantation in Australia

BACKGROUND

Laboratory services for the support of heart and lung transplantation in Australia have adapted to the special needs of the clinicians looking after the heart and lung transplantation patients.

METHODS

Pre-transplantation standardized tests encompassing a wide variety of different parameters are carried out both to establish the suitability of patients for a transplant and to maximize the chance of success following this procedure. Potential solid organ recipients routinely have blood samples sent to a number of centers Australia-wide so that human leukocyte antigen (HLA) presensitization can be checked for at the time a donor becomes available in any state in Australia. Although prospective HLA matching is not performed for thoracic organ transplant recipients, pre-existing antibodies to donor HLA antigens are a contra-indication to transplantation. Following transplantation, the predominant roles of the laboratory are in the monitoring of immunosuppressive drug levels, in the detection of allograft rejection, and in the detection of bacterial infection or viral reactivation. While a number of markers have been proposed in the detection of rejection, we currently rely on interpretation of the histological analysis of biopsies. The treatment with immune suppressive agents, in particular cyclosporin A, has made organ transplantation from non-HLA identical donors possible. As cyclosporin A and other immune suppressive drugs have significant side effects, their concentrations need to be carefully followed to guarantee sufficient immune suppression while avoiding renal failure and other complications including excessive immunosuppression and infectious disease risk. Recently, the role of viral reactivation with the human cytomegalovirus (HCMV) has attained more prominence. HCMV is a potential pathogen in up to 90% of thoracic organ transplant recipients and in the pre-gancyclovir era, it was a major cause of morbidity and mortality in at-risk lung transplant recipients. New PCR-based assays that measure the viral load levels of HCMV allow earlier intervention and more appropriate treatment strategies to prevent the HCMV disease syndromes and optimize the HCMV prophylaxis strategy.

CONCLUSIONS

Diagnostic pathology testing to support heart and lung transplantation is a combination of routine testing and specialized testing. Depending on the time-critical nature of the tests, this testing has to be done on site or in more centralized testing facilities. Further developments in the laboratory support of heart and lung transplantation will hopefully continue to improve both the short- and long-term outcomes of thoracic organ transplant recipients.

Infectious complications of lung transplantation

Lung transplantation is associated with a high incidence of infection which directly impacts the morbidity and mortality associated with the procedure. In addition, these infections may also have immunologic consequences that play a role in the evolution of lung injury syndromes, resulting in earlier loss of graft than otherwise would be expected to occur. Although bacteria are responsible for the majority of infections following lung transplantation, fungal infections are associated with the highest mortality. This paper is an overview of the major infectious complications encountered in the lung transplant population. The epidemiology, prophylaxis, and treatment of infections following lung transplantation are critical areas for continued research.

Quantification of cytomegalovirus DNA in BAL fluid: a longitudinal study in lung transplant recipients

STUDY OBJECTIVES

Cytomegalovirus (CMV) infection is common in patients receiving solid organ transplants, and it is associated with increased morbidity as well as risk for development of chronic rejection. A rapid and sensitive diagnostic method would improve the therapeutic management of CMV infection, including the monitoring of treatment effects. We investigated whether longitudinal determinations of CMV DNA quantities in BAL fluid could be useful for this purpose.

DESIGN

CMV DNA levels in 340 BAL samples from 35 consecutive lung transplant recipients were studied during a median of 18 months. Seventeen (49%) of the patients developed CMV disease with pneumonitis. Twenty-seven CMV disease episodes were diagnosed.

RESULTS

Patients with CMV disease had a significantly higher mean level of CMV copies per milliliter BAL fluid (1,120 +/- 4,379) compared with those without (180 +/- 1,177, p < 0.01). Viral load as well as acute rejection requiring treatment (>/= A2) were independent risk factors associated with CMV disease. Differences between the groups concerning HLA-DR matching, basic immunosuppressive therapy, and CMV serologic status D/R -/+ vs D/R +/+ were not significant. A diagnostic definition of normality based on the mean level of all episodes without CMV disease +2 SD would discriminate only 9 of the 27 CMV episodes.

CONCLUSIONS

Although the viral load is increased during episodes of clinical CMV disease in lung transplant recipients, the quantitative PCR assessment of CMV DNA in BAL fluid is not discriminative enough to be useful as a diagnostic tool for CMV disease.

Passive immunity in prevention and treatment of infectious diseases

Antibodies have been used for over a century in the prevention and treatment of infectious disease. They are used most commonly for the prevention of measles, hepatitis A, hepatitis B, tetanus, varicella, rabies, and vaccinia. Although their use in the treatment of bacterial infection has largely been supplanted by antibiotics, antibodies remain a critical component of the treatment of diptheria, tetanus, and botulism. High-dose intravenous immunoglobulin can be used to treat certain viral infections in immunocompromised patients (e.g., cytomegalovirus, parvovirus B19, and enterovirus infections). Antibodies may also be of value in toxic shock syndrome, Ebola virus, and refractory staphylococcal infections. Palivizumab, the first monoclonal antibody licensed (in 1998) for an infectious disease, can prevent respiratory syncytial virus infection in high-risk infants. The development and use of additional monoclonal antibodies to key epitopes of microbial pathogens may further define protective humoral responses and lead to new approaches for the prevention and treatment of infectious diseases.

Passive immunity in prevention and treatment of infectious diseases

Antibodies have been used for over a century in the prevention and treatment of infectious disease. They are used most commonly for the prevention of measles, hepatitis A, hepatitis B, tetanus, varicella, rabies, and vaccinia. Although their use in the treatment of bacterial infection has largely been supplanted by antibiotics, antibodies remain a critical component of the treatment of diptheria, tetanus, and botulism. High-dose intravenous immunoglobulin can be used to treat certain viral infections in immunocompromised patients (e.g., cytomegalovirus, parvovirus B19, and enterovirus infections). Antibodies may also be of value in toxic shock syndrome, Ebola virus, and refractory staphylococcal infections. Palivizumab, the first monoclonal antibody licensed (in 1998) for an infectious disease, can prevent respiratory syncytial virus infection in high-risk infants. The development and use of additional monoclonal antibodies to key epitopes of microbial pathogens may further define protective humoral responses and lead to new approaches for the prevention and treatment of infectious diseases.

CT findings of pneumonia after lung transplantation

OBJECTIVE

The purpose of this study was to describe the CT findings of pneumonia in patients who had undergone lung transplantation and to determine if specific imaging features existed for the different infectious organisms.

MATERIALS AND METHODS

The authors retrospectively reviewed the medical records of 262 patients with transplanted lungs at two lung transplantation centers. Patients with a documented pneumonia and correlating abnormal findings on CT (39 patients with 45 pneumonias) were included in the study. RESULTS. Of 45 pneumonias, Cytomegalovirus (n = 15), Pseudomonas (n = 7), and Aspergillus (n = 8) organisms were the most common single responsible infectious agents. The most common CT findings of pneumonia consisted of consolidation (n = 37; 82%), ground-glass opacification (n = 34; 76%), septal thickening (n = 33; 73%), pleural effusion (n = 33; 73%), and multiple (n = 25; 56%) or single (n = 2; 4%) nodules. No significant difference in the prevalence of findings was revealed among bacterial, viral, and fungal pneumonias (p >.05, chisquare test). Of 25 pneumonias in patients with a single transplanted lung, parenchymal abnormalities involved both lungs in 12 (48%), only the transplanted lung in 11 (44%), and only the native lung in two (8%).

CONCLUSION

The manifestations revealed on CT of bacterial, viral, and fungal pneumonia after lung transplantation are similar, consisting of a combination of consolidation, ground-glass opacification, septal thickening, pleural effusion, or multiple nodules. Therefore, these findings cannot be used to suggest the infectious organisms in this patient population.

New strategies for prevention and therapy of cytomegalovirus infection and disease in solid-organ transplant recipients

In the past three decades since the inception of human organ transplantation, cytomegalovirus (CMV) has gained increasing clinical import because it is a common pathogen in the immunocompromised transplant recipient. Patients may suffer from severe manifestations of this infection along with the threat of potential fatality. Additionally, the dynamic evolution of immunosuppressive and antiviral agents has brought forth changes in the natural history of CMV infection and disease. Transplant physicians now face the daunting task of recognizing and managing the changing spectrum of CMV infection and its consequences in the organ recipient. For the microbiology laboratory, the emphasis has been geared toward the development of more sophisticated detection assays, including methods to detect emerging antiviral resistance. The discovery of novel antiviral chemotherapy is an important theme of clinical research. Investigations have also focused on preventative measures for CMV disease in the solid-organ transplant population. In all, while much has been achieved in the overall management of CMV infection, the current understanding of CMV pathogenesis and therapy still leaves much to be learned before success can be claimed.

Prevention of infections in solid organ transplant recipients

Solid organ transplantation has become an important therapeutic option for multiple chronic diseases. With the advent of newer and potent immunosuppressive regimens, graft survival has improved, but at the expense of an increased risk for the development of infections secondary to bacterial, fungal, viral and parasitic pathogens. Prevention of such infectious complications with effective, well tolerated, and cost-effective anti-microbials would be ideal to improve the outcome of transplanted patients. However, the emergence of multi-drug resistant pathogens, medication toxicity and drug-drug interactions need to be carefully evaluated. This review summarizes the most relevant data pertaining to our current understanding of infection prevention for solid organ transplant recipients. Specific recommendations are given for the prevention of each group of microorganisms and types of solid organ transplant.