Controversies in lung transplantation: management of cytomegalovirus infections

Prevention of Cytomegalovirus Infection in Solid Organ Transplant Recipients: Guidelines by the Korean Society of Infectious Diseases and the Korean Society for Transplantation

Cytomegalovirus (CMV) is the most important opportunistic viral pathogen in solid organ transplant (SOT) recipients. The Korean guideline for the prevention of CMV infection in SOT recipients was developed jointly by the Korean Society for Infectious Diseases and the Korean Society of Transplantation. CMV serostatus of both donors and recipients should be screened before transplantation to best assess the risk of CMV infection after SOT. Seronegative recipients receiving organs from seropositive donors face the highest risk, followed by seropositive recipients. Either antiviral prophylaxis or preemptive therapy can be used to prevent CMV infection. While both strategies have been demonstrated to prevent CMV infection post-transplant, each has its own advantages and disadvantages. CMV serostatus, transplant organ, other risk factors, and practical issues should be considered for the selection of preventive measures. There is no universal viral load threshold to guide treatment in preemptive therapy. Each institution should define and validate its own threshold. Valganciclovir is the favored agent for both prophylaxis and preemptive therapy. The evaluation of CMV-specific cell-mediated immunity and the monitoring of viral load kinetics are gaining interest, but there was insufficient evidence to issue recommendations. Specific considerations on pediatric transplant recipients are included.

Opportunistic Infections Post-Lung Transplantation: Viral, Fungal, and Mycobacterial

Opportunistic infections are a leading cause of lung transplant recipient morbidity and mortality. Risk factors for infection include continuous exposure of the lung allograft to the external environment, high levels of immunosuppression, impaired mucociliary clearance and decreased cough reflex, and impact of the native lung microbiome in single lung transplant recipients. Infection risk is mitigated through careful pretransplant screening of recipients and donors, implementation of antimicrobial prophylaxis strategies, and routine surveillance posttransplant. This review describes common viral, fungal, and mycobacterial infectious after lung transplant and provides recommendations on prevention and treatment.

Patient years lost due to cytomegalovirus serostatus mismatching in the scientific registry of transplant recipients

Background

The cytomegalovirus (CMV) mismatch rate in deceased donor kidney transplant (DDKT) recipients in the US remains above 40%. Since CMV mismatching is common in DDKT recipients, the cumulative effects may be significant in the context of overall patient and graft survival. Our primary objective was to describe the short- and long-term risks associated with high-risk CMV donor positive/recipient negative (D+/R-) mismatching among DDKT recipients with the explicit goal of deriving a mathematical mismatching penalty.

Methods

We conducted a retrospective, secondary analysis of the Scientific Registry of Transplant Recipients (SRTR) database using donor-matched DDKT recipient pairs (N=105,608) transplanted between 2011-2022. All-cause mortality and graft failure hazard ratios were calculated from one year to ten years post-DDKT. All-cause graft failure included death events. Survival curves were calculated using the Kaplan-Meier estimation at 10 years post-DDKT and extrapolated to 20 years to provide the average graft days lost (aGDL) and average patient days lost (aPDL) due to CMV D+/R- serostatus mismatching. We also performed an age-based stratification analysis to compare the relative risk of CMV D+ mismatching by age.

Results

Among 31,518 CMV D+/R- recipients, at 1 year post-DDKT, the relative risk of death increased by 29% (p<0.001), and graft failure increased by 17% (p<0.001) as compared to matched CMV D+/R+ group (N=31,518). Age stratification demonstrated a significant increase in the risk associated with CMV mismatching in patients 40 years of age and greater. The aGDL per patient due to mismatching was 125 days and the aPDL per patient was 100 days.

Conclusion

The risks of CMV D+/R- mismatching are seen both at 1 year post-DDKT period and accumulated throughout the lifespan of the patient, with the average CMV D+/R- recipient losing more than three months of post-DDKT survival time. CMV D+/R- mismatching poses a more significant risk and a greater health burden than previously reported, thus obviating the need for better preventive strategies including CMV serodirected organ allocation to prolong lifespans and graft survival in high-risk patients.

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.

Opportunistic Infections Post-Lung Transplantation: Viral, Fungal, and Mycobacterial

Opportunistic infections are a leading cause of lung transplant recipient morbidity and mortality. Risk factors for infection include continuous exposure of the lung allograft to the external environment, high levels of immunosuppression, impaired mucociliary clearance and decreased cough reflex, and impact of the native lung microbiome in single lung transplant recipients. Infection risk is mitigated through careful pretransplant screening of recipients and donors, implementation of antimicrobial prophylaxis strategies, and routine surveillance posttransplant. This review describes common viral, fungal, and mycobacterial infectious after lung transplant and provides recommendations on prevention and treatment.

Prevention and management of CMV infection in pediatric solid organ transplant recipients

Human cytomegalovirus (CMV) remains one of the most common opportunistic infections following solid organ transplantation in children. CMV causes morbidity and mortality through direct tissue-invasive disease and indirect immunomodulatory effects. In recent years, several new agents have emerged for the prevention and treatment of CMV disease in solid organ transplant recipients. However, pediatric data remain scarce, and many of the treatments are extrapolated from the adult literature. Controversies exist about the type and duration of prophylactic therapies and the optimal dosing of antiviral agents. This review provides an up-to-date overview of treatment modalities used to prevent and treat CMV disease in solid organ transplant (SOT) recipients.

Laboratory diagnostic testing for cytomegalovirus infection in solid organ transplant patients

Human cytomegalovirus (CMV) infection, which is one of the most common complications in transplant recipients, increases the risk of graft loss and rejection. Laboratory strategies for diagnosing CMV infection rely on the measurement of viral DNAemia and CMV-specific cell-mediated immunity (CMV-CMI). The CMV quantitative nucleic acid amplification test (QNAT) enabled the spread of preemptive therapy and prompted recommendations for surveillance, diagnosis, and monitoring. Despite the implementation of the World Health Organization international standard for calibration, variability of QNAT persists due to technical issues. CMV immunoglobulin G serology is the standard method for CMV immune screening of transplant candidates and donors. Assays for CMV-CMI play an important role in helping to predict the risk and to develop an individualized CMV management plan. Genotypic testing for resistance is needed when drug-resistant CMV infection is suspected. Here, we review the state of the art of laboratory tests for CMV infection in solid organ transplantation.

Cytomegalovirus in solid organ transplant recipients-Guidelines of the American Society of Transplantation Infectious Diseases Community of Practice

Cytomegalovirus (CMV) is one of the most common opportunistic infections that affect the outcome of solid organ transplantation. This updated guideline from the American Society of Transplantation Infectious Diseases Community of Practice provides evidence-based and expert recommendations for screening, diagnosis, prevention, and treatment of CMV in solid organ transplant recipients. CMV serology to detect immunoglobulin G remains as the standard method for pretransplant screening of donors and transplant candidates. Antiviral prophylaxis and preemptive therapy are the mainstays of CMV prevention. The lack of a widely applicable viral load threshold for diagnosis and preemptive therapy is highlighted, as a result of variability of CMV nucleic acid testing, even in the contemporary era when calibrators are standardized. Valganciclovir and intravenous ganciclovir remain as drugs of choice for CMV management. Strategies for managing drug-resistant CMV infection are presented. There is an increasing use of CMV-specific cell-mediated immune assays to stratify the risk of CMV infection after solid organ transplantation, but their role in optimizing CMV prevention and treatment efforts has yet to be demonstrated. Specific issues related to pediatric transplant recipients are discussed.

Burden of cytomegalovirus reactivation post kidney transplant with antithymocyte globulin use in Thailand: A retrospective cohort study

Background: Cytomegalovirus (CMV) is an important cause of infectious complications after kidney transplantation (KT), especially among patients receiving antithymocyte globulin (ATG). CMV infection can result in organ dysfunction and indirect effects such as graft rejection, graft failure, and opportunistic infections . Prevention of CMV reactivation includes pre-emptive or prophylactic approaches. Access to valganciclovir prophylaxis is limited by high cost. Our objective is to determine the burden and cost of treatment for CMV reactivation/disease among KT recipients who received ATG in Thailand since its first use in our center. Methods: We conducted a single-center retrospective cohort study of KT patients who received ATG during 2010-2013. We reviewed patients' characteristics, type of CMV prophylaxis, incidence of CMV reactivation, and outcome (co-infections, graft function and death). We compared the treatment cost between patients with and without CMV reactivation. Results: Thirty patients included in the study had CMV serostatus D+/R+. Twenty-nine patients received intravenous ganciclovir early after KT as inpatients. Only three received outpatient valganciclovir prophylaxis. Incidence of CMV reactivation was 43%, with a median onset of 91 (range 23-1007) days after KT. Three patients had CMV end-organ disease; enterocolitis or retinitis. Infectious complication rate among ATG-treated KT patients was up to 83%, with a trend toward a higher rate among those with CMV reactivation ( P = 0.087). Patients with CMV reactivation/disease required longer duration of hospitalization ( P = 0.018). The rate of graft loss was 17%. The survival rate was 97%. The cost of treatment among patients with CMV reactivation was significantly higher for both inpatient setting ( P = 0.021) and total cost ( P = 0.035) than in those without CMV reactivation. Conclusions: Burden of infectious complications among ATG-treated KT patients was high. CMV reactivation is common and associated with longer duration of hospitalization and higher cost.

CMV Immunoglobulins for the Treatment of CMV Infections in Thoracic Transplant Recipients

Intravenous ganciclovir and, increasingly, oral valganciclovir are now considered the mainstay of treatment for cytomegalovirus (CMV) infection or CMV disease. Under certain circumstances, CMV immunoglobulin (CMVIG) may be an appropriate addition or, indeed, alternative. Data on monotherapy with CMVIG are limited, but encouraging, for example in cases of ganciclovir intolerance. In cases of recurrent CMV in thoracic transplant patients after a disease- and drug-free period, adjunctive CMVIG can be considered in patients with hypogammaglobulinemia. Antiviral-resistant CMV, which is more common among thoracic organ recipients than in other types of transplant, can be an indication for introduction of CMVIG, particularly in view of the toxicity associated with other options, such as foscarnet. Due to a lack of controlled trials, decision-making is based on clinical experience. In the absence of a robust evidence base, it seems reasonable to consider the use of CMVIG to treat CMV in adult or pediatric thoracic transplant patients with ganciclovir-resistant infection, or in serious or complicated cases. The latter can potentially include (i) treatment of severe clinical manifestations, such as pneumonitis or eye complications; (ii) patients with a positive biopsy in end organs, such as the lung or stomach; (iii) symptomatic cases with rising polymerase chain reaction values (for example, higher than 5.0 log₁₀) despite antiviral treatment; (iv) CMV disease or CMV infection or risk factors, such as CMV-IgG–negative serostatus; (vi) ganciclovir intolerance; (vii) patients with hypogammaglobulinemia.

Monoclonal antibody therapy and renal transplantation: focus on adverse effects

A series of monoclonal antibodies (mAbs) are commonly utilized in renal transplantation as induction therapy (a period of intense immunosuppression immediately before and following the implant of the allograft), to treat steroid-resistant acute rejections, to decrease the incidence and mitigate effects of delayed graft function, and to allow immunosuppressive minimization. Additionally, in the last few years, their use has been proposed for the treatment of chronic antibody-mediated rejection, a major cause of late renal allograft loss. Although the exact mechanism of immunosuppression and allograft tolerance with any of the currently used induction agents is not completely defined, the majority of these medications are targeted against specific CD proteins on the T or B cells surface (e.g., CD3, CD25, CD52). Moreover, some of them have different mechanisms of action. In particular, eculizumab, interrupting the complement pathway, is a new promising treatment tool for acute graft complications and for post-transplant hemolytic uremic syndrome. While it is clear their utility in renal transplantation, it is also unquestionable that by using these highly potent immunosuppressive agents, the body loses much of its innate ability to mount an adequate immune response, thereby increasing the risk of severe adverse effects (e.g., infections, malignancies, haematological complications). Therefore, it is extremely important for clinicians involved in renal transplantation to know the potential side effects of monoclonal antibodies in order to plan a correct therapeutic strategy minimizing/avoiding the onset and development of severe clinical complications.

Management strategies for cytomegalovirus infection and disease in solid organ transplant recipients

Cytomegalovirus is the most common viral pathogen that affects solid organ transplant recipients. It directly causes fever, myelosuppression, and tissue-invasive disease, and indirectly, it negatively impacts allograft and patient survival. Nucleic acid amplification testing is the preferred method to confirm the diagnosis of CMV infection. Prevention of CMV disease using antiviral prophylaxis or preemptive therapy is critical in the management of transplant patients. Intravenous ganciclovir and oral valganciclovir are the first line drugs for antiviral treatment. This article provides a comprehensive review of the current epidemiology, diagnosis, prevention and treatment of CMV infection in solid organ transplant recipients.

Infections in Heart and Lung Transplant Recipients

Patients undergoing thoracic organ transplantation procedures involving the heart or lung are at increased risk for developing a wide variety of infections due to their underlying immunosuppression and/or other factors. Lung transplant recipients are at high risk for developing infections caused by bacteria, viruses, and opportunistic fungi, whereas heart transplant recipients are at risk for developing infections caused by these same microorganisms, as well as parasitic infections, including toxoplasmosis and New World trypanosomiasis. This review will highlight the various infections that thoracic organ transplant recipients may develop following their procedures.

Primary response against cytomegalovirus during antiviral prophylaxis with valganciclovir, in solid organ transplant recipients

Antiviral prophylaxis has proved successful for prevention of cytomegalovirus (CMV) disease in solid organ transplant (SOT) patients; though emerging data suggest that antiviral agents interfere with immunity, and may inhibit immune priming. In this context, we investigated levels and phenotype of primary CMV-specific immune responses that developed during antiviral prophylaxis in a cohort of CMV seronegative recipients (R(-) ) of a SOT from a seropositive donor (D(+) ). We longitudinally monitored CMV viral load, antibodies and levels of the negative immuno-modulator IL-10. PBMC were stimulated with CMV-specific peptide libraries to measure CD137 activation marker on CMV-specific T-cells and levels of PD-1 receptor, which is over expressed on exhausted T-cells. Unexpectedly, the majority (13/18) of D(+) R(-) patients who developed a primary CMV response showed early post-transplant CMV-specific responses, though levels of PD-1 on CMV-specific T-cells remained elevated throughout prophylaxis. A strong inverse association was found between levels of plasma IL-10 and CMV-specific cellular immune responses. Our study suggests that during prophylaxis, subclinical CMV infection might have occurred in the D(+) R(-) patients, and primary CMV-specific responses were detected early post-transplant when levels of plasma IL-10 were low. Extended prophylaxis or antiviral treatment did not appear to suppress CMV-specific antibodies or T-cells, which, however, showed exhaustion phenotypes.

Recommendations for the use of extended criteria donors in lung transplantation

Selection criteria for lung donation were based on initial experiences with lung transplantation without further studies to improve them, thereby guaranteeing the best use of donated organs. A definition of an extended criteria donor is therefore required to obtain more lungs to meet the demands of patients awaiting transplantation. Studies have been reviewed for the impact on survival and morbidity of age ranges, oxygen fraction, cause of death, smoking habits, x-ray findings, infection, hepatitis serology and non-heart-beating status, seeking to support physicians to make decisions regarding the use of marginal organs.

Risk factors for development of new-onset diabetes mellitus after transplant in adult lung transplant recipients

The objectives of this study are to examine the incidence of new-onset diabetes mellitus after transplant (NODAT) and to identify its risk factors in adult lung transplant recipients using the Organ Procurement and Transplant Network/United Network of Organ Sharing database. Between July 2004 and December 2007, a total of 3540 adults (≥18 yr old) received their first single- or double-lung transplant alone and had at least one follow-up report of post-transplant diabetic status. Among these, 2991 recipients were identified as not having diabetes mellitus (DM) pre-transplant. Risk factors for NODAT were examined. DM was newly reported in 33.4% of the 2991 recipients over the median follow-up time of 670 d. Significant independent risk factors for the development of NODAT included male gender (HR = 1.15), recipient age ≥50 (1.46), African American (1.39), higher body mass index (1.51 for ≥30 vs. 18-25), cystic fibrosis (3.30), and tacrolimus use at discharge (1.67). NODAT occurred in a third of adult lung transplant recipients during the median follow-up period. Some of the risk factors for NODAT after lung transplant are similar to those reported in other solid-organ transplants. Cystic fibrosis is a strong risk factor for development of NODAT after lung transplant.

A multicenter study of valganciclovir prophylaxis up to day 120 in CMV-seropositive lung transplant recipients

Seventy-six cytomegalovirus (CMV)-seropositive lung transplant recipients receiving valganciclovir (900 mg/day) for CMV prophylaxis were compared with a group of 87 patients receiving oral ganciclovir (3000 mg/day). Prophylaxis was administered to day 120 post-transplantation and follow-up was 1 year. In addition, a study was conducted on risk factors for CMV infection/disease. CMV disease incidence was 7.9% and 16.1% for valganciclovir and oral ganciclovir, respectively (p = 0.11). Patients receiving valganciclovir had fewer viral syndromes (2.6% vs. 11.5%, p < 0.05), a similar rate of tissue-invasive disease (5.2% vs. 4.6%, p = ns), longer time-to-onset of CMV infection/disease (197.5 vs. 155.2 days, p < 0.05), and a lower probability of infection/disease while on prophylaxis (1.3% vs. 12.6%, p < 0.01). Nonetheless, leukopenia incidence was higher with valganciclovir (15.8% vs. 2.3%, p < 0.01), as was the need for treatment withdrawal due to adverse effects (11.8% vs. 1.1%, p < 0.01). CMV infection was similar in both groups (32.9% vs. 34.5%). Induction therapy with basiliximab and glucocorticosteroid treatment were independent risk factors for developing CMV infection/disease. In conclusion, valganciclovir prophylaxis results in a low incidence of CMV disease in lung transplant recipients and appears more effective than oral ganciclovir. Despite the comparatively higher incidence of adverse events with valganciclovir, the drug can be considered safe for prophylaxis.

Update on lung transplantation

Lung transplantation is a suitable treatment to improve the quality of life and the prognosis of patients with various end-stage pulmonary diseases. There is a shortage of organs and the number of patients on waiting list is exceeding the number of transplants per year approximately two-fold in most countries. Strategies to increase the donor pool are therefore crucial. The long-term prognosis after lung transplantation is not yet as good as for other transplantation procedures and special complications should be taken into account. Aside from infections chronic organ dysfunction is the main cause of death and the most important prognosis limiting factor. Other typical problems are rejection, bronchus complications, and primary transplant dysfunction. However, the results of large centers show promising improvements in recent years.

Lung transplantation for cystic fibrosis: Current concepts and one center's experience

BACKGROUND

Although new approaches to the treatment of patients with cystic fibrosis (CF) are significantly prolonging their lives, most patients will eventually develop respiratory failure due to progressive bronchiectasis caused by chronic lung infection and inflammation and die from to respiratory failure. We examined our center's (University of Wisconsin Hospital and Clinics) experience with lung transplantation for patients with CF and reviewed the literature to examine current and evolving approaches to transplantation for this indication.

METHODS

We reviewed all published literature pertaining to lung transplantation for CF through 2006, and we reviewed all aspects of transplantation for patients with CF at our institution from 1994 to 2005.

RESULTS

Major complications following lung transplantation include acute rejection, bacterial infection, and bronchiolitis obliterans. Five-year survival at UWHC (Kaplan-Meier) is 67%, and survival was not adversely affected by transplanting patients receiving mechanical ventilation. The major cause of death for transplant recipients was bronchiolitis obliterans syndrome (BOS).

CONCLUSIONS

Lung transplantation for CF is associated with acceptable survival rates and can improve quality of life. Lung transplant should be offered to all patients with advanced CF lung disease if they meet currently accepted inclusion and exclusion criteria.

Critical care perspective on immunotherapy in lung transplantation

Lung transplantation is now a viable therapeutic option in the care of patients with advanced pulmonary parenchymal or pulmonary vascular disease. Lung transplantation, however, with chronic posttransplant immunosuppression, creates a uniquely vulnerable population of patients likely to experience significant life-threatening complications requiring intensive care. The introduction of several novel immunosuppressive agents, such as sirolimus and mycophenolate mofetil, in conjunction with more established agents such as cyclosporine and tacrolimus, has greatly increased treatment options for lung transplant recipients and likely contributed to improved short-term transplant outcomes. Modern transplant immunosuppression, however, is associated with a host of complications such as opportunistic infections, renal failure, and thrombotic thrombocytopenic purpura. The main focus of this review is to provide a comprehensive summary of modern immunotherapy in lung transplantation and to increase awareness of the serious and potentially life-threatening complications of these medications.

Microbiologic features and outcome of pneumonia in transplanted patients

We prospectively evaluated lower respiratory tract infections in solid organ transplantation (SOT) patients to determine the microbiologic diagnosis and clinical outcomes. We diagnosed 83 cases of pneumonia, 38 of which were community acquired and 45 were nosocomial. Those with bilateral infiltrates or absence of improvement after 3 days of treatment underwent fiberoptic bronchoscopy. Bacterial pneumonia was the most frequent diagnosis and mixed infection predominated in the nosocomial group (11/45 nosocomial versus 1/38 community). Fiberoptic bronchoscopy with bronchoalveolar lavage had higher diagnostic yield in nosocomial pneumonia (77% versus 47%). Mortality differences between the 2 groups were 58% nosocomial versus 8% community-acquired infections (P < 0.001). SOT patients with nosocomial pneumonia, or those who needed mechanical ventilation, had a high mortality rate and benefits from the fiberoptic diagnostic techniques.

Is gammaglobulin anti-CMV warranted in lung transplantation?

The usefulness of anti-CMV hyperimmune gammaglobulin (IgG-CMV, Cytotec) in lung transplant patients (LTx) is controversial. The objective of this study was to analyze the effectiveness of IgG-CMV in our LTx receptors.

PATIENTS AND METHODS

A retrospective study of LTx recipients treated with IgG-CMV as prophylaxis or as treatment for invasive disease. We used IgG-CMV associated with IV ganciclovir (GCV) as treatment for invasive disease. High-risk patients (CMV-negative recipients from CMV-positive donors; CMV-/+) were also with IgG-CMV prophylaxis during the first year. Other prophylactic uses of IgG-CMV were as an alternative to GCV in patients with related GCV toxicity, and as preemptive therapy in cases of persistent positive viral load (antigenemia > or = 1 cell and/or a PCR > or = 400) although oral GCV administration.

RESULTS

Between January 2000 and August 2003, 14 of the 74 lung transplant recipients (19%) received IgG-CMV as treatment for invasive disease (4 cases: 2 gastritis, 1 esophagitis, 1 hepatitis) and/or as prophylaxis (14 cases). All patients treated for invasive disease evolved favorably. No therapeutic failure were observed in CMV-/+ patients during treatment. Three of the six patients treated with IgG-CMV developed positive antigenemia despite treatment. The four patients treated for persistent antigenemia while receiving oral GCV achieved neutralization during the first month of treatment.

CONCLUSION

IgG-CMV associated with Gancyclovir is effective as treatment for invasive disease and as pre-emptive therapy in patients with persistent positive viral load. In CMV-/+ recipients, IgG-CMV prevents pneumonitis and delays the development of invasive disease after the first year.

A prospective study comparing cytomegalovirus antigenemia, DNAemia and RNAemia tests in guiding pre-emptive therapy in thoracic organ transplant recipients

We evaluated the usefulness of DNAemia and mRNAemia tests in guiding the pre-emptive therapy against cytomegalovirus (CMV) infections in thoracic organ transplant recipients using antigenemia test as the reference. Seven lung (LTR) and 14 heart (HTR) transplant recipients were prospectively monitored for CMV by antigenemia, DNAemia (Cobas Amplicor PCR Monitor) and pp67-mRNAemia (NASBA) tests. However, only the antigenemia test guided pre-emptive therapy with cut-off levels of >or=2 and >or=5-10 pp65-positive leukocytes/50 000 leukocytes in the LTRs and HTRs, respectively. CMV DNAemia was detected in 26/28 (93%) and RNAemia in 17/28 (61%) of the CMV antigenemias requiring antiviral therapy (P = 0.01). Optimal DNAemia levels (sensitivity/specificity) estimated from receiver-operating characteristic curve to achieve maximal sum of sensitivity and specificity were 400 (75.9/92.7%), 850 (91.3/91.3%) and 1250 (100/91.5%) copies/ml for the antigenemia of 2, 5 and 10 pp65-positive leukocytes, respectively. The sensitivities of nucleic acid sequence-based amplification (NASBA) were 25.9%, 43.5% and 56.3% in detecting the same cut-off levels of antigenemia. In thoracic organ transplant recipients, the Cobas PCR assay is comparable with the antigenemia test in guiding pre-emptive therapy against CMV infections when threshold levels of over 5 pp65-antigen-positive leukocytes are used as the reference. In contrast, the low sensitivity of NASBA limits its usefulness in the guidance of pre-emptive therapy.

Cytomegalovirus Pneumonia in Transplant Recipients

The incidence of cytomegalovirus CMV pneumonia has been reduced by routine antiviral prophylaxis in susceptible populations. Many of the complications of this infection are caused by indirect effects of the virus, including acute and chronic graft rejection, graft-versus-host disease, and superinfection by other viruses, bacteria and fungi. Distinction must be made between viral secretion and invasion. Invasive procedures are often required for the optimal management of such infections. The use of sensitive and quantitative assays have greatly improved the outcomes of CMV infection.

Preemptive Therapy With Intravenous Ganciclovir for the Prevention of Cytomegalovirus Disease in Lung Transplant Recipients

The most effective strategy for the prevention of cytomegalovirus (CMV) disease in lung transplantation has not been conclusively established. The aim of this study was to determine the efficacy of preemptive ganciclovir therapy for this purpose. Twenty-five consecutive adult patients positive for CMV before transplantation and surviving more than 30 days after the procedure were studied. Mean follow-up was 732.2 days (range, 210-1125). All patients received intravenous (IV) ganciclovir prophylaxis for the first 21 days and subsequently underwent frequent CMV antigenemia monitoring: weekly for the first 3 months, every 15 days between 3 and 6 months, and monthly thereafter. IV ganciclovir was given when antigenemia results were greater than 10 infected cells per 100,000 polymorphonuclears. The study group was compared with a historical group of 30 consecutive patients who had received IV ganciclovir prophylaxis and continued on oral ganciclovir up to day 120 posttransplantation. Eighteen of the 25 patients (72.0%) presented episodes of CMV infection. Six of the 25 patients (24.0%) had CMV disease, including 3 viral syndromes and 3 cases of pneumonitis. Four patients debuted with CMV disease, 1 of them with pneumonitis. CMV resistance to ganciclovir was observed in 2 patients. The incidence of infection was higher than in the historical group (72.0% vs 46.7%; P < .05), but there were no significant differences in the incidence of CMV disease (24.0% vs 40.0%; P = not significant [NS]). Mean time before onset of the first episode of disease was lower in the preemptive therapy group than in the comparison patients (82.8 days; range, 42-240 vs 175 days; range, 90-243; P < .05). In conclusion, preemptive therapy for CMV disease is as effective a prevention strategy as oral ganciclovir prophylaxis. However, the early appearance of CMV disease with preemptive therapy can make this approach inadvisable.

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.

Lung transplantation: opportunities for research and clinical advancement

Lung transplantation is the only definitive therapy for many forms of end-stage lung diseases. However, the success of lung transplantation is limited by many factors: (1) Too few lungs available for transplantation due to limited donors or injury to the donor lung; (2) current methods of preservation of excised lungs do not allow extended periods of time between procurement and implantation; (3) acute graft failure is more common with lungs than other solid organs, thus contributing to poorer short-term survival after lung transplant compared with that for recipients of other organs; (4) lung transplant recipients are particularly vulnerable to pulmonary infections; and (5) chronic allograft dysfunction, manifest by bronchiolitis obliterans syndrome, is frequent and limits long-term survival. Scientific advances may provide significant improvements in the outcome of lung transplantation. The National Heart, Lung, and Blood Institute convened a working group of investigators on June 14-15, 2004, in Bethesda, Maryland, to identify opportunities for scientific advancement in lung transplantation, including basic and clinical research. This workshop provides a framework to identify critical issues related to clinical lung transplantation, and to delineate important areas for productive scientific investigation.

Clinical usefulness of bronchoalveolar lavage in heart transplant recipients with suspected lower respiratory tract infection

BACKGROUND

Bronchoscopy with bronchoalveolar lavage (BAL) is the recommended initial invasive diagnostic procedure when lower respiratory tract infection is suspected in solid-organ transplant recipients. In this study, we evaluated the clinical impact and safety of bronchoscopy with BAL in heart transplant recipients.

METHODS

We reviewed all 44 consecutive diagnostic bronchoscopies with BAL that were performed in 35 heart transplant recipients at Helsinki University Central Hospital between May 1988 and December 2001.

RESULTS

Bronchoscopy findings established specific microbiologic diagnoses in 18 of 44 (41%) cases, and 14 of 44 (32%) bronchoscopic findings led to changes in therapy. The diagnostic yield of bronchoscopy from 1 to 6 months after transplantation was 73%, significantly better (p = 0.002) than diagnostic yield during the first month (18%) and after 6 months (28%). Pneumocystis carinii and cytomegalovirus were the most frequently detected pathogens in the BAL fluid. Cytomegalovirus pneumonia carried a high mortality rate (44%), whereas all patients with P carinii pneumonia recovered. Fourteen episodes were diagnosed as bacterial pneumonia, but because of empiric antibiotic therapy that was started widely before bronchoscopy, a microbiologic diagnosis was established in only 1 case. However, all patients with community-acquired pneumonia responded to empiric therapy. Four cases of major complications occurred after bronchoscopy, all cardiovascular but none fatal.

CONCLUSIONS

Bronchoscopy with BAL is a useful diagnostic tool in heart transplant recipients, especially between 1 and 6 months after transplantation.

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.

Blood cyclosporine C0 and C2 concentrations and cytomegalovirus infections following lung transplantation

The aim of this study was to determine whether cyclosporine levels predose (C0) and at two hours postdose (C2) were higher among patients presenting with cytomegalovirus (CMV) infection or disease. Between days 40 and 365 posttransplantation serial C0 and C2 levels were measured in 15 lung transplant recipients. Nine developed 13 episodes of CMV infection or disease. Both C0 and C2 levels were higher during CMV infection or disease episodes. Eleven of the 13 CMV episodes (84%) displayed C0 >220 ng/mL and none had C0 <200 ng/mL. For C2, 11 of 13 CMV episodes (84%) showed C2 >1200 ng/mL and none had C2 <1000 ng/mL. Among determinations that did not coincide with a CMV episode, 7 of 21 (33%) showed C0 >220 and 9 of 21 (42%) showed C2 >1200, respectively (P<.05). In conclusion, cyclosporine blood levels are higher among patients presenting with CMV infection or disease.