Clinical features and outcomes of paramyxoviral infection in lung transplant recipients treated with ribavirin

Management strategies for common viral infections in pediatric renal transplant recipients

Viral infections have been considered as a major cause of morbidity and mortality after kidney transplantation in pediatric cohort. Children are at high risk of acquiring virus-related complications due to immunological immaturity and the enhanced alloreactivity risk that led to maintenance of high immunosuppressive regimes. Hence, prevention, early detection, and prompt treatment of such infe ctions are of paramount importance. Among all viral infections, herpes viruses (herpes simplex virus, varicella zoster virus, Epstein-Barr virus, cytomegalovirus), hepatitis B and C viruses, BK polyomavirus, and respiratory viruses (respiratory syncytial virus, parainfluenza virus, influenza virus and adenovirus) are common in kidney transplant recipients. These viruses can cause systemic disease or allograft dysfunction affecting the clinical outcome. Recent advances in tech nology and antiviral therapy have improved management strategies in screening, monitoring, adoption of prophylactic or preemptive therapy and precise trea tment in the immunocompromised host, with significant impact on the outcome. This review discusses the etiology, screening and monitoring, diagnosis, pre vention, and treatment of common viral infections in pediatric renal transplant recipients.

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.

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.

Respiratory Syncytial Virus, Human Metapneumovirus, and Parainfluenza Virus Infections in Lung Transplant Recipients: A Systematic Review of Outcomes and Treatment Strategies

Background

Respiratory syncytial virus (RSV), parainfluenza virus (PIV), and human metapneumovirus (hMPV) are increasingly associated with chronic lung allograft dysfunction (CLAD) in lung transplant recipients (LTR). This systematic review primarily aimed to assess outcomes of RSV/PIV/hMPV infections in LTR and secondarily to assess evidence regarding the efficacy of ribavirin.

Methods

Relevant databases were queried and study outcomes extracted using a standardized method and summarized.

Results

Nineteen retrospective and 12 prospective studies were included (total 1060 cases). Pooled 30-day mortality was low (0–3%), but CLAD progression 180–360 days postinfection was substantial (pooled incidences 19–24%) and probably associated with severe infection. Ribavirin trended toward effectiveness for CLAD prevention in exploratory meta-analysis (odds ratio [OR] 0.61, [0.27–1.18]), although results were highly variable between studies.

Conclusions

RSV/PIV/hMPV infection was followed by a high CLAD incidence. Treatment options, including ribavirin, are limited. There is an urgent need for high-quality studies to provide better treatment options for these infections.

Respiratory Viruses in Solid Organ Transplant Recipients

Solid organ transplantation is often lifesaving, but does carry an increased risk of infection. Respiratory viral infections are one of the most prevalent infections, and are a cause of significant morbidity and mortality, especially among lung transplant recipients. There is also data to suggest an association with acute rejection and chronic lung allograft dysfunction in lung transplant recipients. Respiratory viral infections can appear at any time post-transplant and are usually acquired in the community. All respiratory viral infections share similar clinical manifestations and are all currently diagnosed using nucleic acid testing. Influenza has good treatment options and prevention strategies, although these are hampered by resistance to neuraminidase inhibitors and lower vaccine immunogenicity in the transplant population. Other respiratory viruses, unfortunately, have limited treatments and preventive methods. This review summarizes the epidemiology, clinical manifestations, therapies and preventive measures for clinically significant RNA and DNA respiratory viruses, with the exception of SARS-CoV-2. This area is fast evolving and hopefully the coming decades will bring us new antivirals, immunologic treatments and vaccines.

Oral Ribavirin for Treatment of Respiratory Syncytial Virus in Lung Transplantation Recipients

BACKGROUND

Respiratory syncytial virus (RSV) can cause severe respiratory infection and is a risk factor for development of bronchiolitis obliterans syndrome (BOS) in patients who have undergone lung transplantation (LT). The treatment options are limited in this population. We assessed the efficacy of oral administration for the treatment of RSV infection after LT.

METHODS

A retrospective case-control was conducted in LT patients who documented RSV infection. Demographic, clinical, and efficacy variables (resolution infection, recovery of lung function, incidence of BOS, mortality) was compared between the oral ribavirin (RBV) group and the control group.

RESULTS

Thirty-six LT patients were included (19 RBV group, 17 control group). Significant differences were found for age, sex and coinfections. However, no differences of immunosuppressive level and baseline forced expiratory volume in the first second of expiration (FEV₁) were found. RSV clearance was evident in 5 patients (26.3%) of the RBV group vs 2 patients (11.8%) in the control group (odds ratio [OR], 0.37; P = .282). At 3 months, FEV₁ remained stable in 12 patients (80%) of the RBV group vs 13 patients (81.3%) of the control group (OR, 0.92; P = .321). At 6 months, FEV₁ remained stable in 11 patients (73.3%) of the RBV group and 12 patients (75%) of the control group (OR, 1.25; P = .779), and BOS appeared in 6 patients (31.6%) vs 4 patients (23.5%) of the control group (OR, 1.50; P = .591). Mortality rates were 26% (5 patients) in the RBV group vs 29.4% (5 patients) in the control group (OR, 1.40; P = .637).

CONCLUSIONS

No significant differences in efficacy parameters were found between groups; however, stabilization without worsening of respiratory function was observed at 3 and 6 months. Because of the variability in the treatment regimen and the heterogeneity of groups, a protocol was developed to standardize and evaluate the use of oral RBV as treatment for RSV in LT.

Impact of COVID-19 on Lung Allograft and Clinical Outcomes in Lung Transplant Recipients: A Case-control Study

BACKGROUND

The impacts of COVID-19 on lung allograft function, rejection, secondary infection, and clinical outcomes in lung transplant recipients (LTRs) remain unknown.

METHODS

A 1:2 matched case-control study was performed to evaluate rehospitalization, lung allograft function, and secondary infections up to 90 d after COVID-19 diagnosis (or index dates for controls).

RESULTS

Twenty-four LTRs with COVID-19 (cases) and 48 controls were identified. Cases and controls had similar baseline characteristics and lung allograft function. LTRs with COVID-19 had higher incidence of secondary bacterial infection (29.2% versus 6.3%, P = 0.008), readmission (29.2% versus 10.4%, P = 0.04), and for-cause bronchoscopy (33.3% versus 12.5%, P = 0.04) compared with controls. At d 90, mortality in cases versus controls was 8.3% versus 2.1% (P = 0.21), incidence of invasive fungal infections in cases versus controls was 20.8% versus 8.3% (P = 0.13) and forced expiratory volume in 1 s (FEV1) decline ≥10% from baseline occurred in 19% of cases versus 12.2% of controls (P = 0.46). No acute cellular rejection, acute antibody-mediated rejection, or new donor-specific anti-HLA antibodies were observed among cases or controls within 90 d post index date.

CONCLUSIONS

We found LTRs with COVID-19 were at risk to develop secondary infections and rehospitalization post COVID-19, compared with controls. While we did not observe post viral acute cellular rejection or antibody-mediated rejection, further studies are needed to understand if LTRs with COVID-19 who did not recover baseline lung function within 90 d have developed chronic lung allograft dysfunction stage progression.

Community-Acquired Respiratory Viruses Post-Lung Transplant

Survival in lung transplant recipients (LTRs) lags behind heart, liver, and kidney transplant, in part due to the direct and indirect effects of infection. LTRs have increased susceptibility to infection due to the combination of a graft continually exposed to the outside world, multiple mechanisms for impaired mucus clearance, and immunosuppression. Community-acquired respiratory viral infections (CARVs) are common in LTRs. Picornaviruses have roughly 40% cumulative incidence followed by respiratory syncytial virus and coronaviruses. Although single-center retrospective and prospective series implicate CARV in rejection and mortality, conclusive evidence for and well-defined mechanistic links to long-term outcome are lacking. Treatment of viral infections can be challenging except for influenza. Future studies are needed to develop better treatments and clarify the links between CARV and long-term outcomes.

Evaluation of 10 years of parainfluenza virus, human metapneumovirus, and respiratory syncytial virus infections in lung transplant recipients

Respiratory tract infection with pneumoviruses (PVs) and paramyxoviruses (PMVs) are increasingly associated with chronic lung allograft dysfunction (CLAD) in lung transplant recipients (LTRs). Ribavirin may be a treatment option but its effectiveness is unclear, especially with respect to infection severity. We retrospectively analyzed 10 years of PV/PMV infections in LTRs. The main end points were forced expiratory volume in 1 second (FEV₁ ) at 3 and 6 months postinfection, expressed as a percentage of pre-infection FEV₁ and incidence of new or progressed CLAD 6 months postinfection. A total of 139 infections were included: 88 severe infections (63%) (defined as >10% FEV₁ loss at infection) and 51 mild infections (37%) (≤10% FEV₁ loss). Overall postinfection CLAD incidence was 20%. Associations were estimated on postinfection FEV₁ for ribavirin vs no ribavirin (+13.2% [95% CI: 7.79; 18.67]) and severe vs mild infection (-11.1% [95% CI: -14.76; -7.37]). Factors associated with CLAD incidence at 6 months were ribavirin treatment (odds ratio (OR [95% CI]) 0.24 [0.10; 0.59]), severe infection (OR [95% CI] 4.63 [1.66; 12.88]), and mycophenolate mofetil use (OR [95% CI] 0.38 [0.14; 0.97]). These data provide valuable information about the outcomes of lung transplant recipients with these infections and suggests possible associations of ribavirin use and infection severity with long-term outcomes. Well-designed prospective trials are needed to confirm these findings.

Infectious Complications in Lung Transplant Recipients

Lung transplantation is a lifesaving intervention for patients with advanced lung disease. Due to a combination of immunosuppression, continuous exposure of the lungs to the environment, and complications at the anastomotic sites, lung transplant recipients are at high risk for infectious complications. The aim of this review is to summarize recent developments in the field of infectious diseases as it pertains to lung transplant recipients.

Oral and Inhaled Ribavirin Treatment for Respiratory Syncytial Virus Infection in Lung Transplant Recipients

BACKGROUND

Respiratory syncytial virus (RSV) infection in lung transplant recipients (LTRs) causes mortality rates of 10%-20% despite antiviral therapy. Ribavirin (RBV) has been used to treat RSV-infected LTRs with limited data.

METHODS

A retrospective study including all LTRs at Duke Hospital during January 2013-May 2017 with positive RSV polymerase chain reaction respiratory specimens was performed.

RESULTS

Fifty-six of 70 patients in the oral RBV group and 29 of 32 in the inhaled RBV group had symptomatic RSV infection. One patient receiving oral RBV had to prematurely stop drug due to significant nausea and vomiting. While unadjusted all-cause 1-year mortality was significantly higher in the inhaled RBV group (24.1% versus 7.1% [oral RBV], P = 0.03), adjusted hazard ratio (HR) for death and oral RBV use (compared to inhaled RBV), accounting for oxygen requirement and need for mechanical ventilation, showed the HR for death and oral RBV use was 0.38 ([0.10, 1.46], P = 0.38). The HR for death in patients with supplemental oxygen >2 L/min at diagnosis was 6.18 ([1.33, 26.83], P = 0.02). Kaplan-Meier curves showed patients with forced expiratory volume in 1 second decline ≥5% and ≥10% at 90 days post-RSV infection had a higher 1-year mortality (P = 0.004 and P = 0.001, respectively).

CONCLUSIONS

Oral and inhaled RBV appear to be well tolerated in LTRs, and our data support the use of oral RBV as a safe alternative to inhaled ribavirin in LTRs. Oxygen requirement >2 L/min at diagnosis and forced expiratory volume in 1 second decline ≥5% postinfection may be markers for increased mortality.

Ribavirin and cellular ribavirin-triphosphate concentrations in blood and bronchoalveolar lavage fluid in two lung transplant patients with respiratory syncytial virus

Respiratory syncytial virus (RSV) is responsible for significant morbidity and mortality in the lung transplant population. Oral and aerosolized ribavirin may improve outcomes in lung transplant patients with RSV; however, data relating ribavirin concentrations in plasma and intracellular ribavirin triphosphate (iRTP) concentrations in blood and bronchoalveolar lavage (BAL) fluid cells with efficacy and safety are lacking. We describe ribavirin and iRTP concentrations within various compartments in two adult lung transplant recipients with RSV who were sampled throughout successful treatment courses with oral and inhaled ribavirin. In patient 1, iRTP BAL concentrations decreased by 45% over 3 days after changing inhaled ribavirin to oral (6.32 to 3.43 pmol/10⁶ cells). In patient 2, iRTP BAL concentrations were 103 pmol/10⁶ cells after 5 days of oral followed by 5 days of inhaled ribavirin. Further study is needed to describe ribavirin pharmacokinetics in the respiratory compartment to inform clinical use of ribavirin for respiratory viruses.

Incidence, management and outcome of respiratory syncytial virus infection in adult lung transplant recipients: a 9-year retrospective multicentre study

OBJECTIVES

To analyse functional outcome parameters according to antimicrobial treatments after respiratory syncytial virus (RSV)-confirmed infection in adult lung transplant recipients.

METHODS

A 9-year retrospective multicentre cohort study (2011-19) included adult lung transplant recipients with RSV-confirmed infection. The first endpoint determined new allograft dysfunction (acute graft rejection and chronic lung allograft dysfunction (CLAD)) 3 months after infection. Then baseline and 3 months' postinfection forced expiratory volume in 1 second (FEV₁) values were compared according to antimicrobial treatment. Univariate logistic regression analysis was performed.

RESULTS

RSV infection was confirmed in 77 of 424 lung transplant recipients (estimated incidence of 0.025 per patient per year; 95% confidence interval 0.018-0.036). At 3 months, 22 recipients (28.8%) developed allograft dysfunction: ten (13%) possible CLAD, six (7.9%) acute rejection and six (7.9%) CLAD. Recipients with the lowest preinfection FEV₁ had a greater risk of developing pneumonia (median (interquartile range) 1.5 (1.1-1.9) vs. 2.2 (1.5-2.4) L/s, p 0.003) and a higher odds of receiving antibiotics (1.6 (1.3-2.3) vs. 2.3 (1.9-2.5) L/s, p 0.017; odds ratio 0.52, 95% confidence interval 0.27-0.99). Compared to tracheobronchitis/bronchiolitis, RSV-induced pneumonia led more frequently to hospitalization (91.7%, 22 vs. 58.0%, 29, p 0.003) and intensive care unit admission (33.3%, 8 vs. 0, p < 10^-3). For ribavirin-treated recipients (24.7%, 19) and azithromycin prophylaxis (50.6%, 39), 3-month FEV₁ values were not different from untreated recipients. The overall mortality was 2.5% at 1 month and 5.3% at 6 months, unrelated to RSV.

CONCLUSIONS

At 3 months after RSV-confirmed infection, 22 recipients (28.8%) had new allograft dysfunction. Ribavirin treatment and azithromycin prophylaxis did not prevent FEV₁ decline.

A Mini-Review of Adverse Lung Transplant Outcomes Associated With Respiratory Viruses

Due to their overall immunocompromised state, lung transplant recipients (LTRs) are at increased risk for the development of viral respiratory infections compared to the general population. Such respiratory infections often lead to poor transplant outcomes. We performed a systematic review of the last 30 years of medical literature to summarize the impact of specific respiratory viruses on LTRs. After screening 2,150 articles for potential inclusion, 39 manuscripts were chosen for final review. We found evidence for an association of respiratory viruses including respiratory syncytial virus (RSV), parainfluenza virus, and influenza viruses with increased morbidity following transplant. Through the literature search, we also documented associations of RSV and adenovirus infections with increased mortality among LTRs. We posit that the medical literature supports aggressive surveillance for respiratory viruses among this population.

External validation and update of a prognostic model to predict mortality in hospitalized adults with RSV: A retrospective Dutch cohort study

Respiratory syncytial virus (RSV) causes significant mortality in hospitalized adults. Prediction of poor outcomes improves targeted management and clinical outcomes. We externally validated and updated existing models to predict poor outcome in hospitalized RSV-infected adults. In this single center, retrospective, observational cohort study, we included hospitalized adults with respiratory tract infections (RTIs) and a positive polymerase chain reaction for RSV (A/B) on respiratory tract samples (2005-2018). We validated existing prediction models and updated the best discriminating model by revision, recalibration, and incremental value testing. We included 192 RSV-infected patients (median age 60.7 years, 57% male, 65% immunocompromised, and 43% with lower RTI). Sixteen patients (8%) died within 30 days. During hospitalization, 16 (8%) died, 30 (16%) were admitted to intensive care unit, 21 (11%) needed invasive mechanical ventilation, and 5 (3%) noninvasive positive pressure ventilation. Existing models performed moderately at external validation, with C-statistics 0.6 to 0.7 and moderate calibration. Updating to a model including lower RTI, chronic pulmonary disease, temperature, confusion and urea, increased the C-statistic to 0.76 (95% confidence interval, 0.61-0.91) to predict in-hospital mortality. In conclusion, existing models to predict poor prognosis among hospitalized RSV-infected adults perform moderately at external validation. A prognostic model may help to identify and treat RSV-infected adults at high-risk of death.

RNA respiratory viral infections in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of RNA respiratory viral infections in the pre‐ and post‐transplant period. Viruses reviewed include influenza, respiratory syncytial virus (RSV), parainfluenza, rhinovirus, human metapneumovirus (hMPV), and coronavirus. Diagnosis is by nucleic acid testing due to improved sensitivity, specificity, broad range of detection of viral pathogens, automatization, and turnaround time. Respiratory viral infections may be associated with acute rejection and chronic lung allograft dysfunction in lung transplant recipients. The cornerstone of influenza prevention is annual vaccination and in some cases antiviral prophylaxis. Treatment with neuraminidase inhibitors and other antivirals is reviewed. Prevention of RSV is limited to prophylaxis with palivizumab in select children. Therapy of RSV upper or lower tract disease is controversial but may include oral or aerosolized ribavirin in some populations. There are no approved vaccines or licensed antivirals for parainfluenza, rhinovirus, hMPV, and coronavirus. Potential management strategies for these viruses are given. Future studies should include prospective trials using contemporary molecular diagnostics to understand the true epidemiology, clinical spectrum, and long‐term consequences of respiratory viruses as well as to define preventative and therapeutic measures.

Respiratory Viral Infections in Transplant Recipients

Respiratory viral infections (RVIs) are common among the general population; however, these often mild viral illnesses can lead to serious morbidity and mortality among recipients of hematopoietic stem cell and solid organ transplantation. The disease spectrum ranges from asymptomatic or mild infections to life-threatening lower respiratory tract infection or long-term airflow obstruction syndromes. Progression to lower respiratory tract infection or to respiratory failure is determined by the intrinsic virulence of the specific viral pathogen as well as various host factors, including the type of transplantation, status of the host’s immune dysfunction, the underlying disease, and other comorbidities. This chapter focuses on the epidemiology, clinical manifestations, diagnosis, and management of RVIs in this susceptible population and includes respiratory syncytial virus, parainfluenza virus, human metapneumovirus, influenza virus, human coronavirus, and human rhinovirus. The optimal management of these infections is limited by the overall paucity of available treatment, highlighting the need for new antiviral drug or immunotherapies.

Common Infections Following Lung Transplantation

The lungs are the only transplanted organ in direct contact with the ‘outside world’. Infection is a significant cause of morbidity and mortality in lung transplantation. Early accurate diagnosis and optimal management is essential to prevent short and long term complications. Bacteria, including Mycobacteria and Nocardia, viruses and fungi are common pathogens. Organisms may be present in the recipient prior to transplantation, transmitted with the donor lungs or acquired after transplantation. The degree of immunosuppression and the routine use of antimicrobial prophylaxis alters the pattern of post-transplant infections.

Respiratory Viruses and Other Relevant Viral Infections in the Lung Transplant Recipient

As advances occur in surgical technique, postoperative care, and immunosuppressive therapy, the rate of mortality in the early postoperative period following lung transplantation continues to decline. With the improvements in immediate and early posttransplant mortality, infections and their sequel as well as rejection and chronic allograft dysfunction are increasingly a major cause of posttransplant mortality. This chapter will focus on infections by respiratory viruses and other viral infections relevant to lung transplantation, including data regarding the link between viral infections and allograft dysfunction.

Post-transplant Viral Respiratory Infections in the Older Patient: Epidemiology, Diagnosis, and Management

Organ and stem cell transplantation has been one of the greatest advances in modern medicine, and is the primary treatment modality for many end-stage diseases. As our population ages, so do the transplant recipients, and with that comes many new challenges. Respiratory viruses have been a large contributor to the mortality and morbidity of solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients. Respiratory viruses are generally a long-term complication of transplantation and primarily acquired in the community. With the emergence of molecular methods, newer respiratory viruses are being detected. Respiratory viruses appear to cause severe disease in the older transplant population. Influenza vaccine remains the mainstay of prevention in transplant recipients, although immunogenicity of current vaccines is suboptimal. Limited therapies are available for other respiratory viruses. The next decade will likely bring newer antivirals and vaccines to the forefront. Our goal is to provide the most up to date knowledge of respiratory viral infections in our aging transplant population.

Respiratory Viruses: Influenza, RSV, and Adenovirus in Kidney Transplantation

Although advances in immunosuppression and antimicrobial prophylaxis have led to improved patient and graft survival, respiratory viruses continue to be a common cause of morbidity and mortality in immunocompromised populations. We describe the clinical manifestations, diagnosis and treatment options for influenza, respiratory syncytial virus and adenovirus infection in the kidney transplant population.

Update in the treatment of non-influenza respiratory virus infection in solid organ transplant recipients

INTRODUCTION

Despite the improved outcomes in solid organ transplantation with regard to prevention of rejection and increased patient and graft survival, infection remains a common cause of morbidity and mortality. Respiratory viruses are a frequent and potentially serious cause of infection after solid organ transplantation. Furthermore, clinical manifestations of respiratory virus infection (RVI) may be more severe and unusual in solid organ transplant recipients (SOTRs) compared with the non-immunocompromised population. Areas covered: This article reviews the non-influenza RVIs that are commonly encountered in SOTRs. Epidemiologic and clinical characteristics are highlighted and available treatment options are discussed. Expert opinion: New diagnostic tools, particularly rapid molecular assays, have expanded the ability to identify specific RVI pathogens in SOTRs. This is not only useful from a treatment standpoint but also to guide infection control practices. More data are needed on RVIs in the solid organ transplant population, particularly regarding their effect on rejection and graft dysfunction. There is also a need for new antiviral agents active against these infections as well as markers that can identify which patients would most benefit from treatment.

Epidemiology and Immediate Indirect Effects of Respiratory Viruses in Lung Transplant Recipients: A 5-Year Prospective Study

The epidemiology of respiratory viruses (RVs) in lung transplant recipients (LTRs) and the relationship of RVs to lung function, acute rejection (AR) and opportunistic infections in these patients are not well known. We performed a prospective cohort study (2009-2014) by collecting nasopharyngeal swabs (NPSs) from asymptomatic LTRs during seasonal changes and from LTRs with upper respiratory tract infectious disease (URTID), lower respiratory tract infectious disease (LRTID) and AR. NPSs were analyzed by multiplex polymerase chain reaction. Overall, 1094 NPSs were collected from 98 patients with a 23.6% positivity rate and mean follow-up of 3.4 years (interquartile range 2.5-4.0 years). Approximately half of URTIDs (47 of 97, 48.5%) and tracheobronchitis cases (22 of 56, 39.3%) were caused by picornavirus, whereas pneumonia was caused mainly by paramyxovirus (four of nine, 44.4%) and influenza (two of nine, 22.2%). In LTRs with LRTID, lung function changed significantly at 1 mo (p = 0.03) and 3 mo (p = 0.04). In a nested case-control analysis, AR was associated with RVs (hazard ratio [HR] 6.54), Pseudomonas aeruginosa was associated with LRTID (HR 8.54), and cytomegalovirus (CMV) replication or disease was associated with URTID (HR 2.53) in the previous 3 mo. There was no association between RVs and Aspergillus spp. colonization or infection (HR 0.71). In conclusion, we documented a high incidence of RV infections in LTRs. LRTID produced significant lung function abnormalities. Associations were observed between AR and RVs, between P. aeruginosa colonization or infection and LRTID, and between CMV replication or disease and URTID.

Transplantation

Despite improvement in median life expectancy and overall health, some children with cystic fibrosis (CF) progress to end-stage lung or liver disease and become candidates for transplant. Transplants for children with CF hold the promise to extend and improve the quality of life, but barriers to successful long-term outcomes include shortage of suitable donor organs; potential complications from the surgical procedure and immunosuppressants; risk of rejection and infection; and the need for lifelong, strict adherence to a complex medical regimen. This article reviews the indications and complications of lung and liver transplantation in children with CF.

Human metapneumovirus in lung transplant recipients: characteristics and outcomes

Human metapneumovirus (hMPV) causes serious respiratory tract infections in lung transplant recipients (LTRs). We evaluated the characteristics and adverse drug reactions (ADR) of oral ribavirin therapy for hMPV infections in LTRs. LTRs with respiratory symptoms or suspected infection of unknown origin were routinely sampled with nasopharyngeal swabs (NPS) for virological and bacteriological analysis as part of a diagnostic workup. Medical records of hMPV polymerase chain reaction (PCR)-positive LTRs at the University Hospital of Zurich were reviewed retrospectively. Between January 2012 and June 2014, 12 (80%) of 15 consecutive patients with documented hMPV infection received oral ribavirin therapy (800 mg/d, after 48 h: 400 mg/d). Mean duration of therapy was 28.6 days (range: 11-54). Mean duration of viral shedding was 16.3 days (range: 5-48). In general, oral ribavirin was well tolerated in LTRs. The most common ADR was moderate anaemia. All patients recovered from infection without immediate serious sequelae within 3 months of infection.

Infectious Triggers of Chronic Lung Allograft Dysfunction

Survival after lung transplantation is limited in large part due to the high incidence of chronic rejection, known as chronic lung allograft dysfunction (CLAD). Pulmonary infections are a frequent complication in lung transplant recipients, due both to immunosuppressive medications and constant exposure of the lung allograft to the external environment via the airways. Infection is a recognized risk factor for the development of CLAD, and both acute infection and chronic lung allograft colonization with microorganisms increase the risk for CLAD. Acute infection by community acquired respiratory viruses, and the bacteria Pseudomonas aeruginosa and Staphylococcus aureus are increasingly recognized as important risk factors for CLAD. Colonization by the fungus Aspergillus may also augment the risk of CLAD. Fostering this transition from healthy lung to CLAD in each of these infectious episodes is the persistence of an inflammatory lung allograft environment.

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

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

Oral Ribavirin for the Treatment of Noninfluenza Respiratory Viral Infections: A Systematic Review

OBJECTIVE

To review clinical outcomes data for patients treated with oral ribavirin for noninfluenza respiratory viral infections (NIRVIs).

DATA SOURCES

MEDLINE, EMBASE, and PubMed Central (1972 to June 1, 2015) were queried with the following search term combinations: "Oral" AND "ribavirin" AND ("respiratory syncytial virus" OR "metapneumovirus" OR "parainfluenza" OR "coronavirus" OR "rhinovirus" OR "enterovirus" OR "adenovirus").

STUDY SELECTION AND DATA EXTRACTION

Included studies must have characterized the clinical outcomes of a cohort of patients treated with oral ribavirin for symptomatic NIRVIs. Case reports and series with <5 cases, conference abstracts, and articles written in languages other than English were excluded.

DATA SYNTHESIS

Of the 1256 unique reports, 15 met inclusion criteria: 12 retrospective, 3 prospective, and 3 comparative with untreated control groups. All studies except for 2 Middle East respiratory syndrome coronavirus (MERS-CoV) studies were in immunocompromised patients (9 malignancy/stem cell transplant, 4 lung transplant). The mortality rate ranged from 0% to 31% in malignancy/stem cell transplant recipients treated with oral ribavirin, and 1/108 (0.9%) ribavirin-treated lung transplant recipients died at 30 days. Three studies (one each for malignancy, lung transplant, and MERS-CoV) suggested a clinical outcomes benefit with oral ribavirin compared with supportive care alone; however, the nonrandomized design precludes efficacy determination. Hemolysis was the most common adverse reaction, occurring in 14% (54/375) of patients. Ribavirin was discontinued in 4% of patients secondary to adverse reactions.

CONCLUSIONS

Oral ribavirin should be considered for the treatment of NIRVI in immunocompromised adults (malignancy/stem cell transplant or lung transplant) or adults with MERS-CoV.

Oral ribavirin therapy for respiratory syncytial virus infections in moderately to severely immunocompromised patients

BACKGROUND

Respiratory syncytial virus (RSV) infections may be fatal in immunocompromised patients. Aerosolized ribavirin is used for treatment, but it is very costly, teratogenic, and inconvenient. We aimed to assess the outcome of oral ribavirin treatment, with or without intravenous immunoglobulin (IVIG), for RSV infections in moderately to severely immunocompromised patients.

METHODS

Medical records of RSV polymerase chain reaction (PCR)-positive patients during 2011-2013 were reviewed retrospectively. Eligible patients were moderately to severely immunocompromised and received oral ribavirin (600-800 mg twice daily) with or without IVIG (500 mg/kg q 48 h) as per protocol.

RESULTS

Of 96 adults with PCR-proven RSV infection, 34 were moderately to severely immunocompromised and received oral ribavirin treatment. The mean age was 56.2 years (range: 18-90); 21 were male. Underlying conditions were hematologic malignancy with or without hematopoietic stem cell transplant (n = 25), lung transplant (n = 3), or receipt of cytotoxic chemotherapy (n = 11). The presenting symptoms were cough (94%), fever (62%), and dyspnea (59%). The most common radiographic findings were patchy and nodular infiltrates and opacities. Of 34 patients, 31 were hospitalized, with 13 admitted to the intensive care unit and 6 required mechanical ventilation. The median absolute lymphocyte count on presentation was 480 cells/mm(3) . RSV pneumonia developed in 24 patients. The median initial duration of oral ribavirin treatment was 10 days (range: 4-11); 4 patients were re-treated. Of 34 patients, 19 received a mean of 2.7 doses of IVIG. Two patients had adverse reactions to ribavirin (hemolytic anemia and lactic acidosis in 1 patient, and altered mental status in another). No patient died from RSV infection. Three patients died from complications of their underlying illness; all others recovered clinically.

CONCLUSIONS

Oral ribavirin with or without IVIG is a well-tolerated treatment for RSV infection in moderately to severely immunocompromised hosts. Comparative prospective studies should ideally be performed to determine if oral ribavirin is the optimal therapy for RSV infection in this patient population.

Rhinovirus and other respiratory viruses exert different effects on lung allograft function that are not mediated through acute rejection

BACKGROUND

Community acquired respiratory virus (CARV) infections in lung transplant recipients (LTR) have been associated with adverse outcomes, including acute rejection (AR) and decline in allograft function, in some but not in all studies.

METHODS

Spirometry and transbronchial biopsy results of LTR diagnosed with CARV infection over a two-yr period were extracted from clinical records. Primary outcomes, studied at 1-2.5 months postinfection, were as follows: (i) incidence of biopsy-proven AR (grade >A0) and (ii) allograft function, defined by forced expiratory volume in one s (FEV(1)). A reference group of biopsies (n = 526) collected during the study period established the baseline incidence of AR. Rhinovirus (RV) and non-rhinovirus (non-RV) infections were analyzed as subgroups.

RESULTS

Eighty-seven cases of CARV infection were identified in 59 subjects. Incidences of AR were similar in the post-CARV and reference groups and did not differ significantly after RV vs. non-RV infection. Allograft function declined significantly after non-RV infection, but not after RV infection.

CONCLUSIONS

In LTR, CARV infections other than RV are associated with allograft dysfunction at 1-2.5 months after infection. However, CARVs do not appear associated with AR at this time point. The impact of specific CARVs on lung allografts, including the development of chronic allograft rejection, merits further study.

RSV prevention and treatment in pediatric lung transplant patients: a survey of current practices among the International Pediatric Lung Transplant Collaborative

RSV infection can be severe after pediatric lung transplantation. Strategies to prevent and treat RSV in this population are underreported. To assess the current practices, we surveyed the members of the IPLTC regarding RSV prevention and treatment strategies. Twenty-eight programs were surveyed; 18 (64.3%) responded at least partially. A median of 53 transplants (range, 8-355) occurred since inception. RSV testing occurs in asymptomatic (6/17) and symptomatic (17/17) patients. Diagnostic method is polymerase chain reaction at 13 sites and DFA at 8. Transplant candidates were received prophylaxis at 10 sites, with nine following national (5) or local (4) guidelines. All use palivizumab IM and/or IV. Recipients were received prophylaxis with palivizumab at eight centers (eight IM, one IV). Fourteen were treated for RSV (seven all patients; seven age-related). Medications include inhaled (6), oral (4), or IV (4) ribavirin, plus IVIG (9), steroids (8), and IV (2) or IM (3) palivizumab. Prevention and treatment barriers include insurance/hospital concerns, such as institutional reluctance to use inhaled ribavirin. RSV prevention and treatment strategies are diverse at pediatric lung transplant programs. Many centers offer prophylaxis (9/17) and treatments (14/17), but strategies are not uniform.

Respiratory viral infections post-lung transplantation

Community-acquired respiratory viruses (CARVs) are common pathogens in lung transplant recipients. Infection due to these viruses is associated with multiple complications including: rhinitis, pharyngitis, bronchitis, pneumonia, respiratory failure and even death. CARVs have also become increasingly recognized as a risk factor for acute rejection (AR) and bronchiolitis obliterans syndrome (BOS). Newer diagnostic techniques have enhanced the accuracy of diagnosis, but proven treatment options for CARVs are limited. Further insight into the immune response and allograft dysfunction associated with CARV infections is needed in order to develop novel management strategies which can reduce the morbidity and mortality caused by these infectious agents.

Other viral infections in solid organ transplantation

Viral infections are a major cause of morbidity and even mortality in solid organ transplant recipients. This article reviews key aspects of infections in solid organ transplant recipients from respiratory viruses, such as influenza, polyomavirus, erythrovirus B19 and measles.

Monitoring and managing viral infections in pediatric renal transplant recipients

Viral infections remain a significant cause of morbidity and mortality following renal transplantation. The pediatric cohort is at high risk of developing virus-related complications due to immunological naiveté and the increased alloreactivity risk that requires maintaining a heavily immunosuppressive environment. Although cytomegalovirus is the most common opportunistic pathogen seen in transplant recipients, numerous other viruses may affect clinical outcome. Recent technological advances and novel antiviral therapy have allowed implementation of viral and immunological monitoring protocols and adoption of prophylactic or preemptive treatment approaches in high-risk groups. These strategies have led to improved viral infection management in the immunocompromised host, with significant impact on outcome. We review the major viral infections seen following kidney transplantation and discuss strategies for preventing and managing these pathogens.

Prophylaxis and treatment of respiratory syncytial virus in adult immunocompromised patients

OBJECTIVE

To review the literature regarding current strategies and strategies under active development for the prevention and treatment of respiratory syncytial virus (RSV) infections in immunocompromised adults.

DATA SOURCES

The MEDLINE/PubMed, EMBASE, and Cochrane databases were queried from January 1980 to December 2011 for articles in English using these associated search terms: respiratory syncytial virus, ribavirin, intravenous immunoglobulin, IVIG, palivizumab, motavizumab, lung, pneumonia, transplantation, bone marrow, cancer, malignancy, and vaccine.

STUDY SELECTION AND DATA EXTRACTION

All relevant original studies, meta-analyses, systematic reviews, and review articles were assessed for inclusion. References from pertinent articles were examined for additional content not found during the initial search.

DATA SYNTHESIS

RSV in the immunocompromised adult can lead to significant morbidity and mortality. Treatment of RSV-infected adults is limited to antiviral therapy with ribavirin (aerosolized, oral, intravenous) and immunomodulation with intravenous immunoglobulins, corticosteroids, and palivizumab. Existing literature is predominantly case reports, small trials, and retrospective reviews of patients infected with RSV who have undergone lung or hematopoietic stem cell transplantation (HSCT). Palivizumab may be a viable option for prophylaxis against RSV in high-risk adults. Ribavirin is the most studied treatment option and should remain the backbone of multidrug regimens. Of the routes of administration, aerosolized ribavirin carries the preponderance of evidence and, though challenging, is preferred to limit systemic toxicities in the infected patient. Addition of an immunomodulator to ribavirin may provide a survival benefit over ribavirin alone; however, this has only been studied in a subset of HSCT patients with lower respiratory tract RSV infection.

CONCLUSIONS

Research most strongly supports the use of aerosolized ribavirin as the treatment strategy for immunocompromised adults with RSV. Addition of an immunomodulator may provide a survival benefit over ribavirin alone. Strategies and supportive data for the prevention of RSV infection in the high-risk adult are critically needed.

Respiratory syncytial virus pneumonia treated with lower-dose palivizumab in a heart transplant recipient

Respiratory syncytial virus (RSV) is an important community-acquired pathogen that can cause significant morbidity and mortality in patients who have compromised pulmonary function, are elderly, or are immunosuppressed. This paper describes a 70-year-old man with a remote history of heart transplantation who presented with signs and symptoms of pneumonia. Chest computed tomography (CT) imaging demonstrated new patchy ground glass infiltrates throughout the upper and lower lobes of the left lung, and the RSV direct fluorescence antibody (DFA) was positive. The patient received aerosolized ribavirin, one dose of intravenous immunoglobulin, and one dose of palivizumab. After two months of followup, the patient had improved infiltrates on chest CT, improved pulmonary function testing, and no evidence of graft rejection or dysfunction. There are few data on RSV infections in heart transplant patients, but this case highlights the importance of considering this potentially serious infection and introduces a novel method of treatment.

Clinical and radiological features of respiratory syncytial virus in solid organ transplant recipients: a single-center experience

BACKGROUND

Respiratory syncytial virus (RSV) infections range from upper respiratory illness to severe lower respiratory disease. There is no universally accepted treatment for RSV in solid organ transplant (SOT) recipients.

METHODS

Retrospective review of adult SOT patients with RSV infections, between January 2007 and December 2009, in a single transplant center was performed.

RESULTS

During the 3-year period, a total of 24 adults developed RSV infection, including 12 (50%) SOT recipients (5 kidneys, 4 livers, and 3 lungs). Most cases were seen in 2009 during the influenza H1N1 pandemic, likely as a result of increased testing. In 83% of the cases, the diagnosis was based on RSV antigen detection, which was also used to follow subsequent shedding (mean duration: 20.6 days). Most of the cases presented with lower respiratory disease and required hospitalization. All the patients were on at least two classes of immunosuppressive drugs. We observed a lower lymphocyte count in patients with lower respiratory tract infection. Computed tomography was superior to chest x-ray in demonstrating pulmonary disease, with the most common findings being pulmonary nodules and ground-glass opacities. Novel radiographic findings were small cavities and pleural effusions. No co-infections were documented, and no mortality could be attributed to RSV. Inhaled or oral ribavirin was administered in 67% of the cases, with variations in the treatment regimens.

CONCLUSION

SOT recipients accounted for half of all adult cases of RSV at our institution. Type and length of treatment varied widely, and we cannot conclude that outcomes differed between treatments with oral or inhaled ribavirin. Current therapeutic management of RSV in SOT is empiric, and can be rather expensive and difficult, without clear evidence of effectiveness.

Respiratory viral infections in hematopoietic stem cell and solid organ transplant recipients

Respiratory viral infections (RVIs) are common causes of mild illness in immunocompetent children and adults with rare occurrences of significant morbidity or mortality. Complications are more common in the very young, very old, and those with underlying lung diseases. However, RVIs are increasingly recognized as a cause of morbidity and mortality in recipients of hematopoietic stem cell transplants (HSCT) and solid organ transplants (SOTs). Diagnostic techniques for respiratory syncytial virus (RSV), parainfluenza, influenza, and adenovirus have been clinically available for decades, and these infections are known to cause serious disease in transplant recipients. Modern molecular technology has now made it possible to detect other RVIs including human metapneumovirus, coronavirus, and bocavirus, and the role of these viruses in causing serious disease in transplant recipients is still being worked out. This article reviews the current information regarding epidemiology, pathogenesis, clinical presentation, diagnosis, and treatment of these infections, as well as the aspects of clinical significance of RVIs unique to HSCT or SOT.

Respiratory viruses in lung transplant recipients: a critical review and pooled analysis of clinical studies

Lung transplant recipients present an increased risk for severe complications associated with respiratory infections. We conducted a review of the literature examining the clinical relationship between viral respiratory infection and graft complications. Thirty-four studies describing the clinical impact of influenza, respiratory syncytial virus, parainfluenza, human metapneumovirus, rhinovirus, enterovirus, coronavirus, bocavirus or adenovirus were identified. The detection rate of respiratory viral infection ranged from 1.4% to 60%. Viruses were detected five times more frequently when respiratory symptoms were present [odds ratio (OR) = 4.97; 95% CI = 2.11-11.68]. Based on available observations, we could not observe an association between respiratory viral infection and acute rejection (OR = 1.35; 95% CI = 0.41-4.43). We found a pooled incidence of 18% (9/50) of bronchiolitis obliterans syndrome (BOS) in virus-positive cases compared to 11.6% (37/319) in virus-negative cases; however, limited number of BOS events did not allow to confirm the association. Our review confirms a causal relationship between respiratory viruses and respiratory symptoms, but cannot confirm a link between respiratory viruses and acute lung rejection. This is related in part to the heterogeneity and limitations of available studies. The link with BOS needs also to be reassessed in appropriate prospective studies.

Upper and lower respiratory tract viral infections and acute graft rejection in lung transplant recipients

BACKGROUND

Lung transplant recipients are frequently exposed to respiratory viruses and are particularly at risk for severe complications. The aim of this study was to assess the association among the presence of a respiratory virus detected by molecular assays in bronchoalveolar lavage (BAL) fluid, respiratory symptoms, and acute rejection in adult lung transplant recipients.

METHODS

Upper (nasopharyngeal swab) and lower (BAL) respiratory tract specimens from 77 lung transplant recipients enrolled in a cohort study and undergoing bronchoscopy with BAL and transbronchial biopsies were screened using 17 different polymerase chain reaction-based assays.

RESULTS

BAL fluid and biopsy specimens from 343 bronchoscopic procedures performed in 77 patients were analyzed. We also compared paired nasopharyngeal and BAL fluid specimens collected in a subgroup of 283 cases. The overall viral positivity rate was 29.3% in the upper respiratory tract specimens and 17.2% in the BAL samples (P < .001). We observed a significant association between the presence of respiratory symptoms and positive viral detection in the lower respiratory tract (P = .012). Conversely, acute rejection was not associated with the presence of viral infection (odds ratio, 0.41; 95% confidence interval, 0.20-0.88). The recovery of lung function was significantly slower when acute rejection and viral infection were both present.

CONCLUSIONS

A temporal relationship exists between acute respiratory symptoms and positive viral nucleic acid detection in BAL fluid from lung transplant recipients. We provide evidence suggesting that respiratory viruses are not associated with acute graft rejection during the acute phase of infection.

RNA interference therapy in lung transplant patients infected with respiratory syncytial virus

RATIONALE

Lower respiratory tract infections due to respiratory syncytial virus (RSV) are associated with development of bronchiolitis obliterans syndrome in lung transplant (LTX) recipients. ALN-RSV01 is a small interfering RNA targeting RSV replication.

OBJECTIVES

To determine the safety and explore the efficacy of ALN-RSV01 in RSV infection.

METHODS

We performed a randomized, double-blind, placebo-controlled trial in LTX recipients with RSV respiratory tract infection. Patients were permitted to receive standard of care for RSV. Aerosolized ALN-RSV01 (0.6 mg/kg) or placebo was administered daily for 3 days. Viral load was determined by quantitative reverse transcriptase-polymerase chain reaction on serial nasal swabs. Patients completed symptom score cards twice daily. Lung function, including the incidence of new-onset or progressive bronchiolitis obliterans syndrome, was recorded at Day 90.

MEASUREMENTS AND MAIN RESULTS

We enrolled 24 patients (ALN-RSV01, n = 16; placebo, n = 8); randomization was stratified by ribavirin use. ALN-RSV01 was well tolerated, with no drug-related serious adverse events or post-inhalation perturbations in lung function. Interpretation of viral measures was confounded by baseline differences between the two groups in viral load and time from symptom onset to first dose. Mean daily symptom scores were lower in subjects receiving ALN-RSV01, and the mean cumulative daily total symptom score was significantly lower with ALN-RSV01 (114.7 ± 63.13 vs. 189.3 ± 99.59, P = 0.035). At Day 90, incidence of new or progressive bronchiolitis obliterans syndrome was significantly reduced in ALN-RSV01 recipients compared with placebo (6.3% vs. 50%, P = 0.027).

CONCLUSIONS

ALN-RSV01 was safe and may have beneficial effects on long-term allograft function in LTX patients infected with RSV. Clinical trial registered with www.clinicaltrials.gov (NCT 00658086).