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

Proinflammatory indicators and the relevance of echocardiography in children with cystic fibrosis

As the life expectancy improves in cystic fibrosis, cardiac dysfunction is becoming an important risk factor for morbidity and mortality. Here, the association of cardiac dysfunction with proinflammatory markers and neurohormones between cystic fibrosis patients and healthy children was investigated. Echocardiographic measurements of right and left ventricular morphology and functions together with levels of proinflammatory markers and neurohormones (renin, angiotensin-II, and aldosterone) were obtained and analysed in a study group of 21 cystic fibrosis children aged 5-18 years and compared with age- and gender-matched healthy children. It was shown that patients had significantly higher interleukin-6, C-reactive protein, renin and aldosterone levels (p < 0.05), dilated right ventricles, decreased left ventricle sizes, as well as both right and left ventricular dysfunction. These echocardiographic changes correlated with hypoxia, interleukin-1 α, interleukin-6, C-reactive protein, and aldosterone (p < 0.05) levels. The current study revealed that hypoxia, proinflammatory markers, and neurohormones are major determinants of subclinical changes in ventricular morphology and function. While the right ventricle anatomy was affected by cardiac remodeling, the left ventricle changes were induced by right ventricle dilation and hypoxia. A significant but subclinical systolic and diastolic right ventricle dysfunction in our patients was associated with hypoxia and inflammatory markers. Systolic left ventricle function was affected by hypoxia and neurohormones. Echocardiography is a reliable and non-invasive method that is used safely in cystic fibrosis children for screening and detection of cardiac anatomical and functional changes. Extensive studies are needed to determine the time and frequency of screening and treatment suggestions for such changes.

Update on Lung Transplantation for Cystic Fibrosis

Lung transplantation provides a treatment option for many individuals with advanced lung disease due to cystic fibrosis (CF). Since the first transplants for CF in the 1980s, survival has improved and the opportunity for transplant has expanded to include individuals who previously were not considered candidates for transplant. Criteria to be a transplant candidate vary significantly among transplant programs, highlighting that the engagement in more than one transplant program may be necessary. Individuals with highly resistant CF pathogens, malnutrition, osteoporosis, CF liver disease, and other comorbidities may be suitable candidates for lung transplant, or if needed, multi-organ transplant. The transplant process involves several phases, from discussion of prognosis and referral to a transplant center, to transplant evaluation, to listing, transplant surgery, and care after transplant. While the availability of highly effective CF transmembrane conductance regulator (CFTR) modulators for many individuals with CF has improved lung function and slowed progression to respiratory failure, early discussion regarding transplant as a treatment option and referral to a transplant program are critical to maximizing opportunity and optimizing patient and family experience. The decision to be evaluated for transplant and to list for transplant are distinct, and early referral may provide a treatment option that can be urgently executed if needed. Survival after transplant for CF is improving, to a median survival of approximately 10 years, and most transplant survivors enjoy significant improvement in quality of life.

Immunosuppression Drug Therapy in Lung Transplantation for Cystic Fibrosis

Cystic fibrosis (CF) is a common indication for lung transplantation (LTx) in children and adults with severe and irreversible lung disease. In the setting of LTx in the CF population, immunosuppressive medications are used to prevent allograft rejection despite the majority of these patients being chronically infected with numerous, and often antibiotic-resistant, pathogens. There is limited evidence for the optimal post-LTx immunosuppression regimen in patients with CF, particularly in children. This article provides a review of immunosuppression regimens in the pediatric and adult CF post-LTx population, investigating drug dosing and monitoring, and medication combinations. Currently used immunosuppressive medications and related systemic adverse effects are reviewed. With limitations of data in the pediatric population, future research should address immunosuppression in these children to help guide pediatric drug management as a means to optimize clinical outcomes after LTx.

Longitudinal impact of demographic and clinical variables on health-related quality of life in cystic fibrosis

OBJECTIVES

The insights that people with cystic fibrosis have concerning their health are important given that aspects of health-related quality of life (HRQoL) are independent predictors of survival and a decrease in lung function is associated with a decrease in HRQoL over time. Cross-sectional data suggest that key variables, other than lung function, are also associated with HRQoL--although study results are equivocal. This work evaluates the relationship between these key demographic and clinical variables and HRQoL longitudinally.

DESIGN

Longitudinal observational study. Observations were obtained at seven time points: approximately every 2 years over a 12-year period.

SETTING

Large adult cystic fibrosis centre in the UK.

PARTICIPANTS

234 participants aged 14-48 years at recruitment.

OUTCOME MEASURE

Nine domains of HRQoL (Cystic Fibrosis Quality of Life Questionnaire) in relation to demographic (age, gender) and clinical measures (forced expiratory volume in 1 s, (FEV1)% predicted, body mass index (BMI), cystic fibrosis-related diabetes, Burkholderia cepacia complex, totally implantable vascular access device, nutritional and transplant status).

RESULTS

A total of 770 patient assessments were obtained for 234 patients. The results of random coefficients modelling indicated that demographic and clinical variables were identified as being significant for HRQoL over time. In addition to lung function, transplant status, age, having a totally implantable vascular access device, cystic fibrosis-related diabetes, BMI and B. cepacia complex impacted on many HRQoL domains longitudinally. Gender was important for the domain of body image.

CONCLUSIONS

Demographic and changes in clinical variables were independently associated with a change in HRQoL over time. Compared with these longitudinal data, cross-sectional data are inadequate when evaluating the relationships between HRQoL domains and key demographic and clinical variables, as they fail to recognise the full impact of the CF disease trajectory and its treatments on quality of life.

Lung transplantation for cystic fibrosis: results, indications, complications, and controversies

Survival in patients with cystic fibrosis (CF) has improved dramatically over the past 30 to 40 years, with mean survival now approximately 40 years. Nonetheless, progressive respiratory insufficiency remains the major cause of mortality in CF patients, and lung transplantation (LT) is eventually required. Timing of listing for LT is critical, because up to 25 to 41% of CF patients have died while awaiting LT. Globally, approximately 16.4% of lung transplants are performed in adults with CF. Survival rates for LT recipients with CF are superior to other indications, yet LT is associated with substantial morbidity and mortality (∼50% at 5-year survival rates). Myriad complications of LT include allograft failure (acute or chronic), opportunistic infections, and complications of chronic immunosuppressive medications (including malignancy). Determining which patients are candidates for LT is difficult, and survival benefit remains uncertain. In this review, we discuss when LT should be considered, criteria for identifying candidates, contraindications to LT, results post-LT, and specific complications that may be associated with LT. Infectious complications that may complicate CF (particularly Burkholderia cepacia spp., opportunistic fungi, and nontuberculous mycobacteria) are discussed.

Pulmonary hypertension survival effects and treatment options in cystic fibrosis

PURPOSE OF REVIEW

This review discusses the current impact of pulmonary hypertension on the outcome and treatment of cystic fibrosis (CF).

RECENT FINDINGS

Pulmonary hypertension is commonly encountered in advanced lung diseases such as CF. The prevalence of pulmonary hypertension in CF patients varies based on disease severity and methodology used for diagnosis. Chronic alveolar hypoxia is the most likely cause. The majority of recent studies have shown worse survival in CF patients who develop pulmonary hypertension. The impact of pulmonary hypertension-specific therapies on symptomatology and outcomes in CF patients has not been well studied.

SUMMARY

Pulmonary hypertension is common in patients with CF and it occurs largely because of hypoxemia. The presence of pulmonary hypertension in patients with CF is likely associated with worse outcome; however, it remains unknown whether treatment with pulmonary hypertension-specific therapies would be beneficial.

Lung transplantation in patients with cystic fibrosis

Cystic fibrosis (CF) an autosomal recessive genetic disorder, affects many organs. The great majority of deaths occur due to respiratory failure after many years of chronic pulmonary infection. Despite recent progress in early detection by studies of genetic mutations and better understanding to treat nutritional and infectious states, lung transplantation is the CF treatment for most advanced cases. According to the International Society for Heart and Lung Transplantation (ISHLT) data, CF is the third most common reason for lung transplantation (16.8%) showing the best survival rate (60% at 5 years). We have described our experience in lung transplantation of CF patients between January 2000 and December 2011, reviewing medical charts of these patients were for gender, age, body mass index (BMI), comorbidities, disease duration, previous sputum gram stain, ischemic time, incidence of severe primary graft dysfunction (PGD Grade 3), intensive care unit (ICU) length of stay, and Kaplan-Meier survival. Among 150 lung transplantation, the 30 CF patients (20%) represented the second most common cause. The average age was 27.4 ± 9.2 years, with a slight predominance of males (n = 16; 53.3%). The average BMI was 18.9 ± 2.6. Most patients (60%) had pancreatic exocrine dysfunction. Also, 83.3% of patients showed a positive sputum culture for Pseudomonas, while Burkholderia cepacia was identified in only 4 patients (13.3%). The average time of the disease was 20.8 ± 9.7 years. All transplantation were bilateral with an average ischemic time of 472 ± 98.3 minutes and ICU length of stay of 9.9 ± 6.3 days. The survival rates at 1 and 5 years were 92% and 77%, respectively, corresponding to the best outcomes among underlying diseases, comparable with other worldwide series and better than the ISHLT reports. CF, the second most common cause for lung transplantation among our cases, showed the best survival rate among all causes. Our survival rate was comparable with other reports.

Long-term benefits in lung function and nutritional status of strict metabolic control of cystic fibrosis-related diabetes

Cystic fibrosis related diabetes (CFRD) is a strong determinant for lung function decline and increased mortality. Insulin treatment of CFRD is reportedly beneficial for this situation. We report on the long-term impact of insulin treatment of CFRD on pulmonary function and nutritional status in a CF male patient since diagnosis of diabetes. We report the case of a patient diagnosed with CF at the age of 16. Two years later, he experienced a rapidly evolving decrease in pulmonary function, some months later criteria were met warranting lung transplantation. Concomitantly, he was diagnosed with CFRD and insulin therapy was started. Lung function (spirometry), nutritional status (body mass index) and metabolic control (HbA(1c)) were determined every 3 months. After the introduction of insulin treatment, pulmonary function and nutritional status progressively improved and good glycemic control was achieved. The significant and sustained improvement in pulmonary function allowed for the patient's withdrawal from the lung transplantation program within 4 months, a situation which has been maintained until now, 8 years later. The long follow-up of our patient documents the rapid and prolonged beneficial effect of proper metabolic control of CFRD on the respiratory deterioration in CF.

Colon cancer in lung transplant recipients with CF: increased risk and results of screening

OBJECTIVE

To determine the incidence of colon cancer in lung transplant recipients with cystic fibrosis (CF) and review screening colonoscopic findings in other recipients with CF.

METHODS

A retrospective chart review was performed for all patients with CF transplanted at the University of Wisconsin Hospital and Clinics (January 1994 through December 2010).

RESULTS

Four of 70 transplant recipients with CF developed fatal colon carcinoma following transplantation, and the cancer was advanced in all 4 recipients (age 31, 44, 44, 64) at the time of diagnosis. In contrast, only one of 287 recipients transplanted for non-CF indications developed colon cancer. Of all recipients with CF who did not develop colon cancer, 20 recipients underwent screening colonoscopy at 1 to 12 years following transplantation. Seven (35%) of the screened transplant recipients (ages 36, 38, 40, 41, 43, 49, 51) had colonic polyps in locations ranging from cecum to sigmoid colon and up to 3 cm in diameter.

CONCLUSIONS

In contrast to non-CF recipients, patients with CF displayed a significant incidence of colon cancer (4 of 70 recipients; 5.7%) with onset ranging from 246 days to 9.3 years post-transplant, which may be due to a combination of their underlying genetic disorder plus intense, sustained immunosuppression following lung transplantation. Colonoscopic screening may identify patients with pre-malignant colonic lesions and prevent progression to colonic malignancy.

Should lung transplantation be performed for patients on mechanical respiratory support? The US experience

OBJECTIVE

The study objectives were to (1) compare survival after lung transplantation in patients requiring pretransplant mechanical ventilation or extracorporeal membrane oxygenation with that of patients not requiring mechanical support and (2) identify risk factors for mortality.

METHODS

Data were obtained from the United Network for Organ Sharing for lung transplantation from October 1987 to January 2008. A total of 15,934 primary transplants were performed: 586 in patients on mechanical ventilation and 51 in patients on extracorporeal membrane oxygenation. Differences between nonsupport patients and those on mechanical ventilation or extracorporeal membrane oxygenation support were expressed as 2 propensity scores for use in comparing risk-adjusted survival.

RESULTS

Unadjusted survival at 1, 6, 12, and 24 months was 83%, 67%, 62%, and 57% for mechanical ventilation, respectively; 72%, 53%, 50%, and 45% for extracorporeal membrane oxygenation, respectively; and 93%, 85%, 79%, and 70% for unsupported patients, respectively (P < .0001). Recipients on mechanical ventilation were younger, had lower forced vital capacity, and had diagnoses other than emphysema. Recipients on extracorporeal membrane oxygenation were also younger, had higher body mass index, and had diagnoses other than cystic fibrosis/bronchiectasis. Once these variables, transplant year, and propensity for mechanical support were accounted for, survival remained worse after lung transplantation for patients on mechanical ventilation and extracorporeal membrane oxygenation.

CONCLUSION

Although survival after lung transplantation is markedly worse when preoperative mechanical support is necessary, it is not dismal. Thus, additional risk factors for mortality should be considered when selecting patients for lung transplantation to maximize survival. Reduced survival for this high-risk population raises the important issue of balancing maximal individual patient survival against benefit to the maximum number of patients.

Inactivation of the rhlA gene in Pseudomonas aeruginosa prevents rhamnolipid production, disabling the protection against polymorphonuclear leukocytes

Many of the virulence factors produced by the opportunistic human pathogen Pseudomonas aeruginosa are quorum-sensing (QS) regulated. Among these are rhamnolipids, which have been shown to cause lysis of several cellular components of the human immune system, e.g. monocyte-derived macrophages and polymorphonuclear leukocytes (PMNs). We have previously shown that rhamnolipids produced by P. aeruginosa cause necrotic death of PMNs in vitro. This raises the possibility that rhamnolipids may function as a 'biofilm shield'in vivo, which contributes significantly to the increased tolerance of P. aeruginosa biofilms to PMNs. In the present study, we demonstrate the importance of the production of rhamnolipids in the establishment and persistence of P. aeruginosa infections, using an in vitro biofilm system, an intraperitoneal foreign-body model and a pulmonary model of P. aeruginosa infections in mice. Our experimental data showed that a P. aeruginosa strain, unable to produce any detectable rhamnolipids due to an inactivating mutation in the single QS-controlled rhlA gene, did not induce necrosis of PMNs in vitro and exhibited increased clearance compared with its wild-type counterpart in vivo. Conclusively, the results support our model that rhamnolipids are key protective agents of P. aeruginosa against PMNs.

Lung transplantation in older patients with cystic fibrosis: analysis of UNOS data

BACKGROUND

The lifespan for patients with cystic fibrosis (CF) is increasing. As a result, greater numbers of older CF patients are presenting for lung transplantation (LTx). The UNOS database provides an opportunity to examine outcomes for this population.

METHODS

We retrospectively reviewed UNOS data to identify 1,637 first-time LTx recipients with the indication of CF between 1999 and 2007. Patients were stratified by quartile age. Our primary end-point was all-cause mortality. Post-transplant survival was compared using Cox proportional hazards regression.

RESULTS

Of the patients who met the inclusion criteria, the distribution by age quartile was as follows: Quartile 1 (Q1), age 7 to 20 years, N = 408; Q2, 21 to 27, N = 470; Q3, 28 to 34, N = 365; and Q4, >or=35, N = 394. Patients in the lowest quartile had the lowest 5-year cumulative survival (43%); 19% lower than for patients in Quartile 4 (age >or=35, cumulative survival = 62%; p < 0.001). On multivariable analysis, patients in Q3 and Q4 had a 38% and 32% reduction in cumulative hazard for death, respectively (reference Q1, age 7 to 20) (hazards ratios: Q3, 0.62 [0.46 to 0.85], p < 0.001; Q4, 0.68 [0.5 to 0.93], p = 0.02). Thirty-day and 1-year cumulative survival were not different among the four quartiles (30-day survival: Q1, 96.4%; Q2, 96.2%; Q3, 96.2%; and Q4, 95.5% [p = 0.94]; 1-year survival: Q1, 83.7%; Q2, 83.1%; Q3, 85.4%; and Q4, 83.4% [p 0.88]). Increasing age was associated with decreases in early post-operative infections, reduction in the cumulative hazard of developing bronchiolitis obliterans (BO) syndrome, and decreases in hospitalizations and treatment for rejection.

CONCLUSIONS

The UNOS database has provided a large series examining survival after LTx in older CF patients. LTx is safe in this group and older age may be protective against infection, rejection and BO syndrome.

Health-related quality of life measurement in cystic fibrosis: advances and limitations

Health-related quality of life (HRQoL) measurement in cystic fibrosis (CF) allows the inclusion of the patient's perspective in research and clinical practice. HRQoL scales have been used for many purposes and this review focuses on how HRQoL measurement has been implemented in CF research and care. Specifically, the review considers 1) the instruments used to measure HRQoL, 2) the factors that influence how people report HRQoL, 3) the monitoring of HRQoL in clinical practice, 4) HRQoL as an outcome measure in interventions and clinical trials and 5) whether HRQoL can predict survival. The challenge for the future is to use the available information to develop and evaluate psychological interventions that would be expected to improve HRQoL in children and adults with CF.

What's new in cystic fibrosis? From treating symptoms to correction of the basic defect

Chronic relentless lung infection and pancreatic insufficiency are the cardinal features of cystic fibrosis (CF), a life-shortening autosomal recessive disease. Mutations in the 'cystic fibrosis transmembrane conductance regulator' (CFTR) are currently classified into five groups according to their repercussion on CFTR protein synthesis and its chloride channel function. Stop codon mutations (class I) result in a truncated nonfunctional CFTR, class II mutations consist of aberrantly folded CFTR protein that is degraded by the cell quality control system, while class III mutations lead to defective regulation of the CFTR protein and, consequently, the absence of CFTR function. These three classes usually lead to a classic CF phenotype with pancreatic insufficiency. CFTR mutations that lead to defective chloride conductance are grouped together in class IV. Class V mutations interfere with normal transcription, thereby reducing the amount of otherwise normal CFTR. These latter two classes are mostly associated with a milder expression of the disease. In the absence of CFTR function, unrestrained Na+ absorption and the failure of active Cl- secretion lead to a decreased airway surface liquid (ASL) volume and subsequent failure of normal mucociliary clearance. This review highlights recent therapeutic strategies that either target the underlying defect or the early steps in CF pathophysiology. To date, gene therapy has failed to demonstrate a clinical benefit after repeated administration. Mutation-specific chloride channel correction pharmacotherapy is currently being developed, an example of which is PTC124, a new chemical compound that selectively induces read-through of premature stop codons. However, clinical efficacy for most of the compounds still has to be proven in large clinical trials. The positive effect of nebulised hypertonic saline on mucociliary clearance is based on the restoration of ASL height. Recent advances in the current treatment of lung infection and inflammation are highlighted in this review. Lung transplantation should be considered in terminally ill patients, but the timing of the transplantation is crucial: transplanting too early shortens survival, while transplanting too late results in patients dying on the waiting list.

Effects of Sinus Surgery on lung Transplantation Outcomes in Cystic Fibrosis

Background

In cystic fibrosis (CF) patients who are candidates for lung transplant, pretransplant sinus surgery has been advocated to avoid bacterial seeding of the transplanted lungs. This study reviews the 17-year experience of pretransplant sinus surgery among CF patients at a major transplant center.

Methods

Retrospective chart review was performed in all CF patients who underwent heart-lung or lung transplantation at Stanford Medical Center between 1988 and 2005. Postoperative culture data from bronchoalveolar lavage (BAL) and sinus aspirates were evaluated, in addition to survival data.

Results

Eighty-seven CF transplant recipients underwent pretransplant sinus surgery; 87% (n = 59/68) of patients showed recolonization of the lung grafts with Pseudomonas on BAL cultures. The median postoperative time to recolonization was 19 days. Bacterial floras cultured from sinuses were similar in type and prevalence as the floras cultured from BAL. When compared with published series of comparable cohorts in which pretransplant sinus surgery was not performed, there was no statistically significant difference in the prevalence of Pseudomonas recolonization. Times to recolonization also were similar. Survival rates in our cohort were similar to national survival rates for CF lung transplant recipients.

Conclusion

Despite pretransplant sinus surgery, recolonization of lung grafts occurs commonly and rapidly with a spectrum of flora that mimics the sinus flora. Survival rates of CF patients who undergo prophylactic sinus surgery are similar to those from centers where prophylactic sinus surgery is not performed routinely. Pretransplant sinus surgery does not appear to prevent lung graft recolonization and is not associated with overall survival benefit.