Registry of the International Society for Heart and Lung Transplantation: Ninth Official Pediatric Lung and Heart–Lung Transplantation Report—2006

Emergency Department Management of Pediatric Heart Transplant Recipients: Unique Immunologic and Hemodynamic Challenges

BACKGROUND

Since the first heart transplant in 1967, there has been significant progress in this field of cardiac transplantation. Approximately 600 pediatric heart transplants are performed every year worldwide. With the increasing number of pediatric heart transplant patients, and given the few tertiary care pediatric transplant centers, adult and pediatric emergency department (ED) providers are increasingly engaged in the care of pediatric heart transplant recipients in the ED.

OBJECTIVE

The aim of this article is to review common ED scenarios pertinent to the pediatric heart transplant patients.

DISCUSSION

There are complications unique to this population, such as rejection, opportunistic infections, and medication side effects, that require special considerations, and it is helpful for the emergency medicine (EM) provider to have knowledge about them.

CONCLUSIONS

The unique immunological challenges in these patients, including rejection and medication side effects and opportunistic infections, make this population fragile, and the knowledge of these challenges is helpful for EM providers.

[Lung transplantation and rejection. Basic principles, clinical aspects and histomorphology]

Lung transplantation is the ultimate therapeutical approach for the treatment of both children and adults with terminal congenital or acquired lung disease. In contrast to survival rates during the first year following transplantation, the long-term survival for patients after lung transplantation has not significantly improved in the past. In addition to other complications, acute cellular rejection constitutes a major cause for diminished function of pulmonary grafts, and can, among other factors, be causative for chronic rejection (bronchiolitis obliterans syndrome, BOS). In 2006, the International Society for Heart and Lung Transplantation (ISHLT) provided a revised version of the grading system for acute and chronic rejection of pulmonary grafts.

Long-term impact of respiratory viral infection after pediatric lung transplantation

To evaluate the epidemiology and to investigate the impact of RVI on chronic allograft rejection after pediatric lung transplantation, a retrospective study of pediatric lung transplant recipients from 2002 to 2007 was conducted. Association between RVI and continuous and categorical risk factors was assessed using Wilcoxon rank-sum tests and Fisher's exact tests, respectively. Association between risk factors and outcomes were assessed using Cox proportional hazards models. Fifty-five subjects were followed for a mean of 674 days (range 14-1790). Twenty-eight (51%) developed 51 RVI at a median of 144 days post-transplant (mean 246; range 1-1276); 41% of infections were diagnosed within 90 days. Twenty-five subjects developed 39 LRI, and eight subjects had 11 URI. Organisms recovered included rhinovirus (n = 14), adenovirus (n = 10), parainfluenza (n = 10), influenza (n = 5), and RSV (n = 4). Three subjects expired secondary to their RVI (two adenovirus, one RSV). Younger age and prior CMV infection were risks for RVI (HR 2.4 95% CI 1.1-5.3 and 17.0; 3.0-96.2, respectively). RVI was not associated with the development of chronic allograft rejection (p = 0.25) or death during the study period. RVI occurs in the majority of pediatric lung transplant recipients, but was not associated with mortality or chronic allograft rejection.

Respiratory viral infections within one year after pediatric lung transplant

Abstract: To characterize epidemiology and risk factors for respiratory viral infections (RVI) in pediatric lung transplant recipients within the first post‐transplant year, a retrospective multicenter study of pediatric lung transplant recipients from 1988 to 2005 was conducted at 14 centers in the United States and Europe. Data were recorded for 1 year post transplant. Associations between RVI and continuous and categorical risk factors were assessed using Wilcoxon's rank‐sum and χ² tests, respectively. Associations between time to RVI and risk factors or survival were assessed by multivariable Cox proportional hazards models. Of 576 subjects, 79 subjects (14%) had 101 RVI in the first year post transplant. Subjects with RVI were younger than those without RVI (median ages 9.7, 13; P<0.01). Viruses detected included adenovirus (n=25), influenza (n=9), respiratory syncytial virus (n=21), parainfluenza virus (n=19), enterovirus (n=4), and rhinovirus (n=22). In a multivariable model for time to first RVI, etiology other than cystic fibrosis (CF), younger age, and no induction therapy were independently associated with risk of RVI. Cytomegalovirus serostatus and acute rejection were not associated with RVI. RVI was independently associated with decreased 12‐month survival (hazard ratio 2.6, 95% confidence interval 1.6–4.4). RVI commonly occurs after pediatric lung transplantation with risk factors including younger age and non‐CF diagnosis. RVI is associated with decreased 1‐year survival.

Lung transplantation in infants and toddlers from 1990 to 2004 at St. Louis Children's Hospital

In a retrospective, single-center cohort study, outcomes of infants and toddlers undergoing lung transplant at St. Louis Children's Hospital between 1990 and 2004 were compared to older children. Patients with cystic fibrosis (exclusively older children) and those who underwent heart-lung, liver-lung, single lung or a second transplantation were excluded from comparisons. One hundred nine lung transplants were compared. Thirty-six were in infants <1 year old, 26 in toddlers 1-3 years old and 47 in children >3 years old. Graft survival was similar for infants and toddlers (p = 0.35 and p = 0.3, respectively) compared to children over 3 years old at 1 and 3 years after transplant. Significantly more infants (p < 0.0001 and p = 0.003) and toddlers (p = 0.002 and p = 0.03) were free from acute rejection and bronchiolitis obliterans compared to older patients. While most infants and toddlers had only minimal lung function impairment, and achieved normal to mildly delayed developmental scores, somatic growth remained depressed 5 years after transplant. Lung transplantation in infants and young children carries similar survival rates to older children and adults. Further insights into the unique immunologic aspects of this group of patients may elucidate strategies to prevent acute and chronic rejection in all age groups.

Children with chronic organ failure possibly ending in organ transplantation: a survey in an Italian region of 5,000,000 inhabitants

AIM

The Italian Piedmont region sponsored in 2005 a population-based registry to assess the epidemiology of childhood chronic organ failure involving kidneys, liver, heart or lungs.

METHODS

Patients in chronic organ failure who were younger than 18 years were selected, and entered the registry when accomplishing the standard failure criteria for each organ. The cases were reported by the general paediatricians of the region and integrated with the data gathered by the Children University Hospital, a tertiary care centre.

RESULTS

In Piedmont (647,727 inhabitants < 18 years), a total of 146 children (217 cases per million of paediatric population) were found to be affected by chronic organ failure (mean age 10 years; range 0-17). The organ failure involved kidneys in 68 subjects (48%), liver in 24 (17%), heart in 21 (15%) and lungs in 28 (20%), and was severe in 32 subjects (6 on transplantation waiting list). The most represented disease leading to chronic renal failure was renal hypodysplasia (79%). Chronic liver failure was mostly caused by biliary atresia (30%), autoimmune hepatitis (25%) and Wilson's disease (21%). Dilated cardiomyopathy (62%) and surgically treated congenital cardiopathy were the two leading causes of chronic heart failure. The most represented disease leading to chronic lung failure was cystic fibrosis (89%).

CONCLUSION

This is the first report of the literature focusing on the epidemiology of chronic organ failure in children encompassing a region of 4,000,000 inhabitants. This clinical condition is rare, but medically and socially very demanding not only in childhood but the life along, as most of these patients will need solid organ transplantation decades later.

Lung transplantation in a patient with a thrombophilic disorder

The prothrombin G20210A mutation has been associated with an increased risk of graft failure in renal transplant recipients. Little is known about the potential effect of this mutation on lung transplant recipients. We report the case of bilateral lung transplantation in a patient with cystic fibrosis who was heterozygous for the G20210A mutation of the prothrombin gene.

Pediatric transplantation in the United States, 1997-2006

This article represents the sixth annual review of the current state of pediatric transplantation in the United States from the Scientific Registry of Transplant Recipients (SRTR). It presents updated trends, discussion of analyses presented during the year by the SRTR to the committees of the Organ Procurement and Transplantation Network (OPTN) and discussion of important issues currently facing pediatric organ transplantation. Unless otherwise stated, the statistics in this article are drawn from the reference tables of the 2007 OPTN/SRTR Annual Report. In this article, pediatric patients are defined as candidates, recipients or donors aged 17 years or less. Data for both graft and patient survival are reported as unadjusted survival, unless otherwise stated (adjusted patient and graft survival are available in the reference tables). Short-term survival (3 month and 1 year) reflects outcomes for transplants performed in 2004 and 2005; 3-year survival reflects transplants from 2002 to 2005; and 5-year survival reports on transplants performed from 2000 to 2005. Details on the methods of analysis employed may be found in the reference tables themselves or in the technical notes of the 2007 OTPN/SRTR Annual Report, both available online at http://www.ustransplant.org.

Heart-lung transplantation in a 14-year-old boy with Alström syndrome

We present a 14-year-old boy who suffered from progressive biventricular cardiac failure and secondary pulmonary artery hypertension associated with the rarely seen Alström syndrome. The boy underwent successful heart-lung transplantation. We conclude from this report that heart-lung transplantation in patients with Alström syndrome is a viable therapeutic option in select cases.

Pediatric lung transplantation: perspectives for the pathologist

Lung transplantation offers life-saving and life-extending treatment for children and adolescents with congenital and acquired forms of pulmonary and pulmonary vascular disease, for whom medical therapy is ineffective or insufficient for sustained response. This review summarizes the pathology related to lung transplantation for the practicing pediatric pathologist and also highlights aspects of lung transplantation unique to the pediatric population. Clinical issues related to availability of organs, candidate eligibility, surgical technique, and postoperative monitoring are discussed. Pathologic evaluation of routine surveillance transbronchial biopsies requires attention to acute cellular rejection, opportunistic infection, and other forms of acute and resolving lung injury. These findings are correlated in some cases with endobronchial biopsies and bronchoalveolar lavage as adjunctive tools in surveillance. Open or thoracoscopic biopsies also have diagnostic utility in cases with acute or chronic graft deterioration of uncertain etiology. Future challenges in pediatric lung transplantation are similar to those in the adult population, with continued efforts focused on prolonging graft survival, prevention of bronchiolitis obliterans syndrome due to chronic cellular rejection, and evaluation of humoral rejection.

Pediatric organ donation: what factors most influence parents' donation decisions?

OBJECTIVE

To identify factors that influence parents' decisions when asked to donate a deceased child's organs.

DESIGN

Cross-sectional design with data collection via structured telephone interviews.

SETTING

One organ procurement organization in the Southeastern United States.

PARTICIPANTS

Seventy-four parents (49 donors, 25 nondonors) of donor-eligible deceased children who were previously approached by coordinators from one organ procurement organization in the southeastern United States.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Multivariate analyses showed that organ donation was more likely when the parent was a registered organ donor (odds ratio [OR] = 1.4, confidence interval [CI] = 1.1, 2.7), the parent had favorable organ donation beliefs (OR = 5.5, CI = 2.7, 12.3), the parent was exposed to organ donation information before the child's death (OR = 2.6, CI = 1.7, 10.3), a member of the child's healthcare team first mentioned organ donation (OR = 1.4, CI = 1.2, 3.7), the requestor was perceived as sensitive to the family's needs (OR = 0.4, CI = 0.2, 0.7), the family had sufficient time to discuss donation (OR = 5.2, CI = 1.4, 11.6), and family members were in agreement about donation (OR = 2.8, CI = 1.3, 5.2).

CONCLUSIONS

This study identifies several modifiable variables that influence the donation decision-making process for parents. Strategies to facilitate targeted organ donation education and higher consent rates are discussed.

Pediatric lung transplantation: a therapy in its adolescence

Pediatric lung transplant was born at the University of Toronto as an extension of the pioneering work of Cooper and Patterson in adult lung transplant in the 1980s. Through the 1990s, the field of pediatric lung transplantation grew with clinical outcomes in the largest centers being comparable to those in adult lung transplantation. For children and adults, the largest obstacle to long-term survival remains chronic allograft rejection secondary to the development of bronchiolitis obliterans, for which little advancement has been made in prevention or treatment. While transplantation has become accepted therapy for end-stage lung disease in adults, pediatric lung transplant has been less widely embraced for multiple reasons, such as adolescent non-compliance and the investment required in developing freestanding pediatric lung transplant centers. Another factor limiting pediatric lung transplant has been the paucity of suitable donor lungs. In 2002, Texas Children's Hospital and the Baylor College of Medicine successfully collaborated in developing an active and successful pediatric lung transplant program. Through our own work and an international collaborative of pediatric transplant pulmonologists and surgeons, we are hoping to move the field of pediatric lung transplant out of its "adolescence" into adulthood.

Variability in immunization guidelines in children before and after lung transplantation

Lung transplant candidates and recipients are at high risk of infections from vaccine-preventable diseases. However, well-established guidelines neither exist for pre- and post-transplant vaccination nor do monitoring guidelines for pediatric lung transplant recipients. To ascertain the current vaccination and monitoring practices of pediatric lung transplant centers, a self-administered questionnaire was distributed to the 18 pediatric lung transplant centers within the International Pediatric Lung Transplant Collaborative in April 2006. Sixteen of 18 centers (89%) surveyed responded. Pretransplant, national vaccination guidelines are followed. Eleven centers reported following standardized vaccination guidelines post-transplant. Vaccines were more commonly provided by the primary-care physician pretransplant (69%) rather than post-transplant (38%). Post-transplant, 50% of the centers recommend live vaccines for household contacts but not for the transplant recipient. Pretransplant monitoring of response to prior vaccination was performed inconsistently except for varicella (88%). Only 44% of the transplant centers measure for response to vaccination post-transplant, mostly hepatitis B. Current vaccination practices of pediatric lung transplant centers are heterogeneous. The lung transplant community would be well served by studies designed to evaluate the efficacy of vaccinations in this population.

Alemtuzumab in the treatment of refractory acute rejection and bronchiolitis obliterans syndrome after human lung transplantation

Despite substantial improvements in early survival after lung transplantation, refractory acute rejection (RAR) and bronchiolitis obliterans syndrome (BOS) remain major contributors to transplant-related morbidity and mortality. We have utilized alemtuzumab, a humanized anti-CD52 antibody which results in potent lymphocyte depletion, in consecutive patients with RAR (n = 12) or BOS (n = 10). All patients failed conventional treatment with methylprednisolone and antithymocyte globulin and received strict infection prophylaxis. Alemtuzumab significantly improved histological rejection scores in RAR. Total rejection grade/biopsy was 1.98 +/- 0.25 preceding alemtuzumab versus 0.33 +/- 0.14 posttreatment, p-value <0.0001 (with a similar number of biopsies/patient per respective time interval). Freedom from BOS was observed in 65% of RAR patients 2 years after alemtuzumab treatment. Although there was no statistically significant change in forced expiratory volume in 1 second (FEV1) before and after alemtuzumab treatment in patients with BOS, a stabilization or improvement in BOS grade occurred in 70% of patients. Patient survival 2 years after alemtuzumab for BOS was 69%. Despite a dramatic decline in CD4 counts in alemtuzumab-treated patients, only one patient developed a lethal infection. Thus, we provide the first evidence that alemtuzumab is a potentially useful therapy in lung transplant recipients with RAR or BOS.

Combined double lung-liver transplantation for cystic fibrosis without cardio-pulmonary by-pass

Sequential bilateral single lung-liver transplantation (SBSL-LTx) is a therapeutic option for patients with end stage lung and liver disease (ESLLD) due to cystic fibrosis (CF). A few cases have been reported, all of them were performed with the use of cardio-pulmonary by-pass (CPB). We performed SBSL-LTx in three young men affected by CF. All the recipients had respiratory failure and portal hypertension with hypersplenism. Along with lung transplants, two patients received a whole liver graft and one an extended right graft from an in situ split liver. During transplantation neither CPB nor veno-venous by-pass (VVB) were employed. Immunosuppression was based on basiliximab, tacrolimus, steroids and azathioprine. The three recipients are alive with a median follow-up of 670 days (range 244-1,533). Combined SBSL-LTx is a complex but effective procedure for the treatment of ESLLD due to CF, not necessarily requiring the use of CPB or VVB.

Successful lung transplantation for adolescents at a hospital for adults

OBJECTIVE

To describe the results of lung transplantation (LTx) in adolescents at a hospital for adults.

DESIGN AND SETTING

Prospective cohort study set in an LTx unit at an adult tertiary referral hospital from 1991 to 2006.

PATIENTS

37 consecutive adolescent lung transplant recipients including 13 males and 24 females (mean age, 16.7+/-2.0 [SD] years; range 12-19 years) who received heart-lung (six patients) or bilateral LTx (31 patients) for cystic fibrosis (29), congenital heart disease (four), acute respiratory failure (two), or another disorder (two). Two patients were transplanted after invasive ventilation, five after non-invasive ventilation and two after extracorporeal membrane oxygenation.

MAIN OUTCOME MEASURES

Overall survival compared with an adult cohort; survival free of bronchiolitis obliterans syndrome (BOS); overall and BOS-free survival in those transplanted before and after January 2000.

RESULTS

Mean waiting time was 273 days (range, 5-964 days; median, 163 days), mean donor age was 28 years (range, 9-53 years). Median inpatient stay was 11 days (range, 7-94 days). Mean follow-up was 1540+/-1357 days (range, 35-5163 days). The 5-year survival rate for the 16 patients transplanted before January 2000 was 38%, versus 74% for the 21 transplanted since January 2000 (P=0.05; Mantel-Cox). Overall, 18 of 35 evaluable patients developed BOS. Only BOS was associated with an increased mortality risk (P<0.01).

CONCLUSION

LTx may be performed successfully in adolescents at a hospital for adults.

Lung transplantation: does age make a difference?

Significant similarities between the challenges of lung transplantation in patients of all ages should lead to better access to this life-saving surgery for children and adolescents.

Pathology of lung transplantation

The International Society for Heart and Lung Transplantation has a standardized nomenclature for the evaluation of lung allografts. Rejection of the lung allograft is divided into acute and chronic forms. Acute cellular rejection is characterized by perivascular accumulations of mononuclear cells and eosinophils; bronchiolar inflammation is also included in the grading scheme. Acute antibody-mediated rejection in lung allografts is not well defined. Chronic rejection is manifest by fibrous scarring narrowing the lumen of bronchioles, arteries, and veins. The diagnosis of rejection requires the exclusion of infection and other pathology in the allograft.

Long-term Improvement in Pulmonary Function After Living Donor Lobar Lung Transplantation

BACKGROUND

As an alternative to cadaveric transplantation, living donor lobar lung transplantation (LDLLT) has been applied in critical patients with end-stage pulmonary disease because of the mismatch between the supply and demand of lungs for transplantation. However, it is unclear whether two pulmonary lobes can provide adequate long-term pulmonary function and satisfactory clinical outcome in recipients.

METHODS

Between October 1998 and September 2004, 28 females and 3 males, including 5 children, underwent LDLLT at Okayama University Hospital. Their mean age was 31.8 years, and the mean observation period was 53.8 months. One patient who underwent single-lung transplantation and another who died peri-operatively were excluded from further analyses.

RESULTS

The most common indication for transplantation was pulmonary arterial hypertension (32.3%). The overall survival rate was 93.6%. Seven recipients (22.6%) developed bronchiolitis obliterans syndrome after LDLLT. The mean percent predicted forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) improved between 12 and 24 months after transplantation (71.8 +/- 12.9% and 65.8 +/- 17.2% at 12 months vs 77.4 +/- 16.6% and 72.8 +/- 14.6% at 24 months; p < 0.005 and p < 0.05, respectively). The actual recipient FVC ultimately reached 123.0% of the estimated graft FVC of two donor lobes (calculated based on the donor FVC and number of segments implanted) at 36 months after LDLLT.

CONCLUSIONS

Although LDLLT may be associated with the limitation of size mismatch, it holds promise for providing well-functioning pulmonary lobar grafts to critically ill patients with poor life expectancy.

Posttransplant monitoring of pediatric lung transplant recipients

PURPOSE OF REVIEW

This article reviews current trends in pediatric lung posttransplant management, reveals pitfalls that exist, and introduces additional parameters that may have an impact on long-term survival.

RECENT FINDINGS

A number of parameters are monitored after transplantation to prevent or identify early complications related to lung transplantation in hope of reducing morbidity and mortality. These include routine laboratory studies, imaging, and monitoring of drug levels and lung function. Drug monitoring allows individualization of a patient's immunosuppressive therapy; however, drug levels alone may not reflect the patient's immune status. ImmuKnow is a general immune-monitoring assay that may help guide therapy. Two major complications are rejection and infection, and bronchoscopy is used to differentiate these two entities. Silent rejection may occur and increase the chance of developing bronchiolitis obliterans; therefore, many centers perform surveillance bronchoscopies. Recently, de-novo anti-histocompatibility locus antigen antibodies and gastroesophageal reflux have been associated with poor outcomes, and many centers are monitoring these entities as part of care following lung transplant.

SUMMARY

There has been little improvement in long-term outcomes of lung transplantation. Current monitoring methods are utilized to maintain or improve outcomes and recently additional monitoring parameters have been identified which hopefully will improve long-term outcomes.

Repeat organ transplantation in the United States, 1996-2005

The prospect of graft loss is a problem faced by all transplant recipients, and retransplantation is often an option when loss occurs. To assess current trends in retransplantation, we analyzed data for retransplant candidates and recipients over the last 10 years, as well as current outcomes. During 2005, retransplant candidates represented 13.5%, 7.9%, 4.1% and 5.5% of all newly registered kidney, liver, heart and lung candidates, respectively. At the end of 2005, candidates for retransplantation accounted for 15.3% of kidney transplant candidates, and lower proportions of liver (5.1%), heart (5.3%) and lung (3.3%) candidates. Retransplants represented 12.4% of kidney, 9.0% of liver, 4.7% of heart and 5.3% of lung transplants performed in 2005. The absolute number of retransplants has grown most notably in kidney transplantation, increasing 40% over the last 10 years; the relative growth of retransplantation was most marked in heart and lung transplantation, increasing 66% and 217%, respectively. The growth of liver retransplantation was only 11%. Unadjusted graft survival remains significantly lower after retransplantation in the most recent cohorts analyzed. Even with careful case mix adjustments, the risk of graft failure following retransplantation is significantly higher than that observed for primary transplants.