Biomedical subjects
Publications and source records attributed to G B Mallory.
Lung transplantation in children poses distinctly different challenges from those seen in the adult population. This consensus statement reviews the experience in the field of pediatric lung transplantation and highlights areas that deserve further investigation.
BACKGROUND: The most serious complications of cystic fibrosis (CF) relate to respiratory insufficiency. Oxygen supplementation therapy has been a standard of care for individuals with chronic lung diseases associated with hypoxemia for decades. It is common for physicians to prescribe oxygen therapy for people with CF when hypoxemia occurs. However, it is unclear if empiric evidence is available to provide indications for this therapy with its financial costs and often profound impact on lifestyle. OBJECTIVES: To assess whether oxygen therapy improves the longevity or quality of life of individuals with CF. SEARCH STRATEGY: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Most recent search of Group's Trials Register: April 2005. SELECTION CRITERIA: Randomized or quasi-randomized controlled trials comparing oxygen, administered at any concentration, by any route, in people with documented CF for any time period. DATA COLLECTION AND ANALYSIS: Two authors independently assessed study quality and extracted data. MAIN RESULTS: Nine published studies (149 participants) are included in this review, of which only one examined long-term oxygen therapy (28 participants). There was no statistically significant improvement in survival, lung, or cardiac health. Four studies examined the effect of oxygen supplementation during sleep by polysomnography. Although oxygenation improved, there were no demonstrable improvements in qualitative sleep parameters and modest hypoventilation was noted. In three studies, oxygen supplementation was evaluated during exercise. Hypoxemia was prevented, but mild hypercapnia resulted. Work performance was not improved, as measured in one study, but was improved in a second study. Furthermore, in two studies, exercise duration was enhanced by oxygen supplementation. In the study examining the impact of oxygen supplementation after exercise, recovery time was enhanced. AUTHORS' CONCLUSIONS: There are no published data to guide the prescription of chronic oxygen supplementation to people with advanced lung disease due to CF. Short-term oxygen therapy during sleep and exercise improves oxygenation but is associated with modest and probably clinically inconsequential hypercapnia. During exercise, there are improvements in exercise duration and peak performance. There is a need for larger, well-designed clinical trials to assess the benefits of long-term oxygen therapy in people with CF administered continuously or during exercise or sleep or both.
Since 1990, lung transplantation has been performed in infants, children and adolescents in small numbers, and the numbers, in comparison with adult transplants, remain small today. The indications for lung transplantation are similar in childhood when compared with adults, but the disease entities are distinct. In children, severe pulmonary vascular disease is most commonly associated with developmental abnormalities or congenital heart disease, as opposed to idiopathic pulmonary hypertension. Cystic fibrosis is the dominant indication for lung transplantation in older childhood and adolescence. The operative approach to lung transplantation in early life differs from that in adults, in that cardiopulmonary bypass is more likely to be utilised and bilateral lung transplantation is strongly preferred to single lung transplantation. Living donor lung transplantation is proportionately more common in children and adolescents than in adults. Post-transplant complications related to viral infection and post-transplant lymphoproliferative disease are more common and more likely to be severe and life-threatening. Bronchiolitis obliterans is the most important complication after paediatric lung transplantation and limits both the quality of life and duration of survival, as in adults.
Pulmonary surfactant is an amalgam of proteins and phospholipids which serves to maintain a low surface tension within the alveolar regions of the lungs during changes in lung volume. Recently, two of the surfactant proteins--A and D--have been characterised within the collectin family and found to play important roles in the non-specific host defence of the lung. The field of surfactant biology has attracted the attention of physiologists, biochemists, molecular biologists and clinical scientists in an effort to describe the nature and role of pulmonary surfactant in health and disease. This paper will review the history and content of discoveries in the field of surfactant biology together with pulmonary diseases related to surfactant deficiency or dysfunction.
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A major cause of morbidity and mortality following lung transplantation is posttransplant lymphoproliferative disease (PTLD). In a retrospective cohort analysis of pediatric patients, we evaluated the risk factors associated with PTLD in 128 first-time lung transplant recipients from 1990 to 1997. The greatest risk factor for PTLD was a diagnosis of cystic fibrosis (CF). Of the 16 patients in our analysis who had PTLD, 13 had a diagnosis of CF (odds ratio [OR]: 5.8; confidence interval 95% [CI]: 1.6 to 21.4). Because of the high frequency of PTLD in patients with CF (13 of 61; 23%), we performed a retrospective cohort analysis in which patients with CF and PTLD were designated as cases and patients with CF and without PTLD served as controls. In patients with CF, the only risk factor associated with PTLD was two or more episodes of acute rejection within 3 mo after transplantation (OR: 11.0; 95% CI: 2.7 to 55.7). Age, recipient Epstein-Barr virus or cytomegalovirus status, induction with antilymphocyte globulin or antithymocyte globulin (ATG), or use of ATG or OKT3 for acute rejection episodes were not risk factors for PTLD. The high frequency of PTLD in the subgroup of patients with two or more episodes of graft rejection within 2 mo after lung transplantation was unexpected, and warrants further investigation in prospective clinical studies and basic laboratories.
OBJECTIVE: To report neurologic complications in a large population of pediatric lung transplantation patients. METHODS: A retrospective review of the first 135 patients to undergo lung transplantation at St. Louis Children's Hospital from July 1990 to December 1997. RESULTS: Sixty-one (45%) patients had neurologic complications. The most common presenting symptoms were seizures (27%), followed by encephalopathy, headache, depression, and focal neurologic deficits. Cyclosporine toxicity (7%) and hypoxia-ischemia (7%) constituted the most commonly identified etiologies, followed by stroke, metabolic, and infectious causes. Risk factor analysis found that patients with interstitial lung disease had a higher frequency of hypoxic-ischemic events and patients with seizures had significantly elevated trough cyclosporine levels. Patients with stroke and hypoxia had a poor neurologic prognosis, whereas patients with cyclosporine toxicity uniformly had a good outcome. CONCLUSIONS: Neurologic complications occur frequently after lung transplantation in pediatric patients, with seizures being the most common presenting symptom. Except in patients with stroke and hypoxia, prognosis is generally favorable. Seizures not accompanied by an irreversible structural etiology are unlikely to require long-term treatment with antiepileptic medications. Cyclosporine neurotoxicity typically resolves without requiring discontinuation of immunosuppressive therapy.
BACKGROUND/PURPOSE: Distal intestinal obstruction syndrome (DIOS) occurs in 15% of patients with cystic fibrosis (CF). The authors reviewed their experience to determine the incidence, risk factors, and natural history of adhesive intestinal obstruction and DIOS after lung transplantation. METHODS: Eighty-three bilateral transplants were performed in 70 CF patients between January 1990 and September 1998. All were on pancreatic enzymes preoperatively, and none had preoperative bowel preparation. Fifty-six patients (80%) had prior gastrostomy (n = 54) or jejunostomy (n = 2). Eighteen patients (25.7%) had a previous laparotomy for meconium ileus (n = 8), fundoplication (n = 4), liver transplant (n = 1), jejunal atresia (n = 1), Janeway gastrostomy takedown (n = 1), pyloromyotomy (n = 1), free air (n = 1), or appendectomy (n = 1). RESULTS: After lung transplantation, 7 patients (10%) required laparotomy for bowel obstruction (6 during the same hospitalization, and 1 during a subsequent hospitalization). The causes of obstruction were adhesions only (n = 1), DIOS only (n = 2), and a combination of DIOS and adhesions (n = 4). Adhesiolysis was performed in the 5 patients with adhesions, and a small bowel resection was also performed in 1 patient. DIOS was treated by milking secretions distally without an enterotomy (n = 3) with an enterotomy and primary closure (n = 1) or with an end ileostomy and mucus fistula (n = 2). Five had recurrent DIOS early postoperatively. One resolved with intestinal lavage, 2 were treated successfully with hypaque disimpaction, and 2 underwent reoperation; 1 required an ileostomy. The most important risk factor for posttransplant obstruction was a previous major abdominal operation. Obstruction occurred in 7 of 18 (39%) who had undergone a prior laparotomy versus 0 of 52 who had not (P < .001, chi2). CONCLUSIONS: (1) The incidence of intestinal obstruction is high after lung transplantation in children with CF. (2) Previous laparotomy is a significant risk factor. (3) Recurrent obstruction after surgery for this condition is common. (4) Preventive measures such as pretransplant bowel preparation and early postoperative bowel lavage may be beneficial in these patients.
INTRODUCTION: Established successes with adult lung transplantation have laid the foundation for extension of this therapeutic modality to infants and children dying of end-stage pulmonary disease. The purpose of this report is to convey our experience with 19 infants undergoing lung transplantation before the age of 6 months. METHODS: Six patients with predominantly pulmonary vascular disease and 13 patients with primarily pulmonary parenchymal disease have undergone bilateral sequential lung transplantation at our institution since 1990. Mean age at transplant was 104 +/- 44 days, and mean weight was 4.9 +/- 1.6 kg. RESULTS: Although early mortality (32%, 6/19) was higher than that previously reported for older pediatric age groups, long-term survival was similar (44% at a maximum follow-up of 6 years). Although anastomotic complications and infections occurred at a rate approximating that seen in older pediatric age groups, episodes of acute rejection appear to occur with decreased frequency. Similarly, at a mean follow-up of 3 years, only 2 (15%) of 13 long-term survivors have evidence of bronchiolitis obliterans. The functional residual capacity, as measured on infant pulmonary function tests, has gradually increased as the children have grown, suggesting that lung growth is occurring. CONCLUSIONS: Bilateral lung transplantation is a viable alternative in infants dying of end-stage pulmonary disease. Efforts directed toward avoiding the complications that lead to early posttransplant mortality combined with the seemingly lower incidence of early and late rejection may provide long-term results better than those in other age groups.
We report serial measurements of lung volume and airflow in small children after lung transplantation. We expected that immature lungs could grow and develop normal volumes after transplantation, despite denervation and immunosuppression. At predetermined intervals, functional residual capacity (FRC) and forced expiratory flow were measured 86 times in 23 recipients younger than 3 yr of age (age at transplant, 13.2 +/- 8.4 mo; range, 2 to 30 mo). FRC was measured using open-circuit N2 washout. Maximal flow at FRC by rapid thoracoabdominal compression was used to distinguish between infants with and those without airflow obstruction. The slope of FRC (in milliliters) versus body length (in centimeters) for all 23 recipients studied was 8.63. For those children without obstruction (flow at FRC >/= 0.9 FRC/s, n = 16), the slope of FRC versus length was 6.61. The coefficient of variation for FRC measurements for all infants was 3.90 +/- 2.80% (range, 0.3 to 16.9%). We conclude that in the absence of significant airflow obstruction the volume of transplanted immature lungs increases at a rate similar to that reported in normal infants.
BACKGROUND: Early primary graft failure due to reperfusion injury may occur in up to 10% of all patients undergoing lung transplantation. Late graft failure in the form of bronchiolitis obliterans progressively increases in frequency as posttransplantation follow-up increases. In both situations, the degree of pulmonary dysfunction may worsen and result in the death of the recipient. The only treatment in many instances is retransplantation. The results in adults are reasonably well established. METHODS: We reviewed our experience in children. Of the 136 transplant procedures performed to date in children, 14 have been retransplantations. Six patients required retransplantation for early primary graft failure and 8 underwent retransplantation for bronchiolitis obliterans. RESULTS: There were three early and three late deaths. The actuarial survival at 2 years is 58%. The retransplant procedures were more complex than the primary transplant operations as evidenced by the longer time on cardiopulmonary bypass (199 +/- 71 versus 150 +/- 41 minutes; p < 0.01) and the greater volume of blood transfused (1,303 +/- 936 versus 570 +/- 300 mL; p < 0.01). Two of the long-term survivors who received transplants for bronchiolitis obliterans have subsequently had development of this same condition and 1 died secondary to this. In four instances living related donors were used for the retransplant procedure. The most striking difference in these procedures compared with those transplantations performed with cadaveric donors was the shorter donor lung ischemic times (99.5 and 123.3 minutes for the two lungs for living related donors and 251 and 293 minutes for the first and second lung for the cadaveric donors; p < 0.01). CONCLUSIONS: We believe that lung retransplantation in children is a reasonable therapy to offer in the circumstance of severe graft dysfunction. In the older child, the option of living donor transplantation offers advantages that might offset of the overall higher risk of this procedure.
OBJECTIVE: This paper was undertaken to review the experience at our institution with bilateral sequential lung transplantation for cystic fibrosis. METHODS: Since 1989, 103 bilateral sequential lung transplants for cystic fibrosis have been performed (46 pediatric, 48 adult, 9 redo); the mean age was 21 +/- 10 years. Cardiopulmonary bypass was used in all but one pediatric (age <18) transplant, and in 15% of adults. RESULTS: Hospital mortality was 4.9%, with 80% of early deaths related to infection. Bronchial anastomotic complications occurred with equal frequency in the pediatric and the adult populations (7.3%). One- and 3-year actuarial survival are 84% and 61%, respectively (no significant difference between pediatric and adult age groups; average follow-up 2.1 +/- 1.6 years). Mean forced expiratory volume in 1 second increased from 25% +/- 9% before transplantation to 79% +/- 35% 1 year after transplantation. Acute rejection occurred 1.7 times per patient-year, with most episodes taking place within the first 6 months after transplantation. The need for treatment of lower respiratory tract infections occurred 1.2 times per patient in the first year after transplantation. Actuarial freedom from bronchiolitis obliterans was 63% at 2 years and 43% at 3 years. Redo transplantation was performed only in the pediatric population and was associated with an early mortality of 33%. Eight living donor transplants (four primary transplants, four redo transplants) were performed with an early survival of 87.5%. CONCLUSION: Patients with end-stage cystic fibrosis can undergo bilateral lung transplantation with morbidity and mortality comparable to that seen in pulmonary transplantation for other disease entities.
The first successful heart-lung and lung transplant operations in cystic fibrosis (CF) patients were performed in 1983 and 1987, respectively. Lung transplantation is now available at dozens of centers in North America, Europe, and Australia. Recent technical developments and the major limitations of donor organ availability prompted the CF Foundation to sponsor a meeting of 37 experts to evaluate the state of the art in lung transplantation for CF, highlighting areas of consensus, practice variations, and controversy. This document summarizes the work of that group.
Posttransplant Epstein-Barr virus-related lymphoproliferative disease (PT-LPD) is a common and often fatal complication following solid organ and hematopoietic stem cell transplantation. PT-LPD following solid organ transplantation generally occurs in B cells of recipient origin in contrast to PT-LPD in marrow transplant recipients, which is exclusively of donor origin. The efficacy of adoptive immunotherapy using donor leukocytes to treat PT-LPD in bone marrow transplant recipients has recently been reported. Because PT-LPD in solid organ transplant recipients is generally of recipient origin, the potential application of adoptive immunotherapy of PT-LPD in solid organ recipients obligates the use of either autologous or allogeneic HLA identical leukocytes, with the attendant risk of organ rejection if cells mismatched with the transplanted organ are used. Nonirradiated allogeneic mononuclear cells from an Epstein-Barr virus (EBV)-seropositive, HLA-identical normal sibling were used to treat a monoclonal EBV lymphoma of recipient origin in the central nervous system of a child who had undergone an HLA-mismatched cadaveric lung transplant. The patient received three separate mononuclear cell infusions over a 9-month period, each containing 1 x 10(6) CD3+ mononuclear cells per kilogram. Complete clinical, radiological, and pathological remission was achieved with this treatment regimen. The response correlated with in vivo reconstitution of normal EBV-specific cytotoxic activity and cytotoxic T lymphocyte precursor frequency. Use of allogeneic HLA-compatible mononuclear cells may thus offer an additional mode of therapy for EBV-related lymphoproliferative disease in selected solid organ transplant recipients refractory to conventional therapies.
OBJECTIVE: To evaluate lung transplantation for treatment of surfactant protein B (SP-B) deficiency. STUDY DESIGN: We compared surfactant composition and function from pretransplantation and posttransplantation samples of bronchoalveolar lavage fluid, somatic and lung growth, neurodevelopmental progress, pulmonary function, and pulmonary immunohistology in 3 infants with SP-B deficiency who underwent bilateral lung transplantation at 2 months of age and 3 infants who underwent lung transplantation for other reasons. RESULTS: Two years after transplantation, the 2 surviving infants with SP-B deficiency exhibited comparable somatic growth and cognitive development to the comparison infants. All infants had delays in gross motor development that improved with time. Both groups have exhibited normal gas exchange, lung growth, and pulmonary function. The SP-B-deficient infants have also exhibited normal SP-B expression and pulmonary surfactant function after lung transplantation. In two SP-B-deficient infants antibody to SP-B developed. No pathologic consequences of this antibody were identified. CONCLUSIONS: Apart from the development of anti-SP-B antibody, the outcomes for SP-B-deficient infants after lung transplantation are similar to those of infants who undergo lung transplantation for other reasons. Lung transplantation offers a successful interim therapy until gene replacement for this disease is available.
Living donor lung transplantation has been performed in the United States since 1990. Based on the experience in living donor kidney transplantation which began in 1954, and living donor liver transplantation which began in 1989, considerable progress has occurred in surgical technique, selection of recipients and donors, and the indications for and timing of the procedure. The vast majority of living donor lung transplantations have been performed in patients with cystic fibrosis. Early results concerning graft function, donor recovery, and recipient outcome are encouraging.
Pediatric lung transplantation is becoming more common, and with increasing experience there is increasing success. The most common indications for considering lung transplantation are cystic fibrosis, pulmonary vascular disease (usually due to congenital heart disease), and fibrotic lung disease. The contraindications and complications are similar to adult transplant patients, although post-transplant lymphoproliferative disease and airway complications may occur more frequently. The patients with cystic fibrosis face additional obstacles to the success of transplantation: airway colonization with Gram-negative organisms, pancreatic insufficiency, glucose intolerance, and osteoporosis. The survival for children is comparable to adults, reaching about 65% at 1 year, and 69% at 2 years.
Although accepted therapy in adults, lung transplantation in children is less well established. Reports from the few existing pediatric centers have involved relatively small patient number. Seventy-nine patients underwent 88 lung transplant procedures at St. Louis Children's Hospital between June 1990 and August 1995. Twenty-one transplants (24%) were done in 19 infants and children under the age of 3 yr. Twelve-, 24-, and 48-mo actuarial survival for the primary transplants was 69%, 67%, and 60%, respectively. Survival improved over the course of the program: 12-mo survival for patients transplanted during the first 18 mo was 42% compared with 78% for those transplanted after December 1991. Survival of children transplanted at younger than 3 yr of age was comparable to older children and adults. However, younger children had a lower incidence of acute rejection; none developed bronchiolitis obliterans. Both graft growth and linear growth occurred. Risk factors for early mortality included presence of aortopulmonary collateral vessels and prior thoracic surgery. Risk factors for survival duration included requiring assisted ventilation at the time of transplant, continuous supplemental oxygen requirement, and presence of aortopulmonary collateral vessels. The major late complication was bronchiolitis obliterans, which occurred in 27% of patients and played a role in 64% of late deaths. Investigation of the lower incidence of acute rejection and bronchiolitis obliterans in younger versus older children may reveal important information about the etiology of this disease. The ultimate long-term success of lung transplantation will depend on identification and treatment of the mechanisms responsible. A multicenter data registry would facilitate further clinical studies of pediatric lung transplantation.