Jie Zheng

Determinants of asthma after severe respiratory syncytial virus bronchiolitis.

BACKGROUNDnThe development of asthma after respiratory syncytial virus (RSV) bronchiolitis has been demonstrated in case-control studies, although the determinants of post-RSV asthma remain undefined.nnnOBJECTIVESnWe sought to evaluate the potential determinants of physician-diagnosed asthma after severe RSV bronchiolitis during infancy.nnnMETHODSnWe enrolled 206 children during an initial episode of severe RSV bronchiolitis at 12 months of age or less in a prospective cohort study and followed these children for up to 6 years. In a subset of 81 children, we analyzed CCL5 (RANTES) mRNA expression in upper airway epithelial cells.nnnRESULTSnForty-eight percent of children had physician-diagnosed asthma before the seventh birthday. Independent determinants significantly associated with increased risk for physician-diagnosed asthma by the seventh birthday included maternal asthma (odds ratio [OR], 5.2; 95% CI, 1.7-15.9; P = .004), exposure to high levels of dog allergen (OR, 3.2; 95% CI, 1.3-7.7; P = .012), aeroallergen sensitivity at age 3 years (OR, 10.7; 95% CI, 2.1-55.0; P = .005), recurrent wheezing during the first 3 years of life (OR, 7.3; 95% CI, 1.2-43.3; P = .028), and CCL5 expression in nasal epithelia during acute RSV infection (OR, 3.8; 95% CI, 1.2-2.4; P < .001). White children (OR, 0.19; 95% CI, 0.04-0.93; P = .041) and children attending day care (OR, 0.18; 95% CI, 0.04-0.84; P = .029) had a decreased risk of physician-diagnosed asthma.nnnCONCLUSIONSnApproximately 50% of children who experience severe RSV bronchiolitis have a subsequent asthma diagnosis. The presence of increased CCL5 levels in nasal epithelia at the time of bronchiolitis or the development of allergic sensitization by age 3 years are associated with increased likelihood of subsequent asthma.

Decline in rejection in the first year after pediatric cardiac transplantation: A multi-institutional study

BACKGROUNDnRejection is a major cause of morbidity and mortality after pediatric heart transplantation (HTx). Survival after pediatric HTx has improved over time, but whether there has been an era-related improvement in the occurrence of allograft rejection is unknown.nnnMETHODSnThe Pediatric Heart Transplant Study (PHTS) database was queried for patients who underwent HTx from January 1993 to December 2005 to determine the incidence of rejection and identify factors associated with the first episode of rejection in the first year after HTx.nnnRESULTSnData were reviewed in 1,852 patients from 36 centers. The incidence of rejection declined over 13 years at a rate of -2.58 +/- 0.41 (p < 0.001) from approximately 60% to 40% (p < 0.001). The mean number of episodes of rejection also significantly fell at a rate of -0.05 +/- 0.01 per patient/year from 1.19 to 0.66 (p < 0.001). The incidence of rejection with hemodynamic compromise and death from rejection did not change. Multivariate analysis for the risk of a first rejection episode demonstrated decreased risk of rejection with later year of HTx (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.85-0.91; p < 0.001) and use of mechanical support (OR, 0.65; 95% CI, 0.42-0.99; p = 0.046). Increased risk of rejection was associated with positive donor-specific crossmatch (OR, 1.85; 95% CI, 1.18-2.88; p = 0.007) and older recipient age (OR, 1.05; 95% CI, 1.02-1.07; p < 0.001).nnnCONCLUSIONSnAlthough the overall incidence and prevalence of rejection has substantially decreased over time in pediatric HTx recipients in the first year after HTx, the rate of rejection with hemodynamic compromise or death from rejection remains unchanged.

Early survival after heart transplant in young infants is lowest after failed single-ventricle palliation: A multi-institutional study

BACKGROUNDnInfant heart transplant (HT) recipients have the best long-term survival of any age group, but the small donor pool and high early mortality limit the therapeutic effectiveness. We sought to determine the relationship between pre-HT diagnosis and early HT outcome to better define the mortality risk associated with a diagnosis of congenital heart disease (CHD) and to examine differences between early and current HT eras.nnnMETHODSnThe Pediatric Heart Transplant Study (PHTS) database was used to identify 739 infant HT recipients at age ≤ 6 months between 1993 and 2008 divided into the following etiologic groups: cardiomyopathy (CM), 18%; hypoplastic left heart syndrome (HLHS) without surgery, 41%; HLHS with surgery, 9%; other CHD without surgery, 16%; and other CHD with surgery, 15%. Severity of illness at HT, post-HT survival, and era effects were compared.nnnRESULTSnAt 1 year after HT, survival was 89% for the CM group, which was the best, 79% for CHD without surgery, 82% for CHD with surgery, 79% for HLHS without surgery, and 70% for HLHS with surgery, which was the worst outcome. Hazard function analysis demonstrated the difference occurred within the first 3 months after HT. After adjusting for illness severity, differences in mortality risk persisted across etiologic groups. HT survival was similar in the current surgical era for HLHS with surgery, 71% (1993-1998) vs 70% (1999-2008).nnnCONCLUSIONSnInfant HT recipients with different pre-HT diagnoses have significantly different post-HT outcomes. HLHS infants with surgery have the lowest survival and their outcome is unchanged in the current era.

Infection and malignancy after pediatric heart transplantation: The role of induction therapy

BACKGROUNDnVariable rates of malignancy and early infection have previously been reported in heart transplant (HTx) recipients who received induction therapy. This study hypothesized that induced pediatric patients would have an increased risk of these events compared with non-induced patients.nnnMETHODSnData from a prospective, multicenter event-driven registry of outcomes after HTx listing in patients aged < 18 years was used to analyze risks of infection and malignancy and their association with induction between January 1993 and December 2007.nnnRESULTSnOf 2,374 patients, 1,258 (53%) received induction and more frequently from 1999 to 2008 compared with 1993 to 1998 (70.8% vs 57.5%, p < 0.001). At HTx, induced patients were more likely to have congenital heart disease (56.9% vs 48.1%, p < 0.001) but no more likely to be positive for Epstein-Barr virus (50.3% vs 51.4%, p = 0.67). Post-transplant lymphoproliferative disease (PTLD) was the most common malignancy (n = 92) within 5 years of HTx. Patients who received induction had a lower risk for PTLD (hazard ratio [HR], 0.5; 95% confidence interval [CI], 0.3-0.84; p = 0.009) and early fungal infections (HR, 0.60; 91% CI, 0.40-0.91; p = 0.016). Among induction agents used, OKT3 was associated with lowest freedom from PTLD and fungal/cytomegalovirus infection.nnnCONCLUSIONSnInduction use has increased since 1999 and has not been associated with an increased risk of malignancy (predominantly PTLD) or overall infection. Because these adverse events occurred with higher rates in non-induced patients, it is likely that induction alone is not the primary risk determinant for PTLD and infection.

Cytokine response after severe respiratory syncytial virus bronchiolitis in early life

BACKGROUNDnImmune response after viral infection usually involves T(H)1-mediated response; however, severe respiratory syncytial virus (RSV) infection appears to be associated with the development of asthma, a T(H)2-predominant phenotype.nnnOBJECTIVEnTo understand the early and subsequent immunologic response to a serious RSV infection in children over time.nnnMETHODSnA total of 206 previously healthy infants hospitalized with severe RSV bronchiolitis were enrolled in a prospective cohort called the RSV Bronchiolitis in Early Life study. Peripheral blood T cells were obtained immediately after RSV infection and at 2, 4, and 6 years of age, stimulated with phorbol 12-myristate 13-acetate and ionomycin, and analyzed for IL-2, IL-4, IL-13, and IFN-gamma by flow cytometry and real-time PCR.nnnRESULTSnOf the children, 48% (n = 97) developed asthma (physician-diagnosed), and 48% (n = 97) had eczema by age 6 years; 32% (n = 48 of 150) developed allergic sensitization by 3 years of age. Children with asthma had lower IL-13 expression at 6 years of age than those without (P = .001). IFN-gamma, IL-2, and IL-4 levels did not differ by asthma or eczema status during follow-up (all P > .05). Allergic sensitization was not associated with differences in cytokine levels during follow-up (all P > .05).nnnCONCLUSIONnSevere RSV infection early in life is associated with a high incidence of asthma and eczema. Contrary to expectations, subsequent immunologic development in those who developed asthma, eczema, or allergic sensitization was not associated with a T(H)2 phenotype in the peripheral blood.

ABO-incompatible heart transplantation: Analysis of the Pediatric Heart Transplant Study (PHTS) database

BACKGROUNDnABO incompatible (ABOi) heart transplantation is an accepted approach to increasing organ availability for young patients. Previous studies have suggested that early survival for ABOi transplants is similar to ABO compatible (ABOc) transplants. We analyzed the Pediatric Heart Transplant Study (PHTS) database from 1/96 to 12/08 to further assess this strategy.nnnMETHODSnWe analyzed the numbers of ABOi and ABOc done at the PHTS centers. We then compared the clinical characteristics, and short-term freedom from death, rejection and infection in the ABOi patients with the patients that had an ABOc heart transplant during the same period. All patients were less than or equal to 15 months of age at listing (the age of the oldest ABOi patient). We adjusted for co-variates shown to increase risk for mortality (age less than 1 month, extracorporeal membrane oxygenation (ECMO), ventilator, previous sternotomy, and congenital heart disease).nnnRESULTSnThere were 931 total transplants done at 34 PHTS centers during the 12 year time period in patients ≤15 months of age. Of these, 502 transplants were performed at 20 PHTS centers that did at least one ABOi heart transplant. Eighty-five of the 502 (17%) were ABOi. At time of transplant, ABOi recipients compared with ABOc were more likely to be on a ventilator (49.4% vs 36.5%, p=0.025), and more often supported with ECMO (23.5% vs 13.4%, p=0.018). There was similar survival at 12 months (82% vs 84%, p=0.7). In risk adjusted analysis ABOi status was not associated with 1 year mortality (HR 0.85, 95% CI 0.45-1.6, p=0.61). The ABOi patients had greater freedom from rejection when compared with ABOc patients for all 34 centers (75% vs 62%, p=0.016), but the difference was not significant when limited only to the 20 centers doing ABOi transplants (75% vs 69%, p=0.4). The ABOi cohort had lower infection rates (23.5% vs 37.9%, p = 0.013). This difference remained after adjusting for center and other covariates.nnnCONCLUSIONSnIn center and risk adjusted analysis, young children who received an ABOi transplant had equivalent one-year survival and freedom from rejection compared with those who received an ABOc transplant. In spite of the favorable outcome for ABOi recipients, many centers appear to reserve ABOi transplantation for sicker patients. These data mandate reexamination of the current United Network for Organ Sharing (UNOS) policy that gives priority to ABOc over ABOi transplantation in the United States.

Rejection with hemodynamic compromise in the current era of pediatric heart transplantation: a multi-institutional study.

BACKGROUNDnSurvival after pediatric heart transplant has improved over time, as has the incidence of overall rejection. We studied the effect of era on the occurrence and outcome of rejection with hemodynamic compromise (HC).nnnMETHODSnData from 2227 patients who received allografts between 1993 and 2006 at 36 centers in the Pediatric Heart Transplant Study were analyzed to determine incidence, outcome, and risk factors for rejection with HC in early (1993-1999) and recent (2000-2006) eras. Rejection with HC was classified as severe (RSHC) when inotropes were used for circulatory support and mild (RMHC) when inotropes were not used.nnnRESULTSnOf 1217 patients with any episode of rejection, 541 had rejection with HC. Freedom from RMHC improved at 1 year (81% vs 90%, p < 0.001) and at 5 years (74% vs 85%, p < 0.001) in the early vs recent eras, but freedom from RSHC was similar between eras (93% vs 95% at 1 year and 85% vs 87% at 5 years, p = 0.24). Survival after RSHC (63% at 1 year and 49% at 5 years) was worse than after RMHC (87% at 1 year and 72% at 5 years, p < 0.001) and did not change over time. Risk factors for RSHC were non-white race (hazard ratio [HR], 1.73; 95% confidence interval [CI], 1.29-2.32, p < 0.01), older age (HR, 2.85; 95% CI, 1.24-6.53; p = 0.01), and non-A blood type (HR, 1.51;, 95% CI, 1.11-2.04,; p = 0.01), but the only risk factor for RMHC was earlier era of transplant (HR, 1.94; 95% CI, 1.56-2.41; p < 0.001).nnnCONCLUSIONSnThe incidence of RMHC has declined over time but the same era effect has not occurred with RSHC. Close follow-up after RSHC is crucial because mortality is so high.

Risk Factors for Late Renal Dysfunction after Pediatric Heart Transplantation: A Multi-institutional Study

Feingold B, Zheng J, Law YM, Morrow WR, Hoffman TM, Schechtman KB, Dipchand AI, Canter CE and the Pediatric Heart Transplant Study Investigators. Risk factors for late renal dysfunction after pediatric heart transplantation: A multi‐institutional study.u2028Pediatr Transplantation 2011: 15: 699–705.

Has late rejection decreased in pediatric heart transplantation in the current era? A multi-institutional study

BACKGROUNDnLate (occurring >1 year) rejection (LR) has been shown to increase mortality and morbidity after pediatric heart transplantation (HTx). The incidence of rejection has decreased in the first year after pediatric HTx in the current era. We hypothesized a similar phenomenon has occurred with LR.nnnMETHODSnThe Pediatric Heart Transplant Study database was used to analyze the effects of era (1993 to 1998 vs 1999 to 2007) and other factors on the prevalence of LR and its relationship to mortality, moderate-severe coronary vasculopathy (CAV) and retransplantation.nnnRESULTSnFreedom from first LR (59% vs 69% 5-year post-HTx, p < 0.001) and recurrent LR (p < 0.001) was significantly lower in the current vs earlier era. LR was significantly (p < 0.001) associated with early rejection (ER; rejection <1 year post-HTx) in both eras. Independent risk factors for LR were: earlier era (hazard ratio [HR] 1.47, 95% confidence interval [CI] 1.25 to 1.73, p < 0.001); non-white race (HR 1.41; 95% CI 1.19 to 1.67, p < 0.001); older recipient age (HR 1.05, 95% CI 1.03 to 1.06, p < 0.001); recipient Status 2 at transplant (HR 1.21, 95% CI 1.01 to 1.45, p = 0.037); and male donor (HR 1.17; 95% CI 1.0 to 1.37, p = 0.055). Late rejectors had a similar higher risk of mortality (odds ratio [OR] 4.20, 95% CI 3.04 to 5.81, p < 0.001) and incidence of moderate-severe CAV or retransplantation (OR 2.63, 95% CI 1.78 to 3.90, p < 0.001) in both eras.nnnCONCLUSIONSnLR has decreased in the recent era in pediatric HTx recipients. Its effect on mortality and the development of CAV has not changed over time, suggesting an ongoing need for improved primary prevention strategies.

Outcomes after listing for primary transplantation for infants with unoperated-on non-hypoplastic left heart syndrome congenital heart disease: A multi-institutional study

BACKGROUNDnAlthough heart transplantation has been used as the primary therapy for congenital heart lesions in infants other than hypoplastic left heart syndrome (HLHS), the outcomes in this group of patients have not been determined.nnnMETHODSnWe used the Pediatric Heart Transplant Study database (1993 to 2006) to compare outcomes of 388 infants aged < 6 months listed for HLHS, 161 with other congenital heart diseases (non-HLHS), and 145 with cardiomyopathy in early (1993 to 1999) and recent (2000 to 2006) eras.nnnRESULTSnThe cardiomyopathy group was significantly (p < 0.001) different from the HLHS and non-HLHS groups at listing: more girls, older age, and a greater need for high-dose inotropes, mechanical ventilation, and/or mechanical circulatory support. Survival after listing was similar among the groups in the early era. Although outcomes after listing in HLHS and cardiomyopathy patients improved in the recent era, outcomes in non-HLHS patients did not. Survival at 1 and 5 years after listing was significantly worse (p < 0.001) for non-HLHS patients (51%, 48%) vs HLHS (71%, 61%), with age- and sex-adjusted hazard ratio (HR) of 1.79 (95% confidence interval, 1.15-2.77, p = 0.009) and CM (80%, 74%; HR, 2.72; 95% confidence interval, 1.59-4.67, p < 0.001) in the recent era. Post-transplant survival in both eras was not significantly different among the groups.nnnCONCLUSIONnUse of heart transplantation as primary therapy for non-HLHS infants has not improved over time and currently is associated with significantly poorer results vs HLHS and cardiomyopathy due to a higher risk for death before transplant.