Decline in renal function following thoracic organ transplantation in children

Changes in estimated glomerular filtration rate over the first year following repeat heart transplant in children and young adults

BACKGROUND

Renal function is reduced in patients undergoing heart transplant due to hemodynamic compromise, cardiorenal syndrome, and nephrotoxin exposure. No current studies evaluate renal function in retransplants.

METHODS

We reviewed all heart transplants at our center from 1995 to 2021 and matched first-time heart transplants with retransplants, based on age at transplant, sex, and race. Estimated glomerular filtration rate (eGFR) was derived from CKiD-U25 calculator using creatinine and measured prior to transplant, 1-week post-transplant, 1-3, 6, and 12 months post-transplant, and recent follow-up. Changes in eGFR were measured within and between patients using a piecewise linear mixed effect model with matching. Exploratory univariate analysis was performed to evaluate pre-transplant risk factors for decreased eGFR.

RESULTS

The unmatched cohort included 393 heart transplant recipients, with 47 being retransplants. Thirty-eight patients in both groups with at least 1 year of follow-up underwent matching. Both retransplants and first-time transplants had an initial decline in eGFR. eGFR rebounded to baseline or above baseline at 1-3 months post-transplant, but eGFR in retransplants remained significantly lower. At 1-year post-transplant, the average eGFR was 67.8 ± 4.3 mL/min/1.73 m2 versus 104.7 ± 4.3 mL/min/1.73 m2 (p < .001) in the retransplants and first-time transplants group, respectively.

CONCLUSION

This study provides data on anticipated renal trajectory following retransplantation.

Cardiovascular Burden Is High in Pediatric Lung Transplant Recipients

BACKGROUND

Cardiovascular morbidity is common in adults after lung transplantation (LTx) but has not been described for pediatric LTx recipients. Early subclinical cardiovascular damage is reflected by increases in pulse wave velocity (PWV; indicating arteriosclerosis), intima-media thickness (IMT; indicating atherosclerosis), and left ventricular mass index (LVMI; indicating left ventricular hypertrophy).

METHODS

We annually assessed 47 pediatric LTx recipients in a prospective longitudinal study (144 observations, mean 3.1 visits/patient, range of 1-4 visits, mean follow-up 2.2 y).

RESULTS

At inclusion, increased PWV and IMT were detected in 13% and 30%, respectively, and elevated LVMI was detected in 33%. Higher PWV was associated with male sex, longer time since LTx, higher diastolic blood pressure, and lower glomerular filtration rate. Male sex and lower hemoglobin levels were associated with higher IMT, and the presence of diabetes was associated with higher LVMI.

CONCLUSIONS

Pediatric LTx recipients suffer from a high and sustained burden of subclinical cardiovascular damage. In light of improving long-term outcomes, cardiovascular morbidity needs to be addressed. Our analysis identified classical and nonclassical risk factors to be associated with the measures for cardiovascular damage, which could serve as targets for intervention.

Cardiorenal Syndrome

Cardiorenal syndrome (CRS) describes a specific acute and chronic clinical picture in which the heart or the kidney are primarily dysfunctioning and secondarily affect each other. CRS is divided into five classes: acute and chronic CRS, acute and chronic renocardiac syndromes, and secondary dysfunction of heart and kidneys. This article specifically details the classification and the epidemiology, some risk factors, and the pathophysiology of CRS. Some emerging aspects of CRS are also discussed, such as CRS in patients with end-stage heart failure, with mechanical ventricular assistance, and after heart transplantation. Finally, some aspects of pediatric CRS are detailed.

Calcineurin inhibitor- and corticosteroid-free immunosuppression in pediatric heart transplant patients

Pediatric heart transplant patients at our institution are immunosuppressed with a CNI and another immune-modulating agent without utilizing corticosteroids. Patients whose renal function worsened and who did not respond to CNI minimization had their CNI discontinued. The clinical history of 35 pediatric heart transplant patients with significant renal insufficiency whose CNI was discontinued was retrospectively analyzed. Data including serum creatinine and weight were collected before, at time of, and every 3-6 months after CNI discontinuation. This was used to calculate an eGFR. Cardiac allograft rejection and mortality data were also collected. CNI discontinuation occurred 39 times in 35 patients. The median eGFR significantly increased by 14 mL/min 3 months after CNI discontinuation and the increase continued to be significant (P≤.05) at 5 years. Freedom from rejection analysis showed no difference between graft rejection 2 years before versus after CNI discontinuation (P=.437). No mortality was associated with CNI discontinuation. Immunosuppression free of CNIs and corticosteroids appears to be a safe alternative in pediatric heart transplant patients with significant renal insufficiency. Furthermore, this strategy can significantly reverse renal insufficiency, even late after transplantation.

Acute Kidney Injury and Cardiorenal Syndromes in Pediatric Cardiac Intensive Care

OBJECTIVES

The objectives of this review are to discuss the definition, diagnosis, and pathophysiology of acute kidney injury and its impact on immediate, short-, and long-term outcomes. In addition, the spectrum of cardiorenal syndromes will be reviewed including the pathophysiology on this interaction and its impact on outcomes.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSION

The field of cardiac intensive care continues to advance in tandem with congenital heart surgery. As mortality has become a rare occurrence, the focus of cardiac intensive care has shifted to that of morbidity reduction. Acute kidney injury adversely impact outcomes of patients following surgery for congenital heart disease as well as in those with heart failure (cardiorenal syndrome). Patients who become fluid overloaded and/or require dialysis are at a higher risk of mortality, but even minor degrees of acute kidney injury portend a significant increase in mortality and morbidity. Clinicians continue to seek methods of early diagnosis and risk stratification of acute kidney injury to prevent its adverse sequelae.

Heart Retransplant Recipients Have Better Survival With Concurrent Kidney Transplant Than With Heart Retransplant Alone

BACKGROUND

Heart retransplant (HRT) recipients represent a growing number of transplant patients. The impact of concurrent kidney transplants (KTs) in this population has not been well studied. We tested the hypothesis that recipients of HRT with concurrent KT (HRT-KT) would have worse survival than recipients of HRT alone.

METHODS AND RESULTS

A retrospective analysis of the United Network of Organ Sharing database was performed for all patients undergoing HRT from 1987 to 2011. There were 1660 HRT patients, of which 116 (7%) received concurrent KT. Those who received HRT-KT had older age, longer wait-list time, worse kidney function, and more known diabetes. Survival among recipients of HRT-KT was significantly better than that of recipients of HRT alone (P=0.005). A subgroup of 323 HRT patients with severe kidney dysfunction (estimated glomerular filtration rate <30 mL/min per 1.73 m(2) or on dialysis) was studied in more detail, and 76 (24%) received concurrent KT. Those on dialysis at the time of HRT had better survival with versus without concurrent KT (P<0.0001). On multivariable analysis, concurrent KT was independently associated with better outcomes for all patients with HRT and for the subgroup of patients with severe kidney dysfunction.

CONCLUSIONS

Recipients of HRT-KT have better survival than recipients of HRT alone. Further research is needed to determine which HRT patients may benefit the most from concurrent KT.

Longitudinal renal function in pediatric heart transplant recipients: 20-years experience

This study was initiated to assess the temporal trends of renal function, and define risk factors associated with worsening renal function in pediatric heart transplant recipients in the immediate post-operative period. We performed a single-center retrospective study in children ≤18 yr receiving OHT (1993-2012). The AKIN's validated, three-tiered AKI staging system was used to categorize the degree of WRF. One hundred sixty-four patients qualified for inclusion. Forty-seven patients (28%) were classified as having WRF after OHT. Nineteen patients (11%) required dialysis after heart transplantation. There was a sustained and steady improvement in renal function in children following heart transplantation in all age groups, irrespective of underlying disease process. The significant factors associated with risk of WRF included body surface area (OR: 1.89 for 0.5 unit increase, 95% CI: 1.29-2.76, p = 0.001) and use of ECMO prior to and/or after heart transplantation (OR: 3.50, 95% CI: 1.51-8.13, p = 0.004). Use of VAD prior to heart transplantation was not associated with WRF (OR: 0.50, 95% CI: 0.17-1.51, p = 0.22). On the basis of these data, we demonstrate that worsening renal function improves early after orthotopic heart transplantation.

Peri-operative kidney injury and long-term chronic kidney disease following orthotopic heart transplantation in children

Significant advances in cardiac intensive care including extracorporeal life support have enabled children with complex congenital heart disease and end-stage heart failure to be supported while awaiting transplantation. With an increasing number of survivors after heart transplantation in children, the complications from long-term immunosuppression, including renal insufficiency, are becoming more apparent. Severe renal dysfunction after heart transplant is defined by a serum creatinine level >2.5 mg/dL (221 μmol/L), and/or need for dialysis or renal transplant. The degree of renal dysfunction is variable and is progressive over time. About 3-10 % of heart transplant recipients will go on to develop severe renal dysfunction within the first 10 years post-transplantation. Multiple risk factors for chronic kidney disease post-transplant have been identified, which include pre-transplant worsening renal function, recipient demographics and morbidity, peri-transplant haemodynamics and long-term exposure to calcineurin inhibitors. Renal insufficiency increases the risk of post-transplant morbidity and mortality. Hence, screening for renal dysfunction pre-, peri- and post-transplantation is important. Early and timely detection of renal insufficiency may help minimize renal insults, and allow prompt implementation of renoprotective strategies. Close monitoring and pre-emptive management of renal dysfunction is an integral aspect of peri-transplant and subsequent post-transplant long-term care.

Renal function assessment in child and adolescent heart transplant recipients during routine cardiac catheterization

CKD identification after pediatric heart transplantation (PHT) is limited by inaccuracies in estimates of GFR. We hypothesized that GFR can be measured by a modified iohexol clearance protocol in PHT recipients and that the CKiD formula provides a better estimate of GFR than other estimating equations. A cross-sectional study of PHT recipients, ages 2-18 yr, undergoing coronary angiography was undertaken. The angiography dose of iohexol was divided by the area under the curve from three iohexol levels post-infusion to calculate GFR. Agreement between iGFR and multiple estimating equations (eGFR) was assessed. In 31 subjects, median age was 15.0 yr (IQR 7.6, 16.6). Mean iGFR was 93.8 (s.d. 22.5) mL/min/1.73 m(2) ; 16 (52%) had an iGFR <90 mL/min/1.73 m(2) . The full CKiD formula (mean eGFR 88.9, s.d. 14.9) had low bias (-5.0), narrowest 95% limits of agreement (-42.0, 32.1), highest 30% (94%) and 10% (52%) accuracy, and highest correlation coefficient (0.576) relative to iGFR. We describe a novel modified iohexol clearance method to assess GFR after PHT. Over half of the cohort had an iGFR <90, suggesting CKD. The full CKiD formula performs best with respect to bias, accuracy, and correlation.

Incidence, risk factor, and prognosis of end-stage renal disease after heart transplantation in Chinese recipients

BACKGROUND/PURPOSE

End-stage renal disease (ESRD) is an important complication arising after heart transplantation. At least 3-10% of recipients reach ESRD within 10 years after transplant. The incidence of ESRD in Chinese recipients has not been reported. Here we sought to assess the incidence, prognosis, and risk factors for ESRD in Chinese recipients.

METHODS

We conducted a retrospective analysis of 248 heart recipients who survived >1 year from 1998 through 2007. ESRD was defined as the requirement of maintenance dialysis.

RESULTS

Renal dysfunction was present in 20 patients (8%) prior to transplant. With a follow-up duration of 5.8 ± 3.9 years, 30 patients developed ESRD. The cumulative incidence of ESRD after heart transplantation was 2.1% ± 0.9%, 6.5% ± 1.8%, 16.8% ± 3.3%, and 36.5% ± 9.5% at 2, 5, 10, and 15 years after transplant, respectively. Median onset of ESRD was 6.9 years after transplant. Actuarial survival after dialysis was 74.8% ± 8.3%, 66.6% ± 9.2%, and 43.6% ± 12.6% at 1, 2, and 5 years, respectively. Independent risk factors for ESRD included pretransplant serum creatinine (hazard ratio, 1.84; p = 0.001), presence of diabetes prior to transplant (hazard ratio, 2.51; p = 0.017), and old age at transplant (hazard ratio, 1.05; p = 0.008).

CONCLUSION

There was a high incidence of ESRD in Chinese heart recipients. Patients with ESRD had poor prognosis after dialysis.

Risk factors for late renal dysfunction after pediatric heart transplantation: a multi-institutional study

Renal dysfunction is a major determinant of outcome after HTx. Using a large, multi-institutional database, we sought to identify factors associated with late renal dysfunction after pediatric HTx. All patients in the PHTS database with eGFR ≥60 mL/min/1.73 m(2) at one yr post-HTx (n = 812) were analyzed by Cox regression for association with risk factors for eGFR <60 mL/min/1.73 m(2) at >1 yr after HTx. Freedom from late renal dysfunction was 71% and 57% at five and 10 yr. Multivariate risk factors for late renal dysfunction were earlier era of HTx (HR 1.84; p < 0.001), black race (HR 1.42; p = 0.048), rejection with hemodynamic compromise in the first year after HTx (HR 1.74; p = 0.038), and lowest quartile eGFR at one yr post-HTx (HR 1.83; p < 0.001). Renal function at HTx was not associated with onset of late renal dysfunction. Eleven patients (1.4%) required chronic dialysis and/or renal transplant during median follow-up of 4.1 yr (1.5-12.6). Late renal dysfunction is common after pediatric HTx, with blacks at increased risk. Decreased eGFR at one yr post-HTx, but not at HTx, predicts onset of late renal dysfunction. Future research on strategies to minimize late renal dysfunction after pediatric HTx may be of greatest benefit if focused on these subgroups.

Pharmacology of immunosuppressive medications in solid organ transplantation

The multitude of immunosuppressants available for solid organ transplantation allows for many combinations of immunosuppressive therapies that can be tailored to a patient’s specific lifestyle and immunosuppression needs. Newer agents currently being studied offer even more possibilities for the future to further reduce the incidence of acute rejection and prolong graft and patient survival.

Adverse effects of immunosuppression in pediatric solid organ transplantation

Solid organ transplantation is a life-saving treatment for end-stage organ failure in children. Immunosuppressant medications are used to prevent rejection of the organ transplant. However, these medications are associated with significant adverse effects that impact growth and development, quality of life (QOL), and sometimes long-term survival after transplantation. Adverse effects can differ between the immunosuppressants, but many result from the overall state of immunosuppression. Strategies to manage immunosuppressant adverse effects often involve minimizing exposure to the drugs while balancing the risk for rejection. Early recognition of immunosuppressant adverse effects may help to reduce morbidities associated with solid organ transplantation, improve QOL, and possibly increase overall patient survival.

The profile of renal function over time in a cohort of pediatric heart transplant recipients

To assess the burden over time of renal dysfunction in pediatric heart transplant patients using an objective measure on an annual basis for serial comparison. GFR was measured at regular interval by nuclear medicine scintigraphy. Results were analyzed in relation to age, time post-transplantation, gender, and average calcineurin-inhibitor dose for the first two months post-transplantation. Results were compared with cGFR using the Schwartz equation. A total of 91 patients (56 males) transplanted between 1990 and 2004 underwent 373 GFR measurements. Median age at transplantation was 3.3 yr (birth - 17.8). Median first GFR at 0.7 yr (0.1-4.1) post-transplant was normal (94 mL/kg/1.73 m(2)). Freedom from at least mild renal insufficiency was 84% and 33% at one and five years post-transplant. Females had better renal function early post-transplant (GFR 105 mL/min/1.73 m(2)) but an increased probability of an abnormal GFR over time. Higher calcineurin inhibitor dose in the first two months post-transplantation was associated with an increasing probability of an abnormal GFR over time. The cGFR overestimated the measured GFR by 33 +/- 26 mL/kg/1.73 m(2). Renal insufficiency is an important morbidity after pediatric transplantation with the majority of patients experiencing at least mild renal dysfunction. Calculated GFR significantly underestimates the burden of renal insufficiency in this patient population.

Successful renal transplantation following lung transplantation: a survey of the first Hungarian case

A tüdőtranszplantáció széles körben elfogadott kezelési lehetőség végstádiumú tüdőbetegek számára, akiknek a funkcionális státusza maximális kezelés mellett romlik. A szerzők egy fiatal betegük esetét ismertetik, aki végstádiumú idiopathiás tüdőfibrosis miatt Bécsben tüdőtranszplantáción esett át. Az elhúzódó, szövődményes posztoperatív szakban akut veseelégtelenség alakult ki, emiatt a beteg hemodialízisre szorult. Pulmonológiai szempontból teljes rehabilitációja valósult meg, és a rendszeres művesekezelés az opportunista fertőzések kialakulásának a kockázatát jelentős mértékben megnövelte, a beteg életminőségét is jelentősen rontotta, ezért négy évvel a tüdőtranszplantáció után vesetranszplantációra került sor Debrecenben. Ez az első magyar tüdőtranszplantált beteg, aki Magyarországon veseátültetésen is átesett. Több mint két évvel a vesetranszplantáció után a beteg kompenzáltan, rehabilitáltan él, légzésfunkciós értékei tovább javultak, és vesefunkciós paraméterei is kielégítőek. Az elmúlt évek során szignifikánsan megnövekedett a különböző szervtranszplantáción áteső betegek száma világszerte és hazánkban is. Ezeknél a betegeknél elsősorban az immunszuppresszív szerek, calcineurininhibitorok hatására számtalan szövődménnyel kell számolni. Kiemelendő a szekunder veseelégtelenség, amely mind akut, mind krónikus formában jelentkezhet, és akár vesetranszplantáció indikációját is képezheti. A veseátültetés kiváló kezelési lehetőség olyan végstádiumú vesebetegek számára, akik korábban más szervtranszplantáción estek át. A veseátültetés javítja az életminőséget, és a várható túlélést is növeli.

Pre-transplant Risk Factors for Chronic Renal Dysfunction After Pediatric Heart Transplantation: A 10-Year National Cohort Study

BACKGROUND

Chronic renal dysfunction may develop after pediatric heart transplantation (PHTx). We examined the incidence of end-stage renal disease (ESRD) and chronic renal insufficiency (CRI) after PHTx, the associated pre-transplant patient characteristics, and impact of renal disease on survival.

METHODS

Data sources included the Scientific Registry of Transplant Recipients, Centers for Medicare and Medicaid Services and the Social Security Death Master File. All PHTx recipients (age <18 years) in the USA from 1990 to 1999 who survived >1 year were included. ESRD was defined as long-term dialysis and/or kidney transplant. CRI was defined as creatinine >2.5 mg/dl, including those with ESRD. Relationships between pre-transplant characteristics and time to ESRD and CRI were analyzed using Cox proportional hazards models. The effect of renal disease on survival was analyzed using time-dependent Cox models.

RESULTS

During the mean follow-up of 7 years (range 1 to 14 years), 61 of 2,032 (3%) PHTxs developed ESRD. Ten-year actuarial risks for ESRD and CRI were 4.3% and 11.8%, respectively. In a multivariate analysis, significant risk factors for ESRD were: hypertrophic cardiomyopathy; African-American race; intensive care unit (ICU) stay or extracorporeal membrane oxygenation (ECMO) at time of transplant; and pre-transplant diabetes. Risk factors for CRI were: pre-transplant dialysis; hypertrophic cardiomyopathy; African-American race; and previous transplant. Adjusted risk of death in those who developed CRI was 9-fold higher than in those who did not (p < 0.0001).

CONCLUSIONS

After PHTx there is an increasing risk for CRI and ESRD over time. Recipients with the characteristics identified in this study may be at greater risk. Development of renal disease significantly increases the risk of post-transplant mortality.

The challenge of renal function in heart transplant children

Renal dysfunction may occur after pediatric heart transplantation and impacts on long-term prognosis. This study aims to review the incidence and mechanisms of chronic nephropathy following heart transplantation, and suggest therapeutic directions. The proportion of pediatric heart-transplant recipients with impaired renal function varies from 22 to 57%, and end-stage renal failure from 3 to 10%, depending on the method used for estimating the glomerular filtration rate. The pathophysiology of renal dysfunction is in part due to calcineurin inhibitor-induced renal vasoconstriction, through activation of the intrarenal renin-angiotensin system, TGF-beta1 upregulation and TGF-beta1 gene polymorphisms. Overproduction of angiotensin II, associated with angiotensin-converting-enzyme genotype, might be associated with poor prognosis and pharmacological factor gene polymorphisms, and may contribute to variation of calcineurine inhibitor exposure in the kidney. Strategies to prevent renal dysfunction include reducing calcineurine inhibitor exposure or delaying calcineurine inhibitor administration from the early post-transplant period. Calcium channel blockers and angiotensin-converting-enzyme inhibitors, blockade of angiotensin II, or anti-TGF-beta1 antibodies might limit nephrotoxicity. No accurate marker can predict the potential of renal lesions to develop. Lowering calcineurine inhibitors levels with immunosuppressive agents that are either less nephrotoxic or non-nephrotoxic should be formally studied. Of high interest is the impact of genetic polymorphism on the development of renal dysfunction.

Determinants of Renal Function in Pediatric Heart Transplant Recipients: Long-term Follow-up Study

BACKGROUND

Renal insufficiency (RI) is a known complication in heart transplant recipients. We sought to determine the prevalence and risk factors for RI in pediatric heart transplant recipients over a long-term follow-up period.

METHODS

The study cohort included 77 pediatric heart transplant recipients (35 girls, 18 African Americans) who had a minimum follow-up of 1 year. Data were obtained from pre-transplant evaluations and at 1, 6 and 12 months post-transplant and annually thereafter. Factors evaluated for their influence on renal function included duration of listing, age at transplant, gender, race, cardiac diagnosis, use of assist devices, inotropic support, rejection episodes and use of calcineurin inhibitors.

RESULTS

The median age at transplant was 2 years, with a median follow-up duration of 5.1 years. RI was prevalent in 33% pre-transplant, and in 17%, 21% and 25.9% at 1, 3 and 5 years post-transplant, respectively. Two patients developed end-stage renal disease requiring long-term dialysis, with 1 eventually receiving a renal transplant. Significant risk factors for RI were African-American race (p = 0.04), younger age at transplant (p = 0.007), duration of listing (p < 0.0001) and calcineurin inhibitor level (p = 0.003). RI at 6 months post-transplant predicted chronic kidney disease at 5 years (odds ratio = 9).

CONCLUSIONS

The prevalence of RI increased during a median follow-up of 5 years in this pediatric heart transplant cohort. African-American race, younger age at transplant, longer duration of listing, high level of calcineurin inhibitors and RI at 6 months were important determinants of RI. These patients should be followed-up carefully with early referral to a pediatric nephrologist if they develop chronic kidney disease.

Long-term renal function in heart transplant children on cyclosporine treatment

Renal function deterioration is a reason of concern in heart transplantation. Our aim was to evaluate long-term renal function in heart transplant children on cyclosporine (CsA) treatment and to investigate the effect of several variables possibly involved in renal function deterioration. Creatinine clearances were retrospectively reviewed in 50 children (median follow 99.7 months after heart transplant). Gender, age, and body weight at transplant, rejection episodes, CsA cumulative dose, and trough levels were analyzed. After an initial increase of the glomerular filtration rate (GFR), renal function worsened in most patients; 28% of the children developed renal insufficiency (defined as GFR <80 ml/min per 1.73 m2), which was already evident in the first 3 years. Neither CsA dose, trough levels, nor other patient characteristics were found to be associated with renal function deterioration. In this study renal failure occurred in one-third of the patients. The lack of association of CsA with renal insufficiency may be explained by several reasons, including the limitations of the retrospective design of the study. However, it is possible that the nephrotoxic effect of CsA is more likely to occur in a set of predisposed patients. These must be soon identified to evaluate early a calcineurin inhibitor-sparing strategy.

Progressive chronic kidney disease after pediatric lung transplantation

The development of chronic kidney disease (CKD) was evaluated in a large cohort of pediatric lung transplant recipients. Retrospective chart review identified 125 patients undergoing first lung transplant at St. Louis Children's Hospital and surviving 1 year. Mean age at transplant was 10.3 +/- 0.55 years, while mean time after transplant was 4.9 years. Serum creatinine nearly doubled from baseline 0.48 mg/dL +/- 0.02 (n = 125) to 0.87 mg/dL +/- 0.04 (n = 120) at 1 year, and tripled to 1.39 mg/dL +/- 0.15 (n = 23) by 7 years after transplant. The glomerular filtration rate (GFR), as estimated by the Schwartz formula, decreased from baseline 163 +/- 5.9 mL/min/1.73 m(2) (n = 109) to 88 +/- 2.5 (n = 104), reaching 69 +/- 9.0 (n = 6) by 10 years (p < 0.01). Seven patients developed end-stage kidney disease, and by 5 years after transplant, 38% of patients reached GFR < 60 mL/min. Older age at transplant and primary diagnosis of cystic fibrosis (CF) were both associated with decreased renal survival by Kaplan-Meier (KM) analysis. In summary, pediatric lung transplant recipients experience significant loss of renal function over time, as observed in other solid organ transplant recipients, and is most dramatic in adolescents.

Impact of TGFβ1 gene polymorphisms on late renal function in pediatric heart transplantation

Late renal dysfunction may affect long-term outcome of nonrenal transplant recipients. We hypothesized that transforming growth factor beta1 (TGFbeta1) might play a role in the fibrogenic mechanisms leading to renal dysfunction. The aim was to determine whether TGFbeta1 gene polymorphisms are associated with renal outcome in pediatric heart recipients. Eighty-eight patients underwent a first heart transplantation at the age of 7.1 +/- 6.5 years, received tacrolimus-based immunosuppression, and were followed for > or =1 year (6.7 +/- 3.2 years). Creatinine clearance (CrCl; ml/mn/1.73 m2) was calculated (Schwartz) before transplant, then at 1 month, 6 months, and 1 year, and yearly up to 7 years. Impaired function was defined as CrCl <80 ml/mn/1.73 m2. Mean CrCl decreased from 120 +/- 53 ml/mn/1.73 m2 before transplant to 98 +/- 40, 96 +/- 37, 102 +/- 30, and 101 +/- 38 ml/mn/1.73 m2 at, respectively, 6 months and 1, 5 (n = 58), and 7 years (n = 33). The TGFbeta1 high-producer genotype had worse CrCl than intermediate and low producers at every time point, despite similar pretransplant CrCl (pretransplant = 120 +/- 53 vs 118 +/- 55 ml/mn/1.73 m2 [p = 0.8], 1 year = 92 +/- 38 vs 113 +/- 30 ml/mn/1.73 m2 [p = 0.03]) and similar tacrolimus levels. The TGFbeta1 high-producer genotype was associated with CrCl < 80 ml/mn/1.73 m2. The TGFbeta1 high-producer genotype is associated with renal dysfunction in pediatric heart recipients.

Osseous complications of pediatric transplantation

Adult stature and peak bone mass are achieved through childhood growth and development. Multiple factors impair this process in children undergoing solid organ transplantation, including chronic illness, pretransplant osteodystrophy, use of medications with negative impact on bone, and post-transplant renal dysfunction. While growth delay and short stature remain common, the most severe forms of transplant-related bone disease, fracture and avascular necrosis, appear to have become less common in the pediatric age group. Osteopenia is very prevalent in adult transplant recipients and probably also in pediatrics, but its occurrence and sequelae are difficult to study in these groups due to methodological shortfalls of planar densitometry related to short stature and altered patterns of growth and development. Although the effect on lifetime peak bone mass is not clear, data from adult populations suggest an elevated long-term risk of bone disease in children receiving transplants. Optimal management of pretransplantation osteodystrophy, attention to post-transplant renal insufficiency among both renal and non-renal transplant patients, reduction of steroid dose in select patients, and supplementation with calcium plus vitamin D during expected periods of maximal bone loss may improve bone health. Careful research is required to determine the role of bisphosphonate therapy in pediatric transplantation.