Vaccination status in pediatric liver transplant candidates

Abstract:  Infection is a recognized and potentially serious complication in children following solid organ transplantation. This problem is particularly important for young children undergoing any organ transplantation who often have not completed standard childhood immunizations at the time of transplantation and who are therefore at risk for vaccine-preventable infections. To evaluate the vaccination status in liver transplant candidates, vaccination charts of 100 patients who were referred to Organ Transplant Center of Nemazee Hospital were reviewed and the vaccination status considered appropriate according to the recommendation of NIP and the patients' age. Fifty-eight percent of patients were completely vaccinated for HBV, 85% for OPV, 97% for BCG, 63% for DTP, and 58% of the patients were completely vaccinated for MMR. We concluded that the vaccination charts should be periodically reviewed and updated to prevent the vaccine-preventable disease in liver transplant candidates not only before but also after transplant. Every effort should be made to assure that candidates are immunized early in the course of their disease. Also it may be indicated to recommend a special guideline for immunization of liver transplant candidates and add other vaccines such as Haemophilus influenzae and Streptococcus pneumoniae vaccine to their vaccination program.     

血液系统疾病与移植后预防接种问题

<正>对于免疫功能正常的人群,疫苗接种的益处通常大于弊处。而常用疫苗的免疫原性在免疫功能低下患儿,特别是血液系统疾病及移植后患儿的应用始终面临争议和挑     

Tacrolimus vs. cyclosporine A as primary immunosuppression in pediatric renal transplantation: a NAPRTCS study

Using the North American Renal Transplant Cooperative Study (NAPRTCS) database, we performed a retrospective cohort study of 986 pediatric renal transplant recipients (index transplant 1997-2000) who were treated either with Cyclosporine A (CSA), Mycophenolate Mofetil (MMF) and steroids (n = 766) or tacrolimus (TAC), MMF and steroids (n = 220) to examine potential difference in clinical outcomes between these two groups. In the first year post-transplant, time to first rejection (29.1% vs. 29%, p = 0.840), risk for rejection [Adjusted Relative Risk (aRR) 1.01, 95% Confidence Interval (CI) 0.77, 1.323], graft survival (96.8% vs. 97.9%, p = 0.607) and risk for graft failure (aRR 0.988, 95% CI 0.64, 1.928) were not significantly different in TAC and CSA-treated patients. At 2 yr post-transplant, there was also no difference in risk for rejection (aRR 0.918, 95% CI 0.669, 1.259), graft survival (91.4% vs. 95.1%, p = 0.152) and risk for graft failure (aRR 0.702, 95% CI 0.461, 1.762) in the subset of 391 CSA-treated patients and 77 TAC-treated patients on whom 2 yr follow data were available in the database. TAC-treated patients were significantly less likely to require antihypertensive medication at 1 yr [aRR 0.74 (95% CI 0.454, 0.637)] and 2 yr post-transplant [aRR 0.67 (95% CI 0.56, 0.793)]. At 1 yr post-transplant, TAC-treated patients enjoyed a higher mean GFR as estimated by the Schwartz formula [89.1 mL/min/1.73 m(2) (SE 2.64) vs. 78.6 mL/min/1.73 m(2) (SE 1.07), p = 0.0003]. In addition, in the subset of patients with 2 yr of follow-up, TAC patients had a higher mean GFR at both 1 yr [98.6 mL/min/1.73 m(2) (SE 3.83) vs. 78.0 mL/min/1.73 m(2) (SE 1.44), p = 0.0003] and 2 yr post-transplant [96.7 mL/min/1.73 m(2) (SE 3.33) vs. 73.2 mL/min/1.73 m(2) (SE 1.48), p < 0.0001]. In summary, TAC and CSA, in combination with MMF and steroids, produce similar rejection rates and graft survival in pediatric renal transplant recipients. However, TAC is associated with improved graft function at 1 and 2 yr post-transplant. Further analysis as more patient data are obtained will be necessary to determine if this difference in graft function persists and translates into improved graft survival.     

Current immunosuppressive agents in pediatric renal transplantation: efficacy, side-effects and utilization

Advances in immunosuppressive therapy over the past decade have led to dramatic improvements in graft survival. The immunosuppression that is used is center-dependent and is constantly evolving with the development of new medications. The goal remains to find the best combination that will optimize graft survival, while minimizing the adverse effects.     

Liver transplantation in children with metabolic diseases: The studies of pediatric liver transplantation experience

Arnon R, Kerkar N, Davis MK, Anand R, Yin W, González‐Peralta RP for the SPLIT Research Group. Liver transplantation in children with metabolic diseases: The studies of pediatric liver transplantation experience.
Pediatr Transplantation 2010: 14:796–805. © 2010 John Wiley & Sons A/S. Abstract: Metabolic diseases are the second largest indication for LT in children after BA. There are limited data on the long‐term post‐transplant outcome in this unique group of patients. Therefore, our aim was to assess post‐liver transplant outcomes and to evaluate risk factors for mortality and graft loss in children with metabolic disorders in comparison to those with non‐metabolic diagnoses. We reviewed all patients enrolled in the SPLIT registry. Between 1995 and 2008, 446 of 2997 (14.9%) children enrolled in SPLIT underwent liver transplant for metabolic diseases. One‐yr and five‐yr patient survival for children with metabolic diseases was 94.6% and 88.9% and for those with other diseases 90.7% and 86.1% (log‐rank p = 0.05), respectively. One‐yr and five‐yr graft survival for children with metabolic disorders was 90.8% and 83.8%, and for those with other diseases 85.4% and 78.0% (log‐rank p = 0.005), respectively. Children with metabolic diseases were less likely to experience gastrointestinal complications (5.6% vs. 10.7%, p = 0.001), portal vein thrombosis (2.9% vs. 5.2%, p = 0.04), and reoperations within 30 days post‐transplant (33.4% vs. 37.8%, p = 0.05) than those with other indications. In conclusion, children who underwent liver transplant for metabolic disease had similarly excellent patient survival as, and better graft survival than, those who received a liver allograft for other indications.     

Psychosocial predictors of medication adherence in pediatric heart and lung organ transplantation

Few studies have identified the psychosocial characteristics of those children and their families associated with future non‐adherence to immunosuppressive medications following a heart or lung transplant. UNOS data and medical records information were used to test the association between patient and family psychosocial characteristics and medication adherence. Medication adherence outcomes were obtained using the physician assessments in the UNOS data and measured through patient‐level standard deviation scores of immunosuppressive medication blood levels. Complete data were collected on 105 pediatric heart and lung transplant recipients and their families. Multivariate, stepwise analyses were conducted with each adherence outcome. Physician reports of adherence were associated with age of the child at transplantation, parental education, two‐parent families, significant psychosocial problems, and the pretransplant life support status of the child. The resulting model (χ²=28.146, df=5, P<.001) explained approximately 39.5% of the variance in physician reports of adherence (Nagelkerke r²=.395). Blood level standard deviation scores were predicted by age at transplant (F=5.624, P=.02, r²=.05). Results point to the difficulties experienced by children and families when undergoing a heart or lung transplantation. Efforts to develop standardized and evidence‐based pretransplant psychosocial assessments in pediatric populations are suggested, especially those surrounding familial risk factors.     

Immunosuppression in the pediatric transplant recipient

The field of pediatric solid-organ transplantation has significantly evolved since its beginnings in the early 20^th century. As advancements have led to the development of innovative surgical techniques and novel medication regimens, transplantation has now become a routine practice leading to an increase in the rates of organ recipients worldwide.The care of pediatric solid-organ transplant recipients differs from adults in several areas not only due to technically challenging surgeries, but mostly due to the complexity of their immunosuppression management. Although there is large variation of pediatric immunosuppression regimens worldwide, the use of calcineurin inhibitors, either tacrolimus or cyclosporine, still forms the backbone of immunosuppression regimens after solid-organ transplantation. Both medications are relatively well tolerated but are known to have long-term side effects, especially nephrotoxicity and neurotoxicity. The goal of care in long-term pediatric survivors of solid-organ transplant now aims to safely minimize exposure to immunosuppression and to achieve long-term graft tolerance.     

Standard dosing of tacrolimus leads to overexposure in pediatric renal transplantation recipients

Abstract:  Tacrolimus dosage in pediatric RTRs is empirically based on weight. There is evidence that adolescents are at greater risk of toxicity than young children on this dosing regimen. We investigated the rate of tacrolimus overexposure within the first three wk post-transplantation in pediatric RTRs receiving tacrolimus 0.15 mg/kg twice daily. Of 63 RTRs studied, 41 (65.1%) experienced a tacrolimus level above the therapeutic range (supratherapeutic), the majority (48.8%) on days two to four post-transplant. Patients with supratherapeutic levels were older (14.2 vs. 9.9 yr, p = 0.016), taller (146.7 vs. 126.5 cm, p = 0.029), larger (1.36 vs. 1.01 m², p = 0.039) and heavier (44.1 vs. 29.3 kg, p = 0.043) and by day 12 were receiving much lower tacrolimus doses than those without supratherapeutic levels (0.425 vs. 0.198 mg/kg/day, p = 0.0002). Supratherapeutic levels were more common among white (British) children than other ethnic groups (74 vs. 45%, p = 0.02). There were no observed differences in rates of patient or graft survival, or acute rejection during the three-yr study period. Adolescent patients appear to be at greater risk of excessive tacrolimus dosing on a standard regimen. We therefore outline a regimen restricting tacrolimus dosage given to larger/older patients, but emphasize the need for a prospective randomized trial to define optimal dosing.     

Outcome of pediatric renal transplantation in north India

We report our experience and long-term outcome of pediatric renal transplantation at a referral center in New Delhi. During 1995-2008, 45 transplants were performed in 43 patients at a mean age of 13.3 ± 4.0 (range 3.8-18) yr. The chief causes for ESRD were reflux nephropathy, obstructive uropathy, vasculitis, renal dysplasia, and focal segmental glomerulosclerosis. Most (91.1%) donors were living related. Post-transplant immunosuppression comprised prednisolone, a calcineurin inhibitor and azathioprine or MMF. AR and CR were seen in 14 (31.1%) and 12 (26.7%) allografts, respectively. Predictors of CR were unsatisfactory compliance and multiple episodes of AR (p = 0.002 each). Urinary infections (n = 13), septicemia (4), tuberculosis (4), CMV disease (7), viral hepatitis (7), and pneumonia (3) were important causes of morbidity. Two patients each had lymphoproliferative disease and new-onset diabetes. There were eight (17.8%) graft losses and six (14%) deaths. The one-, five- and 10-yr graft survivals were 91.1%, 80.4% and 75.1%, respectively; the mean graft survival was 119.4 ± 8.38 months. The respective patient survivals were 95.3%, 87.9%, and 76.9% at one-, five- and 10 yr. Our results affirm that despite scarcity of resources and frequent infections, long-term outcomes of pediatric renal transplantation are highly satisfactory.     

Varicella vaccination in pediatric kidney and liver transplantation

Prelog M, Zimmerhackl LB. Varicella vaccination in pediatric kidney and liver transplantation.
Pediatr Transplantation 2010: 14: 41–47. © 2009 John Wiley & Sons A/S.
Abstract:  Reports about efficacy and safety of live-virus attenuated vaccines in patients before and after transplantation are mainly based on small patient numbers, making general recommendations for this patient population difficult. Children and adults as well as their close relatives and contact persons should be preferably immune to VZV before solid organ transplantation to avoid VZV-associated complications, thus making VZV vaccination necessary in susceptible individuals. The following literature review focused on efficacy and safety of VZV vaccination in pediatric kidney and liver transplant recipients. Review of literature also revealed that in all pediatric transplant candidates, humoral and cellular immunity against VZV should be consistently monitored to assess waning immunity under immunosuppressive treatment. This approach is desirable to estimate the risk of severe varicella disease after exposure in these patients.     

Hypertension and end-organ damage in pediatric renal transplantation

The prevalence of hypertension in pediatric patients with renal transplant (Tx) has not changed for the last three decades, remaining at 50-80%. Long-standing and uncontrolled hypertension is associated with the development of end-organ damage including allograft dysfunction, early cardiomyopathy and premature atherosclerosis. Aggressive treatment of elevated BP is an essential part of Tx care with the goal to delay graft failure and prevent the development of symptomatic cardiovascular disease in young recipients of renal Tx.     

Airway plaque presenting after alteration of immunosuppression in a pediatric patient remote from heart transplantation

Success after solid organ transplantation is dependent on the proper balance of immunosuppression to prevent rejection of the allograft while limiting the risk of developing infections and malignancy. We present a 9‐year‐old girl, remote from transplant, who presented with airway plaque after a change in immunosuppression to include the mTOR inhibitor sirolimus. Differential diagnosis included direct medication side effect, infection, and neoplasia.     

Isolated unilateral cytomegalovirus retinitis: A rare long‐term complication after pediatric liver transplantation

Squires JE, Sisk RA, Balistreri WF, Kohli R. Isolated unilateral cytomegalovirus retinitis: A rare long‐term complication after pediatric liver transplantation. Abstract: To highlight the rare yet devastating complication of CMV retinitis in a minimally immunosuppressed patient eight yr after liver transplantation for biliary atresia. A 22‐yr‐old female status‐post deceased donor liver transplant at age 13 secondary to biliary atresia receiving single agent immunosuppression presented with acute, unilateral, profound decrease in visual acuity. The patient was diagnosed to have acute onset unilateral CMV retinitis. Retinal examination uncovered classical appearance of retinal whitening and retinal hemorrhages with extensive macular involvement. CMV retinitis can occur as a late complication following liver transplantation. Additionally, CMV retinal disease can occur in the absence of laboratory evidence of CMV infection and independent of additional clinical features suggesting CMV disease. Currently, there is no standard of care regarding screening for CMV retinitis, and thus, further research is needed to define the need for potential changes in current clinical practices and post‐transplant screening protocols.