Background: Children with chronic kidney disease, including those treated with kidney transplantation (KT), have an increased risk of cardiovascular disease. The aim of this study was to examine the cardiopulmonary exercise capacity after KT compared to matched controls, to relate the results to physical activity, blood pressure and biochemical findings and to follow exercise capacity over time.Methods: Patients with KT (n = 38, age 7.7–18 years), with a mean time from transplantation of 3.7 years (0.9–13.0) and mean time in dialysis 0.8 years, were examined at inclusion and annually for up to three years. Healthy controls (n = 17, age 7.3–18.6 years) were examined once. All subjects underwent a cardiopulmonary exercise test, resting blood pressure measurement, anthropometry and activity assessment. Patients also underwent echocardiography, dual-energy X-ray absorptiometry (DXA), 24-h ambulatory BP measurements (ABPM), assessment of glomerular filtration rate (GFR) and blood sampling annually.Results: As compared to healthy controls, KT patients showed decreased exercise capacity measured both as VO2peak (34.5 vs. 43.9 ml/kg/min, p < 0.001) and maximal load (2.6 vs. 3.5 W/kg, p < 0.0001), similarly as when results were converted to z-scores. No significant difference was found in weight, but the KT patients were shorter and had higher BMI z-score than controls, as well as increased resting SBP and DBP z-scores. The patient or parent reported physical activity was significantly lower in the KT group compared to controls (p < 0.001) In the combined group, the major determinants for exercise capacity z-scores were activity score and BMI z-score (β = 0.79, p < 0.0001 and β = −0.38, p = 0.007, respectively). Within the KT group, low exercise capacity was associated with high fat mass index (FMI), low activity score, low GFR and high blood lipids. In the multivariate analysis FMI and low GFR remained predictors of low exercise capacity. The longitudinal data for the KT patients showed no change in exercise capacity z-scores over time.Conclusion: Patients with KT showed decreased exercise capacity and increased BP as compared to healthy controls. Exercise capacity was associated to GFR, physical activity, FMI and blood lipids. It did not improve during follow-up.

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Background Epstein-Barr virus (EBV) infections can induce post-transplant lymphoproliferative disorder (PTLD). A chronic high load (CHL), as indicated by long-term high EBV DNA levels after transplantation, has been associated with an enhanced risk of PTLD. We aimed to evaluate incidence, time of occurrence, risk factors, and outcome of EBV CHL carrier state after pediatric renal transplantation. Methods A retrospective study of 58 children aged 1-17 years (median 10), who underwent renal transplantation between January 2004 and June 2017 at a single medical center. EBV IgG antibodies in serum were analyzed before and yearly after transplantation. EBV DNA in whole blood were analyzed weekly for the first 3 months post-transplant, monthly up to 1 year and then at least once yearly. CHL was defined as EBV DNA ≥ 4.2 log 10 Geq/ml in > 50% of the samples during ≥ 6 months. Results At transplantation, 31 (53%) patients lacked EBV IgG and 25 (81%) of them developed primary EBV infection posttransplant. Of the 27 seropositive patients, 20 (74%) experienced reactivation of EBV. Altogether, 14 (24%) children developed CHL, starting at a median of 69 days post-transplant and lasting for a median time of 2.3 years (range 0.5-6.5), despite reduction of immunosuppression. Patients with CHL were younger and 11/14 were EBV seronegative at transplantation. No child developed PTLD during median clinical follow-up of 7.8 years (range 0.7-13). Conclusions CHL was frequent, long lasting, and occurred mainly in young transplant recipients. The absence of PTLD suggests that monitoring of EBV DNA to guide immunosuppression was effective.

AimRenal transplant patients are particularly susceptible to highly contagious diseases due to their reduced immunity. We studied transplant recipients to gauge their varicella zoster virus (VZV) serology status over time and the outcome of any VZV infections.MethodThis retrospective study comprised 85 children who underwent renal transplants in Gothenburg, Sweden, from 1986 to 2014, at a mean age of eight (1–18) years. The children's medical records were reviewed and 47 had the VZV infection pre‐transplant and 38 had been vaccinated pre‐transplant. Clinical outcomes were available for 85 children and serology results for 72.ResultsAt transplantation, the VZV seropositivity rate was 50% in the vaccination group and 94% in the infection group and the antibody titres were significantly lower in the vaccination group (p = 0.031). During the median follow‐up period of five years post‐transplant, 28% of the vaccinated children and 97% of the infection group remained seropositive and the varicella infection affected eight children: one in the infection group and seven in the vaccination group. The herpes zoster was observed in two children in the infection group.ConclusionThis study demonstrated that VZV vaccination protected from symptomatic infections to a lesser extent than natural infection, but provided effective protection from life‐threatening disease.