Concurrent use of continuous kidney replacement therapy during extracorporeal membrane oxygenation: what pediatric nephrologists need to know-PCRRT-ICONIC practice points.

Extracorporeal membrane oxygenation (ECMO) provides temporary cardiorespiratory support for neonatal, pediatric, and adult patients when traditional management has failed. This lifesaving therapy has intrinsic risks, including the development of a robust inflammatory response, acute kidney injury (AKI), fluid overload (FO), and blood loss via consumption and coagulopathy. Continuous kidney replacement therapy (CKRT) has been proposed to reduce these side effects by mitigating the host inflammatory response and controlling FO, improving outcomes in patients requiring ECMO. The Pediatric Continuous Renal Replacement Therapy (PCRRT) Workgroup and the International Collaboration of Nephrologists and Intensivists for Critical Care Children (ICONIC) met to highlight current practice standards for ECMO use within the pediatric population. This review discusses ECMO modalities, the pathophysiology of inflammation during an ECMO run, its adverse effects, various anticoagulation strategies, and the technical aspects and outcomes of implementing CKRT during ECMO in neonatal and pediatric populations. Consensus practice points and guidelines are summarized. ECMO should be utilized in patients with severe acute respiratory failure despite the use of conventional treatment modalities. The Extracorporeal Life Support Organization (ELSO) offers guidelines for ECMO initiation and management while maintaining a clinical registry of over 195,000 patients to assess outcomes and complications. Monitoring and preventing fluid overload during ECMO and CKRT are imperative to reduce mortality risk. Clinical evidence, resources, and experience of the nephrologist and healthcare team should guide the selection of ECMO circuit.

Systematic use of magnetic double J stent in pediatric kidney transplantation: A single-center experience.

BACKGROUND: The intraoperative insertion of a double J stent (DJS) is known to reduce urological complications and is broadly accepted in kidney transplant (KTx) patients. The magnetic ureteral DJS (mDJS) represents a valid alternative device as it can be removed without cystoscopy, using a transurethral magnet. This is of particular importance in the pediatrics, allowing us to avoid cystoscopy requiring general anesthesia (GA) in this population. To date, few data are available on the systematic use of mDJS in pediatric patients undergoing KTx. METHODS: We report a retrospective analysis of 32 consecutive pediatric KTx at our center from July 2020 to December 2021. RESULTS: Ureteral stents remained in place for a median of 35 days (range: 12-76). Non-surgical magnetic removal of the mDJS was attempted in all cases without complications. In most cases (69%), the removal procedure was performed in an outpatient clinic. In 10 cases, the mDJS was removed in the operating room under sedation before removal of the abdominal Tenckhoff catheter. All patients were clinically followed (range: 3-15 months). CONCLUSIONS: We confirm the safety and feasibility of systematic use of mDJS in the setting of pediatric KTx. The systematic use of this device contributes to reduce the need for GA and the rate of hospital admission.

Anemia after kidney transplantation.

Anemia is a frequent complication in pediatric kidney transplant recipients (KTR) with a variable reported prevalence estimated between 20 and 80% depending on how defined. Causes of and risk factors for post-transplantation anemia (PTA) are multifactorial with iron deficiency being the primary cause of early PTA (within the first 6 months after transplantation) and impaired glomerular filtration rate (GFR) commonly responsible for late PTA (after 6 months). Medications, viral infections, chronic inflammation, and comorbidities also play a role. PTA has relevant long-term consequences and is a potential risk factor for allograft dysfunction, cardiovascular morbidity, and mortality. Thus, an anemia evaluation, approximately 3 months post-transplantation, is recommended in order to start early treatment and improve prognosis. Iron status, vitamin B12, folate, markers of hemolysis, and viral PCR should be checked, and medications, in particular combinations of medications, should be carefully evaluated. PTA treatment may be challenging and should be directed to the underlying causes. Iron supplementation and erythropoietin therapy, not extensively used in KTR, may be indicated. Every effort should be made to avoid blood transfusions in the pre-transplant period to avoid allosensitization. Anemia should be corrected to prepare candidates for kidney transplantation in order to reduce the need for perioperative blood transfusions as well.

A simplified protocol of regional citrate anticoagulation with phosphate-containing solutions in infants and children treated with continuous kidney replacement therapy.

BACKGROUND: Regional citrate anticoagulation (RCA) is the preferred modality of anticoagulation used in continuous kidney replacement therapy (CKRT) in adults and less extensively in children. Potential metabolic complications limit widespread use in infants, neonates, and in children with liver failure. METHODS: We report our experience with a simplified protocol in 50 critically ill children, infants, and neonates, some of them with liver failure, with commercially available solutions containing phosphorous and higher concentration of potassium and magnesium. RESULTS: RCA allowed attainment of a mean filter lifetime of 54.5 ± 18.2 h, 42.5% of circuits lasted more than 70 h, and scheduled change was the most frequent cause of CKRT interruption. Patient Ca++ and circuit Ca++ were maintained in the target range with mean values of 1.15 ± 0.13 mmol/l and 0.38 ± 0.07 mmol/l, respectively. No session had to be stopped because of metabolic complications. The most frequent complications were hyponatremia, hypomagnesemia, and metabolic acidosis mostly related to primary disease and critical illness. No session had to be stopped because of citrate accumulation (CA). Transitory CA occurred in 6 patients and was managed without requiring RCA interruption. No patients with liver failure presented CA episodes. CONCLUSIONS: In our experience, RCA with commercially available solutions was easily applied and managed in critically ill children, even in patients with low weight or with liver failure. Solutions containing phosphate and higher concentrations of magnesium and potassium allowed reduction of metabolic derangement during CKRT. Prolonged filter life was ensured with no detrimental effects on patients and reduced staff workload. A higher resolution version of the Graphical abstract is available as Supplementary information.

The effects of hospital and dialysis unit characteristics on hospitalizations for access-related complications among children on maintenance dialysis: a European, multicenter, observational, cross-sectional study.

BACKGROUND: Previous studies investigating hospitalizations in dialysis patients have focused primarily on patient-centered factors. We analyzed the impact of hospital and dialysis unit characteristics on pediatric dialysis patients' hospitalizations for access-related complications (ARCs). METHODS: This cross-sectional study involved 102 hemodialysis (HD) and 163 peritoneal dialysis (PD) patients. Data between July 2017 and July 2018 were analyzed. RESULTS: Children's hospitals (CHs) had more pediatric nephrologists and longer PD experience (years) than general hospitals (GHs) (p = 0.026 and p = 0.023, respectively). A total of 53% of automated PD (APD) and 6% of continuous ambulatory PD (CAPD) patients were in CHs (p < 0.001). Ninety-three percent of APD and 69% of CAPD patients were treated in pediatric-specific PD units (p = 0.001). CHs had a higher prevalence in providing hemodiafiltration (HDF) than GHs (83% vs. 30%). Ninety-seven percent of HDF vs. 66% for conventional HD (cHD) patients, and 94% of patients with arteriovenous fistula (AVF) vs. 70% of those with central venous catheters (CVC), were dialyzed in pediatric-specific HD units (p = 0.001 and p = 0.016, respectively). Eighty patients (51 PD and 29 HD) had 135 (84 PD, 51 HD) hospitalizations. CAPD was an independent risk factor for hospitalizations for infectious ARCs (I-ARCs) (p = 0.009), and a health center's PD experience negatively correlated with CAPD patient hospitalizations for I-ARCs (p = 0.041). cHD and dialyzing in combined HD units significantly increased hospitalization risk for non-infectious (NI-)ARCs (p = 0.044 and p = 0.017, respectively). CONCLUSIONS: CHs and pediatric-specific dialysis units have higher prevalence of APD and HDF use. Hospitalizations for I-ARCs in CAPD are lower in centers with longer PD experience, and pediatric HD units are associated with fewer hospitalizations due to NI-ARCs. A higher resolution version of the Graphical abstract is available as Supplementary information.

Acute paediatric kidney replacement therapies in Europe: demographic results from the EurAKId Registry.

BACKGROUND: Acute kidney injury (AKI), particularly that requiring dialysis, is a severe complication in hospitalized children that is associated with high morbidity and mortality. A prospective European AKI registry (EurAKId registry, NCT02960867) was created to describe the epidemiology and outcomes of paediatric patients treated with acute dialysis. METHODS: Children were recruited who were between 0 and 18 years of age and were treated both in and outside the paediatric intensive care unit (PICU) with peritoneal dialysis (PD), haemodialysis (HD) or continuous kidney replacement therapy (CKRT) for AKI or metabolic derangement, fluid overload (FO), sepsis or respiratory distress. Five age groups and 12 categories of primary diseases were defined. RESULTS: Data on 340 patients were analysed, of whom 86% received dialysis for AKI and 14% for reasons other than AKI. Boys accounted for 60% of the patients. Illness severity was greater in children with cardiac and haematologic diseases than those with kidney diseases. Most patients received dialysis in the PICU (84%). The most frequently used dialysis modality was CKRT (64%), followed by PD (14%) and HD (14%). The overall survival rate was 65%. Survival was significantly lower in children with three comorbidities than in children with no comorbidities (41% and 83%; P < 0.001). CONCLUSIONS: The EurAKId registry is the first prospective registry considering paediatric acute kidney replacement therapies (KRTs) in both critical and non-critical care settings, focusing on the three dialysis modalities in Europe. The clinical indications for KRT have expanded; our population was characterized by critically ill patients, primarily boys, who frequently received dialysis in the PICU with CKRT.

Reversible glomerular damage in disseminated intravascular coagulation.

BACKGROUND: Brain death secondary to traumatic brain injury is one of the main sources of organs for transplantation but it can be associated with disseminated intravascular coagulation, which has been considered a relative contraindication for kidney donation. METHODS: We describe two successful pediatric cases of kidney transplantation from a single donor with disseminated intravascular coagulation. RESULTS: A 17-year-old male donor died from head injury and both kidneys were offered to our center. Within 24 h, donor's Hb and platelets dropped to 8.3 g/dl and 32 000/mcl, respectively, serum creatinine reached 2.01 mg/dl, and urinalysis showed proteinuria (300 mg/dl). Pre-implant biopsy showed massive occlusion of glomerular capillaries by fibrin thrombi containing fragmented red blood cells and inflammatory cells, and acute tubular damage. Arterioles and small arteries were spared. A diagnosis of DIC was made. The kidneys were transplanted in a 16-year-old girl and a 13-year-old boy. Slow recovery of graft function was observed in both recipients. On post-operative day 3, platelets dropped to a minimum value of 66 000 and 86 000/mcl, respectively. Diuresis was always present. On day 4, platelets started to rise. Six months later, both recipients attained normal renal function. A six-month protocol biopsy showed no microthrombi or other signs of disseminated intravascular coagulation. CONCLUSIONS: Despite the limited data available in literature, the outcome of these two cases is positive. Thus, pre-implant kidney biopsy, even if it reveals massive thrombotic occlusion of glomerular capillaries compatible with diagnosis of disseminated intravascular coagulation, should not be considered an absolute contraindication to transplantation.

Hemoperfusion with CytoSorb to Manage Multiorgan Dysfunction in the Spectrum of Hemophagocytic Lymphohistiocytosis Syndrome in Critically Ill Children.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition characterized by a state of hyperinflammation. Blood purification techniques can blunt the inflammatory process with a rapidly relevant nonselective effect on the cytokine storm, thus potentially translating into survival benefit for these patients. In this cohort, we evaluated the impact of hemoadsorption with CytoSorb combined with continuous kidney replacement therapy used as adjunctive therapy in 6 critically ill children with multiple organ dysfunction due to HLH. In our series, we found a reduction in inflammatory biomarkers in patients with HLH secondary to infection. Ferritin, one of the most important bedside biomarkers of HLH, showed a reduction in most of the treated patients. The same results were found measuring interleukin-6 and interleukin-10. The same patients showed hemodynamic stabilization measured by the Vasopressor-Inotropic-Score, and reduction in the organ disease score measured with the Pediatric Logistic Organ Dysfunction score. In our cohort, mortality was less than expected based on the Pediatric Index of Mortality 3 score at pediatric intensive care unit admission. Our study shows that hemoperfusion could be a valuable therapeutic option in HLH: stronger scientific evidence is needed to confirm our preliminary experience.

Ten-year trends in epidemiology and outcomes of pediatric kidney replacement therapy in Europe: data from the ESPN/ERA-EDTA Registry.

BACKGROUND: For 10 consecutive years, the ESPN/ERA-EDTA Registry has included data on children with stage 5 chronic kidney disease (CKD 5) receiving kidney replacement therapy (KRT) in Europe. We examined trends in incidence and prevalence of KRT and patient survival. METHODS: We included all children aged <15 years starting KRT 2007-2016 in 22 European countries participating in the ESPN/ERA-EDTA Registry since 2007. General population statistics were derived from Eurostat. Incidence and prevalence were expressed per million age-related population (pmarp) and time trends studied with JoinPoint regression. We analyzed survival trends using Cox regression. RESULTS: Incidence of children commencing KRT <15 years remained stable over the study period, varying between 5.5 and 6.6 pmarp. Incidence by treatment modality was unchanged over time: 2.0 for hemodialysis (HD) and peritoneal dialysis (PD) and 1.0 for transplantation. Prevalence increased in all age categories and overall rose 2% annually from 26.4 pmarp in 2007 to 32.1 pmarp in 2016. Kidney transplantation prevalence increased 5.1% annually 2007-2009, followed by 1.5% increase/year until 2016. Prevalence of PD steadily increased 1.4% per year over the entire period, and HD prevalence started increasing 6.1% per year from 2011 onwards. Five-year unadjusted patient survival on KRT was around 94% and similar for those initiating KRT 2007-2009 or 2010-2012 (adjusted HR: 0.98, 95% CI:0.71-1.35). CONCLUSIONS: We found a stable incidence and increasing prevalence of European children on KRT 2007-2016. Five-year patient survival was good and was unchanged over time. These data can inform patients and healthcare providers and aid health policy makers on future resource planning of pediatric KRT in Europe.

Resident foreign patients receive adequate dialysis but fewer preemptive transplantations: data from the Italian pediatric dialysis registry.

BACKGROUND: Sociocultural issues play a key role in children needing kidney replacement therapy (KRT). METHODS: Data of incident patients < 18 years treated with chronic dialysis or preemptive kidney transplantation (pTx) between 2007 and 2016 were retrospectively collected from the Italian Pediatric Dialysis Registry; KRT modality and outcome were compared between patients with at least one non-Italian parent ("resident foreign patients," RFPs) and those from native parents ("domestic patients," DPs) and between the quinquennium 2007-2011 (period 1) and 2012-2016 (period 2). RESULTS: We included 448 children (26.8% RFPs). The percentage of RFPs increased from 23 to 30.3% (p = 0.08) from periods 1 to 2. They were younger (6.7 vs. 9.4 years, p = 0.025) and less often treated with pTx (3.3 vs. 13.4%, p = 0.009) than DPs. The percentage of pTx increased from period 1 to 2 in RFPs only (8.4-18.6%, p = 0.006). Independent predictors of a lower probability of pTx were lower age, belonging to RFPs group, starting KRT in period 1 and focal segmental glomerulosclerosis or glomerulopathy as primary kidney disease. Peritoneal dialysis was the preferred dialysis modality in both groups. Age, primary kidney disease, and center size were independently associated with dialysis modality choice. Patient survival, waiting time to Tx, and dialysis modality survival were not different between the two groups. CONCLUSIONS: The proportion of patients receiving KRT born from immigrant families increased in recent years in Italy. They were younger and less often treated with pTx than domestic patients. In case of dialysis, the outcome was not different between the two groups. Graphical abstract.

Dialysis modalities for the management of pediatric acute kidney injury.

Acute kidney injury (AKI) is an increasingly frequent complication among hospitalized children. It is associated with high morbidity and mortality, especially in neonates and children requiring dialysis. The different renal replacement therapy (RRT) options for AKI have expanded from peritoneal dialysis (PD) and intermittent hemodialysis (HD) to continuous RRT (CRRT) and hybrid modalities. Recent advances in the provision of RRT in children allow a higher standard of care for increasingly ill and young patients. In the absence of evidence indicating better survival with any dialysis method, the most appropriate dialysis choice for children with AKI is based on the patient's characteristics, on dialytic modality performance, and on the institutional resources and local practice. In this review, the available dialysis modalities for pediatric AKI will be discussed, focusing on indications, advantages, and limitations of each of them.

Haemodiafiltration use in children: data from the Italian Pediatric Dialysis Registry.

BACKGROUND: High volume haemodiafiltration (HDF) is associated with better survival than conventional haemodialysis (HD) in adults, but data concerning its use in children are lacking. The aim of this study was to assess the prevalence of paediatric HDF use and its associated factors in recent years in Italy. METHODS: We retrospectively reviewed the files of patients from the Italian Pediatric Dialysis Registry's database who were registered between January 1, 2004 and December 31, 2016 and treated with extracorporeal dialysis for at least 6 months, looking in particular at modality and its associated factors. RESULTS: One hundred forty-one out of 198 patients were treated exclusively with bicarbonate HD (71.2%), 57 with HDF (28.8%). Patients treated with HDF were younger (median 9.7 vs 13.2 years, p = 0.0008), were less often incident patients (52.6% vs 75.9%, p = 0.0031), had longer duration of the HD cycle (26.9 vs 20.8 months, p = 0.0036) and had a longer time to renal transplantation (32 vs 25 months, p = 0.0029) than those treated with bicarbonate HD only. The percentage of patients treated with HDF increased with dialysis vintage (16.9% at 6 months, 38.1% after more than 2 years of dialysis). The use of HDF was stable over time and was more common in the largest centres. CONCLUSIONS: Over the observation period, HDF use in Italy has been limited to roughly a quarter of patients on extracorporeal dialysis, in particular to those with high dialysis vintage, younger age or a long expected waiting time to renal transplantation.

Protocol biopsies in pediatric renal transplantation: a precious tool for clinical management.

BACKGROUND: Kidney transplantation is the best treatment for children with end-stage kidney disease. Early results have improved, but late graft loss is still a major problem. Non-invasive, fully reliable early biomarkers of acute rejection are currently missing. METHODS: Our aim was to evaluate the efficacy of protocol biopsies (PBXs) in a pediatric population. During 11 years, 209 renal transplantations were performed in 204 pediatric patients. Biopsies were performed 3-6 months, 1 year, and 5 years after transplantation. Procedure-related complications were systematically looked for by means of ultrasound scans. RESULTS: Unexpected findings (mainly subclinical rejections) requiring therapeutic intervention were found in 19.3% biopsies performed at 3-6 months, in 18.4% in 12-month biopsies and in none of those performed after 5 years. The 13.6% patients at 12-month biopsies and 23.6% at 5-year biopsies showed calcineurin inhibitor (CNI) toxicity. Interstitial fibrosis and tubular atrophy (IF/TA) was found in 17.6 and 83.6% of patients at 12-month and 5-year biopsies, respectively. Complications of the PBX were infrequent. Five-year estimated glomerular filtration rate (GFR) was not significantly different in patients who received treatment for any cause and patients with normal histology. CONCLUSIONS: Although we do not have a control group, we may speculate that patients who received treatment returned to a "standard" condition possibly improving final outcome. Protocol biopsies are a powerful diagnostic tool for the management of pediatric renal transplant recipients. In view of the lack of evidence that biopsies taken 5 years after transplantation lead to any therapeutic change, their use should be reconsidered.

Renal transplantation in sensitized children and young adults: a nationwide approach.

Background: High levels of preformed anti-HLA antibodies dramatically diminish renal transplant outcomes. Most desensitization programmes guarantee good intermediate outcomes but quite disappointing long-term prognosis. The search for a fully compatible kidney increases time on the waiting list. Methods: In February 2011, a nationwide hyperimmune programme (NHP) was begun in Italy: all available kidneys are primarily proposed to highly sensitized patients with a panel reactive antibody above 80%. In this manuscript, we evaluate the outcome of paediatric patients transplanted with this approach. Results: Twenty-one patients were transplanted. Complete data are available for 20 patients. Mean age at transplantation was 14.5 years [standard deviation (SD) ± 5.5)]. Mean time on the waiting list was 29.3 months (SD ± 27.5). Median follow-up was 29.2 months (range: 11.2-59.3). The average number of HLA mismatches in these patients was 2.3 versus 3.7 in 48 standard patients transplanted in the same period (P < 0.001). Only one graft was lost. Two cases of humoral rejection occurred and were successfully treated. No cellular rejection was reported. Median creatinine clearance was 84, 88, 77 and 77 mL/min/1.73 m 2 respectively 1, 6, 12 and 24 months after transplant. Conclusions: Transplantation of sensitized patients avoiding prohibited antigens is feasible, at least in a selected cohort of patients. In order to be able to further improve this approach, which in our opinion is very successful, it would be necessary to expand the donor pool, possibly increasing the number of countries participating in the programme. In this series, time on the waiting list did not increase significantly. This allocation policy should ideally lead to an outcome comparable to that expected in standard patients, which is particularly desirable in young patients who have the longest life expectancy. Since long-term results of desensitization programmes are not (yet) convincing, we suggest that these programmes should be reserved for selected cases where compatible organs cannot be found within a reasonable time span.

Acute kidney transplant rejection mediated by angiotensin II type 1 receptor antibodies in a pediatric hyperimmune patient.

BACKGROUND: Several cases of severe antibody-mediated rejection (AMR) secondary to antibodies against the angiotensin II type 1 receptor (AT1R-Ab) have been described with variable outcome. CASE-DIAGNOSIS/TREATMENT: We report the case of a 13-year-old boy whose first kidney transplant failed due to steroid-resistant acute cellular rejection, with the subsequent development of sensitization. He received a second kidney transplant which was complicated by early humoral rejection, with weakly positive staining for the complement degradation product C4d. Test results were negative for donor-specific antibodies against human leukocyte antigens (HLA-DSA) and MHC class I-related chain A (MICA) but positive for AT1R-Ab. Retrospective testing of the sera collected during the first kidney transplant was also positive for AT1R-Ab. We therefore hypothesized that the failure of the first transplant was secondary to the same cause. Losartan was immediately introduced into the therapeutic regimen, and the patient showed an excellent clinical and histological recovery. CONCLUSIONS: Testing for AT1R-Ab in any hypertensive patient with acute rejection who tests negative or weakly positive for C4d and negative for HLA-DSA and who is refractory to therapy is highly advisable. Pre-transplant AT1R-Ab may be indicative of the outcome in patients whose first transplant failed. Prompt initiation of treatment with losartan-immediately after transplantation in patients with pre-existing AT1R-Ab-should be encouraged.

Viral load of EBV DNAemia is a predictor of EBV-related post-transplant lymphoproliferative disorders in pediatric renal transplant recipients.

BACKGROUND: Post-transplant lymphoproliferative disorder (PTLD) is a severe complication of solid organ transplantation that can be classified into two major subtypes, namely, early lesions and non-early lesions, based on histopathological findings. In the vast majority of cases, proliferating cells are B lymphocytes and, most frequently, proliferation is induced by Epstein-Barr virus (EBV) infection. METHODS: The aim of our study was to evaluate the natural history of EBV infection and its possible evolution toward PTLD in a pediatric cohort of patients who received a renal transplant between January 2000 and December 2013. A total of 304 patients were evaluated for this study, of whom 103 tested seronegative for EBV at transplantation. RESULTS: Following transplantation, 50 of the 103 seronegative patients (48.5%) developed a first EBV infection, based on the results of PCR assays for EBV DNA, with 19 of these patients ultimately reverting to the negative state (<3000 copies/ml). Among the 201 seropositive patients only 40 (19.9%) presented a reactivation of EBV. Non-early lesions PTLD was diagnosed in ten patients, and early lesions PTLD was diagnosed in five patients. In all cases a positive EBV viral load had been detected at some stage of the follow-up. Having a maximum peak of EBV viral load above the median value observed in the whole cohort (59,909.5 copies/ml) was a significant and independent predictor of non-early lesions PTLD and all PTLD onset. CONCLUSIONS: A high PCR EBV viral load is correlated with the probability of developing PTLD. The definition of a reliable marker is essential to identify patients more at risk of PTLD and to personalize the clinical approach to the single patient.

Continuous renal replacement therapy in children: fluid overload does not always predict mortality.

BACKGROUND: Mortality among critically ill children requiring continuous renal replacement therapy (CRRT) is high. Several factors have been identified as outcome predictors. Many studies have specifically reported a positive association between the fluid overload at CRRT initiation and the mortality of critically ill pediatric patients. METHODS: This study is a retrospective single-center analysis including all patients admitted to the pediatric intensive care unit (PICU) of our hospital who received CRRT between 2000 and 2012. One hundred thirty-one patients were identified and subsequently classified according to primary disease. Survival rates, severity of illness and fluid balance differed among subgroups. The primary outcome was patient survival to PICU discharge. RESULTS: Overall survival to PICU discharge was 45.8 %. Based on multiple regression analysis, mortality was independently associated with onco-hematological disease [odds ratio (OR) 11.7, 95 % confidence interval (CI) 1.3-104.7; p = 0.028], severe multiple organ dysfunction syndrome (MODS) (OR 5.1, 95 % CI 1.7-15; p = 0.003) and hypotension (OR 11.6, 95 % CI 1.4-93.2; p = 0.021). In the subgroup analysis, a fluid overload (FO) of more than 10 % (FO>10 %) at the beginning of CRRT seems to be a negative predictor of mortality (OR 10.9, 95 % CI 0.78-152.62; p = 0.07) only in children with milder disease (renal patients). Due to lack of statistical power, the independent effect of fluid overload on mortality could not be analyzed in all subgroups of patients. CONCLUSIONS: In children treated with CRRT the underlying diagnosis and severity of illness are independent risk factors for mortality. The degree of FO is a negative predictor only in patients with milder disease.

Cellular immune profile of kidney transplant patients developing anti-HLA antibodies during childhood.

BACKGROUND: In the field of kidney transplantation, identifying early signatures of humoral rejection is a key challenge. METHODS: We investigated the presence of anti-HLA antibodies and the distribution of lymphocyte subpopulations in 77 kidney-transplanted children and young adults compared to 23 healthy controls. Moreover, we tested whether the presence of anti-HLA antibodies could be related to modification in lymphocyte phenotype. Finally, we correlated the presence of anti-HLA antibodies and specific alteration of lymphocyte subsets with clinical outcomes. RESULTS: In kidney-transplanted children who developed anti-HLA antibodies, we observed an expansion of double-negative B cells (CD19 + CD27-IgD-), indicating premature aging of this compartment. Moreover, we reported signs of impaired B cell regulation, indicated by a higher IL-21R+ B cell frequency associated with an abnormal increase of follicular helper T cells. Finally, a considerable reduction in CD8+ effector T and invariant Natural killer T (NKT) cells was observed. The stability of graft function over time is significantly correlated with the frequency of peripheral effector CD4+ and CD8+ T cells and invariant NKT cells. CONCLUSIONS: This study supports the usefulness of lymphocyte subset as one of a spectrum of early diagnostic tools required to identify patients at risk of developing donor alloimmune response.