Comparative analysis of hospitalizations among patients treated with hemodialysis and peritoneal dialysis in European pediatric nephrology centers: results from a prospective EPDWG/ESPN Dialysis Working Group study

Background and hypothesis

Hospital admissions in pediatric dialysis patients need to be better studied, and most existing studies are retrospective and based on registry data. This study aimed to analyse and compare hospital admission rates, causes, length of stay (LOS), and outcomes in children treated with peritoneal dialysis (PD) and hemodialysis (HD).

Methods

Data from 236 maintenance PD and 138 HD patients across 16 European dialysis centers were collected between 1 July 2017 and 30 June 2018. A total of 178 hospitalized patients (103 PD, 75 HD) were included for further analyses.

Results

There were 465 hospitalization events (268 PD, 197 HD) with a rate of 0.39 admissions per 100 patient-days at risk (PDAR) and 2.4 hospital days per 100 PDAR. The admission rates were not significantly different between HD and PD patients. The most common causes of hospitalization were access-related infections (ARI) (17%), non-infectious complications of access (NIAC) (14%), and infections unrelated to access (12%). ARI was the leading cause in PD patients (24%), while NIAC was more common in HD patients (19%). PD patients had more ARIs, diagnostic procedures, and treatment adjustments (P < .05), while HD patients had more NIACs, infections unrelated to access, access placement procedures, and interventional/surgical procedures (P < .001). LOS was longer with acute admissions than non-acute admissions (P < .001). Overall LOS and LOS in the intensive care unit were similar between HD and PD patients. High serum uric acid and low albumin levels were significant predictors of longer LOS (P = .022 and P = .045, respectively). Young age, more significant height deficit, and older age at the start of dialysis were predictors of longer cumulative hospital days (P = .002, P = .001, and P = .031, respectively).

Conclusion

Access-related complications are the main drivers of hospitalization in pediatric dialysis patients, and growth and nutrition parameters are significant predictors of more extended hospital stays.

LAMB2 gene: broad clinical spectrum in Pierson syndrome

Pierson syndrome (PS) is a rare autosomal recessive disease, characterized by congenital nephrotic syndrome (CNS), and ocular and neurologic abnormalities. In affected cases, there is abnormal b-2 laminin which is compound of the several basement membranes caused by inherited mutations in the LAMB2 gene. Although patients have mutations in the same gene, the phenotype is highly variable. In this case series, the relationship between genotype and phenotype is emphasized, and information about the clinical follow-up of the patients is presented. Hereby, we report four pediatric cases with PS as a result of mutation in the LAMB2 gene. Clinical spectrum of LAMB2-associated disorders varies from mild-to-severe ocular, kidney, and neurologic involvement. Since genotype-phenotype correlation in PS has not been clearly demonstrated, we recommend that all patients with ophthalmic anomalies and glomerular proteinuria should be tested for LAMB2 mutations.

Impact of coronavirus disease-2019 on pediatric nephrology practice and education: an ESPN survey

BACKGROUND

Coronavirus disease-2019 (COVID-19) has been challenging for patients and medical staff. Radical changes have been needed to prevent disruptions in patient care and medical education.

METHODS

A web-based survey was sent to European Society for Pediatric Nephrology (ESPN) members via the ESPN mailing list to evaluate the effects of the COVID-19 pandemic on delivery of pediatric nephrology (PN) care and educational activities. There were ten questions with subheadings.

RESULTS

Seventy-six centers from 24 countries completed the survey. The time period was between the beginning of the pandemic and May 30, 2020. The number of patients admitted in PN wards and outpatient clinics were significantly decreased (2.2 and 4.5 times, respectively). Telemedicine tools, electronic prescriptions, online applications for off-label drugs, and remote access to laboratory/imaging results were used in almost half of the centers. Despite staff training and protective measures, 33% of centers reported COVID-19 infected staff, and 29% infected patients. Difficulties in receiving pharmaceuticals were reported in 25% of centers. Sixty percent of centers suspended living-related kidney transplantation, and one-third deceased-donor kidney transplantation. Hands-on education was suspended in 91% of medical schools, and face-to-face teaching was replaced by online systems in 85%. Multidisciplinary training in PN was affected in 54% of the centers.

CONCLUSIONS

This survey showed a sharp decline in patient admissions and a significant decrease in kidney transplantation. Telemedicine and online teaching became essential tools, requiring integration into the current system. The prolonged and fluctuating course of the pandemic may pose additional challenges necessitating urgent and rational solutions.

A Nationwide Retrospective Study in Turkish Children With Nephrocalcinosis

BACKGROUND

Nephrocalcinosis (NC) is defined as calcium deposition in the kidney parenchyma and tubules. This study aims to determine the etiology, risk factors and follow-up results of patients with NC in Turkey.

MATERIALS AND METHODS

Patients diagnosed with NC in the Pediatric Nephrology Department Units of 19 centers from all geographical regions of Turkey over a 10-year period (2010?2019) were included in the study. The medical records from the centers were reviewed and demographic data, admission complaints, medical history, systemic and genetic disorders, risk factors for NC, treatment details and presence of NC after one year follow-up were recorded retrospectively.

RESULTS

The study sample included 195 patients (88 females, 107 males). The mean age at diagnosis was 39.44±47.25 (0.5?208) months; 82/190 patients (43.2%) were diagnosed incidentally; 46/195 patients (23.6%) had an underlying disease; idiopathic hypercalciuria was detected in 75/195 (38.4%) patients. The most common systemic diseases were distal renal tubular acidosis in 11/46 patients (23.9%), primary hyperoxaluria in 9/46 patients (19.6%) and Bartter syndrome in 7/46 patients (15.3%). After one year of follow-up, NC resolved in 56/159 patients (35.2%) and they all did not have an underlying systemic disease.

CONCLUSION

The most common presentation of NC was incidental. Distal renal tubular acidosis and primary hyperoxaluria were the main systemic diseases leading to NC, while hypercalciuria was the most common metabolic risk factor. Nephrocalcinosis was found to remain in most of the patients at a one year follow-up. It may resolve particularly in patients with no underlying systemic disease.

Influence of Folate-Related Gene Polymorphisms on High-Dose Methotrexate-Related Toxicity and Prognosis in Turkish Children with Acute Lymphoblastic Leukemia

OBJECTIVE

High-dose methotrexate (HD-MTX) is widely used in the consolidation phase of childhood acute lymphoblastic leukemia (ALL), but the roles that polymorphisms in folate-related genes (FRGs) play in HD-MTX toxicity and prognosis in children with ALL are not understood. The aims of this study were to investigate the frequencies of polymorphisms in the genes for thymidylate synthase (TS), methionine synthase reductase (MTRR), and methylene tetrahydrofolate reductase (MTHFR) in Turkish children with ALL and to assess associations between these polymorphisms and HD-MTX-related toxicity and leukemia prognosis in this patient group.

MATERIALS AND METHODS

FRG polymorphisms were assessed by real-time polymerase chain reaction. Survival status, MTX levels, and toxicity data were retrieved from 106 patients' charts.

RESULTS

The allele frequencies for the FRG polymorphisms were as follows: TS 2R 41.0%, 3R 57.0%, and 4R 2.0%; MTRR 66A 42.4% and 66G 57.6%; MTHFR 677C 59.3% and 677T 40.7%; and MTHFR 1298A 58.1% and 1298C 41.9%. At the 48th hour of HD-MTX infusion, serum MTX was significantly higher in patients who had TS 2R/3R/4R variants as compared to those with wild-type TS (p<0.05). No significant differences were detected with respect to event-free survival or toxicity between wild-type and other FRG variants.

CONCLUSION

The frequencies of FRG polymorphisms in Turkish children with ALL are similar to those reported in other Caucasian populations. This is the first published finding of the TS 3R/4R variant in the Turkish population. The results indicate that HD-MTX can be tolerated by leukemic children with some polymorphic variants of FRG; thus, it may prevent future risk of leukemic relapse.

Relationship of Urothelial Gene Expressions in Urine-Deprived Bladders of Renal Recipients With Posttransplant Urinary Infections

OBJECTIVE

In this study, we analyzed gene expression levels of apoptotic (Fas, FasL, Bcl-2, Bax) and survival (CXCR1, CXCR2, IL-8) signal pathways of the urine-deprived bladder tissues and the relation of urinary tract infections with these pathways.

MATERIAL AND METHODS

We included 37 patients admitted for renal transplantation between December 2009 and December 2012. Bladder mucosal samples were obtained at the time of transplantation and 6-8 weeks posttransplantation, at the time of ureteral catheter removal. RNA extraction and cDNA synthesis were done using guanidium-thiocyanate and colon filter methods. Expression analysis was studied with quantitative real-time polymerase chain reaction optimized with ROX dye and internal control β-actin.

RESULTS

According to our findings Fas, FasL, Bcl-2, and Bax expression was higher in urine-deprived bladder samples than those in the posttransplant samples (P < .05). Although Fas, FasL, Bcl-2, and Bax expression levels increased in pretransplant samples, there was an increase in posttransplant bladder samples; however, this increase was not as marked as those of pretransplant samples. IL-8, CXCR1, and CXCR2 expression was decreased at the pretransplant samples and increased in posttransplant bladder samples.

CONCLUSIONS

We have found an upregulated apoptotic process and decreased survival signals at the urine-deprived bladder tissue. After transplantation, bladder tissue survival parameters were increased, demonstrating the importance of urinary flow for bladder tissue.