ESPN 53rd Annual Meeting

ESPN 2021


 
Lower incidence of idiopathic nephrotic syndrome in children in the Netherlands and Belgium between 2017-2019 and during the Covid-19 pandemic
FLOOR VELTKAMP 1 BAS VAN LIESHOUT 1 CARLIJN MUSSIES 1 DJERA KHAN 2 ELENA LEVTCHENKO 3 ANNA BAEL 4 SANDRINE FLORQUIN 2 ANTONIA BOUTS 1

1- AMSTERDAM UNIVERSITY MEDICAL CENTERS, UNIVERSITY OF AMSTERDAM, EMMA CHILDREN’S HOSPITAL, DEPARTMENT OF PEDIATRIC NEPHROLOGY, AMSTERDAM, THE NETHERLANDS
2- AMSTERDAM UNIVERSITY MEDICAL CENTERS, UNIVERSITY OF AMSTERDAM, DEPARTMENT OF PATHOLOGY, AMSTERDAM, THE NETHERLANDS
3- DIVISION OF PEDIATRIC NEPHROLOGY, UNIVERSITY HOSPITALS LEUVEN, LEUVEN, BELGIUM; DEPARTMENT OF DEVELOPMENT AND REGENERATION, KATHOLIEKE UNIVERSITEIT LEUVEN, LEUVEN, BELGIUM
4- ZNA QUEEN PAOLA CHILDRENS HOSPITAL, DEPARTMENT OF PEDIATRIC NEPHROLOGY, ANTWERP, BELGIUM
 
Abstract:

Background

Idiopathic nephrotic syndrome in children is a rare disease. In the Netherlands, the estimated incidence is 1.52 new cases per 100,000/ year (2006-2009). During the inclusion phase of an ongoing randomised controlled trial (LEARNS study), the number of new cases per year did not meet this estimate. Furthermore, during the Covid-19 pandemic, it seemed that even fewer new cases were identified, yet this needs to be confirmed. We hypothesise that the latter may be due to lower exposure to (viral) infections as a result of social distancing, school closings, and other lockdown measures.

 

Methods

Two separate online surveys were sent to all paediatricians in the Netherlands and Flanders, Belgium on two occasions: May 2020 and June 2021 (planned). Paediatricians were asked to report any case of new onset INS in a child (1-18 years) between January 2017 and December 2019 (survey 1) and March 2020 and March 2021 (survey 2). Census data were retrieved from the Dutch Centraal Bureau voor de Statistiek and the Belgian Statbel. Governmental websites were consulted for SARS-CoV-2 (sero)prevalence, Covid-19 hospital admissions, and lockdown measures. Incidence and corresponding confidence intervals (CIs) were calculated using the exact Poisson test. Incidences were compared using a proportion Z test.

Results

Between 2017 and 2019, the incidence of INS was estimated to be 1.14 (95% CI 0.94-1.37) and 1.12 (95% CI 0.82-1.52) per 100,000 children/year in the Netherlands and Belgium, respectively. The results of survey 2 will be available in September 2021.

Conclusion

The results of the first survey show that the incidence of INS in children is similar in the Netherlands and Belgium, but lower (-27%) than previously reported. A further decrease during the Covid-19 may point towards an infectious event as trigger for the onset of INS. The results will be presented during ESPN 2021.