MO511: Epidemiology of Idiopathic Nephrotic Syndrome in Children Before and During Covid-19 Pandemic in Paris Area

BACKGROUND AND AIMS

The aetiology of idiopathic nephrotic syndrome (INS) remains partially unknown. Viral infections have been reported to be associated with INS onset and relapse. The COVID-19 pandemic led to several national lockdowns aimed at limiting virus transmission. In France, schools were closed during the first lockdown (15 March–11 May 2020). Circulation of other respiratory viruses was lower due to restrictive lockdown measures. We hypothesized that these lockdown measures would be associated with a decrease in the incidence of idiopathic nephrotic syndrome in children. The aim of this study was to describe the incidence of INS over the last 4 years and during the lockdown measures and to compare this incidence with the 2007–10 period (NEPHROVIR-1 cohort).

METHOD

A written questionnaire was sent to corresponding the paediatricians of all 37 hospitals in the Paris area. Children aged 1–15 years with INS onset between January 2017 and December 2020 and living in the Paris area were included. Clinical data were collected from medical charts. To estimate incidence, population-based denominators were obtained from the National Institute for Statistics and Economic Studies (INSEE). For analyses, we separated the study period into two periods: during lockdown measures (2 months) and the rest of the time (46 months).

RESULTS

A total of 95% of centres responded to the questionnaire. On the whole, 248 cases of INS were reported, 94% of whom were steroid sensitive. The median age at diagnosis was 5.6 years. Male/female ratio was 2.1: 1. Annual incidences of INS were 2.66, 2.49, 2.91 and 2.40/100 000 children under age 15 years in 2017, 2018, 2019 and 2020, respectively, with no significant difference between years. There was also no difference between annual incidence of the 2017–20 period and the NEPHROVIR-1 cohort period (2007–10) (P = .6). The incidence of INS during the lockdown measures was 0.51 versus 2.71 for the rest of the study period (P = .03). During week 15 (6–12 April 2020), with the highest number of hospital admissions for COVID-19, no case were reported.

CONCLUSION

Over the last decade, the incidence of childhood INS was stable in the Paris area. In 2020, no peak of incidence occurred concomitantly with the COVID pandemic. In addition, during lockdown measures, the incidence of INS was significantly lower. Interestingly, incidence of other respiratory viral infections was reported decreased during lockdown measures. Together, these results argue again for a link between INS onset and viral infections, while COVID-19 does not appear to be a significative trigger for nephrotic syndrome onset in children.

Association of Intravenous Immunoglobulins Plus Methylprednisolone vs Immunoglobulins Alone With Course of Fever in Multisystem Inflammatory Syndrome in Children

IMPORTANCE

Multisystem inflammatory syndrome in children (MIS-C) is the most severe pediatric disease associated with severe acute respiratory syndrome coronavirus 2 infection, potentially life-threatening, but the optimal therapeutic strategy remains unknown.

OBJECTIVE

To compare intravenous immunoglobulins (IVIG) plus methylprednisolone vs IVIG alone as initial therapy in MIS-C.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study drawn from a national surveillance system with propensity score-matched analysis. All cases with suspected MIS-C were reported to the French National Public Health Agency. Confirmed MIS-C cases fulfilling the World Health Organization definition were included. The study started on April 1, 2020, and follow-up ended on January 6, 2021.

EXPOSURES

IVIG and methylprednisolone vs IVIG alone.

MAIN OUTCOMES AND MEASURES

The primary outcome was persistence of fever 2 days after the introduction of initial therapy or recrudescence of fever within 7 days, which defined treatment failure. Secondary outcomes included a second-line therapy, hemodynamic support, acute left ventricular dysfunction after first-line therapy, and length of stay in the pediatric intensive care unit. The primary analysis involved propensity score matching with a minimum caliper of 0.1.

RESULTS

Among 181 children with suspected MIS-C, 111 fulfilled the World Health Organization definition (58 females [52%]; median age, 8.6 years [interquartile range, 4.7 to 12.1]). Five children did not receive either treatment. Overall, 3 of 34 children (9%) in the IVIG and methylprednisolone group and 37 of 72 (51%) in the IVIG alone group did not respond to treatment. Treatment with IVIG and methylprednisolone vs IVIG alone was associated with lower risk of treatment failure (absolute risk difference, -0.28 [95% CI, -0.48 to -0.08]; odds ratio [OR], 0.25 [95% CI, 0.09 to 0.70]; P = .008). IVIG and methylprednisolone therapy vs IVIG alone was also significantly associated with lower risk of use of second-line therapy (absolute risk difference, -0.22 [95% CI, -0.40 to -0.04]; OR, 0.19 [95% CI, 0.06 to 0.61]; P = .004), hemodynamic support (absolute risk difference, -0.17 [95% CI, -0.34 to -0.004]; OR, 0.21 [95% CI, 0.06 to 0.76]), acute left ventricular dysfunction occurring after initial therapy (absolute risk difference, -0.18 [95% CI, -0.35 to -0.01]; OR, 0.20 [95% CI, 0.06 to 0.66]), and duration of stay in the pediatric intensive care unit (median, 4 vs 6 days; difference in days, -2.4 [95% CI, -4.0 to -0.7]).

CONCLUSIONS AND RELEVANCE

Among children with MIS-C, treatment with IVIG and methylprednisolone vs IVIG alone was associated with a more favorable fever course. Study interpretation is limited by the observational design.

Human bocavirus: a cause of severe asthma exacerbation in children

Real-time polymerase chain reaction for human bocavirus (HBoV) was performed in nasopharyngeal aspirate specimens from 166 children over 2 years of age hospitalized for severe asthma exacerbation. Whereas HBoV was detected in 21 of these children (13%), it was found in only 1 of 50 ambulatory children with stable asthma (2%), suggesting a major role of HBoV in acute exacerbations in asthmatic children.

Motifs d'hospitalisation des patients atteints de varicelle dans un établissement pédiatrique parisien : évolution entre 1990 et 2001

AIMS OF STUDY

To describe the characteristics of paediatric varicella in patients admitted through the emergency department (ED) of the Armand-Trousseau Children hospital in Paris and the evolution of the causes of admission during the study period.

STUDY DESIGN

Retrospective longitudinal cohort study from March 1990 to February 2001.

RESULTS

One hundred and eight children were hospitalized for varicella during these 11 years. Sixty per cent were under 2 years of age and all but one were immunocompetent. The first cause of admission was the presence of at least 1 complication (83,3%) classified as: cutaneous (34%), digestive (19,8,%), respiratory (17,6%), neurological (15,3%) and ENT complications (8,8%). Over 11 years, the rate of overall complications remained stable but there was an important increase in varicella cases admitted through the ED mainly due to increase in cutaneous superinfections.

CONCLUSION

These data confirm the potential severity of varicella and underline the emerging problem of increasing cutaneous complications. Additional studies are necessary to address this phenomenon and to determine optimal prophylactic measures.