Long-term follow-up including extensive complement analysis of a pediatric C3 glomerulopathy cohort

Marloes A.H.M. Michels*, Kioa L. Wijnsma, Roel A.J. Kurvers, Dineke Westra, Michiel F. Schreuder, Joanna A.E. van Wijk, Antonia H.M. Bouts, Valentina Gracchi, Flore A.P.T. Engels, Mandy G. Keijzer-Veen, Eiske M. Dorresteijn, Elena B. Volokhina, Lambertus P.W.J. van den Heuvel, Nicole C.A.J. van de Kar

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

12 Downloads (Pure)

Abstract

BACKGROUND: C3 glomerulopathy (C3G) is a rare kidney disorder characterized by predominant glomerular depositions of complement C3. C3G can be subdivided into dense deposit disease (DDD) and C3 glomerulonephritis (C3GN). This study describes the long-term follow-up with extensive complement analysis of 29 Dutch children with C3G.

METHODS: Twenty-nine C3G patients (19 DDD, 10 C3GN) diagnosed between 1992 and 2014 were included. Clinical and laboratory findings were collected at presentation and during follow-up. Specialized assays were used to detect rare variants in complement genes and measure complement-directed autoantibodies and biomarkers in blood.

RESULTS: DDD patients presented with lower estimated glomerular filtration rate (eGFR). C3 nephritic factors (C3NeFs) were detected in 20 patients and remained detectable over time despite immunosuppressive treatment. At presentation, low serum C3 levels were detected in 84% of all patients. During follow-up, in about 50% of patients, all of them C3NeF-positive, C3 levels remained low. Linear mixed model analysis showed that C3GN patients had higher soluble C5b-9 (sC5b-9) and lower properdin levels compared to DDD patients. With a median follow-up of 52 months, an overall benign outcome was observed with only six patients with eGFR below 90 ml/min/1.73 m 2 at last follow-up.

CONCLUSIONS: We extensively described clinical and laboratory findings including complement features of an exclusively pediatric C3G cohort. Outcome was relatively benign, persistent low C3 correlated with C3NeF presence, and C3GN was associated with higher sC5b-9 and lower properdin levels. Prospective studies are needed to further elucidate the pathogenic mechanisms underlying C3G and guide personalized medicine with complement therapeutics.

Original languageEnglish
Pages (from-to)601-612
Number of pages12
JournalPediatric Nephrology
Volume37
Issue number3
Early online date2 Sept 2021
DOIs
Publication statusPublished - Mar 2022

Keywords

  • C3 glomerulonephritis
  • C3 glomerulopathy
  • C3 nephritic factor
  • Children
  • Complement system
  • Dense deposit disease

Fingerprint

Dive into the research topics of 'Long-term follow-up including extensive complement analysis of a pediatric C3 glomerulopathy cohort'. Together they form a unique fingerprint.

Cite this