Serology-based subtypes of pediatric rapidly progressive glomerulonephritis and early changes in eGFR and KIM-1: a...

Pediatric rapidly progressive glomerulonephritis (RPGN) encompasses heterogeneous serology-based subtypes, including anti-glomerular basement membrane (anti-GBM), immune-complex-associated, and ANCA-associated (pauci-immune) RPGN. Although these subtypes differ in their underlying immune mechanisms, their ability to predict early renal recovery in children remains uncertain. This study aimed to evaluate the association between serology-based RPGN subtypes and early changes in renal function and tubular injury markers.

This prospective cohort study included 30 children with newly diagnosed RPGN treated at Dr. Soetomo General Hospital. Patients were classified into anti-GBM, immune-complex-associated, or ANCA-associated RPGN based exclusively on serologic criteria. Estimated glomerular filtration rate (eGFR) and serum kidney injury molecule-1 (KIM-1) were measured at baseline and at 3 months after induction therapy. Primary outcomes were changes in eGFR (ΔeGFR) and serum KIM-1 (ΔKIM-1). Differences among subtypes were assessed using multivariate analysis of variance.

Of the 30 patients, 67% had immune-complex-associated RPGN, 20% had ANCA-associated RPGN, and 13% exhibited anti-GBM disease. The median age was 15 years. No statistically significant differences in ΔeGFR or ΔKIM-1 were observed among subtypes (MANOVA, p = 0.506), although numerical improvements varied across groups.

Serology-based RPGN subtype was not associated with early improvement in glomerular filtration or reduction in tubular injury markers in pediatric RPGN. Early renal recovery may be influenced more by baseline disease severity and therapeutic responsiveness than by serologic subtype classification alone.