Background Membranoproliferative glomerulonephritis (MPGN) is a rare glomerular disorder characterized by immune complex or complement-mediated injury, often leading to nephrotic syndrome, hypertension, and progressive renal dysfunction. Its management remains challenging, particularly in pediatric patients with coexisting renal pathologies. Case presentation We report a case of an 11-years-old girl who presented with nephrotic syndrome, severe hypertension, and impaired renal function. Renal biopsy confirmed immune complex-mediated MPGN (IC-MPGN), and genetic testing revealed a homozygous, pathogenic missense PKHD1 variant (NM₁38694. 3: c. 4870C T; p. (Arg1624Trp), leading to a diagnosis of autosomal recessive polycystic kidney disease (ARPKD). Initial treatment with prednisolone and mycophenolate mofetil failed to halt disease progression, and the patient became dialysis dependent. Pegcetacoplan, a complement C3 inhibitor, was subsequently initiated. After 11 weeks of pegcetacoplan therapy, the patient achieved renal recovery and was successfully weaned from dialysis. Proteinuria decreased from nephrotic to sub-nephrotic levels without significant adverse effects. Conclusion To our knowledge, this is the first pediatric case of IC-MPGN with genetically confirmed ARPKD successfully treated with pegcetacoplan. The case illustrates that renal recovery occurred following initiation of proximal complement inhibition with pegcetacoplan.
Alrasheed et al. (Tue,) studied this question.