Granulomatosis with polyangiitis associated with IgA nephropathy

Area of Science:

• Pediatric Nephrology
• Rheumatology
• Immunology

Background:

• Granulomatosis with polyangiitis (GPA), a rare vasculitis, affects small-to-medium vessels and commonly involves respiratory tracts and kidneys.
• GPA-related glomerular lesions typically present as crescentic glomerulonephritis without significant immunoglobulin or complement deposition.
• IgA nephropathy is a distinct immune-mediated glomerular disease.

Purpose of the Study:

• To report a unique pediatric case of GPA associated with IgA nephropathy.
• To investigate the potential link between GPA remission and IgA nephropathy development or exacerbation.
• To evaluate the utility of serum IgA levels as a predictive marker.

Main Methods:

• Case report of a pediatric patient with GPA.
• Analysis of initial and follow-up renal biopsy findings.
• Monitoring of clinical symptoms, serum IgA levels, and urinary findings.
• Assessment of treatment response to oral prednisolone.

Main Results:

• Initial renal biopsy showed no IgA deposition, but subsequent biopsies revealed IgA and C3 deposition during GPA remission.
• Elevated serum IgA levels persisted despite clinical remission of GPA.
• A second renal biopsy confirmed IgA nephropathy after an upper respiratory infection.
• Treatment with oral prednisolone led to complete remission of proteinuria within one month.

Conclusions:

• IgA nephropathy may be associated with Granulomatosis with polyangiitis during its remission phase.
• Persistently elevated serum IgA levels could serve as a valuable indicator for predicting IgA nephropathy in GPA patients.
• This case highlights the complex interplay between autoimmune conditions in pediatric patients.