MORPHOLOGICAL FEATURES OF KIDNEY DAMAGE IN CHILDREN WITH IGA NEPHROPATHY

Abstract

Background: IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide and renal biopsy remains the gold standard for diagnosis and provides valuable information about disease severity and prognosis.

Objective: To evaluate renal biopsy findings in children with IgA nephropathy and analyze associations between morphological lesions and clinical parameters at the time of diagnosis.

Methods: A retrospective observational study included 27 children with biopsy‑proven IgA nephropathy. Renal biopsy specimens were evaluated using light microscopy and immunohistochemistry. Histological lesions were classified according to the Haas classification and Oxford MEST‑C scoring system. Clinical and laboratory parameters were analyzed at the time of biopsy.

Results: IgA nephropathy accounted for 45.8% of nephritic syndrome cases in the cohort. The most common clinical manifestations were asymptomatic microhematuria and hematuria with proteinuria. Mesangial proliferation was observed in 73% of biopsies, segmental glomerulosclerosis in 52%, and tubulointerstitial damage in 10%. Immunohistochemical analysis revealed predominant mesangial IgA deposition accompanied by complement component C3.

Conclusion: Renal biopsy findings in pediatric IgA nephropathy are characterized by mesangial proliferation and immune complex deposition. Oxford MEST‑C classification provides important prognostic information and helps identify children at increased risk of disease progression.