Prevalence of nephropathies in children and adolescents and alterations in renal biopsies in Minas Gerais, Brazil, from 1996 to 2010

Renal biopsy is an important method of diagnosis and prognosis in children and adolescents with renal diseases, and there are few studies describing the histopathologic alterations in renal biopsies in these age groups. The aim of this study was to evaluate the incidence of morphologic alterations described in renal biopsies carried out in children and adolescents. Patients aged between 1 month and 18 years were observed from 1996 to 2010 and were separated into 3 age groups: 0 to 6 (group 1, n = 29), 6 to 12 (group 2, n = 31), and 13 to 18 (group 3, n = 77) years. Morphologic alterations were evaluated according to light microscopy, immunofluorescence, and electron microscopy findings. The most common glomerulopathies observed in these different age groups were as follows: group 1-podocytopathy (34.78%), hereditary proteinurias 5 (21.73%), lupus nephritis (13.04%), and Berger disease (8.69%); group 2-podocytopathy (44.44%), acute diffuse glomerulonephritis (22.22%), Berger disease (11.11%), and Alport syndrome or thin membrane disease (11.11%); and group 3-lupus nephritis (22.85%), podocytopathy (20.00%), Berger disease (15.71%), and membranous glomerulopathies (11.42%). This study allows for better knowledge of the prevalence of nephropathies in children and adolescents and shows that a well-supported early diagnosis is indispensable for a more adequate treatment of patients with renal diseases.