The relation of IgM deposition to clinical parameters and histomorphometry in childhood mesangial proliferative glomerulonephritis

We investigated the question of whether IgM deposition causes any difference in the histomorphometry of children with mesangial proliferative glomerulonephritis (MePGN). We retrospectively compared the urinalysis, blood pressure measurements, and serum creatinine levels of children with IgM (+) and IgM (-) MePGN. For histopathological evaluation, the outlines of Bowman's capsules and glomerular tufts of 10 glomeruli were rimmed manually, and the surrounded areas were calculated as pixels. The cells at each tuft of the largest four glomeruli were counted. Bowman's capsular areas, glomerular tuft areas, glomerular cellularities, and the number of cells per tuft area were determined for each patient. There were 24 (M/F: 14/10) patients with MePGN. Twelve of them were IgM (+). Mean age at biopsy was 6.8+/-4.1 years. IgM (+) patients mostly presented with nephrotic syndrome (NS) (n=9) and IgM (-) patients mostly with macroscopic hematuria (n=7). None of the clinical or laboratory findings was statistically different between the groups (p>0.05) except increased NS frequency in IgM (+) patients (p: 0.038). The histomorphometric parameters were similar in both groups (p>0.05). IgM (+) patients with MePGN mostly presented with NS in our study, but their histomorphometric parameters demonstrated no significant difference.