Glomerulonephritis with crescents in childhood; etiologies and significance of M2 macrophages

Background. Crescentic glomerulonephritis (CGN) is a rapidly progressive and rare cause of glomerulonephritis in childhood. The aim of this study is to evaluate demographic data of children with crescentic glomerulonephritis, to classify the etiologies and to investigate the correlation between the severity of kidney disease and the expression of CD163+ macrophages. Methods. Between the years 2000 and 2016 in a single center, patients under 18 years of age with kidney biopsies containing crescents were included in the study. A total of 88 children were enrolled. The expression of CD163 in kidney tissues was detected by immunohistochemistry in 61 patients. Clinical features and outcome were collected from their medical records. Results. The most common etiology was Henoch-Schonlein purpura (HSP) nephritis/Immunglobulin A vasculitis (26.1%), followed by lupus nephritis (22.7%) and idiopathic crescentic glomerulonephritis (18.2%). CD163 positive cell counts in patients with GFR levels less and more than 60 ml/min/1.73 m(2) at their last visit were 7.6 +/- 6.6 cells vs. 2.0 +/- 3.0 cells (p=0.057) per one glomerulus and 52.2 +/- 18.2 cells/hpf vs. 33.3 +/- 10.0 cells/hpf (p<0.05) in tubulointerstitium, respectively. Tubulointerstitital CD163+ cells were also found to be higher in patients with end stage kidney disease than complete and partial responders (68 cells/hpf vs 39 cells/hpf, p<0.05). Conclusions. CD163 positive cell counts, particularly in tubulointerstitial areas, have been associated with poor prognosis of CGN.