OBJECTIVETo examine the cellular components at different stages of the crescent formation in four most common types of human crescentic glomerulonephritis (CGN), including anti-GBM disease (GBM-CGN), crescentic IgA nephropathy (IgA-CGN), ANCA associated pauci-immune CGN (ANCA-CGN) and crescentic lupus glomerulonephritis (LN-CGN).

METHODSRenal biopsy specimens of patients with GBM-CGN (n = 10), IgA-CGN (n = 12), ANCA-CGN (n = 12), and LN-CGN (n = 11) were selected. Immunohistochemistry was adopted to identify the cellular components using different cell markers including cytokeratin (PEC), CD68 (macrophage), nestin (podocyte), podocalyxin (podocyte), CD3 (lymphocyte), CD15 (neutrophil) and PCNA.

RESULTSThere were different subtypes of cell components identified during the formation of a cellular crescent in 4 different types of human CGN. Mainly of PEC 11.4 (0.0, 95.0)%, macrophage 8.0 (0.0, 35.0)% and podocyte 5.5 (0.0, 22.0)% and their constitutive percentages were different among various CGNs (P < 0.01). In all the CGNs studied, there were 50% of cells were negative to all the cell markers adopted for this expeiment. Podocalyxin positive cells 0.5 (0.0, 9.6)% were significantly less than nestin positive cells 5.5 (0.0, 22.0)% in all CGNs. PCNA positive cells were 44.7 (16.7, 83.3)% in the cellular crescent of all CGNs and co-localized with nestin (38/45 cases), CK (42/45 cases) or CD68 (24/45 cases).

CONCLUSIONSPEC, macrophage and podocyte might play important roles in the formation of crescents. The staining disparity of nestin and podocalyxin indicates that podocyte dedifferentiation may occur during the crescent formation. PEC, podocytes and macrophages may participate in the formation of crescent in common CGNs through active cellular proliferation.