Expression of Ki-67 antigen using monoclonal antibody MIB-1 in children with post-streptococcal glomerulonephritis

We investigated the expression of Ki-67 antigen using monoclonal antibody M IB-1 in glomeruli and renal tubules of 21 children (18 males, 3 females) wi th post-streptococcal glomerulonephritis (PSGN). Patients were divided into two groups of active and convalescent phases. The active group (n=13) comp rised those patients with clinical manifestations of the acute nephritic sy ndrome consisting of edema, hypertension, hematuria, and oliguria or those in whom percutaneous renal biopsy was performed within 4 weeks of onset of the symptoms of PSGN and those with serum C3 levels below 55 mg/dl at the t ime of biopsy. MIB-1 expression was considered positive when staining of en docapillary cells was observed. Of the 21 biopsies, expression of MIB-1 in glomeruli and renal tubules was observed in 14 cases (63.6%) and 20 cases ( 95.7%), respectively. The expression of MIB-1 in glomeruli of patients with active disease (11/13, 84.6%) was significantly higher than that of the co nvalescent group (2/8, 25%) (P=0.018). The cellularity in the glomeruli was more severe in the active group than the convalescent group (P=0.0475). Th ere was a significant difference of neutrophilic infiltration in glomeruli between the active group and the convalescent group (P=0.0117). However, gl omerular MIB-1 expression did not correlate with the degree of immunofluore scence, the number of neutrophils in the glomeruli on light microscopy, and the presence of subepithelial dense deposits on electron microscopy. There was no significant correlation between MIB-1 and serum C3 level. There was no significant correlation between glomerular MIB-1 expression and creatin ine clearance (r=-0.180, P=0.556) or 24-h urinary protein excretion (r=0.43 4, P=0.137). Our results suggest that the expression of MIB-1 in glomeruli in the active phase in PSGN was higher than in the convalescent phase and e xpression of glomerular MIB-1 appears to be related to glomerular endocapil lary proliferation with exudative lesions in children with PSGN.