Podocyte injury in pure membranous and proliferative lupus nephritis: distinct underlying mechanisms of proteinuria?

Autor(es)

Rezende, G. M. ^[1] ; Viana, V. S. ^[1] ; Malheiros, D. M. A. C. ^[2] ; Borba, E. F. ^[1] ; Silva, N. A. S. ^[2] ; Silva, C. ^[3] ; Leon, E. P. ^[1] ; Noronha, I. L. ^[3] ; Bonfa, E. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Div Rheumatol, Fac Med, BR-01246903 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Dept Pathol, Fac Med, BR-01246903 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Lab Cellular Genet & Mol Nephrol, Fac Med, BR-01246903 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Lupus; v. 23, n. 3, p. 255-262, MAR 2014.
• Citações Web of Science: 18

Resumo

Proteinuria is a major feature of lupus nephritis (LN) and reflects podocyte injury. Analysis of podocyte biomarkers was performed attempting to identify if podocyte phenotype is distinct in pure membranous and proliferative LN. Expression of synaptopodin, Wilms tumor protein 1 (WT1), glomerular epithelial protein 1 (GLEPP1) and nephrin was evaluated in 52 LN biopsies by immunohistochemistry. Preserved synaptopodin expression was observed in only 10 (19.2%) of all biopsies while 42 (80.8%) had reduced expression. Both groups had comparable proteinuria at the time of biopsy (p = 0.22); however, in the mean follow-up of four years there was a tendency toward lower mean levels of proteinuria in patients with preserved synaptopodin staining (0.26 +/- 0.23 vs. 0.84 +/- 0.90 g/24 h, p = 0.05) compared with those with diminished expression. Thirty-nine (75%) biopsies were classified as proliferative and 13 (25%) as pure membranous. Comparison of podocyte biomarkers demonstrated a predominance of preserved staining of synaptopodin (69.2%), WT1 (69.2%), GLEPP1 (53.9%) and nephrin (60%) in the pure membranous group whereas only <10% of the proliferative showed preserved expression. Our data suggest that in proliferative forms there seems to occur structural podocyte damage, whereas in the pure membranous the predominant preserved pattern suggests a dysfunctional podocyte lesion that may account for the better long-term prognosis of proteinuria outcome. (AU)

• Processo FAPESP: 09/54616-7 - Sinaptopodina e GLEPP1 na nefrite lúpica: expressão em podócitos e autorreatividade
• Beneficiário: Eloisa Silva Dutra de Oliveira Bonfá
• Modalidade de apoio: Auxílio à Pesquisa - Regular