Functional and morphologic evaluation of kidney proximal tubuli and correlation with renal allograft prognosis.
Renal transplant patients with stable graft function and proximal tubular dysfunction (PTD) have an increased risk for chronic allograft nephropathy (CAN). In this study, we investigated the histologic pattern associated with PTD and its correlation with graft outcome. Forty-nine transplant patients with stable graft function were submitted to a biopsy. Simultaneously, urinary retinol-binding protein (uRBP) was measured and creatinine clearance was also determined. Banff's score and semi-quantitative histologic analyses were performed to assess tubulointerstitial alterations. Patients were followed for 24.0 + or - 7.8 months. At biopsy time, mean serum creatinine was 1.43 + or - 0.33 mg/dl. Twelve patients (24.5%) had uRBP > or = 1 mg/l, indicating PTD and 67% of biopsies had some degree of tubulointerstitial injury. At the end of the study period, 18 (36.7%) patients had lost renal function. uRBP levels were not associated with morphologic findings of interstitial fibrosis and tubular atrophy (IF/TA), interstitial fibrosis measured by Sirius red or tubulointerstitial damage. However, in multivariate analysis, the only variable associated with the loss of renal function was uRBP level > or = 1 mg/l, determining a risk of 5.290 of loss of renal function (P = 0.003). Renal transplant patients who present PTD have functional alteration, which is not associated with morphologic alteration. This functional alteration is associated to progressive decrease in renal function.
de Matos
Ana Cristina Carvalho
AC
Division of Nephrology, Universidade Federal de São Paulo, Hospital do Rim e Hipertensão, Fundação Oswaldo Ramos, São Paulo, Brazil. anacmatos@terra.com.br
Câmara
Niels Olsen Saraiva
NO
de Oliveira
Ana Francisca Franco
AF
Franco
Marcello F
MF
Moura
Luiz Antonio Ribeiro
LA
Nishida
Sonia
S
Pereira
Aparecido Bernardo
AB
Pacheco-Silva
Alvaro
A
D000328:Adult; D001706:Biopsy; D005260:Female; D005355:Fibrosis; D006085:Graft Survival; D006801:Humans; D007668:Kidney / Q000378:metabolism; D016030:Kidney Transplantation / Q000379:methods*; D007684:Kidney Tubules / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D054840:Retinol-Binding Proteins, Cellular / Q000378:metabolism; D014184:Transplantation, Homologous / Q000379:methods*; D016896:Treatment Outcome
D054840:Retinol-Binding Proteins, Cellular