Journal de transplantation clinique et expérimentale

Abstrait

Deficient of Megalin in Stable Renal Transplanted Patients with Proximal Tubular Dysfunction

Ana Cristina Carvalho de Matos, Niels Olsen Saraiva Câmara, Alexandre Maurano, Marcelino de Souza Durão, Eduardo José Tonato, Lucio Roberto Requião-Moura, Marcus Vinicius Corpa, Marcello Fabiano Franco, Luiz Antonio Ribeiro Moura and Alvaro Pacheco-Silva

Introduction: Renal-transplant patients with stable graft function and proximal tubular dysfunction (PTD) have an increased risk for IF/TA. The morphological features associated with this dysfunction are unknown. Material and methods: 54 renal transplant patients with normal and stable renal function were submitted to a biopsy and had urinary retinol binding protein (uRBP) and renal function assessment. Patients were divided according to uRBP levels: 1, these findings had no association with uRBP levels. Megalin expression was observed at BB of PTC, 13.7% of bxs presented its expression in less than 50% of tubules, 56.8% had in more than 50% of tubules but with discontinuity over the BB and in 29.5% megalin expressed in more than 50% of tubules continuouslly over the BB. Patients who presented uRBP > 0.6 mg/L had lower amount of megalin expression in their biopsies, p=0.007. Cellular RBP expression was observed diffusely over the cytoplasma of PTC, with different intensities. No correlation was found between tubular megalin expression and uRBP values with CRBP expression. Conclusions: Half of renal transplant patients with normal renal function had PTD. The deficiency of megalin expression could be the subjacent functional alteration found in patients with PTD.