NEF - Comunicações e Conferências
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- Decreased Vascular Endothelial Growth Factor (VEGF) Expression in Focal Segmental Glomeruloesclerosis Lesions of Patients Under SirolimusPublication . Viana, H; Carvalho, F; Pinto, JR; Galvão, MJ; Santos, A; Nolasco, F; Ribeiro Santos, JBackground: Proteinuria (PT) with SRL appears not only after conversion from a calcineurin inhibitor (CI), but also in de novo patients. The PT may be related to a hemodynamic effect of CI withdrawal or to a direct effect of SRL in glomerulus (GL). Recently an association between PT in SRL patients and FSGS lesions has been described. It is also known that SRL decrease VEGF synthesis and experimental data suggest that VEGF is essential to podocyte survival and differentiation. Aim: To determine if glomerular lesions and PT in SRL patients could be related to altered glomerular VEGF expression. Material and methods: We evaluated glomerular VEGF expression in 10 biopsies: A-allograft kidney in backtable (n=3); B-native normal kidney (n=1); C-native kidney with FSGS lesions (n=2); D-allograft kidney with FSGS lesions from proteinuric patients under SRL after conversion from CI (n=3); E-allograft kidney in proteinuric patient under SRL with a membranous glomerulonephritis (n=1). We employed indirect immunohistochemistry in paraffin-embedded sections using a mouse monoclonal antibody against human VEGF-C1 (Santa Cruz). Results: The controls biopsies (A; B) showed normal global VEGF expression, with strong podocyte staining. The VEGF expression in the group C was similar to the controls, although no FSGS lesions were observed in the stained GL. The group D showed normal VEGF expression in the apparently normal GL, hypertrophied podocytes with reduction of VEGF in anomalous GL, and no staining in slcerotic lesions. We observed a gradual reduction of VEGF expression with progressive dedifferentiation of podocytes. In the group E the VEGF was globally reduced, with some hypertrophied podocytes expressing decreased VEGF. Conclusion: We confirmed the diminished VEGF expression in injured podocytes of SRL patients.This decreased expression may result from a direct effect of SRL and precede the appearance of FSGS lesions and PT. Further studies are needed with greater number of cases and controls, including early biopsies of patients under SRL.
- Lesão Crónica do Enxerto. Interferência TerapêuticaPublication . Ferreira, AC; Viana, H; Carvalho, F; Pinto, R; Galvão, MJ; Santos, A; Nolasco, F; Ribeiro Santos, J
- Immunosuppression and Renal Dysfunction in Liver TransplantationPublication . Ferreira, AC; Nolasco, F; Sampaio, S; Baptista, A; Pessegueiro, P; Viana, H; Monteiro, E; Martins, A; Barroso, E
- Impact of RIFLE Classification in Liver TransplantationPublication . Ferreira, AC; Nolasco, F; Sampaio, S; Viana, H; Baptista, A; Pessegueiro, P; Monteiro, E; Mourão, L; Martins, A; Barroso, E
- The Impact of Renal Disease in Liver TransplantationPublication . Ferreira, AC; Nolasco, F; Sampaio, S; Baptista, A; Pessegueiro, P; Monteiro, E; Martins, A; Barroso, E
- Citometria com Esferas na Abordagem do Transplante Renal Precoce. Estudo ProspectivoPublication . Ferreira, AC; Viana, H; Cabrita, A; Carvalho, D; Ferreira, A; Remédio, F; Lima, A; Sancho, R; Trindade, H; Carvalho, F; Nolasco, F
- C4d Presence in Kidney Allograft Biopsy: Sensitivity and Specifity of Immunoperoxidase vs ImmunofluorescencePublication . Viana, H; Carvalho, F; Santos, A; Galvão, MJ; Nolasco, FOBJECTIVES: Evaluate the sensitivity/specificity of immunoperoxidase method in comparison with the standard immunofluorescence. MATERIAL AND METHODS: Retrospective review of 87 biopsies made for allograft dysfunction. Immunofluorescence (IF) was performed in frozen allograft biopsies using monoclonal antibody anti-C4d from Quidel®. The indirect immunoperoxidase (IP) technique was performed in paraffin-embebbed tissue with polyclonal antiserum from Serotec®. Biopsies were independently evaluated by two nephropathologist according Banff 2007 classification. RESULTS: By IF, peritubular C4d deposition were detected in 60 biopsies and absent in 27 biopsies. The evaluation of biopsy by IP was less precise due to the presence of background and unspecific staining. We find 13.8% (12/87) of false negative and Banff classification concordance in 79.3% (69/87) of cases (table1). The ROC curve study reveal a specificity of 100% and sensitivity of 80.0 % of IP method in relation to the gold standard (area under curve:0.900; 95% Confidence interval :0.817-0.954; p=0.0001). Banff Classification C4d Cases Immunofluorescence Immunoperoxidase n =87 Diffuse Negative 3 (3.4%) Focal Negative 9 (10.3%) Negative Negative 27 (31.0%) Diffuse Diffuse 33 (37.9%) Focal Focal 9 (10.3%) Diffuse Focal 6 (6.9%) CONCLUSION: The IP method presents a good specificity, but lesser sensitivity to C4d detection in allograft dysfunction. The evaluation is more difficult, requiring more experience of the observer than IF method. If frozen tissue is unavailable, the use of IP for C4d detection is acceptable.
- Collapsing Glomerulopathy. A Biopsy ReviewPublication . Ferreira, AC; Carvalho, D; Carvalho, F; Nolasco, F; Ribeiro Santos, J
- HIV and KidneyPublication . Ferreira, AC; Carvalho, D; Carvalho, F; Nolasco, F; Ribeiro Santos, J
- Zero-Time Kidney Histology Predicts Early Graft FunctionPublication . Viana, H; Carvalho, F; Galvão, MJ; Santos, A; Nolasco, FOur purposes are to determine the impact of histological factors observed in zero-time biopsies on early post transplant kidney allograft function. We specifically want to compare the semi-quantitative Banff Classification of zero time biopsies with quantification of % cortical area fibrosis. Sixty three zero-time deceased donor allograft biopsies were retrospectively semiquantitatively scored using Banff classification. By adding the individual chronic parameters a Banff Chronic Sum (BCS) Score was generated. Percentage of cortical area Picro Sirius Red (%PSR) staining was assessed and calculated with a computer program. A negative linear regression between %PSR/ GFR at 3 year post-transplantation was established (Y=62.08 +-4.6412X; p=0.022). A significant negative correlation between arteriolar hyalinosis (rho=-0.375; p=0.005), chronic interstitial (rho=0.296; p=0.02) , chronic tubular ( rho=0.276; p=0.04) , chronic vascular (rho= -0.360;P=0.007), BCS (rho=-0.413; p=0.002) and GFR at 3 years were found. However, no correlation was found between % PSR, Ci, Ct or BCS. In multivariate linear regression the negative predictive factors of 3 years GFR were: BCS in histological model; donor kidney age, recipient age and black race in clinical model. The BCS seems a good and easy to perform tool, available to every pathologist, with significant predictive short-term value. The %PSR predicts short term kidney function in univariate study and involves extra-routine and expensive-time work. We think that %PSR must be regarded as a research instrument.