RESUMO
BACKGROUND: Chronic allograft nephropathy (CAN) is the most frequent cause of chronic dysfunction and late loss of renal allografts. Epithelial mesenchymal transition (EMT) has been identified as responsible for the presence of activated interstitial fibroblasts (myofibroblasts) and transforming growth factor beta (TGF-beta)/Smad is the key signaling mediator. It has been proposed that the bone morphogenetic protein 7 (BMP-7) antagonist, Gremlin, could participate in EMT, as a downstream mediator of TGF-beta. METHODS: We evaluated 33 renal allograft biopsies, 16 of which showed CAN, versus 17 controls. By in situ hybridization we studied the expression of TGF-beta and Gremlin mRNA. Gremlin, BMP-7, E-cadherin, and alpha-smooth muscle actin (alpha-SMA) proteins were evaluated by immunohistochemistry and Smad3 activation by Southwestern. In cultured human tubuloepithelial cells (HK2 cell line), Gremlin induction by TGF-beta was studied by confocal microscopy. RESULTS: Among renal biopsies of transplanted patients with CAN, we detected up-regulation of TGF-beta in colocalization with Gremlin (RNA and protein), mainly in areas of tubulointerstitial fibrosis. In the same tubules, we observed decreased expression of E-cadherin and induction of vimentin and alpha-SMA. BMP-7 was significantly decreased in the CAN biopsies. In addition, HK2 stimulated with TGF-beta (1 ng/mL) induced Gremlin production at 72 hours. CONCLUSION: We postulated that Gremlin is a downstream mediator of TGF-beta, suggesting a role for Gremlin in EMT observed in CAN.
Assuntos
Células Epiteliais/patologia , Transplante de Rim/patologia , Mesoderma/patologia , Complicações Pós-Operatórias/patologia , Diferenciação Celular , Doença Crônica , Fibrose , Humanos , Hibridização In Situ , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Transplante HomólogoRESUMO
Cytochrome-P450 enzymes metabolize cyclosporine both in the liver and in the intestinal wall. Diltiazem, by competitive inhibition of these enzymes, may increase the absorption and the bioavailability of cyclosporine. Some evidence points to a higher activity of some specific enzymes in women, such as CYP3A, that may influence differences in cyclosporine pharmacokinetics. We examined possible gender-associated differences in pharmacokinetic profiles of cyclosporine in 19 stable renal transplant recipients cotreated with diltiazem. Ten women and nine men, chronically using diltiazem associated with cyclosporine, azathioprine, and prednisone were randomly assigned to an 8-week period of continued controlled treatment with diltiazem (10 patients) or a wash-out period discontinuing diltiazem (nine patients). At the end of this period, the time-concentration curves of cyclosporine in the first 4 hours were performed after a single dose of cyclosporine. Thereafter, a cross-over between groups was performed, and time-concentration curves repeated. A specific RIA was used to measure cyclosporine concentrations. Comparisons between male and female patients in doses of cyclosporine and other pharmacokinetics parameters (C(0), C(2), AUC(0-4)), with or without diltiazem, did not show any difference related to gender. The association of diltiazem allowed a similar degree of reduction in Neoral dosage in male and female patients (21%). No changes in serum creatinine, blood urea nitrogen, potassium, uric acid, or blood pressure, or other adverse event were observed during the study. In these groups of patients, gender was not an important factor to be considered when diltiazem is added to cyclosporine therapy.
Assuntos
Ciclosporina/farmacocinética , Ciclosporina/uso terapêutico , Diltiazem/uso terapêutico , Transplante de Rim/imunologia , Área Sob a Curva , Bloqueadores dos Canais de Cálcio/uso terapêutico , Ciclosporina/sangue , Interações Medicamentosas , Feminino , Humanos , Imunossupressores/sangue , Imunossupressores/farmacocinética , Imunossupressores/uso terapêutico , Transplante de Rim/fisiologia , Masculino , Caracteres SexuaisRESUMO
BACKGROUND: The area-under-the-curve (AUC) of cyclosporine (CsA) reflects exposure to the drug, but this monitoring strategy is time-consuming and not cost-effective. Recently, it has been suggested that the concentration at 2 hours after dosing (C2) shows the best correlation with AUC. The C2 has been replacing the trough measurement (C0) to monitor CsA therapy, but in patients receiving diltiazem there is not much information about this issue. We investigated the correlations between C2 and C0 with absorption AUC over the first 4 hours (AUC(0-4)) in renal stable transplant patients receiving CsA therapy with or without diltiazem. PATIENTS AND METHODS: Ten patients (five men) of ages 23 to 68 years and 6 to 84 months after transplantation, were randomly assigned to an 8-week initial period of either diltiazem washout or controlled treatment with diltiazem. Time-concentration curves of cyclosporine were performed at the end of this period using a specific RIA measurement of blood samples. Thereafter, a crossover of the groups was performed and after another 8 weeks, a second curve was obtained. Drugs that change the pharmacokinetics of cyclosporine or diltiazem were not allowed. RESULTS: The cyclosporine daily dose was lower with diltiazem (173 +/- 4 mg vs 213 +/- 4 mg, P = .002), but despite a dose reduction of only 19% +/- 1.5%, there was a trend to a larger AUC/dose (28 +/- 5 ng x h/mL x mg vs 17 +/- 2 ng x h/mL x mg, P = .1) and a trend to an increased C2 when treatment included diltiazem (1035 +/- 156 ng/mL vs 652 +/- 126 ng/mL, P = NS). Moreover, we confirmed that C2 showed the best correlation with AUC(0-4), (r = 0.7, P = .04), a correlation that improved with diltiazem (r = 0.9, P < .002). CONCLUSION: C2 is the point that correlates best with AUC(0-4) with or without diltiazem. C2 in the presence of diltiazem was associated with a stronger, more significant correlation with AUC(0-4).
Assuntos
Diltiazem/farmacocinética , Transplante de Rim/imunologia , Vasodilatadores/farmacocinética , Adulto , Idoso , Área Sob a Curva , Ciclosporina/sangue , Ciclosporina/farmacocinética , Ciclosporina/uso terapêutico , Diltiazem/sangue , Diltiazem/uso terapêutico , Monitoramento de Medicamentos/métodos , Humanos , Imunossupressores/farmacocinética , Imunossupressores/uso terapêutico , Pessoa de Meia-Idade , Vasodilatadores/uso terapêuticoRESUMO
BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor type 1 blockers (ARB) are frequently prescribed for renal transplant patients. The main reasons for their use are that their antihypertensive and antifibrogenic effects may prevent chronic renal allograft dysfunction, potentially improving transplant survival. Furthermore, ACE and ARB have been used to reduce the hematocrit in patients with posttransplant erythrocytosis. We evaluated the effects of the ARB valsartan on the evolution of hematocrit in stable renal transplant patients treated with cyclosporine (CsA), azathioprine (Aza), and prednisone. PATIENTS AND METHODS: Twenty-six stable renal transplant patients treated with valsartan 80 mg/d orally were followed for 6 months. Evaluations were performed prior to as well as at 3 and 6 months following the initiation of valsartan. RESULTS: The hematocrit levels decreased significantly at 3 months (46.1 +/- 7.3 vs 39.9 +/- 5.8 ; P < .0001) in patients with a normal hematocrit, namely a level over 38%, with no further reduction at 6 months. In recipients with an hematocrit less than 38%, there was no significant reduction, either at 3 or 6 months follow-up. Valsartan was well tolerated without significant side effects. CONCLUSION: We postulate that inhibition of the proerythropoietic effects of angiotensin II and/or the reduction in hypoxia within the renal tubulointerstitium as well as the vasodilator effects on the efferent arterioles, represent possible mechanisms for the reduction and stabilization of the hematocrit in stable renal transplant patients.
Assuntos
Anti-Hipertensivos/uso terapêutico , Hematócrito , Transplante de Rim/fisiologia , Tetrazóis/uso terapêutico , Valina/análogos & derivados , Adulto , Idoso , Pressão Sanguínea/efeitos dos fármacos , Creatinina/sangue , Quimioterapia Combinada , Feminino , Humanos , Imunossupressores/uso terapêutico , Transplante de Rim/imunologia , Masculino , Pessoa de Meia-Idade , Potássio/sangue , Valina/uso terapêutico , ValsartanaRESUMO
UNLABELLED: Overexpression of chemokines, fibrogenic cytokines, and myofibroblasts in human membranous nephropathy. BACKGROUND: Proteinuria plays a central role in the progression of glomerular disease, and there is growing evidence suggesting that it may determine tubular cell activation with release of chemokines and fibrogenic factors, leading to interstitial inflammatory reaction. However, most studies on this subject have been performed in experimental models, and the experience in human kidney biopsies has been scarce. We analyzed the tissue sections of patients with idiopathic membranous nephropathy (IMN), a noninflammatory glomerular disease that may follow a progressive disease with heavy persistent proteinuria, interstitial cell infiltration, and decline of renal function. METHODS: Paraffin-embedded biopsy specimens from 25 patients with IMN (13 progressive and 12 nonprogressive) were retrospectively studied by immunohistochemistry [monocyte chemoattractant protein-1 (MCP-1), regulated on activation normal T-cell expressed and secreted chemokine (RANTES), osteopontin (OPN), platelet-derived growth factor-BB (PD-GF-BB)] and in situ hybridization [MCP-1, RANTES, PDGF-BB, transforming growth factor-beta1 (TGF-beta1)]. Moreover, we studied the presence of myofibroblasts, which were identified by the expression of alpha-smooth muscle actin (alpha-SMA), the monocytes/macrophages (CD68-positive cells), and T-cell infiltration (CD4+ and CD8+ cells). All of the patients were nephrotic and without treatment at time of the biopsy. RESULTS: A strong up-regulation of MCP-1, RANTES, and OPN expression was observed, mainly in tubular epithelial cells, with a significant major intensity in the progressive IMN patients. A strong correlation between the mRNA expression and the corresponding protein was noted. The presence of these chemokines and OPN was associated with interstitial cell infiltration. TGF-beta and PDGF were also up-regulated, mainly in tubular epithelial cells, with a stronger expression in the progressive IMN, and an association with the presence of myofibroblasts was found. CONCLUSIONS: Patients with severe proteinuria and progressive IMN have an overexpression in tubular epithelial cells of the chemokines MCP-1, RANTES, and OPN and the profibrogenic cytokines PDGF-BB and TGF-beta. Because this up-regulation was associated with an interstitial accumulation of mononuclear cells and an increase in myofibroblastic activity, it is suggested that those mediators are potential predictors of progression in IMN. Finally, based on experimental data and the findings of this article, we speculate that severe proteinuria is the main factor responsible for the up-regulation of these factors in tubular epithelial cells.
Assuntos
Quimiocinas/genética , Citocinas/genética , Glomerulonefrite Membranosa/metabolismo , Adulto , Idoso , Feminino , Fibroblastos/metabolismo , Glomerulonefrite Membranosa/patologia , Humanos , Imuno-Histoquímica , Hibridização In Situ , Rim/metabolismo , Macrófagos/patologia , Masculino , Pessoa de Meia-IdadeRESUMO
El síndrome de Treacher Collins (STC) fue descrito por primera vez en 1846. La ocurrencia familiar ha sido bien establecida y sigue una transmisión regular dominante, con variabilidad interfamiliar e incremento en la severidad en generaciones sucesivas. Se presenta una paciente de 9 años que consulta en Policlínico de Genética por: hipoacusia, cuadros respiratorios a repetición, retraso del desarrollo psicomotor, dismorfias, observación genopatía. Es hija de padres no cosanguíneos, embarazo controlado, actividad fetal lenta, tabaquismo materno, parto eutócico, con peso y talla de nacimiento normales. Al examen físico destaca: facie angosta, oblicuidad antimongoloide de ojos, ausencia de pestañas y coloboma del borde externo del párpado inferior, hipoplasia malar, nariz de pájaro, micrognatia, implantación anormal de pelo en mejillas, comisura labial hacia arriba, hipoacusia. En antecedentes familiares destaca: madre y hermanastra con rasgos físicos similares e hipoacusia. Evaluadas las tres por Otorrino se confirma en ellas hipoacusia de transmisión bilateral y malformaciones de oído medio. El examen radiológico demuestra la hipoplasia malar. Con todos estos antecedentes se concluye que el fenotipo corresponde a un S.T.C.