RESUMEN
BACKGROUND: Chronic allograft nephropathy (CAN) remains a major problem in clinical transplantation. It has been associated with increased transforming growth factor (TGF-beta1). Our goal was to correlate CAN and levels of TGF-beta1 by using a novel competitive quantitative for reverse transcription-polymerase chain reaction-ELISA (RT-PCR-ELISA) assay. METHODS: We studied 12 transplantation patients (posttransplant time: 36.5+/-11.2 months, range (r): 13-52) with stable creatinine and blood pressure and varied proteinuria. A Kidney biopsy was performed in all patients. Six patients with acute tubular necrosis (ATN) immediately after transplantation were used as controls. Histopathological evaluation was based on Banff working classification criteria. We designed an heterologous RNA competitor (IC) for RT-PCR-ELISA, which co-amplified with the same primer as TGF-beta1. Products were viewed on 96-well plates labeled with probes for IC at the desired sequence. RESULTS: Results were expressed as the number of TGF-beta1 copies/microg of total RNA. Six patients showed more than 1000 mg/24 hr proteinuria (2446+/-1421 mg/24 hr, r: 1200-5000) higher CAN Banff scores, and the other six presented <1,000 mg/24 hr (348+/-267 mg/24 hr, r: 114-800). This difference was significant (P=0.01). There were not significant differences in posttransplant time, creatinine, or blood pressure between groups. TGF-beta1 levels by RT-PCR-ELISA were statistically significant (6038+/-5317, r: 1239-12100 versus 177+/-119.7, r: 51-400, P=0.04). The control group showed levels of 228+/-111, r. 140-444, P=0.04) with significant difference only for the higher proteinuria group (P=0.03). CONCLUSIONS: This study showed that those patients with elevated CAN scores and higher proteinuria levels had higher TGF-beta1 intragraft expression.
Asunto(s)
Trasplante de Riñón/patología , Trasplante de Riñón/fisiología , Factor de Crecimiento Transformador beta/análisis , Factor de Crecimiento Transformador beta/genética , Adolescente , Adulto , Secuencia de Bases , Biomarcadores , Biopsia con Aguja , Presión Sanguínea , Creatinina/sangre , Cartilla de ADN , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Humanos , Necrosis Tubular Aguda/patología , Donadores Vivos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Proteinuria , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Donantes de Tejidos , Transcripción GenéticaRESUMEN
BACKGROUND: Cytomegalovirus (CMV) is the most prevalent viral disease in solid organ transplantation. Detection of CMV DNA in peripheral blood mononuclear cells (PBMC) by polymerase chain reaction (PCR) frequently occurs in renal allograft recipients, yielding false positive results in seropositive patients free of CMV disease. We evaluated the clinical utility of a quantitative PCR-enzyme-linked immunosorbent assay (ELISA) for identifying patients with CMV disease. METHODS: Three hundred and fifty samples from 65 consecutive renal transplant recipients were studied. DNA was extracted from PBMC weekly up to the day of discharge and after any further admission. Samples were tested by a qualitative PCR method, and all positive samples were further studied by a quantitative PCR-ELISA method. The quantitative PCR-ELISA method used an internal standard (IS) that contained the primer sequences used in the qualitative CMV PCR. Detection and quantification was performed in 96-well plates coated with IS or CMV specific probes. RESULTS: Forty-one of 65 patients (63.1%) showed positive results by the qualitative PCR, but only 8 of these patients were diagnosed with CMV disease. Positive samples were re-analyzed by the quantitative assay. The 8 patients with CMV disease had a mean CMV viral load of 1,438+/-687 viral copies (VC)/10(6) PBMC, and the 33 without CMV disease had a mean value of 219.6+/-117.2 VC/10(6) PBMC (P<0.01). None of the 33 patients without CMV disease had viral loads higher than 500 VC/10(6) PBMC. Using 500 VC/10(6) PBMC as a cut-off value for CMV disease, the quantitative PCR showed a sensitivity and specificity of 100% compare to clinical diagnosis. CONCLUSION: CMV viral load may be useful in the diagnosis of CMV disease in renal transplant patients.