RESUMEN
BACKGROUND: Several studies have identified an association between body mass index (BMI) and the incidence and severity of Alzheimer's disease (AD) but this relationship is not fully understood. OBJECTIVE: The primary objective of this study was to assess the possible association between BMI and cerebrospinal fluid (CSF) biomarkers of AD pathology in subjects with normal cognition and cognitive impairment. The secondary objective was to test whether BMI may contribute to improve the accuracy of a clinical model to predict AD pathology in memory clinic patients with cognitive impairment. METHOD: One hundred and seven elderly subjects with cognitive impairment (91 memory clinic patients with mild cognitive impairment [MCI] and 16 with dementia of AD type) and 55 cognitively healthy volunteers were included in this study. All subjects received a comprehensive clinical and neuropsychological evaluation and a lumbar puncture for CSF biomarker analysis. Multiple linear regressions and receiver operating characteristic (ROC) analyses were carried out to assess the association between BMI and the CSF biomarkers of AD pathology. RESULTS: BMI was positively correlated with the CSF levels of Aß42 and negatively with tau and P-tau181 in participants with cognitive impairment. The associations were independent of age, sex, educational level, type and severity of cognitive impairment, cerebrovascular risk factors and the presence of the APOEε4 allele. Furthermore, BMI significantly improved the sensitivity and specificity of a multi-factorial model to predict the presence of an AD CSF biomarker profile. CONCLUSION: Lower BMI is associated with cerebral AD pathology rather than with cognitive impairment in elderly subjects with MCI and mild dementia. Along with other clinical factors, decreasing BMI may help the clinician to identify patients with cognitive impairment due to AD.
Asunto(s)
Enfermedad de Alzheimer/líquido cefalorraquídeo , Enfermedad de Alzheimer/diagnóstico , Biomarcadores/líquido cefalorraquídeo , Índice de Masa Corporal , Disfunción Cognitiva/líquido cefalorraquídeo , Disfunción Cognitiva/diagnóstico , Anciano , Anciano de 80 o más Años , Péptidos beta-Amiloides/líquido cefalorraquídeo , Apolipoproteína E4/líquido cefalorraquídeo , Cognición , Progresión de la Enfermedad , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pruebas Neuropsicológicas , Fragmentos de Péptidos/líquido cefalorraquídeo , Pronóstico , Curva ROC , Proteínas tau/líquido cefalorraquídeoRESUMEN
BACKGROUND: Minimal immunosuppression (IS) is desirable in organ transplantation to reduce side effects and to promote the process of tolerance induction. MATERIAL AND METHODS: Between February 2000 and September 2004, 156 adults (>15 years old) receiving a primary liver graft were enrolled in a prospective, randomized, double-blind, placebo-controlled, investigator-driven single-center study comparing tacrolimus (TAC)-placebo (PL) and TAC-low-dose, short-term (64 days) steroid (ST) IS. There were no exclusion criteria at moment of randomization. All patients had a 12-month follow-up (range, 12-84). RESULTS: Three- and 12-month patient survival rates were 93.6% and 87.2% in the TAC-PL group and 98.7% and 94.7% in TAC-ST group (P = 0.096 and P = 0.093, respectively). Three- and 12-month graft survival rates were 92.3% and 85.9% versus 97.4% and 92.3% (P = 0.14 and 0.13, respectively). By 3 and 12 months, rejection treatment had been given in 20.5% (16 pts) and 23% (18 pts) of TAC-PL patients and in 12.7% (10 pts) and 20.5% (16 pts) of TAC-ST patients (P = 0.20 and 0.54). Corticosteroid-resistant rejection (CRR) at 3 and 12 months was recorded in 12.8% (10 pts) of TAC-PL patients and 3.8% (3 pts) of TAC-ST patients (P = 0.04). When considering the 145 patients transplanted without artificial organ support (n = 145), CRR at 3 and 12 months was recorded in 8.8% (6/68 pts) of TAC-PL patients and in 3.9% (3/77 pts) of TAC-ST patients (P = 0.22). Vanishing bile duct syndrome was diagnosed in 1 (1.2%) TAC-PL patient and 4 (5.1%) TAC-ST patients (P = 0.17). By 1 year, 78.2% (61/78) of TAC-PL patients and 82% (64/78) of TAC-ST patients were on TAC monotherapy (P = 0.54). When considering 67 TAC-PL and 74 TAC-ST survivors, rates of monotherapy were 91% (61 pts) and 86.5% (64 pts) (P = 0.39). At 1 year, 62.5% (42 pts) of TAC-PL survivors and 64.9% (48 pts) of TAC-ST survivors were on low-dosage (<6 ng/mL) TAC monotherapy (P 0.79). CONCLUSION: TAC monotherapy can be achieved safely without compromising graft nor patient survival in a primary, even unselected, adult liver transplant population. The higher incidence of early CRR in the TAC-PL group related to the significantly higher number of patients transplanted while being on artificial organ support. In such condition, this monodrug immunosuppressive strategy needs to be adapted. TAC monotherapy strategy should lay the basis for further large scale minimization studies in liver transplantation.
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Inmunosupresores/uso terapéutico , Trasplante de Hígado , Tacrolimus/uso terapéutico , Adulto , Anciano , Colestasis Intrahepática/cirugía , Método Doble Ciego , Femenino , Humanos , Cirrosis Hepática/cirugía , Pruebas de Función Hepática , Trasplante de Hígado/inmunología , Trasplante de Hígado/mortalidad , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Resultado del Tratamiento , Adulto JovenRESUMEN
The aims of this work were both to validate a sensitive and specific method to quantify tacrolimus (TAC) in liver biopsies after hepatic transplantation and to evaluate the predictive value of either tissue or blood TAC concentrations for rejection in 146 adult patients under a TAC-based immunosuppression. Trough blood levels were monitored daily during the hospital stay by immunoassay. Liver biopsies were routinely performed at day 7 posttransplantation. The tissue assay was developed by liquid chromatography-mass spectrometry. The limit of quantification was 5 pg/mg, with intra- and interassay precision ranging from 3.9% to 14.3% and 4.7% to 15.9%, respectively. The extraction efficiency was approximately 80%. TAC found in liver biopsies ranged from less than 5 up to 387 pg/mg. Blood TAC levels ranged from 2.7 to 19.3 ng/mL. Tissue levels displayed excellent correlation with liver histopathologic BANFF rejection score, whereas blood levels did not. Clinically significant rejections (BANFF scores > or = 6) were characterized by mean TAC tissue and blood concentration of 13.1 pg/mg and 7.6 ng/mL, respectively, whereas these mean values became, respectively, 74.9 pg/mg (P < 0.05) and 7.1 ng/mL (not significant) for nonclinically significant rejection episodes (BANFF < 6). In this study, hepatic tissue TAC concentrations were distributed in a wider range and displayed a significantly better correlation with the severity of the organ rejection than predose blood levels. A tissue TAC concentration less than 30 pg/mg is 89% sensitive and 98% specific to discriminate clinically significant cellular rejection. Further studies are required to better understand the factors affecting TAC distribution within liver tissue (such as carrier proteins and cytochrome genetic polymorphism, liver function, age, hepatic blood flow, type of organ transplanted, time posttransplantation) and to define its value in the treatment of liver allograft rejection.
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Monitoreo de Drogas/métodos , Rechazo de Injerto/metabolismo , Inmunosupresores/farmacocinética , Trasplante de Hígado , Hígado/metabolismo , Tacrolimus/farmacocinética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Cromatografía Liquida , Femenino , Rechazo de Injerto/sangre , Humanos , Inmunosupresores/sangre , Inmunosupresores/metabolismo , Hígado/patología , Masculino , Persona de Mediana Edad , Espectrometría de Masa por Ionización de Electrospray , Tacrolimus/sangre , Tacrolimus/metabolismo , Distribución TisularRESUMEN
BACKGROUND: The ever increasing number of, especially, adults waiting for a liver transplantation necessitates to develop techniques allowing to extend the available donor liver pool. MATERIALS AND METHODS: Between November 1988 and December 2004, 37 (6.6%) of 559 adults underwent split liver transplantation at Saint-Luc Hospitals. There were 36 were right and one left split procedures; 27 split grafts were obtained ex-situ and 10 in-situ. Results of these series are analysed and compared to literature data of split liver transplantation. RESULTS: Three and 12 months patient survival rates were 89.2% and 78.4% respectively. Five years actuarial patient survival was 75.7%. Early (< 3 months) and late (> 3 months) mortality rates were 10.8% (4 pat.) and 21.6% respectively. Early mortality was significantly higher in case of urgent split liver transplantation (3/5 patients vs. 2/32 elective patients--p 0.001). At present 25 patients are alive, with a mean Karnofsky score of 90%. Three and 12 months graft survival rates were 91.7% and 87.1% respectively. Three and one grafts were lost due to primary and early graft non-function. In-situ split grafts had shorter mean warm, cold, total ischemia and operating times as well as less need for blood transfusion; all these differences were however not statistically significant. Surgical complications occurred in 19 (51%) patients. All but one complication occurred early (< 3 months). There were sixteen biliary complications in 13 (35.1%) patients: 9 anastomotic stenoses, 3 anastomotic and 4 transection margin leakages. Six vascular complications occurred in 6 (15.2%) patients: three arterial and 3 portal vein thromboses. Seven (18.9%) patients had a postoperative bleeding. CONCLUSIONS: Graft and patient survival rates of split liver transplantation can be compared to those of classic liver transplantation. However the care of these patients is demanding due to the high number of technical complications. Results of split liver transplantation must be further improved in order to foster it's more widespread use necessary to overcome the actual shortage of liver allografts.