RESUMEN
BACKGROUND: Patients with chronic renal failure suffer from bleeding diathesis and a tendency to accelerated atherosclerosis. Altered platelet function plays a well defined role in the hemorrhagic complications of these patients and has a probable impact on atherothrombotic disease in uremia. In this study we investigated the expression of platelet surface receptors, the glycoprotein GPIb (receptor for von Willebrand Factor(vWF) and GPIIb/IIIa (receptor for fibrinogen) in patient with chronic renal failure in pre-dialysis status, under hemodialysis and peritoneal dialysis treatment, in order to assess the impact of the abnormal receptorial status of uremic platelets on the clinical manifestations of hemostatic alterations in uremic patients. METHODS: Thirty-seven normal healthy subjects (controls = Group A), 18 patients with mild chronic renal failure (creatinine = 1.8 +/- 0.5 mg% - Group B), 15 patients with advanced renal failure (creatinine = 5.4 +/- 2. 1 mg% - Group C), 18 hemodialysis patients (Group D) and 11 peritoneal dialysis patients (Group E) were included in the study. The expression of platelet surface receptors GPIb and GPIIb/IIIa was investigated with monoclonal antibodies CD42 and CD41 (Immunotech, Marseille, France) and a FACScan flowcytometer (Becton-Dickinson, USA). RESULTS: Mean values of GPIb glycoprotein (mean flow +/- SD) were: group A = 48.14 +/- 9.31; group B = 40.48 +/- 8.18 (p < 0.005); group C = 34.05 +/- 7.55 (p < 0.0005) versus group A; p = 0.025 versus group B); group D = 34.51 +/- 7.22 (p < 0.0005 versus group A; p = 0.025 group B and p = ns versus group C); group E = 26.34 +/- 4.06 (p < 0.0005 versus group A, p < 0.0005 versus group B, p < 0.005 versus groups C and D). Mean values of glycoprotein GPIIb/IIIa were: group A = 375.32 +/- 90.58; group B = 398.48 +/- 54.26 (p = ns); group C = 426.86 +/- 52.78 (p < 0.025 versus group A; p = ns versus group B); group D = 425.17 +/- 75.03 (p < 0.025 versus group A; p = ns versus groups B and C); group E = 336.39 +/- 43.26 (p = ns versus group A; p < 0.005 versus group B, p < 0.0005 versus group C and p < 0.001 versus group D). CONCLUSIONS: Our data confirm the receptorial defect of glycoprotein GPIb (the receptor for vWF) on the surface of uremic platelets: a negative correlation between serum creatinine and the expression of glycoprotein GPIb was found. The defect was not corrected by hemodialysis and/or peritoneal dialysis. Hemodialysis and peritoneal dialysis have a different impact on the expression of GPIIb/IIIa glycoprotein (the receptor for vWF): peritoneal dialysis seems to have a more favourable effect by restoring normal values of the expression of this membrane integrine. Theoretically the data could be correlated to the better biocompatibility of the peritoneal dialysis and to more favorable clinical behaviour in terms of accelerated atherosclerosis and athero-thrombotic complications in the uremic patients with end stage renal disease. Finally the abnormalities of platelet surface receptors may play a main role in the hemostatic alterations of uremic patients.
Asunto(s)
Plaquetas/metabolismo , Trastornos Hemorrágicos/complicaciones , Diálisis Peritoneal , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/metabolismo , Complejo GPIb-IX de Glicoproteína Plaquetaria/metabolismo , Diálisis Renal , Uremia/complicaciones , Uremia/metabolismo , Plaquetas/química , Creatinina/sangre , Citometría de Flujo , Hemostasis , Humanos , Uremia/terapiaAsunto(s)
Eritropoyetina/uso terapéutico , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/tratamiento farmacológico , Leucemia Mielomonocítica Crónica/complicaciones , Anciano , Anemia/tratamiento farmacológico , Anemia/etiología , Médula Ósea/patología , Humanos , Leucemia Mielomonocítica Crónica/patología , Masculino , Proteínas RecombinantesRESUMEN
UNLABELLED: The objective of this study was to evaluate the role of quantitative perfusion lung scintigraphy (QPLS) in predicting the development of chronic rejection in patients who underwent single-lung transplantation. METHODS: Eighteen patients (15 men, 3 women; age range, 41-60 y; mean age, 54.6+/-6.0 y) who underwent single-lung transplantation for emphysema (n = 14) or pulmonary fibrosis (n = 4) were studied. Patients were evaluated using QPLS and pulmonary function tests before surgery and at 1-3 mo and 1-3 y after transplantation. Relative perfusion of the transplanted lung was calculated from standard perfusion lung scintigrams. Values for forced expiratory volume in the first second (FEV1) were obtained from lung function tests at the same time points. The maximal and minimal relative perfusion and FEV1 values in the early (1-3 mo) and late (1-3 y) follow-up periods were identified for each patient. Receiver operating curve (ROC) analysis was performed on all parameters. RESULTS: In total, 82 lung scans were performed (mean, 4.8+/-1.55 per patient) and 484 FEV1 test determinations were obtained (mean, 30.0+/-15.6 per patient) during a follow-up period ranging from 8 to 84 mo (mean, 39.6+/-19.3 mo). In 7 of the 18 patients, chronic rejection developed, whereas 11 patients had a favorable outcome. No significant difference was found in the number of complications (acute rejection and infection episodes) between patients with a favorable outcome and patients with chronic rejection, up to 1 y after transplantation. At 1-3 mo, minimal relative perfusion values were 67.1%+/-12.2% in the favorable outcome group and 50.8%+/-9.6% in the chronic rejection group (P = 0.02). Before surgery and at 1-3 y, minimal relative perfusion was not significantly different between the 2 groups. The difference in maximal relative perfusion at 1-3 y was marginally significant, with 76.5%+/-8.9% in the favorable group and 64.3%+/-15.0% in the chronic rejection group (P = 0.051). FEV1 values were not significantly different preoperatively and 1-3 mo after surgery between the chronic rejection and the favorable outcome groups. Late in the follow-up period (1-3 y), FEV1 values in the chronic rejection and favorable outcome groups were 35.6%+/-7.9% and 56.9%+/-13.6%, respectively (P = 0.002). ROC analysis of minimal relative perfusion at 1-3 mo identified a threshold of 57% under which the sensitivity and specificity for chronic rejection were 83% and 88%, respectively. Minimal FEV1 for the same period identified a threshold of 48% under which the sensitivity and the specificity were 80% and 67%, respectively. CONCLUSION: QPLS early after transplantation in our patients predicted the development of chronic rejection in patients with single-lung transplantation for emphysema and pulmonary fibrosis, whereas surgical complications, acute rejection, infection episodes, and lung function tests did not predict the outcome. This early prediction could not be obtained from lung function tests performed at the same time.
Asunto(s)
Trasplante de Pulmón , Pulmón/diagnóstico por imagen , Enfisema Pulmonar/cirugía , Fibrosis Pulmonar/cirugía , Adulto , Femenino , Estudios de Seguimiento , Volumen Espiratorio Forzado , Rechazo de Injerto/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Enfisema Pulmonar/diagnóstico por imagen , Enfisema Pulmonar/fisiopatología , Fibrosis Pulmonar/diagnóstico por imagen , Fibrosis Pulmonar/fisiopatología , Curva ROC , Cintigrafía , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Hypoxemia is a common complication of chronic obstructive pulmonary disease and a major factor in patients' prognosis and quality of life. The response to exercise has been evaluated by various means but no standardization has been accepted. OBJECTIVES: To suggest a simple outpatient technique for evaluating the response of arterial oxygen saturation to exercise for use as a marker of disease severity. PATIENTS AND METHODS: Ninety-six patients with various degrees of COPD were divided into three groups: mild (forced expiratory volume in 1 sec > 65%), moderate (FEV1 between 50 and 65%), and severe (FEV1 < 50%). Using continuous oximeter recording we measured oxygen saturation during 15 steps of climbing, and quantified oxygen desaturation by measuring the "desaturation area," defined as the area under the curve of oxygen saturation from the beginning of exercise through the lowest desaturation point and until after recovery to the baseline level of oxygen percent saturation. Desaturation was correlated to spirometry, lung gas volumes, blood gas analysis, and 6 min walking distance. RESULTS: A good correlation was found between severity of COPD and baseline SaO2, lowest SaO2, recovery time, and desaturation area. A negative correlation was found between desaturation area and FEV1 (r = -0.65), FEV1/forced vital capacity (r = -0.58), residual volume to total lung capacity (r = 0.52), and diffusing lung capacity for carbon monoxide (r = -0.52). In stepwise multiple regression analysis only FEV1 correlated significantly to desaturation area. A good correlation was noted between 6 min walking distance and desaturation area with the 15 steps technique (r = 0.56). CONCLUSIONS: In patients with severe COPD, arterial hypoxemia during exercise can be assessed by simple 15 steps oximetry. This method can serve both as a marker for disease severity and to determine the need for oxygen supplementation.
Asunto(s)
Prueba de Esfuerzo , Enfermedades Pulmonares Obstructivas/diagnóstico , Enfermedades Pulmonares Obstructivas/fisiopatología , Oximetría/métodos , Oxígeno/sangre , Adulto , Anciano , Prueba de Esfuerzo/métodos , Femenino , Volumen Espiratorio Forzado , Humanos , Enfermedades Pulmonares Obstructivas/sangre , Masculino , Persona de Mediana Edad , Análisis de Regresión , Índice de Severidad de la EnfermedadAsunto(s)
Eritropoyetina/uso terapéutico , Hemoglobinas/fisiología , Agregación Plaquetaria/fisiología , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/metabolismo , Diálisis Renal , Ristocetina , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas RecombinantesAsunto(s)
Estrógenos/uso terapéutico , Fibrinógeno/efectos de los fármacos , Hemorragia/tratamiento farmacológico , Uremia/complicaciones , Factor de von Willebrand/efectos de los fármacos , Antígenos CD/biosíntesis , Antígenos CD/efectos de los fármacos , Plaquetas/citología , Plaquetas/efectos de los fármacos , Plaquetas/metabolismo , Frío , Eritropoyetina/administración & dosificación , Eritropoyetina/uso terapéutico , Estrógenos/administración & dosificación , Estrógenos/farmacología , Fibrinógeno/metabolismo , Hemorragia/etiología , Hemorragia/terapia , Humanos , Inyecciones Intravenosas , Integrina beta3 , Integrinas/biosíntesis , Integrinas/efectos de los fármacos , Complejo GPIb-IX de Glicoproteína Plaquetaria/biosíntesis , Complejo GPIb-IX de Glicoproteína Plaquetaria/efectos de los fármacos , Glicoproteínas de Membrana Plaquetaria/biosíntesis , Glicoproteínas de Membrana Plaquetaria/efectos de los fármacos , Receptores de Superficie Celular/biosíntesis , Receptores de Superficie Celular/efectos de los fármacos , Diálisis Renal , Uremia/fisiopatología , Uremia/terapia , Factor de von Willebrand/metabolismoAsunto(s)
Plaquetas/química , Trasplante de Riñón , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/análisis , Complejo GPIb-IX de Glicoproteína Plaquetaria/análisis , Adulto , Envejecimiento , Plaquetas/efectos de los fármacos , Niño , Ciclosporina/efectos adversos , Fibrinógeno/metabolismo , Humanos , Inmunosupresores/efectos adversos , Adhesividad Plaquetaria/efectos de los fármacos , Agregación Plaquetaria/efectos de los fármacosRESUMEN
Platelet surface receptors for von Willebrand factor and for fibrinogen (glycoproteins GPIb and GPIIb/IIIa) were studied with monoclonal antibodies CD42 and CD41 and cytofluorometry in 31 healthy subjects, 10 hemodialysis patients with no A-V fistula obstruction (patent original fistula), 10 hemodialysis patients with frequent A-V fistula obstruction (more than twice), 12 patients with mild chronic renal failure (creatinine 1.75 +/- 0.40 mg/100 ml), 11 patients with advanced chronic renal failure (creatinine 5.62 +/- 1.22 mg/100 ml), and 10 patients with end-stage renal disease (ESRD) treated with peritoneal dialysis. There was a significant increase of platelet surface glycoproteins GPIb and GPIIb/IIIa in the population of hemodialysis patients with frequent A-V fistula obstruction. The expression of these platelet receptors might be related to the prothrombotic tendency of a group of patients with ESRD, who suffer more occlusive and thrombotic events of the A-V fistula. This group of patients may also have a higher frequency of systemic thrombotic and atherosclerotic complications.
Asunto(s)
Fístula Arteriovenosa/fisiopatología , Plaquetas/metabolismo , Fibrinógeno/metabolismo , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/biosíntesis , Complejo GPIb-IX de Glicoproteína Plaquetaria/biosíntesis , Factor de von Willebrand/metabolismo , Anticuerpos Monoclonales/inmunología , Proteínas Sanguíneas/metabolismo , Citometría de Flujo , Humanos , Fallo Renal Crónico/inmunología , Diálisis Peritoneal/efectos adversos , Agregación Plaquetaria , Diálisis Renal/efectos adversosAsunto(s)
Antihipertensivos/uso terapéutico , Arteriosclerosis/tratamiento farmacológico , Plaquetas/metabolismo , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/biosíntesis , Receptores de Superficie Celular/sangre , Antihipertensivos/efectos adversos , Plaquetas/efectos de los fármacos , Humanos , Complejo GPIb-IX de Glicoproteína Plaquetaria/biosíntesis , Glicoproteínas de Membrana Plaquetaria/efectos de los fármacos , Receptores de Superficie Celular/efectos de los fármacosAsunto(s)
Plaquetas/efectos de los fármacos , Fibrinógeno/efectos de los fármacos , Aceites de Pescado/farmacología , Fallo Renal Crónico/dietoterapia , Factor de von Willebrand/efectos de los fármacos , Plaquetas/metabolismo , Fibrinógeno/metabolismo , Humanos , Fallo Renal Crónico/metabolismo , Factor de von Willebrand/metabolismoAsunto(s)
Aceites de Pescado/farmacología , Fallo Renal Crónico/tratamiento farmacológico , Fallo Renal Crónico/inmunología , Linfocitos B/efectos de los fármacos , Linfocitos B/inmunología , Humanos , Subgrupos Linfocitarios/efectos de los fármacos , Subgrupos Linfocitarios/inmunología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunologíaRESUMEN
Blood samples in sodium citrate 3.8% (ratio 1:10) of 15 healthy people were subjected to the pressure of 0, 50, 150 mm Hg respectively in a circuit operated by a peristaltic pump as during dialysis. The platelet aggregation induced by adenosine diphosphate (ADP) was determined in all cases. We found a significant reduction of the maximum percent aggregation of the samples exposed to the pressure of 150 mm Hg. We then suppose that a positive correlation exists between high pressure in the dialytic circuit and platelet damage.
Asunto(s)
Riñones Artificiales , Agregación Plaquetaria , Diálisis Renal , Adenosina Difosfato/farmacología , Adulto , Femenino , Humanos , Masculino , Agregación Plaquetaria/efectos de los fármacos , PresiónRESUMEN
Is well-known the haemolitic action that A-vitamine exerts on the erythrocytes. With our study we have submitted the erythrocytes, of forty normal subjects, to incubation to 37 degrees C and to constant traumatic action with and without A-vitamine. After we have dosed the haemoglobin and potassium in the plasma to various times of incubation and traumatic action. The results demonstrate that this vitamine determines an increase of the fragility of the erythrocytes beyond the 100% after 120 minutes, while protects the membrane of erythrocytes to the release of potassium.