[Inflammatory markers in dialysis: epidemiological data]. / Les marqueurs inflammatoires chez les dialysés: données épidémiologiques.

Inflammatory markers such as C-reactive protein are frequently elevated in patients treated by dialysis. Serum concentration of these markers are much higher than in the general population, in which it has been clearly shown that chronic inflammation is associated to the occurrence of cardiovascular events. The mechanisms leading to chronic inflammation in dialysis patients may be related to chronic inflammation per se, or to dialysis. Furthermore, in these patients, raised inflammatory markers are associated to malnutrition and increased cardiovascular morbidity and mortality. The association of inflammation, malnutrition and atherosclerosis defines the so-called MIA syndrome.

Cytomegalovirus infection in transplant recipients resolves when circulating gammadelta T lymphocytes expand, suggesting a protective antiviral role.

gammadelta T cells undergo massive expansion in the peripheral blood of renal transplant recipients who are infected with cytomegalovirus (CMV). In a 3-year prospective study, the relationship between the evolution of CMV infection and the kinetics of gammadelta T cell amplification was followed for 10 months after transplantation. Patients with late gammadelta T cell expansion (>/=45 days) had significantly longer (P<.0001) and higher (P<.0003) pp65 antigenemia and more-symptomatic CMV disease than did patients with early expansion. Analysis of data for each patient showed that gammadelta T cell expansion is concomitant with the resolution of CMV infection and disease, regardless of the CMV serologic status of donor and recipient before transplantation. These observations point to gammadelta T cell percentage determination as a new, rapid, and reliable prognosis factor to predict the resolution of CMV infection and strongly suggest that gammadelta T cells play a protective role against CMV infection.

Determinants of arterial compliance in patients treated by hemodialysis.

BACKGROUND: Cardiovascular disease is the principal cause of morbidity and mortality among hemodialysis patients. Several studies have demonstrated the importance of a reduction in arterial compliance in the development of cardiovascular complications, reflecting the interaction of functional and structural alterations of the peripheral arterial system and left ventricle. The aim of the present study was to demonstrate that arterial compliance, evaluated by automated recording of the QKd interval, was lower in hemodialysis patients than in normal subjects. A secondary objective of the study was to assess the influence of several factors, including calcium-phosphorus parameters, on decreased arterial compliance in these patients. PATIENTS AND METHODS: Arterial compliance was evaluated in 24 chronic hemodialysis patients who had normal (n = 12) or high blood pressure (n = 12), using a method of measuring systolic wave velocity by automated recording of the QKd interval. This interval corresponds to the time (in ms) between the onset of the electrocardiogram QRS complex (Q) and the Korotkoff (K) sound at diastolic pressure (d) heard over the brachial artery during blood pressure measurement. The analysis was performed in comparison with reference values obtained in a population with normal renal function. The other parameters determined were: age, duration of chronic renal failure, duration of hemodialysis therapy, left ventricular mass, vascular calcification score, serum total and ionized calcium, phosphorus, parathyroid hormone, calcidiol, calcitriol, and blood concentration of hemoglobin. RESULTS: The arterial stiffness of all the patients was increased significantly (p < 0.001) compared to reference values obtained from subjects without renal failure, the average age, height, and blood pressure of whom were similar to those of the patients. Multivariate analysis demonstrated a positive relationship among the QKd interval, serum total calcium, and the duration of hemodialysis. This suggested that arterial wall elastic properties were dependent not only on hypertension and constraints of pressure, but that they were also influenced by calcium and phosphorus metabolism and the duration of renal substitution therapy. CONCLUSIONS: Arterial compliance, evaluated by the ambulatory method of QKd measurement, is reduced in chronic hemodialysis patients, and is inversely correlated with serum calcium concentration and dependent on the previous duration of hemodialysis therapy.