No abstract

Hemodialysis influences the transport of water through the erythrocytic membrane, and induces morphologic and functional modifications. Recently water channels, called aquaporins (AQP), have been identified on the membrane of red blood cells. The aim of the present study was, therefore, to evaluate any relationships between volumetric changes in erythrocytes (MCV), plasma osmolarity and membrane expression of AQP1 in 22 uremic patients during a hemodialysis session, and compare value with those in a control group of 22 healthy volunteers. Membranal AQP1 expression was evaluated using three methods: indirect immunofluorescence under confocal microscopy, immunoenzymatic method after membrane extraction, and immunoblotting. In uremic subjects, at baseline membrane AQP1 expression was significantly lower, whereas plasma osmolality was higher than in controls. At 1 and 2 h of replacement therapy, a progressive increase was observed in erythrocytic AQP1, values similar to those in controls being attained after 3.5 h. During the session osmolality values reduced progressively, becoming significantly lower than basal values. The mean erythrocytic corpuscular volume in patients with ESRD was significantly lower than in cntrols at baseline. This value increased during hemodialysis, attaining statistical significance with respect to the basal value at 3.5 h of dialysis. Close correlations were found between plasma osmolality and AQP1 values (r = –0.930; p < 0.05), and also between MCV and plasma osmolality trend (r = –0.909; p < 0.05). There was a linear correlation (r = 0.63, p < 0.05) between plasma AVP concentrations and plasma osmolality. The variations found in plasma osmolarity during hemodialysis, may induce AQP1 expression on the membrane of intact red blood cells.

These results suggest that patients with chronic hepatitis C unresponsive to IFNalpha monotherapy could benefit from combination therapy with IFNalpha + ribavirin.

No abstract

We investigated the efficacy and tolerability of three different types of interferon-alpha, administered with the same schedule to naive patients with chronic hepatitis C. One hundred and seven patients with histologically proven chronic hepatitis C were enrolled during a period of three years and randomly divided into three groups, to receive (a) leukocyte-interferon-alpha, 6 MU three times a week for 4 months, followed by 3 MU three times a week for 8 months (Group I); (b) recombinant-IFN-alpha-2a, with the same schedule (Group II); and (c) lymphoblastoid-IFN-alpha-N1, with the same schedule (Group III). All patients were followed-up for 6 months to evaluate the long-term response. The 'Complete Response' rates at the end of treatment were: 50%, 46.1% and 41.6%, in Groups I, II and III, respectively; most patients relapsed after the end of therapy, so that the 'sustained responders' were, after 6 months of follow-up, 18.7%, 23.1% and 19.4%, respectively. Analysis of pre-treatment variables showed that age, ALT and gamma GT serum levels, as well as the prevalence of liver cirrhosis, were lower in the 'sustained responder' group. Four patients were eliminated from the study because of severe adverse events: 1, 2 and 1, in Groups I, II and III, respectively. Our results indicate a similar response rate with the three different types of interferon-alpha, although at baseline, age, serum levels of gamma globulins and the number of patients with cirrhosis-possible negative-risk factors, were higher in Group I.