[Immune response to influenza vaccination among peritoneal dialysis patients]. / Risposta immune alla vaccinazione antiinfluenzale nei pazienti in dialisi peritoneale.

The influenza vaccination is considered useful in preventing influenza and its complications, but its efficacy is variable especially in uremia. The humoral efficacy in a group of 15 patients in peritoneal dialysis treatment has been evaluated. Antibody responses were measured before vaccination and at time intervals of 1-4 months after vaccination. A good response to viruses A (A/H3N2/Johannesburg 33/94, A/H1N1/Singapore 6/86), respectively 80% and 66.7% and an attenuated response (20%) to virus B (B/Beijing 184/93) was observed. For viruses A, the "non responders" were elder patients with a low count of lymphocytes. For virus B it is suggested that the low response is perhaps related to variable effectiveness of vaccine.

[Effectiveness of influenza vaccination in patients undergoing regular dialysis treatments]. / Efficacia della vaccinazione antifluenzale nei pazienti in trattamento dialitico regolare.

BACKGROUND: The influenza vaccination is considered useful in preventing influenza and its complications, but its efficacy is variable. Recent data on clinical effectiveness of influenza vaccination in renal patients are lacking. MATERIALS AND METHODS: The clinical efficacy in our Hemodialysis Unit during the last three years has been evaluated: 287 patients have been vaccinated. The rate of vaccination achieved has been of 81.3%. RESULTS: The efficacy has been of 46.7%. The difference of efficacy noted among young people (< 60 years) and elderly (> 60 years) in general population is not observed among our hemodialyzed patients. Bronchopulmonary complications (radiographically proven) have been low: 1.7%. No mortality increase has been observed. CONCLUSIONS: These findings suggest that influenza vaccine can reduce the incidence and severity of influenza virus infections also among hemodialyzed patients.

[Evolution of the serum aluminum values in the Piedmont dialysis population. Dialysis Centers of the Piedmont]. / Evoluzione dei valori di alluminio serico nella popolazione dialitica piemontese. Centri Dialisi del Piemonte.

The authors have evaluated the evolution of values of serum aluminium concentration (Als) in the whole pool of patients undergoing RDT in Piedmont in the years 1982-1990. We have compared the data of the Piedmont Regional Registry of Dialysis and Transplantation at the end of 1990 to those obtained in 1982, 1986 and 1989. A progressive reduction has been observed in the percentage of patients with Als > 100 micrograms/l, who were 13.5% of the pool in 1982 and 7.5% in 1986 and finally decreased to 1.5% in 1990. This is yet more evident for patients dialyzing at home as in 1982 43% of them had a Als > 100 micrograms/l, whereas in 1986 only 8.2% did and in 1990 this percentage had decreased to 3.6%. The values of Als (distinguished by type of treatment of chronic renal failure) show end confirm the improvement of the situation of aluminium accumulation, specially as regards bicarbonate HD where the percentage of patients with Als > 100 micrograms/l decreases from 10.5% in 1986 to 1.7% in 1990. These data point out the efficacy of prevention and control programs regarding aluminium pathology performed in the last years in Piedmont. This has led to a reduction of the severe accumulation syndromes observed in the first years of '80 and has allowed the nephrologist to prepare more correct therapeutic prescriptions.

[Biofiltration without buffering substances in the dialysate]. / La biofiltrazione senza sostanze tampone nel dialisato.

A new hemodiafiltration technique, acetate free biofiltration (AFB), has been recently introduced in the treatment of chronic uremia. It is performed with a buffer free dialysate and a simultaneous infusion in post-dilution mode of a sodium bicarbonate solution (concentration 145-166 mEq/l; infusion rate 1.2-2 l/h). A polyacrylonitrile hollow fiber AN69 HF 1.2 sqm dialyzer is employed. In acute studies pCO2 remains stable throughout the treatment, as well as pCO2. We have found a significant inverse correlation between delta[HCO3-] pre and post treatment and basal [HCO3-] (r = -0.88; p less than 0.001), with an excellent correction of uremic acidosis, avoiding post dialytic alkalosis. Our long term experience on 6 patients followed up to 31 months, allows us to consider AFB as a feasible and safe treatment, offering a good correction of uremic acidosis and an excellent hemodynamic tolerance. We propose AFB as a competitive technique with respect to bicarbonate hemodialysis, hemodiafiltration and standard biofiltration.

[Cardiac arrhythmias during dialysis. An unresolved problem]. / Aritmie cardiache in corso di dialisi. Un problema non risolto.

The incidence of the arrhythmias in 47 patients subjected to chronic hospital dialysis using different techniques has been assessed. Cardiopathies and non-cardiopathies were assessed separately. In the first group, no significant differences were observed with respect to the presence of heart rhythm disturbances. The second group showed increased ventricular arrhythmias during the intradialysis and postdialysis period. A statistical correlation was carried out between the presence of arrhythmias and various parameters (technique of dialysis, weight difference, ultrafiltrate/hour, age). The only statistically significant correlation in the non-cardiopathies was age.

Functional changes of monocytes due to dialysis membranes.

The functional effects directly induced by dialysis membranes on peripheral monocytes were analyzed in a plasma-free model of simulated dialysis using Cuprophan, cuprammonium rayon, polyacrylonitrile, polymethylmetacrilate and polysulphone membranes. A severe reduction of monocyte phagocytosis of IgG-coated erythrocytes was found by using Cuprophan and cuproammonium rayon. The cytofluorimetric analysis of several cell surface receptors, involved in the immune phagocytosis and recognizable by five quoted monoclonal antibodies, did not reveal any significant change. The defective phagocytosis of the IgG-coated erythrocytes by monocytes, due to the exposure to cellulose-derived membranes, was paralleled by an impaired interiorization of heat-aggregated human immunoglobulins, as analyzed by electron microscopy. The cell membrane binding of aggregated immunoglobulins was found to be unaffected. The defect was associated to a remarkably depressed generation of reactive oxygen species after Zymosan stimulation. Therefore, the defective immune phagocytosis induced by exposure of monocytes to cellulosic membranes was not due to a receptor rearrangement or an impaired binding of ingestible particles, but to a reduced internalization capacity probably related to an energy source exhaustion (as shown by the lack of response to stimuli able to induce oxidizing species production). These features are similar to those described in monocytes from acute systemic lupus erythematosus patients.

CAPD in a large population: a 7-year experience.

In this report we evaluate the results obtained with CAPD in uremic patients in Piedmont, a Northern Italian region (4.4 million inhabitants) during the last 7 years. Data are gathered from the computerized records of the regional dialysis and transplantation registry, which collects information on 3,567 pts, 2,243 of which entered since Jan. 1981 and 1,808 alive at Dec. 1987. Among these, 193 (11%) were on CAPD, a figure almost constant in the last 7 years. However CAPD diffusion is not uniform among the 20 centers of the region, ranging from 0 to 49.5% of the patients on dialysis. CAPD is particularly employed in the elderly (47.5% of the patients being older than 60 years and 19.5% over 70). This treatment was the first choice in 16% of the patients admitted to dialysis between 1981-87; this figure reaches 33% for the diabetics. High drop out rates still represent a major problem, in a 6 year follow up 66% of the patients being transferred to another dialysis treatment. Peritonitis is the main cause of drop out (22%), while loss of peritoneal membrane efficiency accounts for 7%, patient's choice 14%, catheter complications 14%, inability to cope 8%, clinical problems 20% and other reasons 15%. Drop out rate is not influenced by the presence of high risk condition or age. Survival curves show no significant difference for CAPD in comparison to hemodialysis in all the age groups considered. This epidemiological survey, based on a global 522 pts experience extended over a 7 year period, indicates that CAPD is a competitive mode of treatment in chronic uremia.