[Survival of patients starting dialysis at an advanced age in the Piedmont]. / La sopravvivenza del paziente entrato in dialisi con un'età molto avanzata in Piemonte.

BACKGROUND: Patients starting dialysis in old age (age > 70 and > 80) in Piedmont are widely increasing: the survival curves of this group of patients can give very important information to evaluate the quality of both the delivered therapy and our very wide criteria of acceptance to the treatment. To this end, using data from the Piedmont Dialysis and Transplant Register, the survival curves of patients with age over 70 and 80, beginning dialysis in all Piedmont Dialysis Units between 1981 and 1996, have been examined. METHODS: These curves have been considered both in a general way and according to the presence or absence of further high risk conditions; they show results better than expected and improving from 1981 to 1995. RESULTS: If the survival curves of these patients are considered according to the kind of dialytic treatment performed, they do not show any significative difference. CONCLUSIONS: The conclusion is drawn that these data strongly support first, the fitness of criteria of very wide acceptance to the treatment and modulated choice of the kind of dialytic treatment at present followed in Piedmont; and second, that dialysis treatment can give very good results also in elderly patients. So, it is suggested that the economic and structural difficulties of dialysis Units must not influence the nephrologist's choice towards elderly patients.

Intradialytic cytokine gene expression.

Along with the numerous technological improvements in molecular biology, polymerase chain reaction, which permits analysis of sequences of a very small amount of biological material, enables evaluation of hemodialysis-induced gene transcription of inflammatory cytokines. Blood samples drawn from 22 hemodialysis patients, treated with cellulose-derived or synthetic membranes, were collected at 0 and 15 min of hemodialysis. Total RNA, purified from mononuclear cells, was reverse transcribed and cDNA amplified by polymerase chain reaction primed with specific oligomers in order to determine tumor necrosis factor alpha (TNF alpha), interleukin (IL) 1 beta and IL6 gene expression. Plasma samples were collected at 0 and 180 min for detection of mature cytokines by enzyme immunoassay with plates pre-coated with monoclonal antibodies to TNF alpha, IL1 beta and IL6. A significant increase in TNF alpha mRNA was detected at 15 min of hemodialysis in 12 of 22 patients: 5 of 9 treated with cuprophan; 3 of 3 with cellulose triacetate; 3 of 5 with polysulfone, and only 1 of 5 treated with polymethyl-methacrylate membranes. A parallel increase in IL1 beta or IL6 mRNA was detected, and significant relationships were found between TNF alpha and IL1 beta (p < 0.001), and IL1 beta and IL6 gene expression (p < 0.05). Increased levels of mature TNF alpha and IL1 beta molecules in plasma were detected in the majority of patients showing an increased cytokine gene expression. However, the absolute amount of cytokine mRNA transcription at 15 min did not predict the levels of mature molecules reached in plasma at 180 min. Cytokine mRNA transcription is quite common at the beginning of a dialysis run. Possibly due to intracellular degradation of critical sequences of cytokine mRNA, gene expression does not necessarily imply translation into mature protein. It is suggested that mechanisms related to cell-to-cell interaction, which may possibly involve procytokine biology, are needed to drive phenomena of cytokine activation to clinical effectiveness.

[The complement system in kidney diseases]. / Il sistema del complemento in nefropatologia.

The multifaceted relations between complement system and immune-mediated nephropathies are reviewed. Several conditions in which either the complement activation induces renal damage without hypocomplementemia or hypocomplementemia occurs in the absence of circulating IC are reported as well as disorders in which immune complexes promote hypocomplementemia. The complement system is involved in the clearance of immune complexes, both modifying the immune complex size and favouring the physiologic neutralization by the erythrocyte transport system. In certain pathological conditions the immune complex intrinsic characteristic or genetic abnormalities prevent efficient removal from the blood stream. The purpose of the present review is to summarize these conditions, briefly describing their pathological consequences, and indicate a simple scheme to correctly interpret the biochemical abnormalities of the complement system in nephropathology.

Early increase in blood nitric oxide, detected by electron paramagnetic resonance as nitrosylhaemoglobin, in haemodialysis.

The objective of this study was to determine intradialytic blood levels of nitric oxide (NO), in patients undergoing chronic haemodialysis. This was done by detection of nitrosylhaemoglobin by a sensitive technique of spin trap electron paramagnetic resonance at 0, 5, 15, 60, 180 and 240 min of a 4-h standard bicarbonate dialysis, using the same dose (6000 U) of heparin and different dialysis membranes. The study group included 12 patients treated with cellulose-derived dialysis membranes (nine with cuprophan and three with cellulose triacetate) and 10 patients treated with synthetic membranes (five with polysulfone and five with polymethylmethacrylate). Control groups included 11 normal subjects and six patients with end-stage renal failure who were receiving intermittent peritoneal dialysis. Basal blood levels of nitrosylhaemoglobin in haemodialysis patients were significantly higher than normals, but similar to peritoneal dialysis patients. A significant increase (P < 0.01) in nitrosylhaemoglobin level was detected at 15 min of haemodialysis irrespective of the membrane used. A decrease to basal levels at 180 min was observed in all but two cuprophan-treated patients who, in contrast to the others, had a symptomatic hypotension at the end of the session and a further increase in blood nitric oxide. Patients undergoing peritoneal dialysis did not show any change in blood levels of nitrosylhaemoglobin during the first 180 min of the procedure. Thus, a constant increase in nitrosylhaemoglobin levels was observed early in haemodialysis, but not in peritoneal dialysis patients. Very preliminary evidence was obtained for a role of nitric oxide in the vascular instability at the end of haemodialysis in a few patients who had hypotensive episodes.