Biocompatibility of hemodialysis membranes: interrelations between plasma complement and cytokine levels.

Hemodialysis (HD) membrane biocompatibility is defined as absence of complement activation. We have recently shown that circulating levels of interleukin (IL) 1 and IL-2 predict death and survival, respectively, of HD patients. Studies have assessed IL-1 in treatments with biocompatible and less biocompatible dialysis membranes, but no study has correlated circulating levels of all these immunoreactants. We assessed these immunoreactants, and temperature as an outcome, during HD in patients treated with different membranes. Twelve stable patients, receiving thrice-weekly chronic bicarbonate HD, were randomly dialyzed with three different types of membranes, composed of: Cuprophan, cuprammonium rayon modified cellulose, and Hemophan. Blood was drawn from the arterial line port before (Pre) and 15, 30, and 60 min during and after (Post) HD. Patients' temperatures were measured before and after each treatment. The plasma concentrations of IL-1 and IL-2 and factors C3a and C5a were assessed by ELISA. There were no differences between baseline levels of any of the immunoreactants in patients treated with different dialyzers. C3a, C5a, and IL-1 levels increased significantly during HD treatments with all three different membranes. C3a, C5a, and IL-1 levels during Cuprophan and Hemophan treatments were significantly higher than the levels during modified cellulose treatment at 30 and 60 min and Post (p < 0.01). For all the immunoreactants, however, the Post levels were higher than the Pre levels. In contrast to IL-1, there were no differences in mean IL-2 levels during treatments when different membranes were compared. There were few correlations of plasma C3a and C5a levels with plasma IL-1 levels, but there was only one treatment time in one dialyzer group during which IL-2 and any of the other factors were correlated. Pre and Post temperature values and percent change in temperature were not correlated with any of the immunoreactants measured. These data show that C3a, C5a, and IL-1 responses are similar, but not identical, during treatments with different membranes. The response of circulating IL-2 levels to treatments is quite different from that of plasma C3a, C5a and IL-1 levels and suggests that these changes are not solely due to treatment factors. Treatment with modified cellulose membranes is associated with a different immunoreactive profile as compared with patients dialyzed using other cellulose membranes. We suggest that circulating IL-1 levels are good biocompatibility markers.

Interdialytic weight gain and survival in hemodialysis patients: effects of duration of ESRD and diabetes mellitus.

BACKGROUND: Medical mortality determinants in end-stage renal disease (ESRD) patients treated with hemodialysis (HD) are well known. More recently, associations have been established between the dose of dialysis administered and patient survival. We showed in a prospective study that both dialyzer type and patient compliance with the dialysis prescription were independently associated with survival. Although several parameters of dialytic technique and patient compliance are associated with differential survival in patients with ESRD treated with HD, the association of interdialytic weight gain (IWG) with survival is unclear. No study has assessed the relationship between IWG and mortality in HD patients, controlled for multiple medical risk factors. The aim of our study was to determine whether IWG was associated with survival in patients with ESRD treated with HD, controlling for multiple medical and dialytic risk factors. METHODS: We prospectively conducted an observational, longitudinal, multicenter study of 283 urban HD patients to determine the relationship of IWG with several dialytic parameters and patient survival. Medical risk factors such as demographic indices and comorbid conditions were assessed. We studied Kt/V, the protein catabolic rate (PCR), serum albumin and anthropometric measurements, behavioral compliance indices, dialyzer characteristics, and serum electrolyte concentrations, and correlated these with IWG. In addition, the duration of dialysis was assessed in HD patients with and without diabetes mellitus. Cox proportional hazards models assessed the relative mortality risk of increased IWG, controlling for variations in medical comorbidity and other mortality determinants. RESULTS: The mean (+/- SD) age of our population was 54.6 +/- 14.1 years, and the mean time they were treated with HD was 30.4 +/- 46.9 months. The mean IWG was 1.54 +/- 0.71% dry wt/day. Correlations were found between increased IWG and younger age, and lower midarm circumference, and increased Kt/V, PCR, and serum potassium concentration. The mean follow-up period was 48.9 +/- 10.6 months. An increase in IWG was associated with a significantly increased relative mortality risk in diabetic ESRD patients treated with HD when variations in age, comorbidity, serum albumin concentration, and dialyzer type and site were controlled. There was, however, no association of increased mortality risk with increased IWG in the larger population of patients without diabetes. In further analyses, the increased mortality risk associated with increased IWG was found to be present only in patients with diabetes mellitus who had recently started HD therapy for ESRD. CONCLUSION: IWG is correlated with several nutritional and dialytic variables and with parameters that predict survival in HD patients. Increased IWG is independently associated with decreased survival of diabetic ESRD patients treated with HD, after adjusting for variation in other medical risk factors. The population of incident diabetic HD patients is particularly susceptible to increased risk associated with increased IWG. The mechanisms underlying these results are obscure, but IWG might be associated with poorer survival in this population if it were linked to worsened hypertension, cardiovascular stress, or poorer glycemic control. Interventions to improve compliance with IWG in incident diabetic HD patients are warranted.

Outcome of an opportunistic infection after polymicrobial peritonitis in an HIV-infected patient treated with peritoneal dialysis.

The prevalence of human immuodeficiency virus (HIV)-infected patients with end stage renal disease (ESRD) is likely to increase and many of them will be on peritoneal dialysis as renal replacement therapy. Infectious complications are a major problem associated with peritoneal dialysis (PD). It has been speculated that the HIV-positive peritoneal dialysis population may develop peritonitis more frequently than other peritoneal dialysis patients. We present the complications and unexpected good response to medical management of PD-associated peritonitis in a young HIV-infected black male. He had two unusual and serious infections; the first was a polymicrobial peritonitis which predisposed the patient to an unusual infection caused by Corynebacteria JK for which he was successfully treated without catheter removal.