Susie Q. Lew

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.

Mycobacterium fortuitum Peritonitis in Two Patients Receiving Continuous Ambulatory Peritoneal Dialysis

We present two cases of non-resolving peritonitis treated with a standard peritonitis protocol. The organism identified from the peritoneal effluent was Mycobacterium fortuitum, a group IV (Runyon’s classification) rapidly growing, nontuberculous mycobacterium. M. fortuitum is ubiquitous and can be isolated from a number of natural sources. Risk factors these two patients had for developing M. fortuitum peritonitis included underdialysis, the immunocompromised state associated with end stage renal disease, prior or prolonged broad spectrum antibiotic treatment, and possible exposure to environmental factors, since both were hospitalized at about the same time. The isolates were resistant to the conventional antibiotics recommended for the treatment of this mycobacterium. Both patients, however, responded to catheter removal and antibiotics administered according to the sensitivities of the mycobacterium isolated.

Women Issues in Female Patients Receiving Peritoneal Dialysis

About 50% of the population receiving peritoneal dialysis (PD) in the United States are women. Nephrologists generally address medical issues related to end-stage renal disease, ie, anemia, hypercholesterolemia, secondary hyperparathyroidism. In female PD patients, specific topics should also be addressed. They include menstruation, birth control methods, osteoporosis, child bearing, postmenopausal hormone replacement and its consequences, screening of gynecological malignancies, sexual problems, and hemoperitoneum. We briefly describe in a multidisciplinary view the management of these issues.

Moderate Metabolic Acidosis and Its Effects on Serum Parameters in Hemodialysis Patients

We screened the laboratory data of 50 chronic hemodialysis patients selected randomly over a 21-month period to generate 158 data points which identified two groups: (1) those with a predialysis total CO2 concentration less than or equal to 19 mEq/l (data A; n = 57) and (2) those with a predialysis total CO2 concentration greater than 19 mEq/l (data B; n = 101). Then, both groups were compared for the following parameters: predialysis blood urea nitrogen (BUN), serum phosphorus, uric acid, creatinine, and albumin concentrations, Kt/V, urea reduction ratio, normalized protein catabolic rate, dry weight, ultrafiltration, blood flow and dialysis flow rates, duration of dialysis treatment, and blood pressure. Group data A had significantly higher predialysis BUN, phosphorus, and uric acid concentrations than group data B. There were significant inverse correlations between predialysis serum bicarbonate and predialysis BUN, phosphorus, and uric acid concentrations. Although it is not clear what the long term side effects of moderate metabolic acidosis are, we recommend its correction.

Pharmacokinetics of zidovudine in HIV-infected patients with end-stage renal disease.

We determined the pharmacokinetics of zidovudine (AZT) and its metabolite (GAZT) in HIV-infected patients with end-stage renal disease (ESRD), between dialysis sessions, and compared these to HIV-infected patients with normal renal function. Clearance of AZT in ESRD patients was not significantly different from controls. The mean serum AZT levels in ESRD patients were six times greater than the levels in normal controls at 4 h. Serum levels of GAZT were higher in ESRD patients at 90 min, and by 4 h were more than an order of magnitude greater than normal controls. If the AZT serum level is a good index of toxicity, we conclude that the currently recommended dose of 200 mg AZT three times a day is probably safe for use in HIV-infected patients with ESRD. The enterohepatic metabolism of AZT, the effect of such a dosing schedule and the effects of circulating levels of GAZT on outcomes in HIV-infected patients with ESRD must be further investigated.

Ethical Issues in Aging and Renal Disease

The incidence of elderly patients reaching end-stage renal disease (ESRD) and requiring renal replacement is increasing. Better medical care is helping patients live longer but, at the same time, is raising ethical questions. Treatment decisions for ESRD patients present a forum for the consideration of ethical questions surrounding the issues of scarce health care resource allocation and the withholding or withdrawal of life-sustaining treatment. As background for the consideration of ethical issues in ESRD patients, the quality of life they experience and what they may expect as death approaches also are discussed.

Peritoneal dialysis–associated peritonitis caused by propionibacteria species

There are an increasing number of reports about unusual causes of peritonitis in peritoneal dialysis (PD) patients. The Propionibacteria species is a microorganism that is a normal skin flora. Under the presence of certain risk factors, it may produce serious infections. Patients at risk of having Propionibacteria sp infections have malignancy, diabetes mellitus, foreign bodies, or immunodeficiency. We describe a PD-associated peritonitis in a 51-year-old woman that was caused by Propionibacteria sp. This patients risk factors for developing Propionibacteria sp peritonitis include a history of CREST syndrome, malignancy of the breast, and recent catheter surgery. To our knowledge, this is the first case of a PD-associated peritonitis caused by Propionibacteria sp reported in the literature.

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.

2nd International Congress of the Vascular Access Society / Author Index for Abstracts

May 30 to June 1, 2001, London