In vivo intracellular cytokine production by leukocytes during haemodialysis.

Several chronic inflammatory changes undergone during chronic haemodialysis are associated with increased pro-inflammatory cytokine production. Although generation of anaphylatoxins has been incriminated in the untoward effects of haemodialysis, it is still debated whether anaphylatoxins stimulate monocyte secretion of TNF-alpha and IL-1. We demonstrate that peripheral mononuclear cells isolated from healthy controls and cultured with complement-activated autologous serum or recombinant C5a induced high levels of IL-1, IL-1ra, IL-8 and MCP-1, low levels of TNFalpha and sTNFRII but no IL-10 and MIP-1alpha. Cytokine production by leukocytes was investigated by FACS analysis in six patients dialysed consecutively with three equivalent low permeability membranes known to activate the complement to different degrees: polysulfone (F6HPS), cellulose acetate (CA) and cuprophane (CP). Percentage of leukocytes expressing IL-1, IL-1ra, TNF-alpha and IL-8 is increased in patients dialysed with CP. Moreover, we show for the first time that haemodialysis is associated with the production of cytokines by circulating neutrophils. Predialysis plasma levels of MCP-1 and TNFRII did not increase during the dialysis session at the time when anaphylatoxin generation was highest. Dialysis with membranes that activate the complement to a high extent induce activation of leukocytes which may explain chronic complications associated with dialysing with CP.

[Factors determining the choice of a modality of treatment by dialysis: a study of nine dialysis centers]. / Facteurs déterminant le choix d'une modalité de traitement par dialyse: une enquête dans neuf centres de dialyse.

BACKGROUND: The objective of this cross-sectional study in a population of 1472 dialysis patients was to identify the main factors involved in the choice of a specific option for dialysis therapy, taking into account three different types of criteria such as medical dependence (DM), nurse care requirement (SI) and independence for dialysis therapy (CA). METHODS: Each patient has been analysed, independently of present treatment modality, according to the above three criteria, namely DM, SI and CA. For each type of parameter, patients have been allocated to one of three levels, each level being established to evaluate whether dialytic treatment should be undertaken as hospital centre dialysis (HDC) or in a facility off the hospital. Level 3 of any one category corresponded to the inability of doing haemodialysis at home (HHD) or in self-care unit (AD). Level 2 included patients who could be treated in AD or by peritoneal dialysis (PD) with the assistance of a nurse. CAPD or HHD were considered as potential treatment modalities only in patients qualifying for level 1 of each criterion. RESULTS: In the patient population as a whole, the following treatment options were observed: HHD 3.6%, CAPD 6%, PD 1.8%, AD 16.3% and HDC 72.2%. For medical dependence (DM) there was a relatively even distribution for the three levels in six centres. In contrast, two centres were characterized by a predominance of DM level 3. Differences in DM levels between centres were greatly reduced when considering separately only those patients who were actually treated by CAPD, HDC and AD. SI levels were more uniformly distributed within all centres, and this was true for HCD and AD patients. When considering CA levels in HDC patients, a large predominance of CA level 3 was observed in all centres whereas CA level 1 was nearly in existent. CONCLUSION: The major finding of this study was that the inability or the refusal of dialysis patients to participate at treatment, independently of medical condition and nurse care requirement, was the main factor in the choice of hospital centre dialysis.

Dissociation between complement activation, integrin expression and neutropenia during hemodialysis.

Complement activation, neutrophil stimulation, increased cellular adhesiveness, transient leukocyte margination and pulmonary leukostasis take place during hemodialysis with cellulosic dialysis membranes. Several investigators have hypothesized that complement activation is primarily responsible for the acute neutropenia occurring during the early phase of bio-incompatible hemodialysis. We have investigated the relationship between complement activation, levels of expression of CD11b and CD61 integrins on neutrophils and platelets, neutrophil counts and blood gas measurements in patients dialyzed with three types of membranes, known to activate the complement system to a different extent. Polysulfone, cellulose acetate and cuprophane membranes were used subsequently in six patients in a prospective cross-over trial design to reduce inter-individual variability. Increased levels of CD61 and CD11b, as well as neutropenia, were detected regardless of the type of membrane used. We observed a high inter-individual variation with regard to complement activation suggesting varying susceptibility to dialysis membranes. We also report that the kinetics of anaphylatoxin generation were dissociated from those of the upregulation of adhesion molecules, early neutrophil margination and decrease in PaO2 during the first 30 min of hemodialysis. Similar results were obtained with all three types of dialysis membranes. The data strengthen the hypothesis that factors other than complement are involved in the induction of dialysis-related neutropenia and hypoxemia.

Prevalence of present and past hepatitis G virus infection in a French haemodialysis centre.

BACKGROUND: Previous studies, detecting GB virus-C (GBV-C) or hepatitis G virus (HGV) RNA by using reverse transcriptase polymerase chain reaction (RT-PCR), have shown that haemodialysis (HD) patients had a high risk of being infected and viraemic with this virus. A past GBV-C/HGV contact can now be detected by testing for antibodies directed against the GBV-C/HGV envelope protein E2 (anti-E2). METHODS: In order to evaluate GBV-C/HGV contact, 120 patients undergoing chronic HD were tested for GBV-C/HGV RNA by RT-PCR and anti-E2 antibodies by ELISA. GBV-C/HGV viraemic patients were followed prospectively for 18 months, and retrospectively when sera were stored. The total follow-up was between 18 and 78 months. RESULTS: GBV-C/HGV RNA was detected in 17 patients (14%), and 18 patients (15%) had a significant level of anti-E2 antibodies. No positive anti-E2 specimens were also positive for GBV-C/HGV RNA and vice versa. A total of 35 patients (29%) were contaminated with GBV-C/HGV. Sixteen of the 17 viraemic patients had a persistent viraemia (follow-up 18-78 months) and one cleared the virus during the study period. A past or present GBV-C/HGV contact was statistically correlated with the duration of HD and hepatitis C virus (HCV) infection, but was independent of age, hepatitis B virus (HBV) infection, and alanine aminotransferase (ALT) level. CONCLUSIONS: Twenty-nine per cent of patients who underwent HD in our centre have been infected by GBV-C/HGV, 49% were still viraemic and 51% have developed anti-E2 antibodies, indicating a past contact with GBV-C/HGV. Our results demonstrate that the prevalence of GBV-C/HGV contact in HD was underestimated when only RT-PCR was used. Therefore GBV-C/HGV contact is probably much more frequent in HD than previous studies would suggest and is at this time not correlated with hepatotoxicity. Anti-HCV antibodies blood screening since 1990 and recent changes in managing HD patients have probably reduced GBV-C/HGV contact in the same way.

[Prevalence of HIV infection in dialysis patients: results of a national multicenter study]. / Prévalence de l'infection à VIH chez les patients dialysés: résultats d'une enquête multicentrique nationale.

In order to determine the prevalence of HIV infection in french patients with end-stage renal disease (ESRD) on maintenance dialysis therapy, questionnaire forms were mailed out in february 1997 to the heads of the 260 dialysis facilities. We documented number of patients on maintenance dialysis therapy (hemo and peritoneal dialysis) and for HIV infected dialysis patients: age, gender, cause and duration of ESRD, known duration of HIV infection, risk factors for HIV infection, HBV and/or HCV infection, presence of clinical acquired immunodeficiency syndrome (AIDS), total CD4 count and treatment with antiretroviral agents. Questionnaire forms were returned from 98% of the dialysis facilities. As of february 1997 some 22,707 patients with ESRD were treated by renal replacement therapy, 19,947 by hemodialysis (HD) and 2760 by peritoneal dialysis (PD). 82 patients with ESRD and HIV infection were reported corresponding to 0.36% prevalence rate of all patients undergoing dialysis at the time specified. The 82 study subjects with ESRD and HIV infection received hemodialysis (79 patients) or peritoneal dialysis (3 patients) in 42 facilities. Forty seven patients were treated in Paris and suburbs and 9 in our own center. All 82 patients comprised 63% men and 47% women which included patients coming from Africa (37%), Caribbean and Oceania (28%), Europe (35%) of a mean age of 41.8 years. Modes of transmission were homobisexuals 15%, heterosexuals 31%, intravenous drug abusers 17%, blood transfusion 17% and unknown 20%. The mean duration of HIV infection was 96 months (range 12-168 months) and the mean duration of ESRD was 58 months (range 1-235 months). HIV associated nephropathy was established in 31%. AIDS was diagnosed in 25 patients. Seventy one percent of the patients were receiving an antiretroviral drug (tritherapy in 25% of cases). In conclusion HIV prevalence rate among French dialysis patients is low and focused in Paris and oversea. Sexual transmission is the most important HIV contamination but blood transfusion transmission remains greater than in general HIV population. Survival has improved compared with the survival rate reported in the 1980s.

Dissociation between beta-2 microglobulin and IL-1 production in hemodialyzed patients.

BACKGROUND: beta-2 microglobulin is predominant in amyloid deposits in patients undergoing long term hemodialysis. Amyloid accumulation has been ascribed to dialysis membranes, endotoxin contamination of the dialysate, uremia and chronic systemic inflammation associated with enhanced monocytic cytokine production in hemodialyzed patients. Interleukin-1 has been proposed to play a critical role in the induction of beta-2 microglobulin synthesis and release. METHODS: We examined if monocytes contribute to beta-2 microglobulin production upon stimulation with inflammatory mediators that are generated during hemodialysis and investigated the production of beta-2 microglobulin by cells from patients, with and without clinical signs of amyloidosis, at the time when patients' monocytes contained maximal intracellular accumulation of IL-1. RESULTS: We demonstrated that only monocytes are able to release increased levels of beta-2 microglobulin upon stimulation by IL-1, TNF alpha, C5a and LPS. Increased levels of beta-2 microglobulin were associated with increased levels of beta-2 microglobulin mRNA. Before dialysis session, 20-60% of circulating CD14+ monocytes from patients contained IL-1. At the time when maximal IL-1 production was detected, we showed by RT-PCR increased transcription of IL-1 gene in patients' monocytes. We observed that monocytes from patients with amyloidosis contained higher amounts of IL-1 as compared to monocytes from patients without clinical signs of amyloidosis, but could not secrete increased amounts of beta-2 microglobulin upon LPS-stimulation. CONCLUSIONS: Our data indicated that chronic inflammation, as demonstrated by increased intracellular IL-1 expression, is not associated with increased production of beta-2 microglobulin by monocytes from patients on hemodialysis.

[Prevention of hepatitis C virus transmission in hemodialysis]. / Prévention de la transmission du virus de l'hépatite C en hémodialyse.

The strategy to prevent hepatitis C virus (HCV) transmission to hemodialysed patients includes the screening of blood donors, the use of erythropoietin and the actual, strict application of Universal Precautions. In particular, articles should not be shared between patients, gloves changed and handwashing performed systematically after caring for a patient. The isolation of anti HCV (+) hemodialysed patients is not warranted. The prevention of HCV transmission to staff members relies mainly on the prevention of accidental needlestick injuries.

Adequacy of haemodialysis and nutrition in maintenance haemodialysis patients: clinical evaluation of a new on-line urea monitor.

BACKGROUND: Recent developments in urea sensing monitoring show a good agreement between on-line and direct dialysis quantification which permits evaluation of both effective dialysis efficiency and protein catabolic rate of dialysis patients. METHODS: Fifty chronic haemodialysis patients were enrolled in a prospective study using an automatic urea sensing monitor operating on spent dialysate (U.M. 1000, Baxter). Dietary protein intake (DPI) and energy intake (DEI) were carefully evaluated by a skilled dietitian over 1 week. During this run U.M. 1000 was used to provide urea mass removed, effective Kt/V, and normalized nPCR. Blood samples were drawn pre- and post-dialysis for classical blood-based single pool Kt/V calculations at each session. RESULTS: For all patients results were as follows (mean +/- SD): Effective Kt/V 1.4 +/- 0.3, nPCR 1.2 +/- 0.3 g/Kg/day, DPI 1.2 +/- 0.3 g/Kg/day and DEI 30.1 +/- 7.2 Kcal/kg/day; blood-based single pool Kt/V 1.5 +/- 0.3. A strong correlation was found between nPCR and DPI for the 50 patients over 1 week (r = 0.75, P < 0.0001) and between effective Kt/V and single pool calculated Kt/V (r = 0.76). CONCLUSIONS: Urea Monitor 1000 is easy and convenient to use and there was a good correlation of the predialysis BUN and effective Kt/V with standard blood-side measurements. In stable haemodialysis patients who are not strongly catabolic or anabolic, the urea monitor measurement of nPCR correlated with DPI measured by a 7-day dietary record.

Accumulation of 5 alpha-reduced androgen glucosiduronates associated with impaired removal in young male hemodialysis patients.

Hypothalamic-pituitary gonadal function is commonly altered in dialysis patients. Even though an improvement in general status and well-being has been noted after recombinant human erythropoietin supplementation, no significant changes were observed in the sex hormone profile. Pituitary gonadal axis as well as 5 alpha-reduced androgen glucosiduronates (i.e. 5 alpha-androstane,3 alpha,17 beta-diol and androsterone) profiles were studied in 23 young male stable dialyzed patients and compared to an age-matched group of healthy subjects. 5 alpha-Reduced androgen glucosiduronates are products of peripheral testosterone (T) metabolism and seem to be a useful tool in assessment of the male androgen status. Their polarity facilitates their urinary excretion, and their clearance is similar to the glomerular filtration rate in healthy men. We observed 1) a pituitary-Leydig cell dysfunction supported by normal serum estradiol and T levels, low free T, and increased LH levels; 2) an alteration of the dehydroepiandrosterone (DHEA) sulfate-DHEA interconversion, reflected by a dramatic decrease in DHEA while DHEA sulfate levels remained in the normal range; 3) an accumulation of 5 alpha-reduced androgen glucosiduronates, whose removal was impaired as shown by their very low sieving coefficients (< 0.012). Taken together, the above observations are consistent with alteration of spermatogenesis with respect to dialysis duration in which earlier elevated baseline serum LH levels indicate a primary defect in Leydig cell function.

Genotype distribution and transmission of hepatitis C virus (HCV) in French haemodialysed patients.

BACKGROUND: HCV genotyping was performed to identify the source of HCV infection in haemodialysed patients. METHODS: Specimens from 48 HCV-infected patients treated in the same dialysis unit were genotyped by line probe assay (LiPA). RESULTS: Thirty-seven patients (77%) were infected by genotype 1b. Only four of the 48 patients were never transfused and three of them had genotype 1b. In two of the three genotype 1b-infected patients, seroconversion was observed during the follow-up , suggesting a nosocomial HCV infection. Ten of the 44 transfused patients were infected with genotypes other than 1b. Blood products were very probably the source of infection in these patients. The 34 other patients (77.3%) were infected with genotype 1b and retrospective analysis failed to identify nosocomial and transfusional origin. Eight of the 11 patients with genotypes different from 1b were found in the 16 patients who were more than 55 years old. Only three of the eight originated from France. CONCLUSION: Blood transfusions and nosocomial infections were the main causes of HCV transmission in haemodialysed patients. Both screening of blood donors and aseptic measures in haemodialysis units may prevent HCV transmission.

A major role for CD62P/CD15s interaction in leukocyte margination during hemodialysis.

We investigated expression of several antigens on neutrophils and monocytes, involved in cell adhesion, from patients hemodialyzed with cellulosic and polyacrylonitrile membranes. Among the antigens tested only the expression of CD15s and CD11b was significantly increased on neutrophils and monocytes in patients dialyzed with cellulosic membranes. No changes occurred with polyacrylonitrile membranes. Leukocyte counts from patients dialyzed with cuprophane membranes decreased at the same time as expression of cellular CD15s increased, resulting in a significant negative correlation at all time points tested. No correlation was found between the drop of monocytes and their expression of CD11b. When CD15s expression increased on neutrophils and monocytes, we observed a concomitant increase of CD62P, a specific selectin of activated platelets. When whole blood cells were incubated with complement activated serum both antigens increased but not when cells were incubated with hrC5a. We also observed that CD61, a platelet phenotypic antigen, was present on leukocytes incubated with complement activated serum. At the time when platelet-leukocyte coaggregates decreased, CD62P expression remained stable on leukocytes, suggesting that both neutrophils and monocytes are able to trap either CD62P shed by activated platelets or soluble CD62P present in normal human serum. The present study documents a major role of P-selectin (CD62P)/sialyl-Lewis x (CD15s) interaction in the transient leukocyte margination during hemodialysis.

Hepatitis C virus (HCV) infection in haemodialysed patients: HCV-RNA and anti-HCV antibodies (third-generation assays).

Samples from 128 haemodialysed patients were tested by anti-HCV 2nd- and 3rd-generation assays from Ortho: 53 were positive by ELISA 2.0 and 54 (42%) by ELISA 3.0. The 54 anti-HCV-positive patients were tested by RIBA-2 and RIBA-3 and by PCR for the detection of HCV-RNA: 46 of the 47 patients (98%) reactive by RIBA-2 and 48 of the 51 patients (94%) reactive by RIBA-3 were HCV-RNA positive. Three patients with RIBA-3 indeterminate results were HCV-RNA negative. Among the 74 anti-HCV negative patients, 29 were tested by PCR with negative results. Two distinct episodes of hepatitis C have been observed in two patients during the follow-up and 44 of the 50 patients (88%) known positive for anti-HCV since at least 1989 were still viraemic in 1993. A very high correlation was found between anti-HCV antibodies reactive by RIBA and the presence of HCV-RNA. A lack of protection after a resolved infection and a high frequency of chronic disease have been observed as well as a reinfection or a reactivation of the infection in two patients.

Antibodies to hepatitis C virus by second generation test in hemodialyzed patients.

To assess the prevalence and the incidence of hepatitis C virus (HCV) in a dialysis unit, we prospectively tested for anti-HCV in chronic hemodialysis patients and staff members since January 1989, using a first generation assay. Incidence was nil in staff and low in patients (3.7% in 89, 1% in 90), and prevalence was 30% in patients. In January 1991 blood samples from 115 patients were tested by first (EL1) and second generation (EL2) ELISA (Ortho Diagnostic System). Positive subjects were tested by a RIBA-2 confirmation test. Fifty-three patients were negative by all tests. Positive tests were observed in 62 patients (54%) including 36 positive in EL1 and EL2, and 26 only by EL2. All positive patients were reactive by RIBA-2 but nine were classified undetermined (only one positive band). In five patients reactivity of antibodies to 5-1-1 and C-100-3 gradually declined during the study. Second generation tests gave a better correlation with time on dialysis and blood transfusion. We conclude that second generation tests for HCV are more accurate for estimating true prevalence of HCV infection in hemodialysis units.

Lipid peroxidation abnormalities in hemodialyzed patients.

In order to test the existence of a possible oxidative damage during hemodialysis, plasma conjugated dienes (CD), plasma and red blood cell (RBC) thiobarbituric acid (TBA) reactants were investigated in 25 patients receiving regular dialysis treatment (RDT). The RBC TBA reactant concentration was significantly increased in RDT patients in comparison with healthy subjects. The extracellular antioxidant systems were evaluated by the assay of plasma antioxidant activity, plasma tocopherol, urate, transferrin, haptoglobin and ceruloplasmin levels. Except urate and transferrin, none of these parameters were different between the two groups. On the other hand, in RDT patients, RBC superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were significantly lower than in healthy subjects. There was an inverse correlation between decreased RBC GPX and RBC TBA reactant concentration. These results show in RDT patients the existence of an oxidizing stress, mainly intracellular, which could be due, in part, to a decrease in SOD and GPX activities.

Didanosine pharmacokinetics in patients with normal and impaired renal function: influence of hemodialysis.

The pharmacokinetics of didanosine were investigated following oral administration of a single 375-mg dose to eight human immunodeficiency virus-seropositive patients with normal renal function and eight human immunodeficiency virus-seropositive uremic patients. In uremic patients, the plasma half-life was longer than that in control patients (respectively, 4.5 +/- 2.2 and 1.6 +/- 0.4 h). The ratio of total plasma clearance to absolute bioavailability was four- to fivefold lower in uremic patients than in patients with normal renal function (respectively, 491 +/- 181 and 2,277 +/- 738 ml/min). Because of the decrease in elimination, concentrations in plasma were higher for uremic patients than for control patients; the maximum concentrations of drug in plasma were, respectively, 3,978 +/- 1,607 and 1,948 +/- 994 ng/ml; the areas under the concentration-time curve were, respectively, 14,050 +/- 4,262 and 3,000 +/- 956 ng.h/ml. Didanosine was removed by hemodialysis with an extraction ratio of 53% +/- 8%, a hemodialysis clearance value of 107 +/- 21 ml/min, and a fractional drug removal during a 4-h dialysis of 20% +/- 8% of the dose. Dosage adjustments are necessary in uremic patients.