Influence of autonomy and type of home assistance on the prevention of peritonitis in assisted automated peritoneal dialysis patients. An analysis of data from the French Language Peritoneal Dialysis Registry

BACKGROUND

In France, 48% of home-based peritoneal dialysis (PD) patients require assistance to perform their exchange and manage their treatment. A total of 7% are aided by their family, and 41% by a private nurse. Of all the continuous ambulatory peritoneal dialysis (CAPD) patients, 61.7%, and among automated peritoneal dialysis (APD) patients 23%, are assisted at home for their bag exchanges and connections. Assisted APD patients (AAPD) are more comorbid and elderly so that a home helper is not always available: this explains why most helpers at home are private visiting nurses paid by the National Social Security. In addition to the home helper (nurse or family), 58% of centres make regular additional home visits to check the respect of procedures previously taught during the initial training of the nurse or the family helper. The aim of this study was to evaluate whether the type of home assistance received by dependent patients had an influence on peritonitis rates, and if home visits done by nurses of training centres may improve results.

METHODS

Peritonitis rates and the probability of being peritonitis free were analysed for 1624 new APD patients recorded in the French PD Registry (RDPLF) between 2000 and 2004, and followed-up until early 2005.

RESULTS

Nurse-assisted APD patients had a peritonitis rate of one episode every 36 months, and family-assisted patients one episode every 45 months; using Poisson analysis this trend was not significant (P=0.11). However, the probability of being peritonitis free was significantly higher for family-assisted (69.8% at 2 year) compared with home nurse-aided persons (54.4%) after adjustment for age, diabetes and the Charlson comorbidity index. This difference disappeared when nurses from the training centre regularly visited PD patients at their home in the presence of their helper, whichever type of assistance they received. In addition, when the nurses from the training centres visited private nurse-assisted patients, the probability of being peritonitis free was significantly improved in comparison with those persons who did not receive home visits, from 33.9% to 50.8% at 3 years (P=0.028).

CONCLUSIONS

APD patients assisted at home by a private nurse have a higher risk of developing peritonitis than family-assisted patients, unless additional regular home visits are organized by the original training centre. Therefore, we recommend that home visits be regularly made for dependent PD patients to optimize the quality of care provided by the helper.

[Iron therapy: is it different with peritoneal dialysis compared to haemodialysis?]

This paper reviews literature data on iron replacement (loading) for peritoneal dialysis patients. The 3 main sources of clinical guidelines (American NKF-K/DOQI, European EBPG and French AFSSAPS) agree about the definition of iron deficience, but are not similar about the haemoglobin/hematocrit targets for EPO treatment, and for the route of iron administration (oral versus intravenous). Iron requirements are less in PD HD patients. That could be explained by several factors: less blood losses, preservation of a residual renal function, better digestive iron absorption due to a greater hepcidin excretion. Intravenous route for iron sucrose is more efficient than oral route. Taking into account the iron requirements for PD patients, monthly 200 mg iron sucrose infusions over 5 mn seem to be safe and sufficient for most patients.

APD schedules and clinical results

This chapter exposes the clinical effects of different APD schedules. Clinical studies have shown that Na removal is lower with APD compared to CAPD. Therefore the loss of residual renal function requires continuous therapy with long day-dwell of polyglucose dialysate. Peritoneal small molecule clearances are closely determined by the hourly dialysate flow rate (and not the dwell time, which is a concept coming from equilibrium PD techniques as CAPD) with a maximum reached by 3 l/h for average transporter patients. On the other hand, the optimal intraperitoneal volume should be 1500 ml/m(2) of BSA, and less if the hydrostatic intraperitoneal pressure is higher than 18 cm H(2)O. The optimization of the nocturnal APD session depends on the knowledge of the individual drain flow profile. A new schedule, called 'BreakPoint-APD' is based on the automatic adaptation to the drain profile for each patient and for each cycle. It increases clearances by about 10% compared to tidal and CCPD, though reducing the number of nocturnal alarms. The future of APD is likely to continue thanks to further simplification in the machine use, i.e. with improvements in cycler technology.

Surfactant-free anionic PLA nanoparticles coated with HIV-1 p24 protein induced enhanced cellular and humoral immune responses in various animal models

Microparticles and nanoparticles prepared with poly(D,L-lactide-co-glycolide) (PLGA) or poly(D,L-lactide) (PLA) polymers represent a promising method for in vivo delivery of encapsulated peptide, protein or DNA antigens. However, one major issue that limits the potential of these delivery systems is the instability or the degradation of the entrapped antigen. Charged microparticles carrying surface adsorbed antigen were developed to resolve this problem and appear more suitable for vaccine applications. We describe here new anionic PLA nanoparticles obtained by the dialysis method that are absolutely surfactant-free, which makes them more appropriate for use in humans. The potency of this delivery system as a vaccine carrier was tested in various animal models using HIV-1 p24 protein. p24-coated PLA nanoparticles (p24/PLA) induced high antibody titres (>10(6)) in mice, rabbits and macaques. Moreover, p24/PLA nanoparticles elicited strong CTL responses and a Th1-biased cytokine release (IFNgamma, IL-2) in mice. p24 protein seemed to generate a more Th1-oriented response when administered coated onto the surface of PLA nanoparticles than adjuvanted with Freund's adjuvant. Most importantly, the ability of p24/PLA particles to induce Th1 responses was also confirmed in the macaque model, since high levels of IFNgamma-producing CD4+ T cells and CD8+ T cells could be detected by the ELISPOT assay. This protein delivery system confirms the potential of charged nanoparticles in the field of vaccine development.

Impact of first dialysis modality on outcome of patients contraindicated for kidney transplant

BACKGROUND

We compared, in patients contraindicated for kidney transplant, outcomes between those patients who were only on hemodialysis (HD) and those who were given peritoneal dialysis (PD) as first renal replacement therapy (RRT).

DESIGN

Prospective, population-based cohort study of incident cases of end-stage renal disease between June 1997 and June 1999.

SETTING

A network of dialysis care: NEPHROLOR, that is, all the renal units in Lorraine, one of the 22 French administrative regions (population over 2.3 million people).

PARTICIPANTS

387 patients were contraindicated for kidney transplant during the first 2 years of RRT: 284 were on HD, 103 on PD. Mean age was 67.6 +/- 11.3 years for HD patients and 70.8 +/- 11.4 years for PD patients (p = 0.015).

MAIN OUTCOME MEASURES

Mortality until June 2003, hospitalization over the 2 first years of RRT, and Kidney Disease and Quality of Life Short Form (KDQOL-SF) 6 and 12 months after initiation of RRT.

RESULTS

HD patients were more likely to die from cardiac or cerebrovascular causes, PD from cachexia or withdrawal from dialysis. Whatever mode of RRT, the unadjusted 2-year and 5-year survival rates were similar (p = 0.98). The rate of total duration of hospital stay per month of RRT was similarin HD and PD groups: 2.7 +/- 4.5 and 2.9 +/- 4.2 days respectively (p = 0.7). PD was associated with better quality of life than HD. The dimensions Role limitation due to emotional function, Burden of kidney disease, and Role limitation due to physical function ranked first, second, and third for PD.

CONCLUSION

In Lorraine, end-stage renal disease patients who were given PD as first-line RRT had no excess of death risk or hospitalizations, and better quality of life the first year of RRT.

The efficacy and safety of once-weekly and once-fortnightly subcutaneous epoetin β in peritoneal dialysis patients with chronic renal anaemia

BACKGROUND

Reducing the dosage frequency of subcutaneous epoetin in peritoneal dialysis (PD) patients is convenient and should improve patient satisfaction and, possibly, compliance. We investigated if a weekly dosage of epoetin beta in PD patients safely maintained haemoglobin (Hb) concentrations equivalent to those obtained with previous twice- or thrice-weekly administration. In addition, we investigated if a fortnightly dosage of epoetin beta was safe and as effective as previous weekly administration.

METHODS

After a 4 week run-in period, PD patients were switched to either weekly or fortnightly epoetin beta administration, depending on their previous treatment schedules, for 25 weeks.

RESULTS

The per-protocol cohort included 128 patients, of whom 54 received epoetin beta once weekly and 74 once fortnightly. The mean change in Hb concentration from baseline over weeks 13-25 and the 90% confidence intervals (CIs) remained within the target range (10-12 g/dl) and specified equivalence (+/-0.75 g/dl) limits in the weekly (-0.34 g/dl; 90% CI: -0.14 to -0.54 g/dl) and fortnightly (-0.39 g/dl; 90% CI: -0.24 to -0.55 g/dl) cohorts. The mean change from baseline in the epoetin beta dose was 1.4 IU/kg/week (90% CI: -3.8 to 6.6 IU/kg/week; 2%) in the weekly cohort and 4.4 IU/kg/week (90% CI: 1.7-7.2 IU/kg/week; 13%) in the fortnightly cohort. Both treatment regimens were well tolerated.

CONCLUSIONS

In stable PD patients switched from twice- or thrice-weekly to weekly epoetin beta treatment, Hb concentrations could be maintained within the specified range over 25 weeks without significant change in their mean epoetin beta doses. In patients switched from weekly to fortnightly treatment, Hb concentrations could also be maintained over 25 weeks. There was a small increase in the mean dose during this period, but >/=50% of patients could be maintained without dose increase. Reducing dosage frequency may improve compliance in PD patients who self-administer their epoetin.

[Infection peritonitis in patients undergoing continuous ambulatory peritoneal dialysis: microbiological review during an four-year period]

The purpose of this study was to analyse the microbiological characteristics of infectious peritonitis in patients undergoing continuous ambulatory peritoneal dialysis. This study was conducted at the CHU Nancy from 1999 to 2002. The diagnosis of peritonitis was based on cloudy peritoneal effluent (>100 cells per mm(3)) with an elevated leukocyte count (>50%), on isolation of bacteria or fungi and on symptoms such as abdominal discomfort or pain. The majority of infections associated with continuous ambulatory peritoneal dialysis were caused by Gram-positive bacteria (68%), Gram-negative bacteria (31%), and Candida (1%). The coagulase-negative staphylococci were the most common cause of peritonitis. The antibiotic sensitivity of species corresponded to community-acquired isolation.

Short communication: retrospective study to time the introduction of HIV type 1 non-B subtypes in Lyon, France, using env genes obtained from primary infection samples

Using blood samples from primary HIV-1 infection (PHI) patients obtained in Lyon, France, we characterized the newly transmitted HIV-1 variants in this area during the 1992-1996 period. As PHI samples allowed the precise timing of the transmission event, we were able to date the introduction of non-B subtypes or recombinant forms of the virus in Lyon. Genomic DNA from 18 HIV-1-positive patients at primary infection was used to amplify the full-length env gene by nested PCR; after cloning, the gene was sequenced for subsequent phylogenetic analysis. Several non-B subtypes and recombinant forms of HIV-1 were identified among the 18 patients studied (1 subtype F1, 1 CRF01-AE, 2 subtype G and 2 CRF02-AG). We also found a new J/K recombinant form transmitted in 1995 and never described until now. The introduction of CRF02-AG in Lyon, France, occurred prior to 1992 and six transmission events including non-B subtypes were documented in the following 4 years. Heterosexual contacts appeared as the main introduction pathway for non-B subtypes or recombinant forms. Nevertheless, as transmission of these viruses occurred not only during travel to endemic regions, but also in France or Germany, we conclude that non-B strains entered Europe before the studied period. This retrospective study showed that even if subtype B remained prevalent in the spreading HIV-1 infection in Lyon between 1992 and 1996, non-B subtypes and circulating recombinant forms represented a significantly growing part.

Evaluation in rhesus macaques of Tat and rev-targeted immunization as a preventive vaccine against mucosal challenge with SHIV-BX08

Recent evidence suggests that a CD8-mediated cytotoxic T-cell response against the regulatory proteins of human immunodeficiency virus (HIV) or simian immunodeficiency virus (SIV) may control infection after pathogenic virus challenge. Here, we evaluated whether vaccination with Tat or Tat and Rev could significantly reduce viral load in nonhuman primates. Rhesus macaques were primed with Semliki forest Virus (SFV) expressing HIV-1 tat (SFV-tat) and HIV-1 rev (SFV-rev) and boosted with modified vaccinia virus Ankara (MVA) expressing tat and rev. A second group of monkey was primed with SFV-tat only and boosted with MVA-tat. A third group received a tat and rev DNA/MVA prime-boost vaccine regimen. Monitoring of anti-Tat and anti-Rev antibody responses or antigen-specific IFN-gamma production, as measured by enzyme-linked immunospot assays revealed no clear differences between the three groups. These results suggest that priming with either DNA or SFV seemed to be equivalent, but the additive or synergistic effect of a rev vaccine could not be clearly established. The animals were challenged by the rectal route 9 weeks after the last booster immunization, using 10 MID(50) of a SHIV-BX08 stock. Postchallenge follow-up of the monkeys included testing seroconversion to Gag and Env antigens, measuring virus infectivity in PBMC by cocultivation with noninfected human cells, and monitoring of plasma viral load. None of the animals was protected from infection as assessed by PCR, but peak viremia was reduced more than 200-fold compared to sham controls in one third (6/18) of vaccinated macaques, whatever the vaccine regimen they received. Interestingly, among these six protected animals four did not seroconvert. Altogether, these results clearly indicated that the addition of early HIV proteins like Tat and Rev in a multicomponent preventive vaccine including structural proteins like Env or Gag may be beneficial in preventive vaccinal strategies.

Evaluation of low-pressure arterial and venous clamps: electron microscopic study and possible clinical applications

These authors report on validating their choice of disposable clamps in arterial and venous microsurgery in a comparative and experimental study using the scanning electron microscope. This appears to be the first evaluation of venous endothelial clamping lesions. Early intimal clamping lesions were studied using three different clamps and two protocols in 18 femoral arteries and veins in rabbits. Results were evaluated using a new classification that can be applied to both arterial and venous lesions: Grade I: cellular disorientation and disorganization; endothelial lamination; and absent or very few platelet deposits; Grade II: alterations of the cytoplasmic membranes in fusiform cells; presence of at least one breach of endothelial continuity; and moderate number of platelet deposits; Grade III: presence of endothelial detachment; and large numbers of platelet deposits. They showed that in arteries, all the clamps tested caused only low-grade lesions. In contrast, in veins, they demonstrated both the very fragile nature of the endothelium, and also the comparative safety of the low-pressure venous clamp. Their choice of specific clamps for venous anastomoses was validated.

Mobilization of lead from bone in end-stage renal failure patients with secondary hyperparathyroidism

BACKGROUND

It is now recognized that long-term exposure to even low levels of lead may increase bone lead content. Lead can then be released in toxicologically significant amounts during critical states of increased bone turnover.

METHODS

Two patients with end-stage renal failure, one on haemodialysis and the other on continuous ambulatory peritoneal dialysis (CAPD), had been exposed to lead and developed secondary hyperparathyroidism. An edetate calcium disodium (EDTA) test was performed in combination with haemofiltration or CAPD before and after parathyroidectomy.

RESULTS

Before parathyroidectomy, both patients had low delta aminolaevulinic acid dehydrase (ALA-D) and high concentrations of chelated lead. After parathyroidectomy, there was a dramatic decrease in chelated lead and the ALA-D returned to normal.

CONCLUSION

Secondary hyperparathyroidism increases mobilization of bone lead in dialysis patients with an elevated lead burden. This may cause toxic effects.

[Adequate peritoneal dialysis: limitations of continuous ambulatory peritoneal dialysis (CAPD), place of automated peritoneal dialysis (APD)]

Recent epidemiological studies show a slowing down of the global growth of CAPD which is not compensated by the considerable development of APD. These modifications are the result of the arrival of technologies which allow new strategies as well as an improved knowledge of the adequate dialysis dose for PD. The re-evaluation of the adequate clearance targets show that CAPD does not deliver an adequate dialysis dose for anuric patients but it remains an excellent technique for patients with residual renal function. APD and mixed techniques (APD with automated diurnal exchange(s), CAPD with automated nocturnal exchange) can deliver an adequate dialysis dose if the peritoneal permeability is not too low and if the prescription is adapted to each patient. The growth of CAPD seems to be slowing down due to a better knowledge of its limitations. However the development of APD does not seem to be related to the increasing knowledge of its possibilities. The development of automated techniques, prescribed as substitute treatments, depends on a precise evaluation of the cost/efficiency/quality of life index, compared to the reference treatment which is iterative hemodialysis.

Intraperitoneal hydrostatic pressure and ultrafiltration volume in CAPD

The intraperitoneal hydrostatic pressure (IPP) and overall ultrafiltration (UF) volume were measured in 34 patients after a 2-hour exchange with 2 L of dialysate containing 3.86% glucose. These patients had been treated with continuous ambulatory peritoneal dialysis (CAPD) on average for 26 +/- 20 months under stable conditions. The patients were at rest during the 2-hour exchange. The normal IPP measured with the patient lying completely flat was on inspiration (IPPinsp) 14 +/- 4 cm of water (cmH2O) and on expiration (IPPexp) 12 +/- 3 cm H2O, for an intraperitoneal volume of 2820 +/- 319 mL. The mean UF was 744 +/- 323 mL. The mean IPP (IPPmean), defined by (IPPinsp+IPPexp)/2, had a negative linear correlation to the UF volume (r = 0.66; p = 0.0001). The linear regression test showed that an increase of 1 cm H2O in the IPPmean reduced the overall UF volume by 70 mL in 2 hours. In conclusion, even though the UF is produced by the osmotic pressure of the dialysate, it is also influenced to a great extent by the intraperitoneal hydrostatic pressure, which should not be ignored.

Diagnosis and treatment of chronic lead poisoning in CAPD patients

In order to screen for abstruse lead poisoning in continuous ambulatory peritoneal dialysis (CAPD) patients, delta-aminolevulinic acid dehydratase (ALAD) levels were measured in 18 CAPD patients, 156 patients treated with hemodialysis (HD), and 420 control patients with normal renal function (NRF). An EDTA (ethylenediamine tetraacetic acid) mobilization test was performed in patients with low levels of ALAD (< 0.40 mumol of porphobilinogen formed per milliliter of red blood cells): 1 g of EDTA was infused IV followed by 20 L of hemofiltrate in HD patients and four bags of dialysate in CAPD patients. Lead was assayed in the ultrafiltrate liquid, the bags of dialysate, and in the 24-hour urine. ALAD levels were significantly lower in CAPD and HD patients than in the NRF subjects. ALAD was significantly correlated with EDTA mobilized lead in both dialysis and NRF patients. Using the usual criteria (EDTA mobilized lead > 800 micrograms/24 hours), the rate of lead poisoning observed was similar in the two groups. These results suggest that ALAD assay followed by the EDTA mobilization test is as effective in CAPD patients as in NRF subjects to diagnose and to treat chronic abstruse lead poisoning.