Viral-specific cytotoxic T-cell responses in HLA-sensitized kidney transplant patients maintained on everolimus and low-dose tacrolimus.

BACKGROUND: Maintenance with "everolimus + reduced dose tacrolimus" (Ev + Taclow ) was reported to reduce the risk of viral infections compared to "tacrolimus + mycophenolate mofetil" (Tac + MMF). Here we examined viremia and viral-specific T-cell (viral-Tc) responses in patients treated with Ev + Taclow versus Tac + MMF in highly-human leukocyte antigen (HLA)-sensitized patients. METHODS: HLA-sensitized (HS) kidney transplant patients were monitored pre- and post-transplant for viremia (cytomegalovirus (CMV), BK, and Epstein-Barr virus (EBV)) by polymerase chain reaction (PCR) in 19 Ev + Taclow and 48 Tac + MMF patients. For CMV PCR analysis, we compared infection rates in 19 Ev + Taclow patients to 48 CMV D+/R- (#28) or CMV D-/R- (#20) Tac + MMF patients. CMV-specific cytotoxic T cell (CMV-Tc) and EBV-specific cytotoxic T cell (EBV-Tc) were evaluated by cytokine flow cytometry, and donor-specific antibody (DSA) levels by Luminex for selected patients in both groups. RESULTS: CMV and EBV viremia rates were similar in Ev + Taclow versus Tac + MMF patients, but BK virus (BKV) rates were significantly higher in Ev + Taclow patients. No patient in either group developed BK virus-associated allograft nephropathy (BKAN) or post-transplant lymphoproliferative disorders (PTLD). CMV-Tc and EBV-Tc decreased significantly after alemtuzumab induction but returned to pre-treatment levels 1-2 months post-transplant in most patients. de novo DSA was similar in both groups as were patient and graft survival and graft rejection. CONCLUSIONS: CMV-Tc and EBV-Tc were similar in Ev + Taclow and Tac + MMF patients. EBV and CMV viremia rates were similar over 1 year. BKV rates were significantly higher in Ev + Taclow patients suggesting no benefit for Ev + Taclow in enhancing viral-Tc effector functions or limiting viral infections.

Imlifidase Inhibits HLA Antibody-mediated NK Cell Activation and Antibody-dependent Cell-mediated Cytotoxicity (ADCC) In Vitro.

BACKGROUND: Antibody-dependent cell-mediated cytotoxicity (ADCC) is an important pathway responsible for antibody-mediated rejection (AMR). Imlifidase (IdeS) cleaves human IgG into F(ab')2 and Fc fragments, potentially inhibiting ADCC. Here we examined the effect of IdeS on allo-antibody-mediated NK cell activation (Allo-CFC) and ADCC in vitro. METHODS: For Allo-CFC, normal whole blood was incubated with third-party peripheral blood mononuclear cells (PBMCs) pretreated with anti-HLA antibody positive (HS) or negative (NC) sera to measure IFNγ+ NK cell%. For ADCC, normal PBMCs were incubated with Farage B (FB) cells with HS or NC sera to measure 7-AAD+ lysed FB cell%. To assess the effect of IdeS on these assays, serum-treated PBMCs (Allo-CFC-1) and serum used for PBMC pretreatment (Allo-CFC-2) in Allo-CFC, and serum used for ADCC were preincubated with IdeS. Sera from IdeS-treated patients were also tested for Allo-CFC (Allo-CFC-3). RESULTS: IFNγ+ NK cell% were significantly elevated in HS versus NC sera in Allo-CFC-1 (10 ± 3% versus 2 ± 1%, P = 0.001), Allo-CFC-2 (20 ± 10% versus 4 ± 2%, P = 0.01) and 7AAD+ FB cell% (11 ± 3% versus 4 ± 2%, P = 0.02) in ADCC. These were significantly reduced by IdeS treatment. Patient sera with significantly reduced anti-HLA antibody levels at 1 day postimlifidase lost the capacity to activate NK cells in Allo-CFC-3, but those at 1-3 months postimlifidase regained the capacity. CONCLUSIONS: IdeS inhibited NK cell activation and ADCC in vitro and in treated patients. These results and reported inhibition of complement activating anti-HLA antibodies by IdeS suggest its possible role in treatment of AMR.

Assisted peritoneal dialysis: what is it and who does it involve?

Together with the obvious increase of elderly patients with end-stage renal disease (ESRD), utilization of peritoneal dialysis (PD) has declined since the mid-1990s in a number of countries--a decline that is particularly marked in this elderly ESRD population. A major obstacle that affects any dialysis modality in elderly patients is the greater disease burden than is seen in younger patients. However; this factor may be overcome if patients start PD with assistance provided by visiting helpers (nurses or others) or people at home, mostly family members. Assisted PD (aPD) is suitable for; but not limited to, elderly patients who are unable to perform PD for themselves at home. Important considerations of an assisted model of care include frequency of visits, type of health care, and tasks to be performed for the patient at home. Clinical experience worldwide shows that aPD offers acceptable survival for most elderly and disabled patients, with no significant difference in modality-related complications from those seen in self-performed PD. Elderly patients on aPD experience more frequent hospitalizations, with longer hospital stays. Costs of aPD vary from country to country, depending on the frequency of visits and on reimbursement policies. Most authors believe that aPD can be cost-effective when compared with in-center hemodialysis.

Expression-Based Cell Lineage Analysis in Drosophila Through a Course-Based Research Experience for Early Undergraduates.

A variety of genetic techniques have been devised to determine cell lineage relationships during tissue development. Some of these systems monitor cell lineages spatially and/or temporally without regard to gene expression by the cells, whereas others correlate gene expression with the lineage under study. The GAL4 Technique for Real-time and Clonal Expression (G-TRACE) system allows for rapid, fluorescent protein-based visualization of both current and past GAL4 expression patterns and is therefore amenable to genome-wide expression-based lineage screens. Here we describe the results from such a screen, performed by undergraduate students of the University of California, Los Angeles (UCLA) Undergraduate Research Consortium for Functional Genomics (URCFG) and high school summer scholars as part of a discovery-based education program. The results of the screen, which reveal novel expression-based lineage patterns within the brain, the imaginal disc epithelia, and the hematopoietic lymph gland, have been compiled into the G-TRACE Expression Database (GED), an online resource for use by the Drosophila research community. The impact of this discovery-based research experience on student learning gains was assessed independently and shown to be greater than that of similar programs conducted elsewhere. Furthermore, students participating in the URCFG showed considerably higher STEM retention rates than UCLA STEM students that did not participate in the URCFG, as well as STEM students nationwide.

Impact of Desensitization on Antiviral Immunity in HLA-Sensitized Kidney Transplant Recipients.

Viral infections represent significant morbidity and mortality factors in kidney transplant recipients, with CMV, EBV, and BKV infections being most common. Desensitization (DES) with IVIg and rituximab with/without plasma exchange followed by kidney transplantation with alemtuzumab induction increased successful transplant rates in HLA-sensitized patients but may represent an increased risk for viral infections due to severe lymphocyte depletion. Here, we report on the posttransplant viral infection status in 372 DES versus 538 non-DES patients. CMV and EBV viremia were significantly lower in DES patients, while BKV viremia was similar. This trend was observed primarily in CMV sero(-), EBV sero(+), and sero(-) patients. No patient developed PTLD. The incidence of BKAN, allograft, and patient survival was similar in both groups. These viral infections were not associated with subsequent allograft rejection which occurred within 6 months after the infection. Conclusions. The IVIg + rituximab desensitization combined with alemtuzumab induction with triple immunosuppression maintenance does not increase the risk for CMV, EBV, and BKV infections. Possible factors include, in addition to posttransplant antiviral prophylaxis and PCR monitoring, presence of memory T cells and antibodies specific to CMV and likely EBV, NK cell-mediated ADCC despite lymphocyte depletion, elimination of EBV and CMV reservoirs by rituximab and alemtuzumab, and use of IVIg with antiviral properties.

Predictors of outcome following bacterial peritonitis in peritoneal dialysis.

OBJECTIVE: No studies have been done to examine factors that predict the outcome of bacterial peritonitis during peritoneal dialysis (PD), beyond the contribution of the organism causing the peritonitis, concurrent exit-site or tunnel infection, and abdominal catastrophes. DESIGN: In this study we examined several clinical and laboratory parameters that might predict the outcome of an episode of bacterial peritonitis. Between March 1995 and July 2000, we identified 399 episodes of bacterial peritonitis in 191 patients on dialysis. RESULTS: There were 260 episodes of gram-positive peritonitis, 99 episodes of gram-negative peritonitis, and 40 episodes of polymicrobial peritonitis. Gram-positive peritonitis had a significantly higher resolution rate than either polymicrobial peritonitis or gram-negative peritonitis. Staphylococcus aureus episodes had poorer resolution than other gram-positive infections. Nonpseudomonal peritonitis had a better outcome than Pseudomonas aeruginosa episodes. Among all the gram-negative infections, Serratia marcescens had the worst outcome. Episodes associated with a purulent exit site had poor outcome only on univariate analysis. For those peritonitis episodes in which the PD fluid cell count was > 100/microL for more than 5 days, the nonresolution rate was 45.6%, compared to a 4.2% nonresolution rate when the cell count returned to 100/microL or less in less than 5 days. Those patients that had a successful outcome had been on continuous ambulatory PD for a significantly shorter period of time than those patients that had nonresolution. The nonresolution rate for those patients that had been on PD for more than 2.4 years was 24.4%, compared to 16.5% for those that had been on PD for less than 2.4 years (p = 0.05). CONCLUSION: The duration of PD and the number of days the PD effluent cell count remained > 100/microL were the only factors that independently predicted the outcome of an episode of peritonitis. Caucasians seem to have a higher nonresolution (failure) rate compared to Blacks. Other variables, such as the number of peritonitis episodes before the episode in question, vancomycin-based initial empiric treatment, serum albumin level, total lymphocyte count and initial dialysate white blood cell count, age, sex, diabetes, previous renal transplantation, and the use of steroids did not affect the outcome of peritonitis.

Natural history and outcome of incarcerated abdominal hernias in peritoneal dialysis patients.

Hernias can lead to significant morbidity in patients on peritoneal dialysis (PD). We studied the natural history and outcome of incarcerated hernia (IH), with or without bowel strangulation (IHS), in PD patients. We performed a retrospective chart review on all PD patients who developed an IH (n = 11) or an IHS (7/11) in the last 12 years. Of the 11 patients, 54% were female. The age range was 36 - 86 years (median: 61 years). Seven patients had a known history of a hernia that went on to become the index hernia that incarcerated with or without strangulation. The hernia types were umbilical (n = 8), inguinal (n = 2), and incisional in the area of the PD catheter (n = 1). Clinical presentations included painless abdominal mass (2 patients); tender and painful abdominal mass (4 patients); and abdominal pain, tenderness, and bowel obstruction (5 patients). Nine hernias were treated surgically--5 of them emergently for bowel ischemia. The other 4 patients who had incarcerated, non strangulated hernias were operated electively. One patient with IHS had the hernia manually reduced, and 1 patient with IHS had the hernia manually reduced and subsequently operated electively. Three patients with IHS and 2 with IH required temporary hemodialysis for between 4 days and 21 days. In PD patients, IHs are most commonly umbilical and have a propensity to strangulate. Patients treated operatively have an excellent prognosis and are usually able to continue PD. Abdominal wall hernias should be referred early to minimize mechanical complications.

Peritoneal dialysis in end-stage renal disease after liver transplantation.

Peritoneal dialysis (PD) has seldom been reported in patients developing end-stage renal disease (ESRD) after liver transplantation (LTx). Here we present our recent experience with PD in 5 such patients. Of the 5 patients, 3 were men and 2 were women. Average age at initiation of PD was 64.6 years (range: 54 - 72 years). Chronic renal failure (CRF) was diagnosed an average of 3.8 years (range: 1 - 7 years) post transplant and resulted in ESRD an average of 9.2 years (range: 6 - 15 years) after LTx. Calcineurin inhibitor toxicity was the presumed causative factor in all 5 patients, with biopsy confirmation in 2. All of the patients had hypertension at the time of diagnosis of CRF, 2 had coronary artery disease, and 1 developed diabetes mellitus. No patient had ascites before PD initiation. Peritoneal dialysis catheter implantation was uneventful in all patients. Average duration of follow-up was 13.6 months (range: 6 - 29 months). Three episodes of peritonitis occurred in 2 patients (coagulase-negative staphylococcus, Staphylococcus aureus, and Acinetobacter). All episodes of peritonitis responded to standard treatment. Clearance was found to be adequate in all but 1 patient. One patient died 19 months after initiation of PD. At the time of writing, the remaining 4 patients are alive on PD after an average of 12.2 months (range: 6 - 29 months). We conclude that PD is a viable and safe option for managing ESRD that develops after LTx.

Differences in survival on peritoneal dialysis between oriental Asians and Caucasians: one center's experience.

BACKGROUND: Recently it has been suggested that the survival of dialysis patients may differ among different races. Both registry data and data from Asian countries indicates that Asians on peritoneal dialysis may survive longer than their Caucasian counterparts. In the present study, we performed a detailed analysis of survival differences between oriental Asians and Caucasians on peritoneal dialysis in our multiethnic, multicultural program. METHODS: Retrospectively we analyzed the survival data for patients who started peritoneal dialysis after January 1, 1996 and before December 31, 1999, in our hospital. They were followed for at least for two years. Excluded from the present analysis were those who survived for less than three months on peritoneal dialysis. The patient demographic characteristics, comorbidities, and residual renal function at the start of dialysis were collected. Indices for adequacy of dialysis were collected 1-3 months after the initiation of dialysis. Actuarial survival rates were determined by the Kaplan-Meier method. The Cox proportional hazards model was used to classify risk factors for a high mortality. RESULTS: There were 87 Caucasians and 29 Oriental Asian peritoneal dialysis patients. No differences were found in age, gender, primary renal disease, and residual renal function between the two groups. The Caucasians had significantly higher body surface area and urea volume and higher incidence of cardiovascular diseases. Even with slightly higher dialysis dose, the peritoneal creatinine clearance was significantly lower among the Caucasians than among Asians. There was no difference in the peritoneal D/P value between the two groups. However, compared to the Caucasians, the 24hr peritoneal fluid removal and total fluid removal volumes were significantly lower in the Asian patients. The one, two, three and four year survival rates were 95.8%, 91%, 86% and 80% for Asians and 91.3%, 78.1%, 64.7% and 54.1% for Caucasians. Significant predictors for a higher mortality were the presence of cardiovascular disease (42% increase in risk), Caucasians (39% increase in risk) and older age (37% increase in risk for age older than 65). CONCLUSIONS: Our study confirms that oriental Asians on peritoneal dialysis patients survive much longer than their Caucasian counterparts; this was partly due to the fact that Asian patients have less cardiovascular disease when they began peritoneal dialysis. Due to their smaller body size, the Asians tended to have a higher peritoneal small solute clearances despite their smaller dialysis doses, indicating that, to achieve the same solute clearance targets, Asians need a smaller dialysis dose compared to Caucasians.

Chronic peritoneal dialysis in the tenth decade of life.

In this retrospective study we present our experience with chronic peritoneal dialysis in nine patients with ESRD in their 10th decade of life (> or =90 years) at the Toronto Western Hospital. A family member or a private nurse assisted all patients in dialysis procedure. The co-morbid illnesses, survival, hospitalizations and complications related or unrelated to peritoneal dialysis were reviewed. Four patients started dialysis before and five after their 90th birthday, their mean age was 90.61+/-4.04 years. All patients had three or more co-morbid illnesses at the start of dialysis. Total duration of PD treatment was 210 patient months with a median duration of 25 months (range 4-68 months). Of the nine patients, four died after a mean follow up of 38.5 months on dialysis. Of the remaining five, one was transferred to hemodialysis after remaining for 10 months on peritoneal dialysis and the other four are continuing on PD for a mean duration of 9.25 months. Peritonitis (1/13.4 patient months) and exit site infection (1/100.5 patient months) responded to treatment. Hospitalization rate was one admission per 2.5 patient years. Most often, the cause of hospitalization was unrelated to PD, e.g., cardiovascular events, pneumonia and peripheral vascular disease etc. Patient survival at 1, 3 and 5 years was 88%, 58% and 24% respectively. The technique survival was 69%, 47% and 23% at 1, 3 and 5 years respectively. We conclude that continuous peritoneal dialysis is a safe and suitable treatment even in nonagenarians (> or =90 years) ESRD patients.

Peritoneal dialysis outcomes in a modern cohort of overweight patients.

BACKGROUND: The incidence of obesity is increasing both in the general population and in incident dialysis patients. While there is evidence that being overweight is associated with good outcomes in hemodialysis, the evidence in peritoneal dialysis (PD) patients is not very clear. We studied a modern cohort of PD patients to examine outcomes in large patients. METHODS: Forty-three patients who started PD, who weighed more than 90 kg at dialysis initiation, between January/2000 and June/2010 were matched with 43 control patients who weighed less than 90 kg. Detailed review of the charts was undertaken. RESULTS: The mean weight and body mass index of the wt < 90 kg group were 69.3 ± 11.3 kg and 25.0 ± 3.9 kg/m(2). The number of peritonitis episodes per year was 0.33 ± 0.6 (wt < 90 kg) and 0.82 ± 1.7 (wt ≥ 90 kg) (p = 0.26). The median time to first peritonitis showed a trend toward earlier peritonitis in larger patients [9.5 (4.3, 27) months in wt ≥ 90 kg, 19.1(7.9, 30.8) months in wt < 90 kg] but did not reach statistical significance (p = 0.12). Surprisingly, hernias and leaks were more common in the weight <90 kg group (44 vs. 18.6 % p = 0.02). There was no difference in total number of hospitalizations or the number of days hospitalized. Kaplan-Meier analysis of survival on PD showed no differences between the two groups (logrank p = 0.99). Cox regression analysis using age, race, cause of ESRD due to diabetes and Charlson comorbidity index as the covariates did not show weight to be associated with survival on PD. CONCLUSIONS: Large patients tend to do just as well on PD, with survival on PD being no different compared to individuals with lower weight and body mass index.

Encapsulating peritoneal sclerosis: a single-center experience and review of the literature.

Encapsulating peritoneal sclerosis (EPS) is a serious and often fatal complication of long-term PD with severe malnutrition and poor prognosis. It causes progressive obstruction and encapsulation of the bowel. This retrospective study reviews our experience and that reviewed in the literature concerning EPS. It refers to a total of 1966 patients treated with chronic PD between 1974 and 2008. Twenty one of them (1.1%) developed EPS, with the incidence increasing with the duration of PD. Mean age of our patients with EPS was 43, ranging from 18 to 71 years, 8 were men and 13 women with a mean body mass index (BMI) of 21.6 kg/m(2). Only one patient had Type II diabetes, 15 patients had glomerular disease, and six of these 15 had an autoimmune disease such as Wegener's granulomatosis and SLE. Thirteen patients developed EPS while on PD, 7 within 2 years after transfer to HD, and only one after renal transplantation. However, 7 patients had a previous renal transplant before returning to PD and subsequently developing EPS. Interestingly, we did not observe more episodes of EPS after transplantation. In the patients who developed EPS, the peritonitis rate over the period of observation was 1/15.6 pt-months and was due to Staphylococcus aureus, coagulase-negative staphylococcus, Pseudomonas and fungi. A history of peritonitis was not a prerequisite for developing EPS, since one patient had no episodes of peritonitis and 4 had just one previous episode. Fifteen patients presented with peritonitis within 4 months before the diagnosis of EPS with particularly virulent micro-organisms such as S. aureus, Candida, Pseudomonas, Corynebacterium, and Peptostreptococcus. Eleven patients were treated with hypertonic dextrose solutions (4.25 g/dl of dextrose) and seven with icodextrin, indirectly suggesting problems with ultrafiltration. Nine of 21 patients were on beta-blockers. The diagnosis of EPS was made either surgically or radiologically with signs of small bowel obstruction in combination with severe malnutrition. Eleven of our patients (52%) had evidence of small bowel obstruction and 14 patients required total parenteral nutrition (TPN). Tamoxifen (10-20 mg daily) was started in 6 patients, 4 of whom are alive and 2 deceased 3 and 5 years after EPS was diagnosed. Of the 12 patients who were not given tamoxifen, 2 are alive and 10 died. No side effects of tamoxifen were reported. Only 7 of our patients (33%) died during the first year after the diagnosis of EPS. Currently, 4 patients are on HD and 3 have had a renal transplant. Six patients of the fourteen who underwent surgery (42.8%) died within the first 6 months after operation and five died after an average of 6.6 years, mostly due to cardiovascular causes, three are still alive. As EPS becomes more prevalent with longer duration of PD, large multicenter prospective studies are needed to establish its incidence and identify risk factors, therapeutic approach, and prognosis.

Two icodextrin exchanges per day in peritoneal dialysis patients with ultrafiltration failure: one center's experience and review of the literature.

BACKGROUND: At present, only one exchange of an icodextrin-based solution is recommended to increase peritoneal ultrafiltration (UF) during long-dwell exchanges in peritoneal dialysis (PD) patients with impaired UF. AIM: To review our experience with two icodextrin exchanges per day on net UF and body weight in PD patients with poor UF. METHODS: Data were analyzed on nine patients with poor UF on chronic PD who were given two icodextrin exchanges per day for 6 months and had various clinical and biochemical parameters assessed monthly. RESULTS: Administration of icodextrin twice daily reduced the body weight in six of nine patients by an average of 2.9 ± 1.2 kg, a reduction that was maintained throughout the study; two patients gained 0.5 kg; and, in one patient, the measurements were inadequate. Mean blood pressure was reduced. Mean serum creatinine increased slightly. Serum sodium levels decreased from a mean baseline level of 134 ± 3 to 132 ± 4 mmol/L at three and six months. Among the diabetics in this group, average daily insulin requirements were 44 ± 35 units/day at baseline and 40 ± 23 units/day after 6 months. Hb1Ac levels remained stable throughout the study period. CONCLUSION: The use of two icodextrin exchanges per day reduced body weight in six of the nine patients and appeared to be safe. Long-term prospective studies are needed to assess the contribution of twice-daily icodextrin to the management of peritoneal dialysis patients with ultrafiltration failure and its long-term safety.

Discordant PD catheter and effluent culture results. The limited clinical relevance of culturing PD catheters.

OBJECTIVES: To determine if discordance in culture results between the effluent and the tip of the peritoneal catheter had an effect on outcome in patients whose peritoneal dialysis (PD) catheter was removed mostly for nonresolving peritonitis. Reasons for and outcomes of PD catheter removal were also analyzed. METHODS: We retrospectively reviewed the charts of all PD patients with recent peritonitis for which the PD catheter was removed between 1 January 2003 and 30 April 2009. Data including basic demographics, the organism isolated from effluent and from the PD catheter, reason for catheter removal, duration of hospitalization, and development of intra-abdominal collection were extracted as well as mortality within 8 weeks post removal and return to PD after catheter removal. RESULTS: Fungal peritonitis was the most common reason for PD catheter removal. 20% of the patients developed an intra-abdominal collection. Mortality related to PD catheter removal was low (3/53; 5.6%). The patients (n =53) were divided into 3 groups: group 1 (n = 20) had the same culture result of effluent and catheter tip; group 2 (n = 19) had a negative culture of the catheter tip; and group 3 (n = 14) had different organism(s) growing from effluent and catheter tip. We found no remarkable differences in duration of PD, catheter age, peritonitis rate, or mortality. Patients in group 1 had significantly more fungal peritonitis than the other 2 groups. In only 4 of the 53 patients (7.5%), the anti-infectious management was changed according to the catheter culture result. CONCLUSIONS: Discordant results between catheter tip culture and effluent culture did not have a significant impact on patient outcome. Sending PD catheters for culture has limited clinical importance.

Perioperative management of peritoneal dialysis patients undergoing hernia surgery without the use of interim hemodialysis.

OBJECTIVE: To review the feasibility of undertaking elective hernia repair in peritoneal dialysis (PD) patients without converting them to hemodialysis. DESIGN: A 10-year retrospective review of prospectively collected data. SETTING: PD unit of a university-based hospital. PATIENTS AND METHODS: All patients received regular exchanges until the morning of the surgery and remained off dialysis for the first 48 hours postoperatively. After that, PD was gradually reintroduced. The patients on continuous ambulatory PD (CAPD) received intermittent PD (IPD) 3 times per week for 10 hours per day for 2 weeks, followed by 5 exchanges of low volume (1-1.5 L) CAPD for 2 weeks, returning to the pre-surgery prescription by 4 weeks. Patients on continuous cycling PD (CCPD) received 1 week of IPD followed by 4 weeks of nocturnal IPD and returned to the original dose in 5 weeks. Between 1 April 1995 and 31 March 2005, 50 consecutive patients were managed by this protocol. Average age was 65 years and 67.7% were males. The original disease was diabetes mellitus (19 patients), hypertension (6), chronic glomerulonephritis (13), polycystic kidney disease (6), and others (6). The types of abdominal hernias included umbilical (25 patients), inguinal (18), incisional (5), and epigastric (2). 42 patients were on CAPD and 8 on CCPD. Average duration of PD prior to development of hernia was 16.4 months. RESULTS: Average pre-surgery creatinine was 673 mumol/L, increasing to 968 mumol/L on IPD. Serum potassium increased from 3.4 to 4.7 mmol/L. No episodes of hyperkalemia were noted. The average total follow-up was 33.4 months. None of the patients had leakage or early hernia recurrence due to early resumption of PD; 13 patients had recurrence of the same hernia after a median 19.9 months; 4 patients had hernias at different sites after an average of 55 months. CONCLUSIONS: Based on this experience, we recommend that PD patients undergoing elective abdominal hernia surgery should continue PD according to the prescribed protocol. Interim hemodialytic support does not appear to be necessary in most patients.

Routine use of mupirocin at the peritoneal catheter exit site and mupirocin resistance: still low after 7 years.

OBJECTIVE: The purpose of this study (the third in a series of similar studies) is to evaluate the prevalence of Staphylococcus aureus (SA), methicillin-resistant SA (MRSA) and mupirocin-resistant SA (MuRSA) carriers in a peritoneal dialysis centre where patients have been instructed to use prophylactic mupirocin ointment at the catheter exit site over the last 7 years. METHODS: Swabs were taken from catheter exit site, nares, axillae and groin in 147 chronic peritoneal dialysis out-patients between November 2003 and January 2004. Axillae/groin and nasal samples were pooled and cultured in the same medium, whereas exit site swabs were cultured separately. All SA isolated were tested for methicillin and mupirocin resistance using oxacillin screening plates and E-test strips. RESULTS: Sixteen of 147 patients (10.9%) were found to be SA carriers: of these 13 (8.8%) had a positive nasal/axillae/groin culture; two (1.4%) had both nasal/axillae/groin- and exit site-positive culture; and one (0.7%) had only exit site-positive culture. In these 16 SA carriers, we found mupirocin-resistant strains (MuRSA) in four patients (25%) and MRSA in two patients (12.5%). Among the four MuRSA carriers, one had both nasal/axillae/groin- and exit site-positive culture and three had only nasal/axillae/groin-positive culture. Three high-level resistance and one low-level resistance MuRSA carriers were isolated. One MuRSA strain was also methicillin resistant. All MRSA strains were sensitive to vancomycin and rifampicin. CONCLUSION: After 7 years' routine use of prophylactic mupirocin ointment at the catheter exit site in non-selected chronic peritoneal dialysis patients, MuRSA was found in 25% of SA strains isolated or in 2.7% of the patients. Compared with our previous study, 3 years earlier, there is no significant increase in the MuRSA prevalence in peritoneal dialysis patients who routinely apply mupirocin ointment at the catheter exit site.