Feasibility of intermittent back-filtrate infusion hemodiafiltration to reduce intradialytic hypotension in patients with cardiovascular instability: a pilot study.

BACKGROUND: Intradialytic hypotension (IDH) is one of the major problems in performing safe hemodialysis (HD). As blood volume depletion by fluid removal is a major cause of hypotension, careful regulation of blood volume change is fundamental. This study examined the effect of intermittent back-filtrate infusion hemodiafiltration (I-HDF), which modifies infusion and ultrafiltration pattern. METHODS: Purified on-line quality dialysate was intermittently infused by back filtration through the dialysis membrane with a programmed dialysis machine. A bolus of 200 ml of dialysate was infused at 30 min intervals. The volume infused was offset by increasing the fluid removal over the next 30 min by an equivalent amount. Seventy-seven hypotension-prone patients with over 20-mmHg reduction of systolic blood pressure during dialysis or intervention-requirement of more than once a week were included in the crossover study of 4 weeks duration for each modality. In a total of 1632 sessions, the frequency of interventions, the blood pressure, and the pulse rate were documented. RESULTS: During I-HDF, interventions for symptomatic hypotension were reduced significantly from 4.5 to 3.0 (per person-month, median) and intradialytic systolic blood pressure was 4 mmHg higher on average. The heart rate was lower during I-HDF than HD in the later session. Older patients and those with greater interdialytic weight gain responded to I-HDF. CONCLUSIONS: I-HDF could reduce interventions for IDH. It is accompanied with the increased intradialytic blood pressure and the less tachycardia, suggesting less sympathetic stimulation occurs. Thus, I-HDF could be beneficial for some hypotension-prone patients. UMIN REGISTRATION NUMBER: 000013816.

Dialysis Amyloid Deposition in the Aortic Valve and Its Association with Aortic Stenosis.

BACKGROUND: The relationship between dialysis amyloid (DA) deposition in the aortic valve (AV) and aortic stenosis (AS) is unknown. METHODS: This was a cross-sectional study. AV specimens of dialysis patients (median vintage: 8.8 years) consecutively collected from cardiac surgeries (n = 56) or autopsies (n = 13) were examined by a board-certified pathologist blinded to clinical data. DAs were considered to be present if deposits were stained both by Congo red with apple-green birefringence under polarized light and by anti-ß2-microblobulin antibody. Degree of deposition was graded as follows: Amyloid (-), no deposit; Amyloid (1+), occasional small deposits; Amyloid (2+), multiple small to large deposits or a single large deposit. Calcification was defined as a calcified deposit with a diameter >1 mm in the specimen. Severe AS (sAS) was defined as a mean gradient >50 mm Hg by echocardiogram. We examined the proportion of DAs and the association between DAs and the sAS. RESULTS: DAs were present in 71% (n = 49) of specimens and primarily co-localized with calcification. Non-dialysis related amyloid was found in one specimen. After excluding this specimen, sAS was associated with 'Amyloid (1+) and Calcification >1 mm' and 'Amyloid (2+) and Calcification >1 mm' (vs. 'Amyloid (-) and Calcification ≤1 mm', odds ratios (ORs): 13.5 and 34.2, respectively). Furthermore, after adjustment for covariates, sAS was found to be associated with 'Amyloid (2+) and Calcification >1 mm' (OR: 24.3). CONCLUSIONS: DA deposition in the AV was prevalent among dialysis patients. DA deposition with accompanying calcification might contribute to the severity of AS.

Association between abnormal myocardial fatty acid metabolism and cardiac-derived death among patients undergoing hemodialysis: results from a cohort study in Japan.

BACKGROUND: Detecting myocardial ischemia in hemodialysis patients is crucial given the high incidence of silent ischemia and the high cardiovascular mortality rates. Abnormal myocardial fatty acid metabolism as determined by imaging with (123)I-labeled BMIPP (ß-methyl iodophenyl-pentadecanoic acid) might be associated with cardiac-derived death in hemodialysis patients. STUDY DESIGN: Prospective observational study. SETTING & PARTICIPANTS: Asymptomatic hemodialysis patients with one or more cardiovascular risk factors, but without known coronary artery disease, were followed up for 3 years at 48 Japanese hospitals (406 men, 271 women; mean age, 64 years). PREDICTOR: Baseline BMIPP summed scores semiquantified using a 17-segment 5-point system (normal, 0; absent, 4). OUTCOMES: Cardiac-derived death, including cardiac and sudden death. MEASUREMENTS: HRs were estimated using a Cox model for associations between BMIPP summed scores and cardiac-derived death, adjusting for potential confounders of age, sex, body mass index, dialysis duration, and cardiovascular risk factors. RESULTS: Rates of all-cause mortality and cardiac-derived death were 18.5% and 6.8%, respectively. Cardiac-derived death (acute myocardial infarction [n = 10], congestive heart failure [n = 13], arrhythmia [n = 2], valvular heart disease [n = 1], and sudden death [n = 20]) accounted for 36.8% of all-cause deaths. Cardiac-derived death (n = 46) was associated with age, history of heart failure, and BMIPP summed scores of 4 or higher (HR, 2.9; P < 0.001). Three-year cardiac-derived death-free survival rates were 95.7%, 90.6%, and 78.8% when BMIPP summed scores were 3 or lower, 4-8, and 9 or higher, respectively. BMIPP summed score also was a predictor of all-cause death (HR, 1.6; P = 0.009). LIMITATIONS: Sudden death of unknown cause was considered to have been cardiac derived, although a coronary origin was not confirmed. CONCLUSIONS: Abnormal myocardial fatty acid metabolism is associated with cardiac-derived death in hemodialysis patients. BMIPP single-proton emission computed tomography appears clinically useful for predicting cardiac-derived death in this population.

AA amyloid nephropathy with predominant vascular deposition in Crohn's disease.

A 44-year-old man with a 17-year history of Crohn's disease (CD) was referred to our nephrology department on suspicion of drug-induced nephrotoxicity. Over the preceding 18 months, he had slowly progressive renal insufficiency with slight urinary abnormalities. His disease activity had been well controlled up to that point with 5-aminosalicylic acid and azathiopurine. Laboratory examination revealed slight proteinuria without hematuria and an elevated serum creatinine level of 1.4 mg/dl. Pathological examination revealed amyloid A (AA) deposition in the kidney, predominantly in the arterial and arteriolar walls with little to none in the glomerular capillaries. AA amyloidosis is typically accompanied by glomerular amyloid deposition and massive proteinuria. In the present case, however, vascular amyloid deposition was predominant, and the renal function was deteriorated with slight urinary abnormalities. The present case confirmed the importance of conducting a definitive pathological diagnosis of renal insufficiency in CD patients.

Acute systemic hypotension after arteriovenous fistula construction in a patient with severe aortic stenosis.

We report the case of a 53-year-old hemodialysis patient with severe aortic stenosis, who developed acute systemic hypoperfusion after arteriovenous fistula (AVF) construction. He presented with hypotension and repeated syncope soon after distal radiocephalic AVF construction, and finally developed a respiratory arrest. His blood pressure and hemodynamics recovered promptly by sub-emergent aortic valve replacement surgery. In the present case, the heart with severe aortic stenosis could not increase cardiac output in response to the reduction in peripheral vascular resistance caused by the AVF. High-output heart failure, a relatively rare AVF-associated disorder, occurs with an excessive AVF flow, usually more than 3 L/min or 30% of cardiac output. However, heart failure may develop soon after construction of an AVF with a moderate blood flow if a patient's cardiac function is severely impaired. In addition, heart failure may improve with AVF preservation if the underlying heart disease is treatable.

Malnutrition and inflammation determine prognosis of patients with CRS type 4.

BACKGROUND/AIMS: A significant number of uremic patients develop ischemic heart disease before hemodialysis (HD) is initiated. Recently, chronic cardiorenal syndrome among predialysis patients has been recognized. However, little is known about prognostic factors in this subgroup of incident HD patients. METHODS: A total of 87 incident HD patients, who were classified into cardiorenal syndrome type 4 (chronic cardiorenal syndrome), were identified at Mitsui Memorial Hospital between 1984 and 2003. The survival and risk factors for mortality were examined. RESULTS: 25 patients died and the 5-year survival rate amounted to approximately 75%. Both all-cause mortality and the adjusted mortality for age and sex were higher in patients with a lower serum albumin level (p = 0.03) or higher serum C-reactive protein level (p = 0.02). CONCLUSION: The poor survival rate of incident HD patients with a medical history of ischemic heart disease was predicted by malnutrition and inflammation at the start of HD.

[Case of mesangial proliferative glomerulonephritis complicated with multicentric Castleman's disease].

We report a case of a 47-year-old man with multicentric Castleman's disease (MCD) and progressive renal dysfunction due to mesangial proliferative glomerulonephritis, possibly from IgA nephropathy. At age 36 years, he was referred to a hematologist due to hypergammaglobulinemia. Because of systemic lymph node swelling, he underwent right cervical lymph node biopsy at age 41 years and MCD (plasma cell type)was diagnosed. During this period, microscopic hematuria and persistent proteinuria occurred and his renal function deteriorated (serum creatinine (Cr) rising from 0.7 mg/dL to 1.4 mg/dL). Treatment with intravenous methylprednisolone at the dose of 1 g daily for 3 days followed by oral prednisolone at 20 mg daily reduced his lymphadenopathy and improved the renal function. However, his renal function deteriorated again, from Cr 0.8 mg/dL to 1.8 mg/dL over 6 years in line with gradual prednisolone tapering to 6 mg daily. At age 47 years, he was referred to our nephrology department and underwent a renal biopsy. The microscopic examination showed IgA nephropathy with crescent formation, accompanied by mild lymphoplasmacytic tubulointerstitial nephritis. Treatment with the same dose of intravenous methylprednisolone therapy followed by oral prednisolone at 40 mg daily, improved his proteinuria, hematuria and renal dysfunction. The coexistence of MCD and IgA nephropathy is a rare phenomenon. In addition, IL-6, overproduced by MCD might have influenced the mesangial cell proliferation and the activity of IgA nephropathy in the present case.

A case of Churg-Strauss syndrome with necrotizing crescentic glomerulonephritis accompanied by acute coronary syndrome due to vasospasm.

We report a case of Churg-Strauss syndrome coexistent with coronary vasospasm and pauci-immune necrotizing crescentic glomerulonephritis. A 54-year-old man with bronchial asthma and allergic rhinitis was admitted to our hospital because of acute coronary syndrome. Angiography showed diffuse coronary artery spasm without anatomic stenosis. Acute coronary syndrome due to vasospasm was diagnosed. However, subsequent administration of vasodilators did not suppress angina symptoms. In addition, marked eosinophilia, eosinophilic pneumonitis, chronic sinusitis, pericardial effusion, and slight hematuria with red blood cell casts were detected. Although kidney function was normal, a kidney biopsy showed necrotizing crescentic glomerulonephritis with eosinophilic infiltration in both glomeruli and interstitium. With the diagnosis of Churg-Strauss syndrome, oral prednisolone at a dose of 60 mg/d was administered. Cardiac symptoms, pulmonary and sinonasal lesions, pericardial effusion, and urine sediment resolved rapidly. Six months later, a repeated kidney biopsy showed remarkable improvement and no eosinophilic infiltration. Coronary vasospasm with eosinophilia might be refractory to vasodilators and sensitive to corticosteroid therapy and often has been related to Churg-Strauss syndrome. Slight abnormalities in urine sediment can be the clue to the diagnosis of severe kidney involvement of Churg-Strauss syndrome.

Myeloperoxidase-antineutrophil cytoplasmic antibody-associated crescentic glomerulonephritis with rheumatoid arthritis: a comparison of patients without rheumatoid arthritis.

BACKGROUND: Several cases of rheumatoid arthritis (RA) with myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-associated crescentic glomerulonephritis (CrGN) have been reported. However, its clinical characteristics are not clear. METHODS: We summarized 3 patients of concurrent RA and MPO-ANCA-associated CrGN, diagnosed in our hospital from 1992 to 2006, and compared their clinicopathological data with those of 10 MPO-ANCA-associated CrGN patients without RA in the same period. RESULTS: All three RA patients were middle-aged or young adult women with 7-14 years of RA history. The initial clinical symptom was microhematuria, and mean duration from hematuria onset to histological confirmation of CrGN was 17 months. At renal biopsy, serum creatinine concentration (sCr) was modestly elevated, with the mean value of 3.4 mg/dl. Crescents were detected in 30% of glomeruli, whereas advanced glomerular sclerosis, tubular atrophy, and interstitial fibrosis were also observed. In comparison with patients without RA, patients with RA were significantly younger and showed a longer duration from the onset to histological confirmation of CrGN. Serum creatinine concentration at referral was significantly lower; however, estimated glomerular filtration rate (eGFR) was comparable. The Birmingham Vasculitis Activity Score and the Disease Extent Index were significantly lower, and pathological examination showed less crescent formation and a tendency to advanced glomerular sclerosis in patients with RA. CONCLUSIONS: In patients with RA, MPO-ANCA-associated CrGN appeared to develop at younger ages and often showed a slowly progressive deterioration of the renal function with slight extrarenal manifestations. These smoldering clinical features may result in late referral from rheumatologists to nephrologists and therefore poor prognosis.

Left ventricular geometry and cardiovascular mortality based on haemodialysis patient autopsy analyses.

AIM: In end-stage renal disease (ESRD) patients, left ventricular hypertrophy (LVH) is common and a risk for cardiovascular events. LVH is geometrically classified into two major groups, concentric and eccentric, and accumulating evidence suggests eccentric LVH has a more negative effect than concentric LVH on ESRD outcome. However, there have been very few studies on the cardiac findings from ESRD patient autopsy in which the relationship between LVH geometry and mortality was analyzed. METHODS: An observational study was performed with the autopsy findings in 30 haemodialysis patient cases between 2001 and 2006 at Mitsui Memorial Hospital, Tokyo. Between those who died of a cardiovascular cause and those who died of non-cardiovascular causes, we compared the heart/bodyweight ratio, left ventricular dilatation, and the extent of fibrosis of the left ventricle. RESULTS: Heart/bodyweight ratio was significantly higher (P < 0.0001) in the cardiovascular mortality group (n = 11, 11.7 +/- 2.5 g/kg) compared to the non-cardiac cause of death group (n = 19, 8.05 +/- 0.7 g/kg). The dilatation of the left ventricle was significantly more frequent in the cardiovascular than the non-cardiac cause of death group (P = 0.016). Additionally, the fibrotic area of left ventricular cross-section was larger in the cardiovascular (1.63 +/- 1.6%) than the non-cardiac group (0.83 +/- 1.7%, P = 0.04). CONCLUSION: This autopsy study indicates that eccentric LVH in haemodialysis patients is closely associated with cardiovascular mortality. LVH geometry, as well as LVH severity, is worthy of consideration as a clinical predictor for cardiovascular mortality.

Clinical and angiographic outcomes following percutaneous coronary intervention with sirolimus-eluting stents versus bare-metal stents in hemodialysis patients.

BACKGROUND: Percutaneous coronary intervention for hemodialysis patients has been hampered by the high rate of adverse cardiac events. Our aim was to investigate whether sirolimus-eluting stents (SESs) improve clinical outcomes of hemodialysis patients compared with bare-metal stents (BMSs). STUDY DESIGN: Retrospective study. SETTING & PARTICIPANTS: 123 consecutive patients on hemodialysis therapy treated with either an SES or BMS. There were 56 patients with 68 lesions treated with SESs between August 2004 and April 2006 (SES group) and 67 patients with 71 lesions treated with BMSs 4 years before approval of SESs in Japan (BMS group). PREDICTOR: SES and BMS implantation for hemodialysis patients with coronary artery disease. OUTCOMES & MEASUREMENTS: Follow-up angiography was performed at 6 to 8 months and clinical follow-up was obtained at 9 months after the procedure. Late lumen loss and major adverse cardiac events, including all-cause death, myocardial infarction, and target-lesion revascularization, were investigated. RESULTS: Clinical follow-up was obtained in all patients. Angiographic follow-up was obtained in 50 patients (89.3%) in the SES group and 50 patients (74.6%) in the BMS group. The SES group had more complex lesions than the BMS group. Quantitative angiographic analysis showed a significant difference for in-stent late lumen loss (SES, 0.62 +/- 0.75 mm; BMS, 1.07 +/- 0.75 mm; P = 0.003). Of angiographic restenosis lesions analyzed, a focal restenotic pattern was observed more frequently in the SES group than the BMS group (SES, 87.5%; BMS, 23.8%; P < 0.001). The rate of major adverse cardiac events was significantly lower in the SES group (n = 14; 25.0%) than the BMS group (n = 26; 38.9%; log-rank P = 0.02). LIMITATIONS: Retrospective study design, small sample size, and a single-center study. CONCLUSIONS: Clinical and angiographic data in the present study suggest that SESs are more effective than BMSs in hemodialysis patients.

Effects of icodextrin on glycemic and lipid profiles in diabetic patients undergoing peritoneal dialysis.

AIM: Icodextrin reduces glucose absorption from the peritoneal dialysate. We conducted this prospective, open-labeled, multicenter study to determine the effects of icodextrin on glycemic and lipid parameters in diabetic patients undergoing continuous ambulatory peritoneal dialysis (PD) or automated PD. METHODS: Patients were recruited from 15 institutions in Japan, and a total of 51 patients (15 women and 36 men, mean age: 59 +/- 10 years, median duration of PD: 13 months) were enrolled. The patients were administered an overnight or daytime dwell of 1.5 or 2.0 l of 7.5% icodextrin-containing solution. At baseline and 3, 6, 9 and 12 months after the start of icodextrin, nonfasting blood was drawn for measurement of glycated hemoglobin (HbA1C) and serum lipids. RESULTS: During icodextrin treatment, there was no change in overall HbA1C levels compared to baseline values; however, for those with baseline HbA1C > or =6.5% (n = 22), significant decreases in HbA1C were observed. Mean total/LDL cholesterol and triglycerides were decreased significantly during icodextrin treatment, with greater decreases for patients with baseline total cholesterol > or =220 mg/dl, LDL cholesterol > or =120 mg/dl or triglycerides > or =150 mg/dl. HDL cholesterol did not differ at any time point; however, values for patients with baseline HDL cholesterol <40 mg/dl tended to increase with marginal significance. CONCLUSIONS: In the current study, switching from glucose-containing dialysis solution to icodextrin resulted in improved lipid profiles and possibly a favorable metabolic profile, particularly in patients with poor glycemic control. These hypotheses remain to be proven in controlled clinical trials.

2005 Japanese Society for Dialysis Therapy guidelines for vascular access construction and repair for chronic hemodialysis.

The guideline committee of Japanese Society for Dialysis Therapy (JSDT), chaired by Dr Ohira, has published an original Japanese guideline, 'Guidelines for Vascular Access Construction and Repair for Chronic Hemodialysis'. The guideline was created mainly because of the existence of numerous factors characteristic of Japanese hemodialysis therapy, which are described in this report, and because we recognized the necessity for standardization in vascular access-related surgeries. This guideline consists of 10 chapters, each of which includes guidelines, explanations or comments and references. The first chapter discusses informed consent of vascular access (VA)-related surgeries, which often resulted in trouble between dialysis staff and patients. The second chapter describes the fundamentals of VA construction and timing of the introduction of hemodialysis with emphasis on the avoidance of catheter indwelling if at all possible. In the third chapter, arteriovenous fistula (AVF) construction and management are discussed from the viewpoint of the most preferable type of VA. The fourth chapter deals with arteriovenous grafts (AVG) which has recently increased in clinical applications. The factors which improve the AVG patency rate are discussed and postoperative management methods are emphasized to avoid possible complications. The fifth chapter deals with short and long-term vascular catheters. It is emphasized that these methods are definitely effective but, at the same time, are apt to be associated with several serious complications and might result in vascular damage. In the sixth chapter, superficialization of an artery is explained. This was originally for emergency use or backup but has been used permanently in 2-3% of Japanese hemodialysis patients. In the seventh chapter, methods for the use of VA are described and the buttonhole method is referred to as one of the options for patients who complain of intense pain at every cannulation. In the eighth chapter, the importance of continuous monitoring is stressed for maintaining appropriate function of VA. As a rule, the internal shunt type VA (AVF, AVG) places a burden on cardiac function. Thus, in the ninth chapter, it is stressed that VA construction, maintenance and repair should always be carried out with consideration of cardiac function which is not constant but variable. The 10th chapter forms one of the cores of this guideline and deals with repair and timing of VA. It is shown how to select a surgical or interventional repair method. In the final 11th chapter, VA types and resultant morbidity and mortality of hemodialysis patients are reviewed.

Successful use of icodextrin in elderly patients on continuous ambulatory peritoneal dialysis.

In peritoneal dialysis (PD), a 7.5% polyglucose-containing dialysis solution (icodextrin) provides prolonged ultrafiltration as compared with glucose-based dialysis solutions. In the present study, we attempted to clarify the safety and effectiveness of icodextrin in elderly patients on continuous ambulatory peritoneal dialysis (CAPD). Clinical data and outcomes of 16 patients aged 65 or older were monitored for 12 weeks before and during icodextrin treatment. The group included 13 men and 3 women with a mean age of 69 +/- 5 years (range: 66-78 years). The underlying kidney disease was chronic nephritis in 7 patients, diabetes mellitus in 8 patients, and nephrosclerosis in I patient. From the beginning of peritoneal dialysis, 1 patients had been treated with icodextrin; the other 10 were changed to icodextrin from glucose dialysis solution. At the end of study, body weight had increased to 63.8 +/- 9.3 kg from 61.6 +/- 9.3 kg, accompanied by an increase in ultrafiltration to 480 +/- 207 mL daily from 369 +/- 436 mL daily. No significant change in urine volume occurred. Despite the increase in body weight, cardiothoracic rate decreased to 51.1% +/- 3.4% from 52.3% +/- 4.9%. All patients reported an improvement of edema and appetite. Edema scores were significantly decreased to 0.85 +/- 0.90 from 1.63 +/- 0.96 (p < 0.03). No adverse side effects were associated with the use of icodextrin. From the foregoing data, we concluded that, as compared with conventional glucose solution, icodextrin has beneficial effects on ultrafiltration volume and clinical symptoms in elderly patients on CAPD.

[Clinical outcome assessment of membranous nephropathy].

Appropriate treatment of idiopathic membranous nephropathy (IMN) remains a controversial issue. Whereas some authors recommend a conservative approach, based on the considerable rate of spontaneous remissions, others utilize early immunosuppressive treatment for most nephrotic patients with IMN. Our retrospective study consisted of 34 patients who presented with IMN between the period from 1987 to 2002. The patients were divided into two groups based on the type of treatment they received the immunosuppressive group comprised 18 patients who received corticosteroids with/without other immunosuppressive drugs and the supportive group comprised 16 patients who were treated with anti platelet drugs as supportive therapy. The amount of proteinuria at the base line was significantly higher in the immunosuppressive group than in the supportive group(4.7 +/- 2.9 vs. 2.7 +/- 2.7 g/24 h). At the end of the follow-up, complete remission was achieved more frequently in the immunosuppressive group than in the supportive group(9/18 vs. 3/16). This suggests that immunosuppressive treatment has the effect of decreasing proteinuria. At the end of the follow-up, 3 patients in the immunosuppressive group and 2 patients in the supportive group showed renal insufficiency (serum creatinine concentration > or = 1.5 mg/dl). Side effects besides diabetes were not seen as a result of immunosuppressive treatment. Our findings suggest that immunosuppressive treatment in IMN cases appears to be beneficial for decreasing proteinuria, but the effect on prevention of renal failure was not evident.

Glucose dialysate induces mitochondrial DNA damage in peritoneal mesothelial cells.

BACKGROUND: It is known that peritoneal mesothelial cells (PMCs) are denuded in patients undergoing long-term continuous ambulatory peritoneal dialysis (CAPD); the mechanism of damage is not well known. A high quantity of glucose loaded onto PMCs in these patients may generate toxic radicals during the mitochondrial metabolism, leading to mitochondrial DNA damage that accumulates due to the incomplete repair system of this DNA. OBJECTIVE: To study damage to the PMCs of long-term CAPD patients, and to examine whether glucose overload accelerates this damage in vitro. DESIGN: Descriptive clinical and in vitro study. PARTICIPANTS: Stable CAPD patients and nonuremic patients undergoing elective abdominal surgery. METHODS: (1) Clinical Samples: 13 peritoneal tissue samples from CAPD patients and 5 omental tissue samples from patients with normal renal function were investigated. PMCs in dialysate effluent were collected from another 13 stable CAPD patients. (2) In Vitro Samples: Primary PMCs were incubated for up to 144 hours in medium containing one of the following: 5.6 mmol/L glucose (control), 56 mmol/L glucose (G), 222 mmol/L glucose (high G), or 222 mmol/L mannitol (high M; osmolar control for high G). The tissues and cells of clinical and in vitro samples were stained for light and immunoelectron microscopy with anti-8-hydroxy-2'-deoxyguanosine (anti-8-OH-dG) antibody, a marker of oxidative DNA damage. In vitro cells were also studied using transmission electron microscopy. Cellular ATP content, mitochondrial membrane potential, and intracellular generation of reactive oxygen species (ROS) were analyzed by luciferase-luciferin system, or by flow cytometry using rhodamine 123 and 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). RESULTS: Biopsy specimens showed strong cytoplasmic staining with 8-OH-dG in patients on long-term CAPD, but only faint staining in patients with end-stage renal disease before the initiation of CAPD, and no staining in patients with normal renal function. Dialysate effluent showed strong granular staining with 8-OH-dG in most PMCs in all long-term CAPD patients, but only faint and focal staining in patients at the start and after 3-5 months of CAPD. In vitro experiments also showed strong granular staining by 8-OH-dG in most PMCs cultured in high G, weak staining in G and high M, and no staining in the control. Immunoelectron microscopy revealed the localization of 8-OH-dG to mitochondria. Transmission electron microscopy showed swelling of mitochondria, with decreased cristae, in PMCs cultured in high G. However, only partial expansion of mitochondria was seen in G and high M, and no changes were seen in the control. Cellular ATP content and mitochondrial membrane potential were reduced early, followed by an increase when cultured in high G. Intracellular ROS production was also increased in PMCs cultured in high G and high M. CONCLUSIONS: These data suggest that high-glucose peritoneal dialysate may promote oxidative mitochondrial DNA damage in PMCs in CAPD patients.

AP-VAS 2012 case report: two patients with rheumatoid arthritis suspected of relapsed microscopic polyangiitis after initiation of dialysis.

We report two patients with rheumatoid arthritis (RA) who were suspected of microscopic polyangiitis during maintenance dialysis. Case 1 was a 52-year-old woman with RA diagnosed at the age of 38 years and treated successfully with gold compounds. At the age of 43 years, she presented with progressive renal dysfunction and abnormal urine sediments, and a renal biopsy revealed crescentic nephritis with advanced glomerular sclerosis. Myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) was not measured on that occasion. She reached end-stage renal failure within 4 months and started peritoneal dialysis. Eight years later, soon after she was switched to hemodialysis, she developed fever of unknown origin. MPO-ANCA was elevated to 37 EU, although there were no other signs or symptoms suggestive of vasculitis. After taking prednisolone orally (10 mg/day), her fever withdrew, and MPO-ANCA became undetectable. Case 2 was a 71-year-old woman with RA diagnosed at the age of 60 years and treated with gold compounds. She developed renal failure of unknown cause (no biopsy was performed), and started hemodialysis at the age of 69 years. One year later, she presented with fever and subsequently developed cough with hemoptysis. MPO-ANCA was elevated to 62 EU. Treatment with azathioprine 50 mg and prednisolone 35 mg daily brought remarkable clinical improvement, and MPO-ANCA became undetectable. These cases highlight the importance of measuring ANCA even in RA patients on dialysis who present with fever of unknown origin or with underlying kidney disease of uncertain etiology.