Masatsugu Nakao

Estimation of salt intake from spot urine samples in patients with chronic kidney disease

BackgroundHigh salt intake in patients with chronic kidney disease (CKD) may cause high blood pressure and increased albuminuria. Although, the estimation of salt intake is essential, there are no easy methods to estimate real salt intake.MethodsSalt intake was assessed by determining urinary sodium excretion from the collected urine samples. Estimation of salt intake by spot urine was calculated by Tanaka’s formula. The correlation between estimated and measured sodium excretion was evaluated by Pearson´s correlation coefficients. Performance of equation was estimated by median bias, interquartile range (IQR), proportion of estimates within 30% deviation of measured sodium excretion (P30) and root mean square error (RMSE).The sensitivity and specificity of estimated against measured sodium excretion were separately assessed by receiver-operating characteristic (ROC) curves.ResultsA total of 334 urine samples from 96 patients were examined. Mean age was 58 ± 16 years, and estimated glomerular filtration rate (eGFR) was 53 ± 27 mL/min. Among these patients, 35 had CKD stage 1 or 2, 39 had stage 3, and 22 had stage 4 or 5. Estimated sodium excretion significantly correlated with measured sodium excretion (R = 0.52, P < 0.01). There was apparent correlation in patients with eGFR <30 mL/min (R = 0.60, P < 0.01). Moreover, IQR was lower and P30 was higher in patients with eGFR < 30 mL/min. Estimated sodium excretion had high accuracy to predict measured sodium excretion, especially when the cut-off point was >170 mEq/day (AUC 0.835).ConclusionsThe present study demonstrated that spot urine can be used to estimate sodium excretion, especially in patients with low eGFR.

Risk Factors for Encapsulating Peritoneal Sclerosis in Long‐Term Peritoneal Dialysis: A Retrospective Observational Study

Encapsulating peritoneal sclerosis (EPS) is a serious complication that occurs in patients with long‐term peritoneal dialysis (PD). Investigation of risk factors that contribute to EPS in patients on long‐term PD therapy is needed. In a retrospective, observational study, data were collected for 107 patients treated with PD therapy for more than 5 years. Fifty cases of EPS were compared with 57 cases of non‐EPS. To evaluate the impact of PD‐associated peritonitis in EPS, univariate and multivariate logistic regression models were applied. Episodes of peritonitis, number of peritonitis episodes and the duration of peritonitis were included as explanatory variables in addition to previously reported risk factors. D/P Cr and serum β2MG levels in the EPS and non‐EPS groups were: 0.82 ± 0.10 and 0.67 ± 0.12 (P < 0.01), and 33.8 ± 8.54 and 29.2 ± 8.18 mg/L (P < 0.01), respectively. Episodes of peritonitis, number of peritonitis episodes and the duration of peritonitis was 68% and 42% (P < 0.01), 1.80 ± 2.19 and 0.75 ± 1.07 times (P < 0.01), and 18.1 ± 15.3 and 10.2 ± 4.90 days (P < 0.01), in the EPS and non‐EPS groups, respectively. Furthermore, multivariate logistic regression models demonstrated that both D/P Cr and the duration of peritonitis were independently associated with EPS (P < 0.01 and P < 0.05, respectively). In patients on long‐term PD therapy, D/P Cr and the duration of peritonitis are independently associated with EPS. Earlier treatment to promote an early recovery from PD‐associated peritonitis could be critical in preventing EPS.

Fungal granulomatous interstitial nephritis presenting as acute kidney injury diagnosed by renal histology including PCR assay

We describe two cases of fungal granulomatous interstitial nephritis (GIN) presenting as acute kidney injury (AKI). Increased serum creatinine was detected in Patient 1 after chemotherapy for pharyngeal cancer and in Patient 2 after steroid pulse therapy for bronchial asthma. Renal histology of both patients revealed GIN. Polymerase chain reaction (PCR)-based detection of fungal DNA sequences from kidney tissue demonstrated Trichosporon laibachii and Candida albicans, respectively. When AKI occurs in an immunocompromised host, differential diagnosis of fungal interstitial nephritis should be considered. Furthermore, PCR-based detection of fungal DNA sequences from renal specimens can be useful for rapid diagnosis.

33 Years of Peritoneal Dialysis-Associated Peritonitis: A Single-Center Study in Japan

Peritoneal dialysis‐associated peritonitis (PD‐associated peritonitis) could influence the outcome of PD patients, including technique survival. Although the use of the twin‐bag system has decreased the incidence of peritonitis, the effects of biocompatible PD solutions are controversial. Additionally, since both infection‐causing microorganisms and antimicrobial therapies have changed over time, the duration of treatment of peritonitis (the duration of peritonitis) seems to have changed. The study included 527 patients who received PD between January 1980 and December 2012 at a single center. We divided patients undergoing PD into three groups according to the type of PD system used, namely single‐bag and conventional PD solutions (S+C group, N = 145), twin‐bag and conventional PD solutions (T+C group, N = 171) and twin‐bag and biocompatible PD solutions (T+B group, N = 211), and analyzed PD‐associated peritonitis incidences. Incidences of PD‐associated peritonitis (times per patient‐months) and peritonitis‐free time were 1/59.4, 1/70.6 and 1/103.1, and 52, 97, and 100 months for the S+C, T+C and T+B groups, respectively. The duration of peritonitis, has thus, become dramatically shorter in recent years. Streptococcus sp. were associated with shortest and fungi with longest durations of peritonitis. Staphylococcus sp. and Pseudomonas aeruginosa were predominant in the S+C group. The twin‐bag system has made a greater contribution to reductions in PD‐associated peritonitis than biocompatible PD solutions. Furthermore, changes in microorganisms, antimicrobial therapies, patient education and improved PD system devices have presumably affected the reduction in the duration of peritonitis.

Possible prevention of dialysis-requiring congestive heart failure by angiotensin-II receptor blockers in non-dialysis Japanese patients with Stage 5 chronic kidney disease

Background: Preventive medications for dialysis-requiring congestive heart failure (CHF) in non-dialysis Japanese patients with Stage 5 chronic kidney disease (CKD) are unknown. Our aim was to explore which CKD medication was associated with a reduced prevalence of dialysis-requiring CHF in non-dialysis Japanese patients with Stage 5 CKD. Methods: The present multicenter, retrospective, cross-sectional study examined the association between CKD medications and the prevalence of dialysis-requiring CHF in non-dialysis Japanese patients with Stage 5 CKD. Results: There were 1536 Japanese Stage 5 CKD patients who satisfied our inclusion criteria. We had 309 (20.1%) patients whom had developed dialysis-requiring CHF and 940 patients (60.8%) whom had been using angiotensin-II receptor blockers (ARBs) before initiating dialysis. In our multivariate analysis, only ARB use was significantly associated with a lower risk of CHF (Odds ratio (OR): 0.680, 95% confidence interval (CI): 0.516–0.897; p = 0.0064), of the CKD treatments examined in this study. Conclusions: We found that ARB use during the pre-dialysis period is associated with a lower prevalence of CHF in the non-dialysis Japanese patients with Stage 5 CKD, suggesting a possible prevention of dialysis-requiring CHF by ARBs, in non-dialysis Japanese patients with Stage 5 CKD.

Risk factors for encapsulating peritoneal sclerosis: analysis of a 36-year experience in a University Hospital.

Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication that occurs in peritoneal dialysis (PD) therapy. The present study aimed to identify the risk factors, especially peritonitis and biocompatible PD fluid.

Successful treatment of ocular toxoplasmosis that developed four years after kidney transplantation

Dear Sirs, Toxoplasmosis after solid organ transplantation is associated with high morbidity and mortality rates and is usually diagnosed after the first month post-transplantation [1,2]. Approximately one-third of humans worldwide are chronically infected with Toxoplasma gondii [3,4]. However, the prevalence of the disease and the sources of infection vary between geographic regions, with differences in toxoplasmic environments, climates, eating habits and hygiene status [5]. Ocular toxoplasmosis is caused by Toxoplasma gondii through congenital or acquired routes. Although several studies have reported on patients who developed toxoplasmosis after kidney transplantation, only a few have reported on ocular toxoplasmosis after transplantation. Here, we report a rare case of ocular toxoplasmosis that developed 4 years after kidney transplantation. A 39-year-old Paraguayan man with chronic renal failure caused by IgA nephropathy had undergone kidney transplantation from a living-related donor in March 2007. The blood type was compatible, and human leucocyte antigen typing had shown a 2/6 locus mismatch. The standard complement-dependent cytotoxicity cross-match test was negative. Induction therapy for immunosuppression comprised tacrolimus (TAC), mycophenolate mofetil (MMF), methylprednisolone (mPSL) and basiliximab. Subsequent maintenance immunosuppression therapy comprised TAC, MMF and mPSL. His serum creatinine (S-Cr) level was 1.8 mg/dl immediately after kidney transplantation, and he did not present proteinuria or microhaematuria. However, in September 2009, his S-Cr level increased to 2.1 mg/dl, and he presented proteinuria of 4.59 g/day and microhaematuria 20–29/high-power field (HPF). Based on a renal biopsy performed in February 2010, we diagnosed recurrent IgA nephropathy and chronic active antibody-mediated rejection. The patient underwent tonsillectomy in April 2010 and had received steroid pulse therapy 3 times, and he was administered i.v. mPSL 500 mg/day for three consecutive days in addition to his maintenance immunosuppressive therapy (TAC 2.5 mg/day, MMF 1000 mg/day, and mPSL 4 mg/day). Subsequently, his S-Cr level, proteinuria and microhaematuria were at 2.3 mg/dl, 2.23 g/day and 0–1/HPF, respectively. In April 2011, the vision on his left eye became blurry. He revisited our hospital in May 2011. The visual acuity of his left eye reduced from a minimum angle of resolution (log MAR) 0.3 to +1.0. Initially, we diagnosed uveitis with iritis and purulent accumulation in the anterior chamber of his left eye and suspected herpes zoster ophthalmia; therefore, we administered valacyclovir 500 mg/day and decreased MMF to 500 mg/day. However, visual acuity of his left eye deteriorated from log MAR +1.0 to +1.7, and his left eye pain exacerbated; therefore, we increased the dose of mPSL from 4 mg/day to 20 mg/day as a treatment for uveitis, increased the administration of valacyclovir to 1000 mg/day, and stopped MMF. Test results showed significantly high levels of serum toxoplasma IgG antibodies (940960) and toxoplasma antigen (92048) using a serum latex agglutination method; therefore, in May 2011, we started the administration of clindamycin (CLDM) 2400 mg/day. Furthermore, later in May 2011, polymerase chain reaction (PCR) test results of the anterior chamber aqueous humour were positive for Toxoplasma gondii [Fig. 1 (I)]. We confirmed that he had been living in South America where the infection rate of Toxoplasma is high, and he had a history of frequent contact with cats, an animal frequently associated with Toxoplasma infection. We finally made the definitive diagnosis of ocular toxoplasmosis. On 28 May 2011, in addition to CLDM, we administered pyrimethamine (25 mg/day) and folinate (10 mg/day) 3 times a week. CLDM, pyrimethamine and folinate were administered for 28 days (Day 74 after the development of eye symptoms); treatment concluded in June 2011. His intra-ocular findings improved markedly, and his visual acuity recovered to log MAR +0.52 on 24 June 2011. Further, we tapered PSL gradually from 20 mg/ day to 5 mg/day in 4 months. The TAC trough level was adequately maintained at 3.0–5.0 ng/ml during his followup. The subsequent clinical course was good, and the visual acuity of his left eye improved to log MAR +0.22 after 5 months [Fig. 1 (II)]. Figure 1 (III) shows the fundus and

Clinical outcome of incident peritoneal dialysis patients with diabetic kidney disease

BackgroundAlthough peritoneal dialysis (PD) is becoming more widespread, PD among diabetic patients carries some concerns, such as worsened glycemic control due to constant exposure to glucose and operational errors due to diabetic complications. However, several technical advances could overcome these disadvantages. We, therefore, aimed to compare technical and patient survival between diabetic and non-diabetic PD patients.MethodsWe conducted a historical cohort study of 103 patients (mean age, 57 ± 16 years; 75 males, 32 diabetic patients) who started PD between January 2011 and January 2016. Kaplan–Meier survival analysis was used to compare technical and patient survivals between diabetic and non-diabetic patients. Multivariate Cox regression analysis was used to estimate the effects of the presence of diabetes on these outcomes.ResultsTechnical and patient survivals did not differ significantly between groups (P = 0.62, P = 0.34, respectively). In addition, presence of diabetes affected neither technical nor patient survival in multivariate analysis (hazard ratio [HR], 1.31; 95% confidence interval [CI], 0.58–2.82 and HR 0.80; 95% CI 0.22–2.68, respectively).ConclusionsTechnical and patient survivals of diabetic PD patients were not inferior to those of non-diabetic PD patients. These results suggest that no hesitation is warranted in initiating PD for diabetic patients with end-stage renal disease.

Beneficial Effect of Intradialytic Electrical Muscle Stimulation in Hemodialysis Patients: A Randomized Controlled Trial: EMS IN HEMODIALYSIS PATIENTS

Many hemodialysis (HD) patients cannot perform self-administered exercise training for their muscle wasting, weakness, and sarcopenia. Electrical muscle stimulation (EMS) has the advantages of easy application, and minimal risks for these patients. This study aimed to evaluate the effects of intradialytic EMS. This was a prospective, open-label, randomized controlled trial. Twenty-nine HD patients were randomly assigned to either the EMS group or the control (no training) group, and 13 patients in each group were eventually analyzed. The EMS group received intradialytic EMS over an 8-week period. Measurement of isometric knee extensor strength using a handheld dynamometer, evaluation of the quadriceps cross-sectional area (CSA) using magnetic resonance imaging (MRI), the Timed Up & Go Test (TUG) for physical function assessment, the Japanese version of the Short Form-8 Health Survey (SF-8), and blood tests were performed before and after the intervention period. The primary and secondary outcomes were improvement of quadriceps muscle strength and size, respectively. The EMS group demonstrated significant improvement compared with the control group in terms of knee extensor strength (right: 22.3 ± 12.8 vs. -10.8 ± 22.3 N, P < 0.001; left: 26.1 ± 29.7 vs. -8.3 ± 18.7 N, P < 0.001), quadriceps CSA at three positions, 25, 50, and 75% of the segment length from the greater trochanter to the inferior border of the lateral epicondyle of the femur (25% right: EMS group 1.7 ± 2.0 vs. Control group -0.4 ± 1.8cm2 , P = 0.05; 25% left: EMS group 1.3 ± 1.1 vs. Control group -0.6 ± 1.8cm2 , P = 0.01; 50% right: EMS group 2.0 ± 2.2 vs. Control group -0.7 ± 1.9cm2 , P = 0.004; 50% left: EMS group 2.7 ± 2.1 vs. Control group -0.7 ± 1.6cm2 , P = 0.001; 75% right: EMS group 1.8 ± 2.2 vs. Control group -0.7 ± 1.5cm2 , P = 0.003; 75% left: EMS group 2.1 ± 1.9 vs. Control group -0.4 ± 1.5cm2 , P = 0.003); and TUG time (-0.8 ± 0.6 vs. 0.2 ± 0.5s, P < 0.001). The EMS group showed improvement after intervention in all components of SF-8, but these were not statistically significant. EMS could be an effective exercise training tool for HD patients with either muscle wasting, weakness, or sarcopenia.

The differences in acid-base status and the calcium parathyroid axis between peritoneal dialysis and hemodialysis.

BACKGROUND Several guidelines have set the target levels of serum Ca, phosphorus, and parathyroid hormone (PTH) for better management of chronic kidney disease-mineral and bone disorders (CKDMBD) in dialysis patients. Although serum ionized Ca (iCa) is a biologically active component, corrected Ca (cCa) is used in clinical settings. However, the association between iCa and cCa is affected by acid-base status. We investigated the difference in acid-base and the calcium-parathyroid status between hemodialysis (HD) and peritoneal dialysis (PD). METHODS The markers associated with CKD-MBD were measured in 142 patients receiving chronic dialysis (69 on PD and 73 on HD). RESULTS Serum bicarbonate levels were significantly higher in the PD group than in the HD group (26.6 ± 2.8 vs. 22.9 ± 2.0 mEq/L, p < 0.01). The serum iCa levels and the iCa/cCa ratio were significantly lower in the PD group than in the HD group (iCa 1.07 ± 0.08 vs. 1.14 ± 0.08 mmol/L, p < 0.01; iCa/cCa ratio 45.5 ± 3.1% vs. 49.7 ± 3.2%, p < 0.01). The cCa levels were significantly higher in the PD group than in the HD group (9.4 ± 0.4 vs. 9.1 ± 0.4 mg/dL, p < 0.01). Intact PTH levels were significantly higher in the PD group than in the HD group (220 (40 - 581) vs. 133 (30 - 666) pg/mL, p < 0.01). CONCLUSIONS We found that PD patients had lower iCa and higher PTH levels despite higher cCa levels as compared to HD patients. These results suggested that the assessment of both Ca and PTH should be different between PD and HD.