Kiyotaka Uchiyama

Non-tuberculous mycobacterial infections related to peritoneal dialysis

Most infections related to peritoneal dialysis (PD) are caused by common bacteria, and non-tuberculous mycobacteria are rare. The clinical characteristics and prognosis of PD patients with non-tuberculous mycobacterial infections were investigated at our hospital. Non-tuberculous mycobacteria were detected in 11 patients (exit-site infection, tunnel infection, and peritonitis in 3, 5, and 3 patients, respectively). Mycobacterium fortuitum, Mycobacterium chelonae, and Mycobacterium abscessus were identified in 4, 2, and 2 patients, respectively. Most patients with peritonitis or tunnel infection required catheter removal. During the study period (2007 – 2017), peritonitis occurred in 44 patients, including 3 patients (6.8%) with non-tuberculous mycobacterial peritonitis. When non-tuberculous mycobacterial infection occurs, multi-agent antibiotic therapy, unroofing surgery, and/or catheter replacement should be performed to prevent peritonitis.

Baseline and Time-Averaged Values Predicting Residual Renal Function Decline Rate in Japanese Peritoneal Dialysis Patients

Residual renal function (RRF) is a strong prognostic factor of morbidity and mortality in patients undergoing peritoneal dialysis (PD). We determined predictors of the RRF rate of decline using both baseline values and time‐averaged ones. We retrospectively analyzed 94 patients being treated with PD at the Japanese Red Cross Medical Center. The decline rate of RRF was calculated by a diminution in the weekly renal Kt/V between the first and last follow up divided by follow‐up years. The mean follow‐up period was 2.28 years, and the mean decline rate of weekly renal Kt/V was 0.25 per year. A multivariate analysis using baseline parameters identified dialysis‐to‐plasma ratios of creatinine at 4 h (P = 0.02), urinary protein (P = 0.02), and mean blood pressure (MBP) (P < 0.01) as being positively associated with the RRF rate of decline, while the use of angiotensin converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB) had a negative correlation (P = 0.03). When using time‐averaged values as independent variables, a lower weekly total renal Kt/V (P < 0.0001), higher urinary protein (P < 0.0001), and higher MBP (P = 0.04) independently predicted a faster RRF rate of decline. We demonstrated that PD patients with a lower MBP and lower urinary protein both at baseline and throughout their PD duration had a slower RRF rate of decline. We recommend strict control of blood pressure and anti‐proteinuric therapy for PD patients.

Membranous Nephropathy Associated with Atheroembolism

Membranous nephropathy (MN) is one of the most common biopsy diagnoses in adults, and it has been associated with chronic infections, autoimmune diseases, malignancies, and drugs. However, MN associated with cholesterol crystal emboli has never been reported. Here we present a patient with MN as an unusual manifestation of atheroembolism. A 75-year-old man with worsening renal function after catheter ablation developed moderate proteinuria and underwent a renal biopsy. Findings on light, immunofluorescence, and electron microscopy were all compatible with membranous nephropathy. Moreover, one occluded interlobular artery contained a pathognomonic, biconvex, needle-shaped cleft, which indicated a cholesterol crystal emboli. The degree of proteinuria was in parallel with the number of eosinophils, which indicated a close relationship between MN disease activity and renal atheroembolism. Hypereosinophilic syndrome secondary to atheroembolism may cause MN; thus, corticosteroid therapy was likely to be effective.

Long-Term Peritoneal Dialysis in 2 Patients with Takayasu's Arteritis

1. Reddy DK, Moore HL, Lee JH, Saran R, Nolph KD, Khanna R, et al. Chronic peritoneal dialysis in iron-deficient rats with solutions containing iron dextran. Kidney Int 2001; 59(2):764–73. 2. Suzuki K, Twardowski ZJ, Nolph KD, Khanna R, Moore HL. Absorption of iron from the peritoneal cavity of rats. Adv Perit Dial 1994; 10:42–3. 3. Gupta A, Amin NB, Besarab A, Vogel SE, Divine GW, Yee J, et al. Dialysate iron therapy: infusion of soluble ferric pyrophosphate via the dialysate during hemodialysis. Kidney Int 1999; 55(5):1891–8. 4. Fishbane SN, Singh AK, Cournoyer SH, Jindal KK, Fanti P, Guss CD, et al. Ferric pyrophosphate citrate (TrifericTM) administration via the dialysate maintains hemoglobin and iron balance in chronic hemodialysis patients. Nephrol Dial Transplant 2015;pii: gfv277. [Epub ahead of print]. DOI: 10.1093/ndt/gfv277 https://doi.org/10.3747/pdi.2016.00045

Importance of Neurogenic Bladder as a Cause of Drainage Failure.

Editor: Drainage failure is one of the peritoneal dialysis (PD) catheter-related problems that cause morbidity and greatly reduce quality of life (1). We report here 2 cases of outflow failure due to neurogenic bladder. The f irst case was a 62-year-old female with diabetic nephropathy. Peritoneal dialysis was initiated 4 years prior, and 1 year later, hemodialysis (HD) was combined with PD. She developed outflow failure, but X rays showed no signs of catheter malposition. Suction and injection of fibrinolytic agent had no effect. A plain computed tomography (CT) scan revealed the tip of the catheter pressed against the abdominal wall by a dilated bladder containing a large amount of urine (Figure 1), despite the fact that she had been considered to be anuric for several years. Approximately 1 L of urine was drained by urethral catheterization, and outflow failure was completely resolved. The second case was a 79-year-old male with diabetic nephropathy with a 3-year history of PD, and 8-month history of bimodal therapy with PD and HD. He experienced sudden outflow failure, but X rays, intraluminal suction or injection, and intraluminal fibroscopy were performed without effect. He continued to void 100 – 300 mL of urine per day, but a plain CT scan showed an extended urinary bladder wall and considerable remaining urine, which pushed the tip of the catheter into the rectum (Figure 1). After urethral catheterization, approximately 500 mL of urine flowed out and drainage from the catheter improved dramatically. Major causes of outflow failure include malposition of the catheter tip, catheter omental wrap, and catheter obstruction by luminal plug (2–4); and X rays, catherogram, suction or injection of a fibrinolytic agent, and intraluminal fibroscopy are used to diagnose it (2–5). However, a plain CT scan was critical to diagnose such a case. Moreover, treatment was quite easy with urethral catheterization, while some catheter malfunctions require surgical intervention. An important lesson here is that, even if patients are considered to be anuric or oliguric, they may have urine remaining in the bladder, and urinary bladder dilatation should be suspected as a cause of drainage failure.

Effect of tolvaptan in a patient with autosomal dominant polycystic kidney disease after living donor liver transplantation

Recently, a large randomized placebo-controlled trial indicated a beneficial effect of tolvaptan on the progression of autosomal dominant polycystic kidney disease (ADPKD) with near-normal kidney function. Meanwhile, the evidence of tolvaptan’s efficacy in ADPKD with severe renal insufficiency was limited and higher frequency of liver enzyme elevations were observed in patients taking tolvaptan. Liver transplantation (LT) is the only curative treatment for patients with severe polycystic liver disease associated with ADPKD, but considering that liver injuries should be avoided particularly in patients who underwent LT, we must be careful to start tolvaptan in post-LT ADPKD patients. We describe the case of a patient who had developed severe renal insufficiency after living donor LT, for whom tolvaptan therapy showed marked reduction of total kidney volume and maintenance of renal function without any serious adverse events. This is the first report to show the beneficial effect and safety of tolvaptan, in a post-LT ADPKD patient with severe renal insufficiency, and hopefully will help broaden the spectrum of patients who will benefit from tolvaptan.