Fabry disease is an X-linked recessive inborn metabolic disorder caused by a deficiency of the lysosomal enzyme α-galactosidase A (EC 3.2. throughout the 7 exons of the α-galactosidase A gene (GLA). Mutation hotspots for Fabry disease do not exist. We examined 62 Fabry patients in Japan and found 24 GLA mutations, including 11 novel ones. A potential treatment reported for Fabry disease is active site specific chaperone (ASSC) therapy using 1-deoxygalactonojirimycin (DGJ), an inhibitor of α-galactosidase A, at subinhibitory concentrations. We transfected COS-7 cells with the 24 mutant GLAs and analyzed the α-galactosidase A activities. We then treated the transfected COS-7 cells with DGJ and analyzed its effect on the mutant enzyme activities. The activity of 11 missense mutants increased significantly with DGJ. Although ASSC therapy is useful only for misfolding mutants and therefore not applicable to all cases, it may be useful for treating many Japanese patients with Fabry disease. © 2007 Wiley-Liss, Inc.KEY WORDS: α-galactosidase A; GLA; lysosomal storage disease; 1-deoxygalactonojirimycin; chaperone therapy INTRODUCTIONFabry disease (FD; MIM# 301500) is a pan-ethnic, X-linked, lysosomal storage disorder caused by a deficiency in the lysosomal enzyme α-galactosidase A (EC 3.2.1.22) (Brady et al., 1967). Human α-galactosidase A is a homodimeric glycoprotein with three N-linked oligosaccharide chains on each subunit. Enzyme deficiency results in a systemic lysosomal accumulation of glycolipids, primarily globotriosylceramide (Gb3), in the vascular endothelium and other tissues. In the classical form of the disease, the patient develops angiokeratoma, hypohidrosis, and episodic pain crises in the extremities during childhood or adolescence. With advancing age, the morbidity of renal failure, cardiac disease, and early onset of stroke increases. The severity of the clinical manifestations depends on the amount of residual α-galactosidase A activity. Hemizygous male patients with no or very low α-galactosidase A activity usually have severe clinical symptoms and die as young adults. Heterozygous female Fabry patients exhibit a wide range of severity, from a virtually symptom-free course (Marguery et al., 1993) to one comparable to that of their male counterparts (Whybra et al., 2001), although they usually have no symptoms or very mild manifestations.We examined Fabry patients in Japan and sequenced the patients' α-galactosidase A gene (GLA) (MIM# 300644). To analyze the mutant α-galactosidase A activities, we transfected COS-7 cells with the mutant GLAs. In addition, since 1-deoxygalactonojirimycin (DGJ) stabilizes the α-galactosidase A conformation and improves its stability (Asano et al., 2000;Ishii et al., 2000;Yam et al., 2006), we added DGJ to the incubation medium and examined its effect on the mutant α-galactosidase A activities. MATERIALS AND METHODS PatientsWe examined 62 Fabry patients from 31 unrelated families. Diagnosis was based on reduced or absent α-galactosidase A activity and typical signs an...

Background/Aims: Combining peritoneal dialysis (PD) and hemodialysis (HD) has been common treatment option in Japan. Methods: In this retrospective, multicenter, observational study, the clinical characteristics and outcomes of 104 patients (57 w 11 years, males 72%) who had switched from PD alone to combined therapy with PD and HD were studied. Clinical parameters were measured at baseline and after 3 months of combined therapy. Results: At baseline, urine volume, dialysate-to-plasma ratio of creatinine (D/P Cr), and total Kt/V were 150 ml/day (range: 0-2,000 ml/day), 0.67 w 0.11, and 1.8 w 0.4, respectively. During the first 3 months of combined therapy, body weight, urine volume, serum creatinine level, and D/P Cr decreased, whereas hemoglobin levels increased. Conclusions: In patients where PD does not result in acceptable outcomes, combined therapy with PD and HD may have potential benefits in terms of dialysis adequacy and hydration status. Video Journal Club “Cappuccino with Claudio Ronco” at http://www.karger.com/?doi=368389 i 2014 S. Karger AG, Basel

Activation of neutrophil by the dialysis membrane and peroxidative stress plays an important role on the pathogenesis of complications in hemodialysis (HD) patients. Vitamin E is one of the potent scavengers for reactive oxygen species. Recent studies suggest that a vitamin E-modified multilayer membrane (Excebrane, CL-EE dialyzer) has an inhibitory effect on serum lipids peroxidation in HD patients. To determine the effect of CL-EE on biocompatibility in clinical use, we measured the superoxide anion radical producing ability (SOPA) of polymorphonuclear leukocytes (PMNLs), the plasma hydroxyl radical producing ability (OHPA) and superoxide anion radical scavenging activity (SSA). SOPA was measured after stimulation of PMNLs with phorbol myristate acetate using electron paramagnetic resonance (EPR) method. Plasma OHPA and SSA were also determined using the EPR method. In addition, the plasma concentrations of malondialdehyde (MDA) and oxidized low-density lipoprotein (LDL), as the parameters for lipid peroxidation, were measured. SOPA was decreased in patients who used conventional filter membrane compared with healthy controls. In the patients using the CL-EE membrane, SOPA gradually increased and reached control levels after six months. However, no significant increase was observed in patients who used a conventional filter membrane. OHPA of HD patients was significantly decreased compared with controls. In the CL-EE membrane patient group, OHPA was significantly increased at six months. SSA was significantly higher in the conventional filter membrane group than controls. In the CL-EE membrane patient group, SSA gradually decreased at six months. Plasma MDA and oxidized LDL levels were significantly higher in HD patients compared with controls. These values slowly decreased, and significant differences were found after nine months of using the CL-EE membrane. These findings suggest that activation of PMNLs and plasma OHPA and SSA in HD patients is attenuated by antioxidant effects of the CL-EE.

Background/Aim: An imbalance in renal redox status contributes to progression of renal dysfunction. We investigated the effects of an oral charcoal adsorbent (AST-120) on renal redox status, superoxide production from renal mitochondria, and serum lipid peroxidation using chronic kidney disease (CKD) model rats. Methods: CKD was induced by 5/6 nephrectomy. CKD rats were divided into 2 groups: controls, and those treated with AST-120 for 20 weeks. We evaluated: (1) renal redox status by in vivo low-frequency electron spin resonance imaging (EPRI); (2) renal superoxide scavenging activity (SSA); (3) superoxide production from renal mitochondria; (4) immunostaining for Cu-Zn superoxide dismutase (SOD), and (5) oxidative stress markers including LDL-negative charge (LDL-CMF), serum lipid peroxide (LPO) and urinary hexanoyl-lysine (HEL). The effect of indoxyl sulfate, a uremic toxin, on mitochondrial superoxide production was also investigated. Results: AST-120 treatment improved renal function, renal SSA, renal mitochondrial superoxide production, renal SOD expression, renal redox status by EPRI, and oxidative stress profiles by LDL-CMF, LPO and urinary HEL. Addition of indoxyl sulfate increased mitochondrial superoxide production and AST-120 also decreased this. Conclusions: Improvements in the redox status and lipid peroxidation induced by AST-120 may delay the progression of CKD.

Patients undergoing continuous ambulatory peritoneal dialysis (CAPD) who developed carpal tunnel syndrome (CTS) were retrospectively studied in 143 centers in Japan. Among the total 5,050 patients undergoing CAPD between 1980 and 1993 only 7 patients (0.14%) given CAPD developed CTS. Five of these 7 patients treated solely with CAPD developed CTS 12-108 months after starting CAPD. The remaining 2 patients who were initially treated with HD for 7-9 years and then switched to CAPD developed this complication 9 years after starting CAPD. All 7 patients were women, ranging in age from 32 to 70 (average 52) years. We detected the presence of amyloid deposits in 2 of 5 specimens and Β₂-microglobulin in 2 of 4 specimens from these patients. It was concluded that CAPD minimizes the emergence of CTS although constant surveillance is necessary to detect CTS in patients during CAPD.