Fabry Disease in Hemodialysis Patients in Southern Brazil: Prevalence Study and Clinical Report

Background. Fabry disease (FD) is a lysosomal storage disorder caused by a deficiency of α-Galactosidase A (α-Gal A). Fabry nephropathy typically progresses throughout the fifth decade to end-stage renal disease (ESRD), requiring hemodialysis and/or kidney transplantation. Objective. To estimate the prevalence of FD among ESRD males on hemodialysis treatment in Rio Grande do Sul, the southernmost state of Brazil. Methods. Screening for α-Gal A activity was performed by a dried blood spot (normal reference value: >1.5 nmoles/hour/mL). Positive screening results were confirmed by plasma α-Gal A activity assay (reference value: >3.3 nmoles/hour/mL). Results. Five hundred fifty-eight male patients on hemodialysis were evaluated. Of these, only two had low α-Gal A activity and were diagnosed with Fabry disease (0.36%). One of these, age 42, had left ventricular hypertrophy and renal manifestations of Fabry disease without the classic symptoms. The other, age 46, had the classical manifestations of angiokeratomas, acroparesthesias, hypohidrosis, and ocular opacities. Conclusions. Although the prevalence of Fabry disease was very low in our study (0.36%), routine screening of male hemodialysis patients would enable earlier identification of many other affected relatives in their families who might benefit from specific clinical treatment.     

Identification of Fabry's disease by the screening of alpha-galactosidase A activity in male and female hemodialysis patients

BACKGROUND: Although previous studies reported that the prevalence of Fabry's disease was 0.16 - 1.2% in hemodialysis (HD) patients based on measurement of a-galactosidase A (alpha-Gal A) activity, few reports detected female patients by the screening for alpha-Gal A. Here we determined the prevalence of Fabry's disease not only in male but also in female HD patients by measuring alpha-Gal A. METHODS: Plasma alpha-Gal A was measured in 696 consecutive males (n = 401) and females (n = 295) on HD. Patients with low plasma alpha-Gal A were examined for leukocyte alpha-Gal A, and patients with low leukocyte alpha-Gal A underwent alpha-Gal A gene sequence analysis for possible mutations, and family survey. RESULTS: Among 15 patients with low plasma alpha-Gal A activity, 4 male patients with low leukocyte alpha-Gal A and 1 female patient revealing low plasma alpha-Gal A were detected in 696 HD patients (0.7% of total patients). 3 of these 5 patients were already diagnosed to have the classical type of Fabry's disease. The other 2 patients were newly diagnosed as Fabry's disease, and did not have typical manifestations of Fabry's disease other than renal failure and left ventricular hypertrophy. DNA analysis of these 2 newly diagnosed patients revealed that each had an alpha-Gal missense mutation, previously identified (E66Q, M2961). CONCLUSION: Fabry's disease should be considered in the etiology of unexplained end-stage renal disease. Not only affected males but also affected females undergoing HD patients can be readily diagnosed by alpha-Gal A activities and gene analysis. These patients and their family members may benefit from enzyme replacement therapy for Fabry's disease.     

A nationwide blood spot screening study for Fabry disease in the Czech Republic haemodialysis patient population.

BACKGROUND: Fabry disease (FD) is a genetic disorder characterized by accumulation of trihexosylceramide in lysosomes of various tissues leading to multiorgan manifestations, including progressive renal disease. Previous screening studies have shown that a non-neglectable proportion of haemodialysis(HD) patients have unsuspected FD. An extensive FD screening study, the largest to date, has been conducted in HD patients in Czech Republic. We aimed to uncover previously undiagnosed FD patients, to enable them to benefit from cause-specific therapeutic intervention with enzyme replacement therapy (ERT). METHODS: Large-scale screening was executed using a convenient automated enzymatic (alpha-galactosidose A, alpha-Gal A) dried blood spot on filter paper fluorescence method. RESULTS: In total, 3370 (45.1% males, 54.9% females) out of 4058 HD patients (83%) in Czech Republic participated in this blood spot screening (BSS) study. Abnormal low fluorescence readings were obtained in 117 patients (3.5%). Subsequent determination of plasma alpha-Gal A activity identified four males and three females with deficient plasma enzyme activity. Determination of alpha-Gal A activity in peripheral blood leucocytes and confirmatory molecular analysis resulted in four newly diagnosed Fabry males and one female. Subsequent family screening identified 10 family members with genotypically proven FD. Based on these screening results, ERT could be offered to five male FD patients. CONCLUSIONS: BSS represents a promising screening tool that has proven to be convenient and effective in uncovering unrecognized FD patients among the chronic HD population in Czech Republic.     

alpha-Galactosidase A deficiency in Dutch patients on dialysis: a critical appraisal of screening for Fabry disease.

INTRODUCTION: Fabry disease or alpha-galactosidase A (alpha-Gal A) deficiency is an X-linked lysosomal storage disorder that often leads to renal insufficiency in males and occasionally in females. The disease is rare, but its prevalence may be underestimated due to its variable clinical picture. Enzyme supplementation therapy with rHu-alphaGal A is currently available. Limited experience has so far shown that therapy may at best stabilize renal function. Despite these preliminary findings, much effort is being put into screening high-risk groups for undiagnosed alpha-Gal A deficiency. We studied the prevalence of alpha-Gal A deficiency in a Dutch dialysis cohort to establish possible underdiagnosis. We discuss the benefits of screening for Fabry disease. METHODS: Activity of alpha-Gal A in whole blood was measured in a group of 508 male Dutch dialysis patients. RESULTS: Of the 508 patients studied only one patient, already known with Fabry disease, had a alpha-Gal A deficiency, a prevalence of 0.22% (95 CI 0-1.1%). CONCLUSIONS: No undiagnosed Fabry patients were found, indicating that in our studied cohort there is no large-scale underestimation of its prevalence. Even though screening of dialysis patients for Fabry disease might identify patients who remain otherwise unrecognized, screening of high-risk populations for alpha-Gal A deficiency should be carried out with caution since long-term efficacy of treatment is currently unknown.     

Henoch-Schoenlein nephritis in adults-clinical features and outcomes in Finnish patients

Fabry disease, an X-linked lysosomal storage disease, results from the deficient activity of the enzyme alpha-galactosidase A (alpha-Gal A) and the progressive accumulation of globotriaosylceramide (GL-3) and related glycosphingolipids. In classically affected males with this inherited nephropathy, early and marked GL-3 deposition in the podocytes leads to proteinuria in childhood or adolescence. With increasing age, GL-3 deposition in renal microvascular endothelial cells, and to a lesser extent in interstitial and mesangial cells, leads to renal insufficiency in the third to fifth decades of life. Recently identified "renal variants" who lack the classical disease manifestations of acroparesthesias, angiokeratoma, hypohidrosis, and characteristic corneal/lenticular opacities also develop renal failure. In contrast, "cardiac variants" who also lack the classical phenotype, develop proteinuria in adulthood, but survive a normal lifespan without developing renal failure. Here, we review the renal involvement and pathology in the classical, renal and cardiac variant phenotypes, and present highlights of the preclinical studies and clinical trials that demonstrated the safety and effectiveness of recombinant alpha-Gal A replacement for this inherited nephropathy.     

A nonsense mutation (R220X) in the alpha-galactosidase A gene causes typical Fabry disease in both genders

BACKGROUND: Fabry disease is an X-linked recessive disorder resulting from a deficiency of lysosomal alpha-galactosidase A (alpha-Gal A). Chronic renal failure is an important cause of death in patients with Fabry disease. We report on patients with Fabry disease (a hemizygous male and his mother) due to a nonsense mutation (R220X) in the alpha-Gal A gene. METHODS: The proband, a 41-year-old man, and his 71-year-old mother presented with renal and cardiac manifestations of Fabry disease. Histological examination and molecular analysis of the alpha-Gal A gene were performed. RESULTS: Typical histological findings of Fabry disease were observed in a renal biopsy specimen from the proband and in renal and myocardial necropsy specimens from the mother. Sequencing of a full-length alpha-Gal A cDNA from the proband indicated a C-T transition at codon 220, resulting in substitution of the predictable termination for arginine (R220X). Examination of genomic alpha-Gal A DNA revealed that the proband was a hemizygote and the mother was a heterozygous carrier for the mutation. CONCLUSION: This is the first detailed report of family members with Fabry disease due to a nonsense mutation (R220X) in the alpha-Gal A gene. Our study indicates that this mutation causes the typical disease in both genders.     

Safety and pharmacokinetics of agalsidase alfa in patients with Fabry disease and end-stage renal disease.

BACKGROUND: Fabry disease (FD) is caused by an X-linked deficiency in the activity of alpha-galactosidase A and the resultant accumulation of globotriaosylceramide (Gb3) in multiple tissues. Nearly all classically affected males with FD experience kidney dysfunction, with progression to end-stage renal disease (ESRD) in the third decade of life or shortly thereafter. METHODS: Twenty-two FD patients (20 men and 2 women) receiving dialysis or who had a history of kidney transplantation were treated with agalsidase alfa in an open label setting using the same dosing regimen given to patients without ESRD (0.2 mg/kg every other week). Pharmacokinetics (PK) were determined during and following the initial dose, and safety was evaluated during therapy. Change in plasma Gb3 level was used as a surrogate marker of enzyme activity in vivo. RESULTS: A typical biphasic plasma elimination profile was seen in both dialysis and transplant patients, similar to that observed in 18 non-ESRD FD patients. Calculated PK parameters were similar to the three patient groups. In the male patients, plasma Gb3 level declined by 43% after 6 months (P<0.001). Infusion reactions were experienced by 8 of 21 (38%) patients, but did not result in any infusions being stopped prematurely. Anti-agalsidase alfa IgG antibodies were detected in 15.8% of males and 0% female patients. No anti-agalsidase alfa IgE antibodies were detected. CONCLUSIONS: The same dosing regimen of agalsidase alfa may be safely administered to FD patients with ESRD as given to those without ESRD.     

Fabry disease: diagnosis and treatment

Fabry disease is an X-linked lysosomal storage disorder that results from a deficiency of the enzyme alpha-galactosidase A (alpha-Gal A). The lack of alpha-Gal A causes an intracellular accumulation of glycosphingolipids, mainly globotriaosyceramide (GL3). Affected organs include, among others, the vascular endothelium, heart, brain, and kidneys, leading to end-stage renal disease (ESRD). Since Fabry disease cannot be cured at present, clinical management is symptomatic. Enzyme replacement therapy (ERT) with recombinant alpha-Gal A has been introduced as a new therapeutic option for the treatment of Fabry patients. Short-term (one year) clinical studies have positively correlated ERT with improvement of clinical symptoms and microvascular endothelial cell clearance. Treatment outcome concerning severe organ manifestations such as proteinuria and renal function impairment, left ventricular hypertrophy, and heart failure in the long run has yet to be shown. In our studies we used sensitive and noninvasive techniques such as ultrasound-based strain rate imaging and magnetic resonance imaging (MRI), combined with MR-spectroscopy (MR-S), for the quantification of functional abnormalities at an early stage of the disease and during long-term follow-up. Future issues should determine the appropriate timing to start therapy and how children and heterozygous females should be managed. Given the diagnostic and therapeutic potential today, it is of importance to identify patients at an early stage and to start therapeutic intervention before progression of organ damage is inevitable.     

Fabry disease: clinical spectrum and evidence-based enzyme replacement therapy

The clinical spectrum of Fabry disease, an X-linked lysosomal storage disorder due to alpha-galactosidase A (alpha-Gal A) deficiency, has been expanded beyond the classic phenotype to include the recently recognized later-onset "cardiac" and "renal" variants. The clinical manifestations in each of these disease subtypes are presented with particular emphasis on early recognition among pediatric patients as well as identification of unrecognized patients diagnosed as hypertrophic cardiomyopathy or in renal dialysis clinics. Previously, treatment of patients with Fabry disease was limited to palliative care of the excruciating pain, cardiac and cerebrovascular manifestations, and renal failure. Recently, Fabry-specific enzyme replacement therapy (ERT) with recombinant alpha-Gal A (Fabrazyme) has proven safe and effective. The preclinical, Phase 1/2 and multicenter, double-blind, randomized, placebo-controlled Phase 3 and 4 trials provided the evidence for the safety and efficacy of Fabrazyme treatment. The preclinical and Phase 1/2 studies demonstrated that enzyme delivery to various tissues and GL-3 clearance were dose-dependent. The Phase 3 clinical trial and 3-year extension study provided long-term data documenting the safety and effectiveness of 1 mg/kg of Fabrazyme for this disease. Finally, the "top-line" data from the Phase 4 trial indicates that in patients with mildly to moderately advanced renal disease, Fabrazyme can slow the progression of renal, cardiac, and cerebrovascular events taken together or individually. The Phase 4 trial results also emphasize the importance of early treatment. In sum, these clinical trials provide the evidence-based safety and efficacy of Fabrazyme replacement therapy for Fabry disease.     

Kidney transplantation and enzyme alpha-galactosidase A therapy in patient with Fabry disease: a case report

Fabry disease, an X-linked recessive glycolipid storage disease, is caused by a deficiency of the lysosomal enzyme alpha-galactosidase A (alpha-Gal A), which cleaves a fatty substance called globotriaosylceramide (GL3). The abnormal storage of GL3 in blood vessel walls leads to ischemia and necrosis, particularly in blood vessels of the skin, kidneys, heart, brain, and nervous system. The aim of our study was to present the results of cadaveric kidney transplantation with enzyme alpha-Gal A therapy in a patient with Fabry disease. The patient was diagnosed with Fabry disease at the age of 33 years, based on enzymatic tests. Renal manifestations occurred a year later as proteinuria. At the age of 35 years, the glomerular filtration rate (GFR) was within the normal range. The patient received supplemental enzyme treatment with alpha-Gal (1 mg/kg every 2 weeks). At 3 months after starting supplementation, renal function worsened with serum creatinine levels at 1.7 to 1.8 mg/dL. The following months of supplementation (alpha-Gal 1 mg/kg) concurred with progressive renal dysfunction. After 27 months of supplementation at 37 years, with a creatinine value of 5.5 mg/dL, hemodialysis began and months later the patient received a cadaveric kidney graft. The patient no longer required dialysis. On postoperative day 5 the serum creatinine was 3.9 mg/dL; on day 7, 2.2 mg/dL; on day 14, 1.5 mg/dL. Enzyme supplementation began on posttransplant day 13. Renal graft function has been good during 5 months of observation with creatinine levels at 1.2 to 1.3 mg/dL. The treatment does not interfere with tacrolimus metabolism. Simultaneous chronic enzyme supplementation is the optimal treatment in the fifth stage of end-stage renal disease in Fabry disease.     

Plasma lyso-Gb3: a biomarker for monitoring fabry patients during enzyme replacement therapy

Background

Recently, globotriaosylsphingosine (lyso-Gb3) has attracted interest as a biomarker of Fabry disease. However, little is known regarding its utility for the evaluation of the therapeutic efficacy.

Method

We measured plasma lyso-Gb3 concentration in Japanese healthy subjects and Fabry patients by means of liquid chromatography–tandem mass spectrometry (LC–MS/MS). We determined the reference interval in Japanese (UMIN000016854), and examined the effect of enzyme replacement therapy (ERT) with recombinant α-galactosidase A (GLA) and the influence of antibodies against the enzyme on the plasma lyso-Gb3 level in Fabry patients (UMIN000017152).

Results

The reference interval was determined to be 0.35–0.71 nmol/L, this being almost the same as the normal range in a non-Japanese population previously reported. The analysis revealed that the plasma lyso-Gb3 level was strikingly increased in classic Fabry males, and to a lesser extent in later-onset Fabry males and Fabry females. The elevation of the plasma lyso-Gb3 level was related to renal involvement in the Fabry females. ERT gave a rapid reduction in the elevated plasma lyso-Gb3 level in the classic Fabry males, and a gradual one or stabilization in most of the later-onset Fabry males and Fabry females. However, formation of antibodies against the recombinant GLA had a negative effect on the reduction of plasma lyso-Gb3.

Conclusions

Regular observation of plasma lyso-Gb3 and antibodies is useful for monitoring of Fabry patients during ERT.

     

Enzyme replacement therapy in Fabry's disease: recent advances and clinical applications

Fabry's disease is a rare X-linked recessive disorder resulting from deficient lysosomal enzyme, alpha-galactosidase A (alpha-Gal A) activity. The deficiency leads to progressive glycosphingolipid globotriaosylceramide (Gb3) accumulation in fluids and tissues, including vascular endothelium, connective tissue, kidney, heart, brain and peripheral nerves. Classic Fabry's disease in hemizygous males has high morbidity and mortality due to end-stage renal disease (ESRD) requiring hemodialysis (HD) or kidney transplantation, myocardial involvement and central nervous system (CNS) complications. Most heterozygous females can also suffer from this severe disease deterioration. Until recently, Fabry's disease management consisted of symptomatic and palliative treatment, but this has changed with the availability of the recombinant human alpha-Gal A enzyme, agalsidase. Two different agalsidase formulations have been obtained: one from human fibroblast (agalsidase alpha), and one from Chinese hamster ovary (CHO) cells (agalsidase beta). Both preparations underwent clinical trials that documented the feasibility, efficacy and safety of the treatment. In addition, several clinical observations have proved that agalsidase reduces the storage of the substrate from several organs and tissues and, consequently, improves signs and symptoms of Fabry's disease. Additional clinical experiences have confirmed the initial clinical trial results, but further studies are needed to evaluate the long-term outcome of enzyme replacement therapy (ERT). We reviewed the clinical trial observations, as well as subsequent clinical experiences with ERT in patients with Fabry's disease.     

Agalsidase therapy in patients with Fabry disease on renal replacement therapy: a nationwide study in Italy.

BACKGROUND: In Fabry disease, end-stage renal disease (ESRD) and severe neurologic and cardiac complications represent the leading causes of late morbidity and mortality. A comprehensive Italian nationwide survey study was conducted to explore changes in cardiac status and renal allograft function in Fabry patients on renal replacement therapy (RRT) and enzyme replacement therapy (ERT). METHODS: This study was designed as a cross-sectional survey study with prospective follow-up. Of the 34 patients identified via searches in registries, 31 males and 2 females who received RRT and ERT (agalsidase beta in 30 patients, agalsidase alpha in 3) were included. Left ventricular mass index (LVMI), interventricular septal thickness at end diastole (IVSD), left ventricular posterior wall thickness (LVPWT) and renal allograft function were assessed at ERT baseline and subsequently at yearly intervals. RESULTS: The patients in the dialysis and transplant groups had been started on dialysis at age 42.0 and 37.1 years (mean), respectively, and patients in the transplant group received their renal allograft at age 39.8 years (mean). The mean age at the start of ERT was similar, 44.1 and 44.6 years, respectively. The mean RRT follow-up was 61.1 and 110.6 months for dialysis and transplant patients, respectively, whereas the ERT duration was 45.1 and 48.4 months, respectively. Cardiac parameters increased in dialysis patients. In transplant patients, mean LVMI seemed to plateau during agalsidase therapy at a lower level as compared to baseline. Decline in renal allograft function was relatively mild (-1.92 ml/min/year). Agalsidase therapy was well tolerated. Serious ERT-unrelated events occurred more often in the dialysis group. CONCLUSIONS: Kidney transplantation should be the standard of care for Fabry patients progressing towards ESRD. Transplanted Fabry patients on ERT may do better than patients remaining on maintenance dialysis. Larger, controlled studies in Fabry patients with ESRD will have to demonstrate if ERT is able to change the trajectory of cardiac disease and can preserve graft renal function.     

A case of Fabry's disease with chronic renal failure]

Fabry's disease is a genetic disorder caused by the absence of alpha-galactosidase (alpha-Gal), the gene of which is carried on the long arm of the X chromosome. This enzymatic defect leads to an accumulation of glycosphingolipids in the plasma and lysosomes of endothelial, perithelial, and smooth muscle cells, especially involving those of the cardiovascular, renal and cerebrovascular systems. We report one male case of Fabry's disease with renal deterioration. A 36-year-old man who was a classic case with acroparesthesia, angiokeratoma, and hypohidrosis from 10 years of age, was diagnosed to be a hemizygote of Fabry's disease at 27 years as a result of severe decreased alpha-Gal activity of his peripheral white blood cells. This patient was found to have a point mutation of a G to A transition in exon 1. In May, 1989, he was reported to have proteinuria with normal renal function and admitted to our hospital due to renal deterioration in September, 1993. Laboratory examinations revealed a serum urea nitrogen of 65 mg/dl and creatinine value of 6.9 mg/dl. Urinary protein excretion was 3.9 g/day and urinary sugar was negative. On the renal biopsy specimens, light microscopic examinations revealed multiple sclerosing and collaptic lesions in glomeruli without severe tubulo-interstitial damage, but with stenotic change of the small arteries and arterioles. Electron microscopic examinations revealed a large number of electron dense deposits in the tubules. We diagnosed this case as Fabry's disease with chronic renal failure, however the pathogenesis of this renal progressive deterioration remained obscure. In this case, degenerative changes in the renal vessels due to Fabry's disease may be associated with rapid deterioration in renal function.     

Fabry disease: renal biopsy-proven cases from China

BACKGROUND: Fabry disease is a rare metabolic disorder resulting from deficient activity of the lysosomal enzyme alpha-galactosidase A (alpha-GalA). Renal involvement is the major cause of morbidity and mortality in male patients. Here, we describe the largest series ever reported for this condition in China. METHODS: Nine patients were enrolled in this study. Routine light microscopy (including toluidine blue staining), immunofluorescence and electron microscopic examinations were performed. We measured alpha-GalA activity in leukocyte and gene mutation analysis. Clinical and laboratory data of the patients were collected. RESULTS: Eight of the 9 patients were hemizygous males. Proteinuria was obvious in all patients. Three patients presented with mild renal function impairment. Light microscopy revealed glomeruli full of enlarged podocytes with abundant foamy cytoplasm. Toluidine blue stain revealed abundant cytoplasmic granular inclusions within the podocytes, tubular epithelial cells and endothelial cells of peritubular capillaries. Electron microscopy showed abundant electron-dense myelin figures within the podocyte cytoplasm. Arteriolar hyalinization and occlusion were also observed. Extrarenal manifestations, including acroparesthesia, hypohidrosis, abnormal electrocardiography and angiokeratoma were noted. No cornea verticillata or lenticular opacities were observed. These patients had about 0.3%-1.3% residual alpha-GalA activity in leukocytes. We identified a novel missense mutation (F273L) causing nonclassical Fabry disease.CONCLUSIONS: Fabry disease is relatively rare in China. Renal biopsy and specific staining is efficacious in the correct diagnosis of the disease. Discrepancies in the clinical manifestations of Fabry disease (i.e., eye disorders and hypertension) exist between cases found in China and those detailed in Western reports.     

Enzyme therapy for Fabry disease: neutralizing antibodies toward agalsidase alpha and beta

BACKGROUND: Fabry disease is an X-linked inherited disorder that is caused by excessive lysosomal globotriaosylceramide (CTH) storage due to a deficiency in alpha-galactosidase A (alpha-Gal A). Two recombinant enzyme preparations have been approved as treatment modality. We studied emergence and properties of alpha-Gal A antibodies in treated patients. METHODS: During the first 6 to 12 months of intravenous administration of recombinant enzymes (rh-alpha-Gal A) formation of antibodies was studied in 18 adult Fabry patients (two females). RESULTS: The female patients did not develop detectable amounts of antibodies following enzyme therapy. After 6 months of treatment with either agalsidase alpha or beta, 11/16 male patients showed high titers of immunoglobulin G (IgG) antibodies that cross-react in vitro similarly with both recombinant enzymes. The anti-rh-alpha-Gal A IgG neutralizes rh-alpha-Gal A activity in vitro for 65% to 95%. During infusion with rh-alpha-Gal A, circulating enzyme-antibody complexes are formed and these complexes are taken up by leukocytes in the peripheral blood. After 6 months of treatment all IgG-negative patients showed a significant (P < 0.01) reduction of urinary CTH (1890 +/- 797 to 603 +/- 291 nmol CTH/24hr urine), compared to IgG-positive patients (mean increase from 2535 +/- 988 to 2723 +/- 1212), suggesting a negative effect of circulating antibodies on renal tubular CTH clearance. CONCLUSION: Emergence of antibodies with in vivo neutralizing capacities is frequently encountered in treated Fabry disease patients. Complete cross-reactivity of these antibodies suggests that it is unlikely that switching from one to the other recombinant protein prevents the immune response and related effects. Further studies on the clinical implications of alpha-Gal A antibodies are essential.     

Significance of screening for Fabry disease among male dialysis patients

Background Fabry disease is an X-linked disorder resulting from a deficiency of the lysosomal enzyme alpha-galactosidase A(α-Gal A). Renal insufficiency is a very important manifestation and affects the prognosis of patients. Recently, a renal variant type that is characterized by low plasma α-Gal A activity and a milder phenotype, but which progresses to end-stage renal failure, has been reported. In this study, we clarified the incidence of this atypical variant of Fabry disease in hemodialysis patients. Methods We measured plasma α-Gal A activity in 450 male dialysis patients who had never been diagnosed with Fabry disease. Results The mean of the α-Gal A activity of the patients was 9.75 ± 3.20 nmol/h/ml, while the controls with classical Fabry (n = 3) were 0.52–1.04 nmol/h/ml. Among the patients, one patient was found to exhibit low α-Gal A activity in plasma (3.18 nmol/h/ml) and in leukocytes (0.639 nmol/h/mg). This patient was a 43-year-old Japanese man who had been on regular dialysis since the age of 23. He did not present typical clinical signs of classical Fabry, such as acroparesthesias or hypohidrosis, but did present renal insufficiency and severe left ventricular hypertrophy which had developed only recently, suggesting a variant form of Fabry disease. Sequencing of the DNA of this patient revealed a deletion of a single amino acid of valine in 10252. Conclusions A case of an atypical variant of Fabry among 450 male dialysis patients (0.22%) was found in the survey. This indicates the potential for undiagnosed Fabry disease among dialysis patients. The results of this study indicate the significance of screening for Fabry disease among male dialysis patients.     

Reduced hemodialysis-induced oxidative stress in end-stage renal disease patients by electrolyzed reduced water

BACKGROUND: Increased oxidative stress in end-stage renal disease (ESRD) patients may oxidize macromolecules and consequently lead to cardiovascular events during chronic hemodialysis. Electrolyzed reduced water (ERW) with reactive oxygen species (ROS) scavenging ability may have a potential effect on reduction of hemodialysis-induced oxidative stress in ESRD patients. METHODS: We developed a chemiluminescence emission spectrum and high-performance liquid chromatography analysis to assess the effect of ERW replacement on plasma ROS (H2O2 and HOCl) scavenging activity and oxidized lipid or protein production in ESRD patients undergoing hemodialysis. Oxidized markers, dityrosine, methylguanidine, and phosphatidylcholine hydroperoxide, and inflammatory markers, interleukin 6 (IL-6), and C-reactive protein (CRP) were determined. RESULTS: Although hemodialysis efficiently removes dityrosine and creatinine, hemodialysis increased oxidative stress, including phosphatidylcholine hydroperoxide, and methylguanidine. Hemodialysis reduced the plasma ROS scavenging activity, as shown by the augmented reference H2O2 and HOCl counts (Rh2o2 and Rhocl, respectively) and decreased antioxidative activity (expressed as total antioxidant status in this study). ERW administration diminished hemodialysis-enhanced Rh2o2 and Rhocl, minimized oxidized and inflammatory markers (CRP and IL-6), and partly restored total antioxidant status during 1-month treatment. CONCLUSION: This study demonstrates that hemodialysis with ERW administration may efficiently increase the H2O2- and HOCl-dependent antioxidant defense and reduce H2O2- and HOCl-induced oxidative stress.     

Long-term therapy with agalsidase alfa for Fabry disease: safety and effects on renal function in a home infusion setting.

BACKGROUND: Fabry disease is an X-linked disorder of glycosphingolipid catabolism that is the result of an intracellular deficiency in the lysosomal enzyme alpha-galactosidase A (alpha-Gal A). This enzymatic defect results in the accumulation of globotriaosylceramide (Gb(3)) within cells and causes progressive neurological, cardiovascular and renal dysfunction. Our objective is to describe the safety and renal effects of long-term enzyme replacement therapy. METHODS: This was a single centre, prospective open-label treatment trial in 25 adult male Fabry patients who had completed a 6-month randomized placebo-controlled study and subsequently enrolled in an open-label extension study. Patients were treated every other week with agalsidase alfa (0.2 mg/kg) infused intravenously over 40 min. The main outcome measures were safety, antibody response and renal glomerular filtration rate (GFR). RESULTS: During the 4-4.5 years of enzyme replacement therapy, all eligible subjects were able to transition to home therapy. Eight patients developed persistent IgG antibodies to agalsidase alfa, but IgE antibodies were not detected in any patient. The development of IgG antibodies appeared not to affect any clinical end points. Estimated GFR remained stable in subgroups of patients with Stage I (GFR >90 ml/min) or Stage II (GFR 60-89 ml/min) chronic kidney disease at baseline. In contrast, in the subgroup of patients with Stage III chronic kidney disease (GFR 30-59 ml/min), the slope of the decline in GFR was reduced compared with comparable historical controls, suggesting that enzyme replacement therapy was slowing the decline of renal function in this susceptible population. CONCLUSIONS: Long-term enzyme replacement therapy with agalsidase alfa is safe and may slow the progressive decline in renal function that was commonly observed in adult males with Fabry disease.