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Improvement of splenomegaly and pancytopenia by enzyme replacement therapy against type 1 Gaucher disease: a report of sibling cases.

Gaucher disease is a genetic lipid storage disease and represents a potentially serious health problem. It arises from a deficiency of glucocerebrosidase activity with secondary accumulation of large quantities of glucocerebroside. Symptoms are usually multisystemic, often debilitating or disabling, and sometimes disfiguring, and they can lead to death. We report objective clinical response's to repeated infusion of human placental and recombinant glucocerebrosidase in 2 patients with type 1 Gaucher disease and increased hemoglobin levels and platelet counts. Splenic volume decreased during the period of enzyme administration. Enzyme replacement therapy has improved the treatment of type 1 Gaucher disease by safely and effectively arresting, decreasing, or normalizing many of its major signs and symptoms. Consideration by physicians must be given to Gaucher disease, and appropriate treatments must be given when confronted with cryptogenic pancytopenia or hepatosplenomegaly.

Adult↗

Early-onset severe neurological involvement and D409H homozygosity in Gaucher disease: outcome of enzyme replacement therapy.

Gaucher disease, in most cases, is the result of mutations in the beta-glucocerebrosidase gene. More than 150 such mutations have been identified so far. Mutation D409H is the second most frequent in Greek patients, accounting for 15.5% of all identified mutated alleles. D409H homozygosity has, so far, been associated with a unique type III subtype of Gaucher disease that is characterized by the presence of devastating valvular heart disease, oculomotor apraxia, and, sometimes, features normally associated with mucopolysaccharidoses or oligosaccharidoses. Common manifestations of Gaucher disease tend to be less evident or even absent. We report the first Greek patient bearing the D409H/D409H genotype with onset of the disease in the first months of life and a phenotype dominated by severe neurological involvement. Enzyme replacement therapy, while improving the hematological parameters and organomegaly, failed to improve or even arrest the neurological condition.

Age of Onset↗

Regional cerebral hyperperfusion and nitric oxide pathway dysregulation in Fabry disease: reversal by enzyme replacement therapy.

BACKGROUND: Fabry disease is an X-linked lysosomal deficiency of alpha-galactosidase A that results in cellular accumulation of galacto-conjugates such as globotriosylceramide, particularly in blood vessels. It is associated with early-onset stroke and kidney and heart failure. METHODS AND RESULTS: Using [(15)O] H(2)O and PET, we found increased resting regional cerebral blood flow in Fabry disease without evidence of occlusive vasculopathy or cerebral hypoperfusion. Because nitric oxide is known to play an important role in vascular tone and reactivity, we studied plasma nitrate, nitrite, and low-molecular-weight S-nitrosothiol levels by chemiluminescence. Skin biopsy specimens and archived brain tissue were also examined immunohistochemically for nitrotyrosine. Plasma nitrate, nitrite, and low-molecular-weight S-nitrosothiol were in the normal range; however, enhanced nitrotyrosine staining was observed in dermal and cerebral blood vessels. After a double-blind, placebo-controlled trial of alpha-galactosidase A therapy, the resting regional cerebral blood flow in the treated group was significantly reduced, with a notable decrease of nitrotyrosine staining in dermal blood vessels. CONCLUSIONS: These findings suggest a chronic alteration of the nitric oxide pathway in Fabry disease, with critical protein nitration that is reversible with enzyme replacement therapy.

Adult↗

Alpha-L-iduronidase and enzyme replacement therapy for mucopolysaccharidosis I.

Mucopolysaccharidosis I (McKusick 25280, Hurler syndrome, Scheie syndrome) is caused by a deficiency in the lysosomal hydrolase, alpha-L-iduronidase (EC 3.2.1.76) and results in a failure to degrade the glycosaminoglycans, dermatan sulfate and heparan sulfate. Mucopolysaccharidosis I patients present within a spectrum of clinical phenotypes, where Hurler and Scheie syndromes represent the two extremes. In the 80 or more years since the discovery of mucopolysaccharidosis I, the molecular defect has been defined, the alpha-L-iduronidase protein purified and characterised, the alpha-L-iduronidase (IDUA) gene cloned, molecular genetic studies performed and expression systems developed. These advances have allowed the development of alpha-L-iduronidase enzyme replacement therapy as a treatment strategy for mucopolysaccharidosis I patients. Using animal models of mucopolysaccharidosis I, the efficacy of alpha-L-iduronidase replacement therapy has been evaluated and justified the initiation of human clinical trials in mucopolysaccharidosis I patients. Phase I/II and Phase III clinical trials have recently been conducted and demonstrated that this therapy is effective in treating patients with the attenuated forms of mucopolysaccharidosis I (that is, little or no neuronal involvement). Further development of this technology is required to effectively treat the problem sites of neuronal and skeletal pathology, present in severe Hurler syndrome patients.

Animals↗

Efficacy of enzyme replacement therapy in alpha-mannosidosis mice: a preclinical animal study.

Alpha-mannosidosis is a lysosomal storage disorder which manifests itself in the excessive storage of mannose-containing oligosaccharides in the lysosomes of multiple peripheral tissues and in the brain. Here we report on the correction of storage in a mouse model of alpha-mannosidosis after intravenous administration of lysosomal acid alpha-mannosidase (LAMAN) from bovine kidney, and human and mouse recombinant LAMAN. The bovine and the human enzyme were barely phosphorylated, whereas the bulk of the mouse LAMAN contained mannose 6-phosphate recognition markers. The clearance decreased from bovine to human to mouse LAMAN with plasma half-times of 4, 8 and 12 min, respectively. The apparent half-life of the internalized enzyme was dependent on the enzyme source as well as tissue type and varied between 3 and 16 h. The corrective effect on the storage of neutral oligosaccharides was time-, tissue- and dose-dependent, and the effects were observed to be transient. After a single dose of LAMAN the maximum corrective effect was observed between 2 and 6 days after injection. In general the corrective effect of the human LAMAN was higher than that of the mouse LAMAN and lowest for the bovine LAMAN. Injection of 250 mU human LAMAN/g body weight followed by a subsequent injection 3.5 days later was sufficient to clear liver, kidney and heart from neutral oligosaccharides. Surprisingly a decrease in mannose containing oligosaccharides was also observed in the brain, with storage levels reported at <30% than that found in controls. These data clearly underline the efficacy of enzyme replacement therapy for the correction of storage in alpha-mannosidosis and suggest that this treatment can substantially decrease storage in the brain.

Animals↗

Enzyme replacement therapy in Japanese Fabry disease patients: the results of a phase 2 bridging study.

Fabry Disease (alpha-galactosidase A deficiency) is an X-linked hereditary disorder leading to the pathological accumulation of globotriaosylceramide (GL-3) in lysosomes, particularly in the vascular endothelium of the kidney, heart and brain. We report the results of an open-label phase 2 study that was undertaken to evaluate whether ethnic differences exist that would affect agalsidase beta (Fabrazyme) treatment of Fabry patients in the Japanese population, relative to safety and efficacy. The study design mirrored the design of the completed phase 3 clinical trial that led to approval of the product agalsidase beta. The 13 Japanese, male Fabry patients enrolled in the study received the enzyme replacement therapy over a period of 20 weeks as biweekly infusions. All selected efficacy end points showed improvements that were comparable with findings from the phase 3 study. These improvements included reductions of GL-3 accumulation in both kidney and skin capillary endothelial cells to (near) normal levels (92% of patients). Kidney and plasma GL-3 levels decreased by 51.9% and 100%, respectively, by ELISA. Renal function remained normal. Fabry-associated pain, and quality of life, showed improvement over baseline in multiple categories. Related adverse events were mild or moderate in intensity and mostly infusion-associated (fever and rigors). As expected, IgG antibody formation was observed in 85% of the patients, but had no effect on treatment response. These results suggest that treatment with agalsidase beta is safe and effective in Japanese patients with Fabry disease. With regard to safety and efficacy, no differences were observed as compared to the caucasian population.

Adult↗

Fabry disease and the heart: an overview of the natural history and the effect of enzyme replacement therapy.

UNLABELLED: Fabry disease is a genetic disorder caused by the deficiency of alpha-galactosidase A, resulting in the lysosomal accumulation of glycosphingolipids. Fabry disease may result in cardiac, cerebral and renal complications. Cardiac abnormalities in patients with Fabry disease were first described in the 1960s. In the 1990s a form of Fabry disease confined to the heart was reported; however, this variant is extremely rare and a more appropriate concept is of cardiac predominance of the disease in some patients. Up to 60% of males with classic Fabry disease have cardiac abnormalities, including left ventricular hypertrophy, valvular dysfunction and conduction abnormalities. Recent data suggest that left ventricular mass and systolic function in patients with Fabry disease improve after 12 months of enzyme replacement therapy (ERT); however, many of the patients studied are relatively young and have mild cardiac abnormalities, suggesting that more research into the efficacy of ERT in older patients is necessary. CONCLUSION: Cardiac manifestations are common in patients with Fabry disease and are not confined to a 'cardiac variant' of the disease.

Cardiomyopathies↗

Fabry disease in the era of enzyme replacement therapy: a renal perspective.

Fabry disease, the second most prevalent lysosomal storage disorder after Gaucher disease, is caused by mutations of the gene encoding the lysosomal hydrolase, alpha-galactosidase A. The enzymatic defect is inherited in an X-linked recessive fashion and leads to systemic glycosphingolipid deposition, resulting in profound dysfunction of neurological, renal, cardiac, and cerebrovascular systems. Although symptoms typically appear in childhood in hemizygous males and some heterozygous females, the diagnosis is often delayed or unrecognized, owing to variable presentations and low incidence. The initial phase begins in childhood or adolescence and is characterized by neuropathic pain, angiokeratomas, and ocular deposits. The later phase is distinguished by progressive cardiac, cerebral, and renal involvement, leading to multi-organ dysfunction and death. Recently published clinical trials have demonstrated the efficacy of enzyme replacement therapy in decreasing neuropathic pain and substrate deposition in target organs. Pediatricians have a key role to play in making the diagnosis, so that therapy can be initiated before irreversible tissue injury develops. Further research is required to determine optimal dosing protocols for treatment and to establish whether therapy can retard the progression of organ dysfunction, or even prevent these complications altogether.

Adult↗

Adult-type Gaucher disease in children: genetics, clinical features and enzyme replacement therapy.

Clinical manifestations of type 1 (Adult) Gaucher disease usually start in childhood. However, most of the previously published data describe the features of this disorder in adults. We present the clinical and genetic characteristics of 34 children and adolescents with type 1 Gaucher disease evaluated in our clinic during the past two years. Patients were aged 2-18 years; 18 were boys and 16 girls. The majority presented before the age of 10. Growth retardation appeared as a prominent feature, with 26% in or below the third percentile in weight, and 30% so in height, especially in the youngest age group (2-5 years). Anaemia and thrombocytopenia occurred in 80% and 60% of the children, respectively. Hepatosplenomegaly was noted in all the children; only 3 were splenectomized. Skeletal involvement was evident on X-rays in 90% of the patients, but only 50% complained of bone pains. Three patients had severe bone disease, with avascular necrosis of the hip joint. Mutation analysis at the DNA level revealed the 1226/1226 genotype in 12 (35%) patients and 1226/84GG in 13 (38%). Correlation was found between the genotypes and the severity of the disease, including growth retardation. A positive response was documented in all 9 patients who completed 12 months of the recently-introduced enzyme replacement therapy for Gaucher disease.

Adolescent↗

Plasma chitotriosidase in male Fabry patients: a marker for monitoring lipid-laden macrophages and their correction by enzyme replacement therapy.

Increased plasma chitotriosidase is a well established surrogate marker for the occurrence of lipid-laden macrophages in the glycosphingolipidosis Gaucher disease. The complete lack of surrogate markers for Fabry disease, X-linked globotriaosylceramidosis stemming from deficiency in the lysosomal alpha-galactosidase A (AGA), prompted us to study chitotriosidase in this disorder. In male Fabry patients plasma chitotriosidase is significantly elevated, consistent with the presence of lipid-laden macrophages in several tissues. Increased levels are detectable at very young age and precede clinical manifestations. No strict correlation exists with severity of disease manifestations. Upon therapy with either of the two available recombinant AGA preparations, plasma chitotriosidase levels are nicely normalized in male Fabry patients. However, in patients developing neutralizing antibodies towards AGA, reduction in plasma chitotriosidase is hampered. In sharp contrast to the situation in male patients, females heterozygous for AGA deficiency show no significantly elevated plasma chitotriosidase. This suggests that circulating endogenous AGA in heterozygotes is sufficient to supplement enzyme-deficient macrophages. In conclusion, for the first time a biological marker for lipid-laden cells in Fabry patients is demonstrated; elevated plasma chitotriosidase levels reflecting lipid-laden macrophages. Corrections in this marker illustrate the efficacy of enzyme replacement therapy in clearing the lipid accumulation in this particular cell type.

Adolescent↗

The expanding clinical spectrum of Anderson-Fabry disease: a challenge to diagnosis in the novel era of enzyme replacement therapy.

Anderson-Fabry disease is an X-linked recessive lysosomal storage disease resulting from deficient alpha-galactosidase A activity. The conception of the disease has changed within the last decade. Studies of the last years have shown that the disease is not limited to the classical full-blown manifestation in affected males, which is well known since more than a century, but may also occur in carrier females. The phenomenology may differ in severity and kind of organ manifestation. Cardiac and renal variants with solely disease manifestation of these organs have also been described in an increasing number. It is likely that a spectrum exists regarding alpha-galactosidase A activity in both genders on the one hand, and an additional one regarding the severity and the number of organs affected on the other. The purpose of this review is to sharpen physicians' perception of this disease. Early and accurate diagnosis is mandatory considering that this disorder is now, after introduction of the novel enzyme replacement therapy, a treatable disease.

Eye Diseases↗

Enzyme replacement therapy in fibroblasts from a patient with cholesteryl ester storage disease.

Enzyme replacement has long been considered only a remote possibility in the treatment of a wide range of genetic disorders, many manifested as lysosomal storage diseases. The complexity of having a particular enzyme gain access to the lysosomal compartment in a specific cell seemed insurmountable. We report here on an attempt to introduce the enzyme cholesteryl esterase into fibroblasts from a patient with cholesteryl ester storage disease (CESD). The enzyme gains access to the lysosomal compartment and the accumulating cholesteryl ester by virtue of being carried into the cell conjugated to a ligand (insulin or apoprotein B [apoB]) that binds to its own specific receptor and is internalized by the well-described process of receptor-mediated endocytosis. Regardless of whether the enzyme enters the cell via the insulin receptor or via the low-density lipoprotein (ApoB) receptor, it can be found associated with a lysosomal fraction and is effective in lowering levels of accumulated substrate, cholesteryl ester. The time course of the substrate degradation and the dependence on the receptor density and receptor density and receptor-ligand interaction indicate that the enzyme is simply being carried to the site of substrate accumulation by virtue of the fact that that is the destination of the ligand (along with its conjugated enzyme) following internalization.

Apolipoproteins B↗

Massive accumulation of Man2GlcNAc2-Asn in nonneuronal tissues of glycosylasparaginase-deficient mice and its removal by enzyme replacement therapy.

Aspartylglycosaminuria (AGU) is caused by deficient enzymatic activity of glycosylasparaginase (GA). The disease is characterized by accumulation of aspartylglucosamine (GlcNAc-Asn) and other glycoasparagines in tissues and body fluids of AGU patients and in an AGU mouse model. In the current study, we characterized a glycoasparagine carrying the tetrasaccharide moiety of alpha-D-Man-(1-->6)-beta-D-Man-(1-->4)-beta-D-GlcNAc-(1-->4)-beta-D-GlcNAc-(1-->N)-Asn (Man2GlcNAc2-Asn) in urine of an AGU patient and also in the tissues of the AGU mouse model. Quantitative analysis demonstrated a massive accumulation of the compound especially in nonneuronal tissues of the AGU mice, in which the levels of Man2GlcNAc2-Asn were typically 30-87% of those of GlcNAc-Asn. The highest level of Man2GlcNAc2-Asn was found in the liver, spleen, and heart tissues of the AGU mice, the respective amounts being 87%, 76%, and 57% of the GlcNAc-Asn levels. In the brain tissue of AGU mice the Man2GlcNAc2-Asn storage was only 9% of that of GlcNAc-Asn. In contrast to GlcNAc-Asn, the storage of Man2GlcNAc2-Asn markedly increased in the liver and spleen tissues of AGU mice as they grew older. Enzyme replacement therapy with glycosylasparaginase for 3.5 weeks reduced the amount of Man2GlcNAc2-Asn by 66-97% in nonneuronal tissues, but only by 13% in the brain tissue of the AGU mice. In conclusion, there is evidence for a role for storage of glycoasparagines other than aspartylglucosamine in the pathogenesis of AGU, and this possibility should be taken into consideration in the treatment of the disease.

Animals↗

A phase I/II clinical trial of enzyme replacement therapy in mucopolysaccharidosis II (Hunter syndrome).

OBJECTIVE: To evaluate the safety and explore the efficacy of idursulfase (recombinant human iduronate-2-sulfatase) treatment for mucopolysaccharidosis II (MPS II). STUDY DESIGN: Twelve patients were enrolled into a randomized, double-blind, placebo-controlled trial for 24 weeks followed by an open-label extension study. Three groups of 4 patients were enrolled sequentially, with 3 patients in each group receiving idursulfase and 1 patient receiving placebo. The first group received idursulfase at 0.15 mg/kg infused every other week with the 2nd and 3rd groups receiving 0.5 and 1.5 mg/kg, respectively. After 24 weeks the placebo-treated patients were changed to idursulfase at the dose of their group. The primary endpoint was a change from baseline in urinary excretion of glycosaminoglycans. Results were pooled for analysis by ANOVA and compared to baseline. RESULTS: Urinary glycosaminoglycans were reduced within 2 weeks of initiating idursulfase and were decreased 49% after 48 weeks of treatment (P<0.0001). Both liver and spleen volume were decreased at 24 weeks (P<0.01) and 48 weeks (P<0.001). The 6-minute walk test distance increased an average of 48 meters after 48 weeks (P=0.013). Six patients in the higher dose groups developed IgG antibodies that did not influence the clinical effects of idursulfase. CONCLUSIONS: This study describes the first experience with enzyme replacement therapy for the treatment of patients with MPS II. Idursulfase was generally well tolerated and was associated with reductions in urine glycosaminoglycans levels and organ size, as well as an increased 6-minute walk test distance.

Adolescent↗

Enzyme replacement therapy in heterozygous females with Fabry disease: results of a phase IIIB study.

Fabry disease is an X-linked glycosphingolipid storage disorder caused by a deficiency of alpha-galactosidase A. Affected patients experience debilitating neuropathic pain and have premature mortality due to renal failure, cardiovascular disease or cerebrovascular complications. The disease may be X-linked dominant, since most females heterozygous for Fabry disease are affected clinically. We evaluated the safety, efficacy and pharmacokinetics of agalsidase alfa (Replagal) administered intravenously to female patients with Fabry disease in an open-label, single-centre study. Fifteen severely affected patients received agalsidase alfa at 0.2 mg/kg every other week for up to 55 weeks. Agalsidase alfa was safe and well-tolerated in female patients. None of the patients developed antibodies or experienced an infusion reaction to agalsidase alfa. The pharmacokinetic profile of agalsidase alfa in female patients is comparable to the pharmacokinetics of agalsidase alfa in male patients. Mean urine sediment and plasma Gb3 levels decreased from baseline at 13, 27 and 41 weeks. A significant decrease in left ventricular mass from baseline was seen at weeks 27 (p = 0.003) and 41 (p = 0.039), and a significant reduction in QRS durations was seen at week 27 (p = 0.007). Furthermore, there was a significant improvement in quality of life. Renal function did not deteriorate in these 15 female patients over the 13- to 41-week period of observation. We conclude that enzyme replacement therapy with agalsidase alfa was safe and effective in female patients heterozygous for Fabry disease.

Adolescent↗

Long-term safety and efficacy of enzyme replacement therapy for Fabry disease.

Elsewhere, we reported the safety and efficacy results of a multicenter phase 3 trial of recombinant human alpha -galactosidase A (rh-alpha GalA) replacement in patients with Fabry disease. All 58 patients who were enrolled in the 20-wk phase 3 double-blind, randomized, and placebo-controlled study received subsequently 1 mg/kg of rh-alpha GalA (agalsidase beta, Fabrazyme, Genzyme Corporation) biweekly in an ongoing open-label extension study. Evidence of long-term efficacy, even in patients who developed IgG antibodies against rh- alpha GalA, included the continuously normal mean plasma globotriaosylceramide (GL-3) levels during 30 mo of the extension study and the sustained capillary endothelial GL-3 clearance in 98% (39/40) of patients who had a skin biopsy taken after treatment for 30 mo (original placebo group) or 36 mo (original enzyme-treated group). The mean serum creatinine level and estimated glomerular filtration rate also remained stable after 30-36 mo of treatment. Infusion-associated reactions decreased over time, as did anti-rh- alpha GalA IgG antibody titers. Among seroconverted patients, after 30-36 mo of treatment, seven patients tolerized (no detectable IgG antibody), and 59% had > or =4-fold reductions in antibody titers. As of 30 mo into the extension trial, three patients were withdrawn from the study because of positive serum IgE or skin tests; however, all have been rechallenged successfully at the time of this report. Thus, enzyme replacement therapy for 30-36 mo with agalsidase beta resulted in continuously decreased plasma GL-3 levels, sustained endothelial GL-3 clearance, stable kidney function, and a favorable safety profile.

Adult↗

Enzyme replacement therapy of exocrine pancreatic insufficiency in man. Relations between in vitro enzyme activities and in vivo potency in commercial pancreatic extracts.

I assayed 16 commercially available pancreatic extracts (representing capsules, tablets and enteric-coated tablets) for enzyme activities and the relation between the in vitro activities and in vivo potency evaluated in man. Lipase activity ranged from 10 to 3600 units per unit, with 11 preparations containing less than 600 units per unit. The preparations with the highest lipase activities were llozyme, 3600, Kuzyme HP, 2330, Festal, 2073, Cotazym, 2014, and Viokase, 1636 units. Lipase activity in vitro correlated with potency in vivo for tablets and capsules, with tablets and capsules being effective in reducing steatorrhea by 56.1 +/- 9 per cent and 48.6 +/- 10 per cent (mean +/- S.E.M.) respectively, P less than 0.001. Enteric-coated tablets were less effective (20 +/- 13 per cent reduction, P greater than 0.02). The longer the gastric pH remained greater than or equal to 4 (r = 0.915, P less than 0.01) and the higher the average duodenal pH (r = 0.966, P less than 0.01), the more marked the reduction in steatorrhea.

Administration, Oral↗