Enzyme Replacement Therapy in a Patient with Gaucher Disease Type III: A Paradigmatic Case Showing Severe Adverse Reactions Started a Long Time After the Beginning of Treatment.

INTRODUCTION: There are three recombinant enzymes available for the treatment of Gaucher disease (GD): imiglucerase, velaglucerase alfa, and taliglucerase alfa. CASE REPORT: A male GD type III patient, 14 years old, genotype p.L444P/L444, diagnosed at 2 years old. He had been treated with imiglucerase for 9 years since the diagnosis. In 2008, however, he presented a severe adverse reaction to imiglucerase, characterized by cough, laryngeal stridor, and periorbital edema. The infusions were suspended for 3 months when imiglucerase was restarted with premedication and a slower infusion rate. After 5 months, he presented a new adverse reaction with vomiting, tachypnea, cough, and periorbital edema. Intradermal testing confirmed IgE-mediated reaction but serological tests were negative. After 2 years and 10 months with no specific treatment and a significant worsening of the clinical picture, taliglucerase alfa was prescribed, with premedication and a slower infusion rate. At the first infusion, he presented moderate adverse reaction and the infusions were suspended. After 2 months, velaglucerase alfa was initiated uneventfully. He maintains day-hospital infusions without premedication and shows improvement of clinical and laboratory parameters. CONCLUSION: This is the first report of the use of velaglucerase alfa in patients with GD type III. The use of recombinant enzymes is safe for the majority of GD patients, but severe reactions may occur even many years after the beginning of the treatment. Premedication and slower infusion rate reduce the incidence of adverse reactions but may not solve the problem. This case report further demonstrates the different safety profile among all the recombinant enzymes available for the treatment of GD.

Comparison between the biochemical properties of plasma chitotriosidase from normal individuals and from patients with Gaucher disease, GM1-gangliosidosis, Krabbe disease and heterozygotes for Gaucher disease.

OBJECTIVES: The aim of the present work was to establish the range of chitotriosidase (CT) activity in normal individuals (controls), patients with Gaucher disease (GD), GM1-gangliosidosis (GM1), Krabbe disease (KD) and heterozygotes for Gaucher disease (HG). The kinetics of the enzyme in the five groups was also investigated. DESIGN AND METHODS: Plasma CT activity, as well as Km, Vmax, optimum pH and thermal stability of the enzyme was determined in plasma of controls, GM1, KD, GD and HG subjects. RESULTS: CT activity in GD, GM1 and KD patients was, respectively, around 600-fold, 15-fold and 12-fold greater than in normal individuals. There was no significant difference between CT activity in the HG and the control group. We also demonstrated that all CT kinetic parameters evaluated (optimum pH, Km, Vmax, thermal stability) in plasma of GD, KD and GM1 patients were significantly different from those of normal individuals. Regarding to thermal stability, our results show that CT activity in the control group was more stable than in the other groups. CONCLUSIONS: Based on the differences found in the biochemical parameters studied, we presume that the parameters analyzed may be useful in the diagnosis of the Lysosomal Storage Diseases.

Twelve different enzyme assays on dried-blood filter paper samples for detection of patients with selected inherited lysosomal storage diseases.

BACKGROUND: Diagnoses of inherited lysosomal storage diseases are based on specific enzymatic assays performed on plasma, leukocytes, fibroblasts, and lately, dried-blood filter paper samples. We evaluated feasibility of detecting of patients with several inherited lysosomal storage diseases using dried-blood filter paper samples for appropriate enzyme assays. METHODS: Fluorometric methods were used to evaluate the activities of arylsulfatase B, alpha-N-acetylglucosaminidase, chitotriosidase, alpha and beta-galactosidases, beta-glucosidase, beta-glucuronidase, total hexosaminidases, hexosaminidase A, alpha-iduronidase, and iduronate-2-sulfatase. A radiometric method was used for sphyngomyelinase determination. Single 3.0-mm diameter disks containing dried-blood samples were incubated at 37 degrees C with appropriate dilution buffers and artificial substrates, and the fluorescence or radioactivity was measured. RESULTS: Our results showed a statistically significant difference of the enzyme activity between affected individuals and controls, in all the assays performed. In contrast, we have not obtained a complete differentiation between heterozygotes and controls with these assays. CONCLUSIONS: Enzyme assay on dried-blood filter paper is a suitable method to screen for several lysosomal storage diseases. Despite the low individual incidence of these pathologies, the incorporation of individual enzyme assays in neonatal screening programs could be justified to screen for diseases with relatively high local frequency and therapeutic measures available.

Biochemical properties of beta-glucosidase in leukocytes from patients and obligated heterozygotes for Gaucher disease carriers.

BACKGROUND: Gaucher's disease (GD) is a disorder caused by the deficiency of lysosomal beta-glucosidase, an enzyme that participates in the degradation of glycosphingolipids. Deficiency of this enzyme results in the storage of glucocerebrosides in lysosomes of macrophage. No studies are available in the literature comparing biochemical and kinetic behavior of this enzyme in leukocytes and fibroblasts from normal individuals, obligate heterozygotes and patients with GD. METHODS: The behavior of beta-glu in terms of optimum pH, heat stability, Km and Vmax in leukocytes from patients with GD and obligated heterozygotes with different genotypes and normal individuals were characterized. RESULTS: Optimum pH was similar in all groups analyzed. In terms of Km and Vmax, several differences among heterozygotes and homozygotes groups and among these groups and normal enzyme were observed. Enzyme from all groups were inactivated when preincubated at 60 degrees C, but some enzymes were more stable than other. Results showed a different behavior of the enzyme in the 3 groups under analysis. Such behavior varied according to individual mutation. CONCLUSIONS: The catalytic gradient presented by beta-glu allowed the correlation of N370S mutation-which presented more stable biochemical properties-with the non-neurological clinical condition of the disease and the catalytically less stable mutation (D409H), with the neurological clinical condition of GD. This study contributes to a better understanding of the repercussion of the different mutations on the protein function, thus allowing to predict the severity of such complex metabolic disorder and to anticipate the most appropriate intervention for each case specifically.

Application of a comprehensive protocol for the identification of Gaucher disease in Brazil.

Gaucher disease (GD) is a sphingolipidosis caused by a genetic defect that leads to glucocerebrosidase (beta-glucosidase) deficiency. Between January 1982 and October 2003, 1,081 blood samples from patients suspected of having GD were referred for biochemical analysis. The activities of the enzymes beta-glucosidase (beta-glu) and chitotriosidase (CT) were measured in these samples. Among the 412 diagnosed cases of GD (38.1%), the great majority were GD type 1. The Brazilian regions with the greatest concentration of these patients were the Southeast, South, and Northeast. The mean age of patients at diagnosis was 19 years. The activity of beta-glu in patients with GD was, on average, 10.7% of that of normal individuals. CT was, on average, 269 times more elevated in this group of patients. Among the 669 cases with no confirmation of GD, there were patients with Niemann-Pick disease types A, B, or C (44 cases), possible heterozygotes for GD (59 cases), patients with other lysosomal storage diseases (LSDs) (19 cases) or with other inborn errors of metabolism (3 cases). In 508 cases, no metabolic disorder was found. This study shows that the biochemical protocol employed was effective for the detection of GD, a disease that is reasonably frequent in Brazil.

Biochemical characterization of chitotriosidase enzyme: comparison between normal individuals and patients with Gaucher and with Niemann-Pick diseases.

OBJECTIVES: The aim of the present study was to establish the range of chitotriosidase (CT) activity in normal individuals, patients with Gaucher disease (GD) and Niemann-Pick disease (NPD), types A or B. The kinetics of CT in these three groups was also investigated. DESIGN AND METHODS: CT activity, as well as Km, Vmax, optimum pH, and thermal stability of the enzyme were determined in the plasma of control, GD, and NPD subjects. RESULTS: CT activity in GD and NPD patients was, respectively, around 600-fold and 30-fold greater than in normal individuals. We observed significant differences in optimum pH, Vmax, and thermal stability between the various groups. Km was different in normal individuals relative to GD and NPD patients. However, there was no significant difference between Km values in patients with GD and with NPD. CONCLUSIONS: Based on the differences found in the biochemical parameters studied, our results may be important to help the identification of patients not only with GD but also with NPD.

Biochemical study on beta-glucosidase in individuals with Gaucher's disease and normal subjects.

BACKGROUND: Gaucher's disease (GD) is a disorder caused by the deficiency of lysosomal beta-glucosidase, an enzyme that participates in the degradation of glycosphingolipids. Deficiency of this enzyme results in the accumulation of glucocerebrosides in macrophage lysosomes. No studies comparing the biochemical and kinetic behavior of this enzyme in leukocytes and fibroblasts from normal individuals and patients with Gaucher's disease are available. METHODS: We compared the activities of beta-glu and chitotriosidase between normal subjects and Gaucher disease patients, and characterized the behavior of beta-glu in terms of pH optimum, heat stability, Km and Vmax. RESULTS: The results showed a different behavior of the enzyme in the groups analyzed. CONCLUSIONS: This finding might be useful in cases in which the measurement of enzyme activity alone is not reliable for the establishment of the diagnosis of Gaucher's disease.

Effect of amikacin, cephalothin, clindamycin and vancomycin on in vitro fibroblast growth

The effect of four antibiotics (amikacin, clindamycin, cephalothin and vancomycin) was investigated considering that bacterial infection in fibroblasts cultures is a very frequent event. The investigation included the effect of the antibiotics on fibroblast growth and on the activity of the enzyme glucocerebrosidase. The antibiotics were added to the fibroblast cultures and cell growth was evaluated by counting the number of cells and their viability. After cell harvesting, the enzyme activity and content of protein were measured. The results allowed us to conclude that none of the antibiotics affected the cellular number nor the cellular viability. The content of protein decreased when cephalothin and clindamycin were added to the cultures, and glucocerebrosidase was affected in the presence of amikacin. Vancomycin did not interfere with any of the parameters analyzed, so it was chosen to be used in cell cultures to prevent the contamination by gram positive bacteria.