James M. Dambrosia

Replacement therapy for inherited enzyme deficiency--macrophage-targeted glucocerebrosidase for Gaucher's disease.

BACKGROUND AND METHODS Gauchers disease, the most prevalent of the sphingolipid storage disorders, is caused by a deficiency of the enzyme glucocerebrosidase (glucosylceramidase). Enzyme replacement was proposed as a therapeutic strategy for this disorder in 1966. To assess the clinical effectiveness of this approach, we infused macrophage-targeted human placental glucocerebrosidase (60 IU per kilogram of body weight every 2 weeks for 9 to 12 months) into 12 patients with type 1 Gauchers disease who had intact spleens. The frequency of infusions was increased to once a week in two patients (children) during part of the trial because they had clinically aggressive disease. RESULTS The hemoglobin concentration increased in all 12 patients, and the platelet count in 7. Serum acid phosphatase activity decreased in 10 patients during the trial, and the plasma glucocerebroside level in 9. Splenic volume decreased in all patients after six months of treatment, and hepatic volume in five. Early signs of skeletal improvements were seen in three patients. The enzyme infusions were well tolerated, and no antibody to the exogenous enzyme developed. CONCLUSIONS Intravenous administration of macrophage-targeted glucocerebrosidase produces objective clinical improvement in patients with type 1 Gauchers disease. The hematologic and visceral responses to enzyme replacement develop more rapidly than the skeletal response.

A Controlled Trial of High-Dose Intravenous Immune Globulin Infusions as Treatment for Dermatomyositis

BACKGROUND Dermatomyositis is a clinically distinct myopathy characterized by rash and a complement-mediated microangiopathy that results in the destruction of muscle fibers. In some patients the condition becomes resistant to therapy and causes severe physical disabilities. METHODS We conducted a double-blind, placebo-controlled study of 15 patients (age, 18 to 55 years) with biopsy-proved, treatment-resistant dermatomyositis. The patients continued to receive prednisone (mean daily dose, 25 mg) and were randomly assigned to receive one infusion of immune globulin (2 g per kilogram of body weight) or placebo per month for three months, with the option of crossing over to the alternative therapy for three more months. Clinical response was gauged by assessing muscle strength, neuromuscular symptoms, and changes in the rash. Changes in immune-mediated muscle abnormalities were determined by repeated muscle biopsies. RESULTS The eight patients assigned to immune globulin had a significant improvement in sores of muscle strength (P < 0.018) and neuromuscular symptoms (P < 0.035), whereas the seven patients assigned to placebo did not. With crossovers a total of 12 patients received immune globulin. Of these, nine with severe disabilities had a major improvement to nearly normal function. Their mean muscle-strength scores increased from 74.5 to 84.7, and their neuromuscular symptoms improved. Two of the other three patients had mild improvement, and one had no change in his condition. Of 11 placebo-treated patients, none had a major improvement, 3 had mild improvement, 3 had no change in their condition, and 5 had worsening of their condition. Repeated biopsies in five patients of muscles whose strength improved to almost normal showed an increase in muscle-fiber diameter (P < 0.04), an increase in the number and a decrease in the diameter of capillaries (P < 0.01), resolution of complement deposits on capillaries, and a reduction in the expression of intercellular adhesion molecule 1 and major-histocompatibility-complex class I antigens. CONCLUSIONS High-dose intravenous immune globulin is a safe and effective treatment for refractory dermatomyositis.

Functional relevance of cross-modal plasticity in blind humans.

Functional imaging studies of people who were blind from an early age have revealed that their primary visual cortex can be activated by Braille reading and other tactile discrimination tasks. Other studies have also shown that visual cortical areas can be activated by somatosensory input in blind subjects but not those with sight. The significance of this cross-modal plasticity is unclear, however, as it is not known whether the visual cortex can process somatosensory information in a functionally relevant way. To address this issue, we used transcranial magnetic stimulation to disrupt the function of different cortical areas in people who were blind from an early age as they identified Braille or embossed Roman letters. Transient stimulation of the occipital (visual) cortex induced errors in both tasks and distorted the tactile perceptions of blind subjects. In contrast, occipital stimulation had no effect on tactile performance in normal-sighted subjects, whereas similar stimulation is known to disrupt their visual performance. We conclude that blindness from an early age can cause the visual cortex to be recruited to a role in somatosensory processing. We propose that this cross-modal plasticity may account in part for the superior tactile perceptual abilities of blind subjects.

Enzyme Therapy in Type 1 Gaucher Disease: Comparative Efficacy of Mannose-Terminated Glucocerebrosidase from Natural and Recombinant Sources

Gaucher disease, an inborn error of glycosphingolipid metabolism, is the most frequent lysosomal storage disease [1]. Non-neuronopathic or type 1 disease is the most common variant and the most prevalent genetic disease among Ashkenazi Jews [2, 3]. Various point mutations, deletions, and insertions within the glucocerebrosidase (acid -glucosidase, EC 3.2.1.45) locus at chromosome 1q21 result in a deficiency of this lysosomal enzyme [4, 5]. The subsequent accumulation of glucocerebroside (glucosylceramide) in cells of monocyte-macrophage lineage leads to the visceral manifestations of anemia, thrombocytopenia, hepatosplenomegaly, skeletal disease, and, less frequently, primary lung involvement [1]. Gaucher disease has become a prototype genetic disease for the development of prenatal diagnosis [6], genotype-phenotype correlations [2, 7, 8], and effective therapy [9-13]. On the basis of the clear efficacy of targeted enzyme therapy [10], recent studies [9, 12, 14, 15] in more than 90 patients have established that regular infusions of enzyme purified from placenta (alglucerase [Ceredase; Genzyme Corp., Cambridge, Massachusetts]) lead to regression of the clinical manifestations of Gaucher disease. In addition, antibody-mediated and non-antibody-mediated adverse events have occurred in only 5% to 7% of treated patients [15, 16]. Ceredase is a commercial form of placenta glucocerebrosidase that has been modified for targeting mannose receptor sites on macrophages and other cells [17, 18]. A theoretical limitation to the use of Ceredase is the remote possibility of infective contaminants in the preparation from human placenta. A practical limitation is the finite availability of acceptable placentae. For each patient, approximately 10 to 12 tons of placentae or about 50 000 per year are needed as source material for Ceredase. Enzyme produced by heterologous expression of human complementary DNA (cDNA) for glucocerebrosidase in eukaryotic cells could eliminate both of these limitations. To determine the efficacy of recombinant glucocerebrosidase, we did a randomized, double-blind, parallel trial with mannose-terminated glucocerebrosidase (alglucerase, Ceredase) from human placenta and the human enzyme that is produced in Chinese hamster ovary cells and deglycosylated to expose mannose residues in the oligosaccharide chains (imiglucerase, Cerezyme [Genzyme Corp.]). Methods Thirty patients with non-neuronopathic type 1 Gaucher disease were entered into the trial after consent was obtained. Deficiency of glucocerebrosidase (5% to 15% of mean normal activities) was shown by natural or artificial substrates in peripheral blood mononuclear cells, cultured skill fibroblasts, or lymphoblastoid cell lines obtained from each patient [19, 20]. Inclusion criteria for the study were as follows: 1) enzymatically confirmed glucocerebrosidase deficiency; 2) patient age between 2 and 75 years; 3) an intact, enlarged spleen; 4) a hemoglobin level at least 10 g/L less than the lower limit of normal; and 5) in women, a willingness to avoid pregnancy during the trial. Exclusion criteria were as follows: 1) inability to comply with study requirements; 2) previous receipt of any form of glucocerebrosidase; 3) total splenectomy; 4) a concurrent major medical disorder, such as active infectious disease or substance abuse; and 5) positive serologic response to hepatitis B surface antigen or human immunodeficiency virus (HIV) type 1, or both. The patients had moderate to severe Gaucher disease. The study was a double-blind, parallel trial with random assignment to Ceredase or Cerezyme. We categorized randomization into three groups according to patient age: 1) younger than 12 years; 2) 12 to 17 years; and 3) older than 17 years. In each study center, patients were independently randomly assigned in blocks by age and were assigned study numbers. All study personnel except the pharmacist at each institution were blinded to the allocated treatment. No children younger than 12 years were enrolled in the study. Of the 30 patients enrolled, 17 were male and 13 were female (age range, 12 to 69 years). Of the 7 patients between 12 and 17 years of age, 4 received Ceredase and 3 received Cerezyme. Twenty-three patients older than 17 years were enrolled; 11 of them received Ceredase and 12 received Cerezyme. The groups of patients treated with Ceredase or Cerezyme did not differ in sex distribution, age, weight, or height. All patients received Cerezyme or Ceredase at a dose of 60 U/kg body weight once every 2 weeks for 9 months. Complete hematologic and clinical chemistry data were available for this period. At this dose, complete data for hepatic and splenic volumes were available for all patients for the first 6 months. Hepatic and splenic volumes were evaluated in the 16 patients from the Mt. Sinai School of Medicine at 9 months, just before a dose-reduction study began. The hepatic and splenic volumes of the patients from the National Institutes of Health (NIH) were evaluated at 12 months. We did not include these data in our report. We did analyses of variance and other statistical analyses using Systat software (Systat Inc., Evanston, Illinois). In addition to physical examinations, clinical laboratory studies were done to monitor both therapeutic efficacy and potential toxic effects, including total serum acid phosphatase levels, angiotensin-converting enzyme levels, serum bilirubin levels, hemoglobin levels, platelet counts, peripheral blood leukocyte counts, and serum iron and clotting studies. At baseline and at study completion, hepatitis B surface antigen assay; HIV-1 serologic testing; serum protein electrophoresis; and complement C3, C4, and CH-50 studies were done. Hepatic and splenic volumes were estimated by computed tomography (at Mt. Sinai School of Medicine) [12, 15] or magnetic resonance imaging (at NIH) [21]. We calculated the increases over normal volumes by assuming that the hepatic and splenic masses (1 g/mL density) were 2.5% and 0.2% of body weight, respectively [22]. To avoid biasing the results because of the nearly universal weight gain in treated patients, we averaged the body weight of adults over the study period. In children (patients younger than 18 years), we calculated the hepatic and splenic volumes on the basis of body weight at each time point to allow for growth. We monitored the formation of antibodies to natural or recombinant glucocerebrosidases every 3 months by radioimmunoprecipitation assay [16]. Adverse events were monitored at each infusion. Before each infusion, we also obtained a history of intra-infusion adverse events. Ceredase was supplied as a clear liquid solution stored at 4 C, solubilized in the presence of albumin. Cerezyme was purified from culture media of Chinese hamster ovary cell clones that contained numerous copies of the human glucocerebrosidase cDNA. Carbohydrate removal to expose core mannose moieties was done by the sequential exoglycosidase treatment used to produce Ceredase. The amino acid sequences of glucocerebrosidase in Ceredase and Cerezyme were identical except for a single amino acid substitution of a histidine for a natural arginine at position 495 in the latter. The lack of effect of this amino acid change on the catalytic function of glucocerebrosidase has been documented [23]. Cerezyme was supplied as a lyophilized powder containing mannitol, sodium citrate, and polysorbate 80. Cerezyme as lyophilized powder was stored at 4 C until use. Immediately before administration, Cerezyme was reconstituted with sterile water to a concentration of 40 U/mL. Ceredase or Cerezyme stocks were diluted in 0.9% NaCl just before infusion. During the study, the patients were weighed at each infusion, and the total dose to be administered was adjusted to 60 U/kg on the basis of the current weight. A unit of enzyme activity (U) is defined as the amount of enzyme required to cleave 1 mol of p-nitrophenol--d-glucopyranoside per minute. Results Hematologic Findings The effects of Ceredase and Cerezyme infusions on hemoglobin levels by 6 and 9 months are shown in Tables 1 and 2. Neither the mean initial hemoglobin level (approximately 107 g/L) nor changes in hemoglobin levels differed between the two treatment groups. During the first 6 months of therapy, hemoglobin levels increased by a mean of 17.1 g/L. In patients with hemoglobin levels less than 120 g/L, 54% and 30% of the patients receiving Ceredase and Cerezyme, respectively, achieved this or a greater level by 6 months. Sixty-nine percent and 40%, respectively, of patients receiving Ceredase and Cerezyme achieved these levels by 9 months. The rates at which hemoglobin levels increased by 10 and 15 g/L were also similar. An average of 92 days was required for the hemoglobin level to increase 10 g/L in the Ceredase group, whereas an average of 77 days was needed in the Cerezyme group. For the Ceredase and Cerezyme groups, hemoglobin levels increased 15 g/L in 113 and 125 days, respectively. None of the above differences was significant (P > 0.2). In both treatment groups, we observed lesser degrees of response in patients with higher initial hemoglobin levels. However, this conclusion was strongly influenced by two patients who had initial hemoglobin levels less than 90 g/L and large responses to treatment, that is, an increase of more than 30 g/L during the first 6 months of therapy. Table 1. Clinical Findings from Patients with Type I Gaucher Disease Treated with Ceredase and Cerezyme* Table 2. Effects of Ceredase and Cerezyme on Hematologic Measurements All patients in the study had thrombocytopenia (mean platelet count, approximately 71.5 109/L). About half (7 of 15) of the patients in each group had increases in platelet counts of 20% and 40% or more during the 6- and 9-month treatment periods, respectively (Table 2). These responses to therapy did not differ between the Ceredase and Cerezyme groups. In each group and in the entire st

Neuropeptides and neurotrophins in neonatal blood of children with autism or mental retardation.

There has been little exploration of major biologic regulators of cerebral development in autism. In archived neonatal blood of children with autistic spectrum disorders (n = 69), mental retardation without autism (n = 60), or cerebral palsy (CP, n = 63) and of control children (n = 54), we used recycling immunoaffinity chromatography to measure the neuropeptides substance P (SP), vasoactive intestinal peptide (VIP), pituitary adenylate cyclase–activating polypeptide (PACAP), calcitonin gene–related peptide (CGRP), and the neurotrophins nerve growth factor (NGF), brain‐derived neurotrophic factor (BDNF), neurotrophin 3 (NT3), and neurotrophin 4/5 (NT4/5). Neonatal concentrations of VIP, CGRP, BDNF, and NT4/5 were higher (ANOVA, all p values < 0.0001 by Scheffe test for pairwise differences) in children in the autistic spectrum and in those with mental retardation without autism than in control children. In 99% of children with autism and 97% with mental retardation, levels of at least one of these substances exceeded those of all control children. Concentrations were similar in subgroups of the autistic spectrum (core syndrome with or without mental retardation, other autistic spectrum disorders with or without mental retardation) and in the presence or absence of a history of regression. Among children with mental retardation, concentrations did not differ by severity or known cause (n = 11, including 4 with Down syndrome). Concentrations of measured substances were similar in children with CP as compared with control subjects. SP, PACAP, NGF, and NT3 were not different by diagnostic group. No measured analyte distinguished children with autism from children with mental retardation alone. In autism and in a heterogeneous group of disorders of cognitive function, overexpression of certain neuropeptides and neurotrophins was observed in peripheral blood drawn in the first days of life.

Uncertain Value of Electronic Fetal Monitoring in Predicting Cerebral Palsy

BACKGROUND Electronic monitoring of the fetal heart rate is commonly performed, in part to detect hypoxia during delivery that may result in brain injury. It is not know whether specific abnormalities on electronic fetal monitoring are related to the risk of cerebral palsy. METHODS Among 155,636 children born from 1983 through 1985 in four California counties, we identified singleton infants with birth weights of at least 2500 g who survived to three years of age and had moderate or severe cerebral palsy. The children with cerebral palsy were compared with randomly selected control children with respect to characteristics noted in the birth records. RESULTS Seventy-eight of 95 children with cerebral palsy and 300 of 378 controls underwent intrapartum fetal monitoring. Characteristics found to be associated with an increased risk of cerebral palsy were multiple late decelerations in the heart rate, commonly defined as slowing of the heart rate well after the onset of uterine contractions (odds ratio, 3.9; 95 percent confidence interval, 1.7 to 9.3), and decreased beat-to-beat variability of the heart rate (odds ratio, 2.7; 95 percent confidence interval, 1.1 to 5.8); there was no association between the highest or lowest fetal heart rate recorded for each child and the risk of cerebral palsy. Even after adjustment for other risk factors, the association of abnormalities on fetal monitoring with an increased risk of cerebral palsy persisted (adjusted odds ratio, 2.7; 95 percent confidence interval, 1.4 to 5.4). The 21 children with cerebral palsy who had multiple late decelerations or decreased variability in heart rate on fetal monitoring represented only 0.19 percent of singleton infants with birth weights of 2500 g or more who had these fetal-monitoring findings, for a false positive rate of 99.8 percent. CONCLUSIONS Specific abnormal findings on electronic monitoring of the fetal heart rate were associated with an increased risk of cerebral palsy. However, the false positive rate was extremely high. Since cesarean section is often performed when such abnormalities are noted and is associated with risk to the mother, our findings arouse concern that, if these indications were widely used, many cesarean sections would be performed without benefit and with the potential for harm.

Treatment of inclusion-body myositis with IVIg A double-blind, placebo-controlled study

Article abstract-We randomized 19 patients with inclusion-body myositis (IBM) to a double-blind, placebo-controlled, crossover study using monthly infusions of 2 g/kg intravenous immunoglobulin (IVIg) or placebo for 3 months. Patients crossed over to the alternate treatment after a washout period. We evaluated responses at baseline and at the end of each treatment period using expanded (0-10) MRC scales, the Maximum Voluntary Isometric Contraction (MVIC) method, symptom and disability scores, and quantitative swallowing studies. We calculated the differences in scores between IVIg and placebo from baseline to end of treatment. Of the 19 patients, 9 (mean age, 61.2 years; mean disease duration, 5.6 years) were randomized to IVIg and 10 (mean age, 66.1 years; mean disease duration, 7.4 years) to placebo. During IVIg the patients gained a mean of 4.2 (-16 to +39.8) MRC points, and during placebo lost 2.7 (-10 to +8) points (p < 0.1). These gains were not significant. Similar results were obtained with the MRC and MVIC scores when the patients crossed to the alternate treatment. Six patients had a functionally important improvement by more than 10 MRC points that declined when crossed over to placebo. Limb-by-limb analysis demonstrated that during IVIg the muscle strength in 39% of the lower extremity limbs significantly increased compared with placebo (p < 0.05), while a simultaneous decrease in 28% of other limbs was detected. The clinical importance of these minor gains is unclear. The duration of swallowing functions measured in seconds with ultrasound improved statistically in the IVIg-randomized patients (p < 0.05) compared with placebo. Although the study did not establish efficacy of IVIg, possibly because of the small sample size, the drug induced functionally important improvement in 6 (28%) of the 19 patients. Whether the modest gains noted in certain muscle groups justify the high cost of trying IVIg in IBM patients at a given stage of the disease remains unclear. NEUROLOGY 1997;48: 712-716

A three-item scale for the early prediction of stroke recovery

BACKGROUND Accurate assessment of prognosis in the first hours of stroke is desirable for best patient management. We aimed to assess whether the extent of ischaemic brain injury on magnetic reasonance diffusion-weighted imaging (MR DWI) could provide additional prognostic information to clinical factors. METHODS In a three-phase study we studied 66 patients from a North American teaching hospital who had: MR DWI within 36 h of stroke onset; the National Institutes of Health Stroke Scale (NIHSS) score measured at the time of scanning; and the Barthel Index measured no later than 3 months after stroke. We used logistic regression to derive a predictive model for good recovery. This logistic regression model was applied to an independent series of 63 patients from an Australian teaching hospital, and we then developed a three-item scale for the early prediction of stroke recovery. FINDINGS Combined measurements of the NIHSS score (p=0.01), time in hours from stroke onset to MR DWI (p=0.02), and the volume of ischaemic brain tissue on MR DWI (p=0.04) gave the best prediction of stroke recovery. The model was externally validated on the Australian sample with 0.77 sensitivity and 0.88 specificity. Three likelihood levels for stroke recovery-low (0-2), medium (3-4), and high (5-7)-were identified on the three-item scale. INTERPRETATION The combination of clinical and MR DWI factors provided better prediction of stroke recovery than any factor alone, shortly after admission to hospital. This information was incorporated into a three-item scale for clinical use.

Placebo-Controlled Trial of Rituximab in IgM Anti-Myelin-Associated Glycoprotein Antibody Demyelinating Neuropathy

Report a double‐blind, placebo‐controlled study of rituximab in patients with anti–MAG demyelinating polyneuropathy (A‐MAG‐DP).

Enzyme replacement therapy improves peripheral nerve and sweat function in Fabry disease

Fabry disease is an X‐linked disorder caused by a deficiency of lysosomal α‐galactosidase A resulting in accumulation of α‐D‐galatosyl conjugated glycosphingolipids. Clinical manifestations include a small‐fiber neuropathy associated with debilitating pain and hypohidrosis. We report the effect of a 3‐year open‐label extension of a previously reported 6‐month placebo‐controlled enzyme replacement therapy (ERT) trial in which 26 hemizygous patients with Fabry disease received 0.2 mg/kg of α‐galactosidase A every 2 weeks. The effect of ERT on neuropathic pain scores while off pain medications, quantitative sensory testing, quantitative sudomotor axon reflex test (QSART), and thermoregulatory sweat test (TST) is reported. In the patients who crossed‐over from placebo to ERT (n = 10), mean pain‐at‐its‐worst scores on a 0–10 scale decreased (from 6.9 to 4.5). There was a significant reduction in the threshold for cold and warm sensation in the foot. At the 3‐year time‐point, pre‐ERT sweat excretion in 17 Fabry patients was 0.24 ± 0.33 μl/mm2 vs. 1.05 ± 0.81 in concurrent controls (n = 38). Sweat function improved 24–72 h post‐enzyme infusion (0.57 ± 0.71 μl/mm2) and normalized in four anhidrotic patients. TST confirmed the QSART results. We conclude that prolonged ERT in Fabry disease leads to a modest but significant improvement in the clinical manifestations of the small‐fiber neuropathy associated with this disorder. QSART may be useful to further optimize the dose and frequency of ERT. Muscle Nerve 28: 703–710, 2003