S. vom Dahl

Magnetic resonance imaging of bone marrow changes in Gaucher disease during enzyme replacement therapy: first German long-term results

Abstract.Objective:. Since 1991, enzyme replacement therapy (ERT) has been available for patients with Gaucher disease in Germany. The aim of this study was to analyse the MR pattern of bone marrow involvement and response to ERT in Gaucher disease type I. Patients and design:. Thirty patients with Gaucher disease type I had MRI examinations prior to initiation of ERT with alglucerase/imiglucerase and during follow-up. Median MR follow-up and duration of ERT were 36 months. Coronal T1- and T2-weighted spin-echo images of the lower extremities were obtained to evaluate changes in the appearance of yellow marrow. MR images were categorized as having either a homogeneous (type A) or non-homogeneous patchy (type B) appearance of bone involvement and response to ERT was assessed by two radiologists. Results:. Overall, 19 of 30 patients (63%) showed an increased signal intensity on T1- and T2-weighted images after 36 months of ERT, consistent with partial reconversion of fatty marrow during treatment. Focal bone lesions surrounded by a low signal intensity (SI) rim did not respond to ERT, suggesting bone infarcts. Of the 11 patients with bone infarcts (low SI rim lesion), 82% had the non-homogeneous type B pattern (P=0.0021). In 86% of patients with splenectomy, bone infarcts were seen (P<0.05). Conclusions:. MRI using T1- and T2-weighted spin-echo sequences is a valuable, non-invasive method for monitoring bone marrow response in patients receiving ERT. A non- homogeneous patchy signal intensity of bone marrow involvement correlates with the presence of bone infarcts (P=0.0021).

Phosphoinositide 3-kinase-dependent Ras activation by tauroursodesoxycholate in rat liver.

Ursodesoxycholic acid, widely used for the treatment of cholestatic liver disease, causes choleretic, anti-apoptotic and immunomodulatory effects. Here the effects on choleresis of its taurine conjugate tauroursodesoxycholate (TUDC), which is present in the enterohepatic circulation, were correlated with the activation of important elements of intracellular signal transduction in cultured rat hepatocytes and perfused rat liver. TUDC induced a time- and concentration-dependent activation of the small GTP-binding protein Ras and of phosphoinositide 3-kinase (PI 3-kinase) in cultured hepatocytes. Ras activation was dependent on PI 3-kinase activity, without the involvement of protein kinase C- and genistein-sensitive tyrosine kinases. Ras activation by TUDC was followed by an activation of the mitogen-activated protein kinases extracellular-signal-regulated kinase-1 (Erk-1) and Erk-2. In perfused rat liver, PI 3-kinase inhibitors largely abolished the stimulatory effect of TUDC on taurocholate excretion, suggesting an important role for a PI 3-kinase/Ras/Erk pathway in the choleretic effect of TUDC.

Liver cell hydration

Liver cells possess potent mechanisms to maintain their volume, i.e., their hydration state. These volume-regulatory mechanisms, however, are apparently not designed to maintain absolute cell volume constancy; they rather act as dampeners to prevent excessive cell volume deviations, which would otherwise result from cumulative substrate uptake or anisotonic stress. Furthermore, these volume-regulatory mechanisms can even be activated in the resting state by hormones and other stimuli, and by that means cell volume changes are affected secondarily. Thus, liver cell hydration can change within minutes under the influence of aniso-osmolarity, hormones, nutrients, and oxidative stress. Such short-term modulation of cell volume within a narrow range acts as an independent and potent signal which modifies hepatocellular metabolism and gene expression. Accordingly, cell volume homeostasis involves the integration of events that allow cell hydration to play a physiologic role as a regulator of cell function.

Type I Gaucher disease: extraosseous extension of skeletal disease

Abstract  Objective. To investigate the frequency and morphology of extraosseous extension in patients with Gaucher disease type I. Design and patients. MRI examinations of the lower extremities were analyzed in 70 patients with Gaucher disease type I. Additionally, the thoracic spine and the midface were investigated on MRI in two patients. Results. Four cases are presented in which patients with Gaucher disease type I and severe skeletal involvement developed destruction or protrusion of the cortex with extraosseous extension into soft tissues. In one patient, Gaucher cell deposits destroyed the cortex of the mandible and extended into the masseter muscle. In the second patient, multiple paravertebral masses with localized destruction of the cortex were apparent in the thoracic spine. In the third and fourth patient, cortical destruction with extraosseous tissue extending into soft tissues was seen in the lower limbs. Conclusions. Extraosseous extension is a rare manifestation of Gaucher bone disease. While an increased risk of cancer, especially hematopoietic in origin, is known in patients with Gaucher disease, these extraosseous benign manifestations that may mimic malignant processes should be considered in the differential diagnosis of extraosseous extension into soft tissues. A narrow neck of tissue was apparent in all cases connecting bone and extraosseous extensions.

Gaucher disease of the spleen: CT and MR findings.

We present a 26-year-old male patient with Gaucher disease who presented with epigastric pain and a palpable mass in the left abdomen. Ultrasound, abdominal computed tomography, and magnetic resonance imaging showed massive splenomegaly with multiple splenic nodules up to 7 cm in diameter. Splenic nodules should be included in the differential diagnosis of splenic masses. Follow-up is necessary because of the increased incidence of hematologic malignancies in Gaucher disease.

Hyperargininemia due to arginase I deficiency: the original patients and their natural history, and a review of the literature

Hyperargininemia is caused by deficiency of arginase 1, which catalyzes the hydrolysis of l-arginine to urea as the final enzyme in the urea cycle. In contrast to other urea cycle defects, arginase 1 deficiency usually does not cause catastrophic neonatal hyperammonemia but rather presents with progressive neurological symptoms including seizures and spastic paraplegia in the first years of life and hepatic pathology, such as neonatal cholestasis, acute liver failure, or liver fibrosis. Some patients have developed hepatocellular carcinoma. A usually mild or moderate hyperammonemia may occur at any age. The pathogenesis of arginase I deficiency is yet not fully understood. However, the accumulation of l-arginine and the resulting abnormalities in the metabolism of guanidine compounds and nitric oxide have been proposed to play a major pathophysiological role. This article provides an update on the first patients ever described, gives an overview of the distinct clinical characteristics, biochemical as well as genetical background and discusses treatment options.

Extraosseous manifestation of Gaucher's disease type I: MR and histological appearance.

Abstract. Gauchers disease type I is the most prevalent lysosomal storage disorder caused by an autosomal-recessive inherited deficiency of glucocerebrosidase activity with secondary accumulation of glucocerebrosides within the lysosomes of macrophages. The storage disorder produces a multisystem disease characterized by progressive visceral enlargement and gradual replacement of bone marrow with lipid-laden macrophages. Skeletal disease is a major source of disability in Gauchers disease. Extraosseous extension of Gaucher cells is an extremely rare manifestation of skeletal Gauchers disease. This is a report on the MRI and histopathological findings of an extraosseous Gaucher-cell extension into the midface in a patient with Gauchers disease.

Decrease of plasma taurine in Gaucher disease and its sustained correction during enzyme replacement therapy.

Summary. Gaucher disease is caused by an autosomal-recessive deficiency of glucocerebrosidase. Cells of monocytic/macrophagic origin accumulate glucosylceramide. This leads to hepatosplenomegaly, bone destruction, thrombocytopenia and anemia. Enzyme replacement therapy (ERT) with macrophage-targeted glucocerebrosidase leads to normalization of these parameters. The way of macrophage activation in Gaucher disease is not known. Recently, the osmolytes taurine, betaine and inositol were identified as important regulators of macrophage function in liver. Therefore, the role of plasma taurine in Gaucher disease as a primarily macrophage-derived disease was studied.Fasting plasma levels were measured from blood samples of healthy control subjects (n = 29, m : f = 11 : 18, mean age 37 ± 3 years), from un-treated Gaucher patients (n = 16, m : f = 7 : 9, mean age 44 ± 4 years) and those treated for 37 ± 2 months (n = 54, m : f = 19 : 35, mean age 47 ± 2 years). Amino acid analysis was carried out in a BioChrom amino acid analyzer.In the untreated patients, plasma taurine was 45 ± 3 μM, as compared to the controls with a plasma taurine of 63 ± 4 μM (p < 0.01). The aver-age increase of plasma taurine during the first year of ERT was 18 ± 8 μM (n = 10). Patients treated for an average of 37 months (range 1–9 years of ERT) had a plasma taurine of 65 ± 4 μM (n = 54), which was not different from the controls.It is concluded that Gaucher patients show decreased plasma taurine levels and that therapy of Gaucher disease might correct this. It has to be established, whether decreased taurine availability is a cofactor of the permanent activation of glucosylceramide-storing monocytes/macrophages in this disease.

Management goals for type 1 Gaucher disease: An expert consensus document from the European working group on Gaucher disease

Gaucher Disease type 1 (GD1) is a lysosomal disorder that affects many systems. Therapy improves the principal manifestations of the condition and, as a consequence, many patients show a modified phenotype which reflects manifestations of their disease that are refractory to treatment. More generally, it is increasingly recognised that information as to how a patient feels and functions [obtained by patient- reported outcome measurements (PROMs)] is critical to any comprehensive evaluation of treatment. A new set of management goals for GD1 in which both trends are reflected is needed. To this end, a modified Delphi procedure among 25 experts was performed. Based on a literature review and with input from patients, 65 potential goals were formulated as statements. Consensus was considered to be reached when ≥75% of the participants agreed to include that specific statement in the management goals. There was agreement on 42 statements. In addition to the traditional goals concerning haematological, visceral and bone manifestations, improvement in quality of life, fatigue and social participation, as well as early detection of long-term complications or associated diseases were included. When applying this set of goals in medical practice, the clinical status of the individual patient should be taken into account.

Different dose-dependent correction of MIP-1β and chitotriosidase during initial enzyme replacement therapy

SummaryIn tissue lesions of type I Gaucher patients, characteristic lipid-laden macrophages, ‘Gaucher cells’, are surrounded by inflammatory phagocytes. Gaucher cells secrete the elevated plasma chitotriosidase. The elevated plasma MIP-1β in Gaucher patients stems from the phagocytes surrounding the Gaucher cells. Plasma chitotriosidase and MIP-1β decrease upon successful enzyme replacement therapy (ERT) with mannose-terminated recombinant glucocerebrosidase (alglucerase). Previous histochemical analysis of Gaucher spleens revealed that Gaucher cells express little mannose receptor, in contrast to surrounding phagocytes. We therefore investigated the corrective effects of ERT on plasma MIP-1β and chitotriosidase in more detail. We also compared effects of one year of treatment with a relatively low dose and a relatively high dose of ERT. A more rapid correction in plasma MIP-1β, compared to chitotriosidase, was observed in most patients on low-dose ERT. Correction of plasma MIP-1β and chitotriosidase levels was more pronounced in the higher-dosed patient group. Upon prolonged treatment, differences in the effects of enzyme dose were no longer significant. Normalization of plasma MIP-1β and chitotriosidase levels was attained in the majority of patients. In conclusion, ERT with mannose-terminated gluocerebrosidase results in prominent corrections of plasma chitotriosidase, a marker of Gaucher cells, and in particular of plasma MIP-1β, a marker of inflammatory phagocytes. The sharper response in plasma MIP-1β to ERT is in line with the observation that especially phagocytes surrounding Gaucher cells express mannose-receptors.