Bone ultrasonometry, bone density, and turnover markers in type 1 Gaucher disease

In 12 patients (mean age, 33 ± 13 years) with type 1 Gaucher disease (GD), we evaluated bone mass by broadband ultrasound attenuation (BUA) of the calcaneus and dual X-ray absorptiometry (DXA) of the total body, lumbar spine, and hip. In all patients, we measured serum levels of osteocalcin (OC) and bone-specific alkaline phosphatase (BAP) and urinary excretion of pyridinoline (Pyr/Cr) and deoxypyridinoline (D-Pyr/Cr) cross-links. Compared to age- and sex-matched healthy controls, patients with GD showed marked osteopenia at all measuring sites as expected. Values of BUA (67.25 ± 15.83 dB/MHz) were also significantly reduced. OC and BAP concentrations were within the normal range. Pyr/Cr and D-Pyr/Cr were significantly higher than in controls. Calculating T- and Z scores, we found a significant correlation between the Bone Severity Score Index (BSSI) and both BUA and BMD measurements. A significant correlation was also found between pyridinoline urinary excretion and both BSSI and BUA at the calcaneus. Our data suggest that type 1 GD in adulthood is associated with increased bone resorption and that BUA at the calcaneus may be a relevant tool in the assessment of bone status in these patients. Received: April 2, 2001 / Accepted: August 6, 2001     

Lepirudin use in a neonate with heparin-induced thrombocytopenia

OBJECTIVE: To describe a case of heparin-induced thrombocytopenia (HIT) in a premature infant and the doses of danaparoid and lepirudin needed to achieve appropriate therapeutic endpoints. CASE SUMMARY: A 30-week gestational age infant was diagnosed with HIT with heparin antibodies. Danaparoid 2.0-2.4 units/kg/h achieved anti-Xa levels of 0.2-0.4 U/mL, but thrombocytopenia failed to resolve. Lepirudin was started in place of danaparoid. Lepirudin doses of 0.03-0.05 mg/kg/h achieved target activated partial thromboplastin time values of 1.5-2.0 times baseline. DISCUSSION: Dosing information for danaparoid in neonates is limited, and information for lepirudin appears only in German literature at this time. HIT is well documented in newborns, and lepirudin use in these situations is likely to increase. This report provides some guidance for optimal dosing. It also provides some guidance for HIT evaluation in preterm infants, in whom blood volume for laboratory tests is a major issue. CONCLUSIONS: HIT is an important and potentially fatal problem in neonates. Lepirudin may be the drug of choice, especially since danaparoid is now unavailable. Initial lepirudin dosing should not exceed 0.05 mg/kg/h.     

Meeting report: FDA public meeting on patient‐focused drug development and medication adherence in solid organ transplant patients

The Food and Drug Administration (FDA) held a public meeting and scientific workshop in September 2016 to obtain perspectives from solid organ transplant recipients, family caregivers, and other patient representatives. The morning sessions focused on the impact of organ transplantation on patients’ daily lives and the spectrum of activities undertaken to maintain grafts. Participants described the physical, emotional, and social impacts of their transplant on daily life. They also discussed their posttransplant treatment regimens, including the most burdensome side effects and their hopes for future treatment. The afternoon scientific session consisted of presentations on prevalence and risk factors for medication nonadherence after transplantation in adults and children, and interventions to manage it. As new modalities of Immunosuppressive Drug Therapy are being developed, the patient perceptions and input must play larger roles if organ transplantation is to be truly successful.     

The biology of stem cell factor,a new hematopietic growth factor involved in stem cell regulation

Summary Recently, a new hematopoietic growth factor, stem cell factor, the ligand for the c-kit-proto-oncogene, has been cloned. The gene for this factor or for its receptor are deleted in two well know series of mice mutants which display pleiotropic stem cell defects. Therefore, this factor supposedly plays an important role in stem cell biology. This paper reviews some of the elegant genetic work which led to the discovery of the factor and of its receptor, the biological effects that this factor exerts in the hematopoietic system in normal individuals and in patients with Diamond-Blackfan anemia and speculates on some of its potential clinical applications.     

Acidic Sphingomyelinase (ASM) Is Necessary for Fas-induced GD3 Ganglioside Accumulation and Efficient Apoptosis of Lymphoid Cells

Ceramides deriving from sphingomyelin hydrolysis are important mediators of apoptotic signals originating from Fas (APO-1/CD95). However, definitive evidence for the role played by individual sphingomyelinases is still lacking. We have analyzed lymphoblastoid cell lines derived from patients affected by Niemann Pick disease (NPD), an autosomal recessive disorder caused by loss-of-function mutations within the acidic sphingomyelinase (ASM) gene. NPD lymphoblasts, which display normal neutral sphingomyelinase activity, fail to activate ASM in response to Fas cross-linking, unlike normal lymphoblasts. NPD lymphoblasts also fail to accumulate GD3 ganglioside, a downstream mediator of ceramide-induced cell death (De Maria, R., L. Lenti, F. Malisan, F. D'Agostino, B. Tomassini, A. Zeuner, M.R. Rippo, R. Testi. 1997. Science. 277:1652–1655), and display a substantially inefficient apoptosis after Fas cross-linking. Inefficient apoptosis is due to lack of ASM activity, because proximal signaling from Fas in NPD lymphoblasts is not impaired and apoptosis can be efficiently triggered by passing the ASM defect with exogenous ceramides. Moreover, mannose receptor–mediated transfer of ASM into NPD lymphoblasts rescues their ability to transiently activate ASM, accumulate GD3, and rapidly undergo apoptosis after Fas cross-linking. These results provide definitive genetic evidence for the role of ASM in the progression of apoptotic signals originating from Fas.     

Fatigue, level of everyday physical activity and quality of life after liver transplantation.

OBJECTIVE: To assess whether liver transplant recipients have a hypoactive (sedentary) lifestyle and whether the level of everyday physical activity is related to complaints of fatigue. In addition, we explored the relationship between activity level and health-related quality of life. DESIGN: Case comparison. SUBJECTS: Eight persons 6-36 months after liver transplantation with varying severity of fatigue and 8 persons without known impairments (matched for gender, age, social situation and employment). METHODS: Activity levels were assessed during 2 randomly selected consecutive weekdays with an accelerometry-based Activity Monitor. In the transplantation group, severity of fatigue (Fatigue Severity Scale) and health-related quality of life (RAND-36) were also assessed. RESULTS: Five liver transplant recipients had a hypoactive lifestyle, but there was no significant difference in activity level between the transplantation group and comparison group. Severity of fatigue was correlated (p=0.01) with both duration of dynamic activities and intensity of everyday activity (r(s)=-0.81 and -0.84, respectively). Activity level was correlated (p< or =0.05) with several domains of health-related quality of life (r(s)=0.72-0.78). CONCLUSION: As a group, liver transplant recipients were not significantly less active than comparison subjects. Activity level was related with severity of fatigue and health-related quality of life. These findings have implications for the development of interventions needed to rehabilitate persons after liver transplantation.