Gaucher disease and bone manifestations

Deep learning-based quantification of osteonecrosis using magnetic resonance images in Gaucher disease

Gaucher disease is one of the most common lysosomal storage disorders. Osteonecrosis is a principal clinical manifestation of Gaucher disease and often leads to joint collapse and fractures. T1-weighted (T1w) modality in MRI is widely used to monitor bone involvement in Gaucher disease and to diagnose osteonecrosis. However, objective and quantitative methods for characterizing osteonecrosis are still limited. In this work, we present a deep learning-based quantification approach for the segmentation of osteonecrosis and the extraction of characteristic parameters. We first constructed two independent U-net models to segment the osteonecrosis and bone marrow unaffected by osteonecrosis (UBM) in spine and femur respectively, based on T1w images from patients in the UK national Gaucherite study database. We manually delineated parcellation maps including osteonecrosis and UBM from 364 T1w images (176 for spine, 188 for femur) as the training datasets, and the trained models were subsequently applied to all the 917 T1w images in the database. To quantify the segmentation, we calculated morphological parameters including the volume of osteonecrosis, the volume of UBM, and the fraction of total marrow occupied by osteonecrosis. Then, we examined the correlation between calculated features and the bone marrow burden score for marrow infiltration of the corresponding image, and no strong correlation was found. In addition, we analyzed the influence of splenectomy and the interval between the age at first symptom and the age of onset of treatment on the quantitative measurements of osteonecrosis. The results are consistent with previous studies, showing that prior splenectomy is closely associated with the fractional volume of osteonecrosis, and there is a positive relationship between the duration of untreated disease and the quantifications of osteonecrosis. We propose this technique as an efficient and reliable tool for assessing the extent of osteonecrosis in MR images of patients and improving prediction of clinically important adverse events.

Osteonecrosis in Gaucher disease in the era of multiple therapies: Biomarker set for risk stratification from a tertiary referral center

Background

A salutary effect of treatments for Gaucher disease (GD) has been a reduction in the incidence of avascular osteonecrosis (AVN). However, there are reports of AVN in patients receiving enzyme replacement therapy (ERT) , and it is not known whether it is related to individual treatments, GBA genotypes, phenotypes, biomarkers of residual disease activity, or anti-drug antibodies. Prompted by development of AVN in several patients receiving ERT, we aimed to delineate the determinants of AVN in patients receiving ERT or eliglustat substrate reduction therapy (SRT) during 20 years in a tertiary referral center.

Methods

Longitudinal follow-ups of 155 GD patients between 2001 and 2021 were analyzed for episodes of AVN on therapy, type of therapy, GBA1 genotype, spleen status, biomarkers, and other disease indicators. We applied mixed-effects logistic model to delineate the independent correlates of AVN while receiving treatment.

Results

The patients received cumulative 1382 years of treatment. There were 16 episodes of AVN in 14 patients, with two episodes, each occurring in two patients. Heteroallelic p.Asn409Ser GD1 patients were 10 times (95% CI, 1.5-67.2) more likely than p.Asn409Ser homozygous patients to develop osteonecrosis during treatment. History of AVN prior to treatment initiation was associated with 4.8-fold increased risk of AVN on treatment (95% CI, 1.5-15.2). The risk of AVN among patients receiving velaglucerase ERT was 4.68 times higher compared to patients receiving imiglucerase ERT (95% CI, 1.67-13). No patient receiving eliglustat SRT suffered AVN. There was a significant correlation between GlcSph levels and AVN. Together, these biomarkers reliably predicted risk of AVN during therapy (ROC AUC 0.894, p<0.001).

Conclusions

There is a low, but significant risk of AVN in GD in the era of ERT/SRT. We found that increased risk of AVN was related to GBA genotype, history of AVN prior to treatment initiation, residual serum GlcSph level, and the type of ERT. No patient receiving SRT developed AVN. These findings exemplify a new approach to biomarker applications in a rare inborn error of metabolism to evaluate clinical outcomes in comprehensively followed patients and will aid identification of GD patients at higher risk of AVN who will benefit from closer monitoring and treatment optimization.

Funding

LSD Training Fellowship from Sanofi to MB.

Advantages of digital technology in the assessment of bone marrow involvement in Gaucher's disease

Gaucher disease (GD) is a genetic lysosomal disorder characterized by high bone marrow (BM) involvement and skeletal complications. The pathophysiology of these complications is not fully elucidated. Magnetic resonance imaging (MRI) is the gold standard to evaluate BM. This study aimed to apply machine-learning techniques in a cohort of Spanish GD patients by a structured bone marrow MRI reporting model at diagnosis and follow-up to predict the evolution of the bone disease. In total, 441 digitalized MRI studies from 131 patients (M: 69, F:62) were reevaluated by a blinded expert radiologist who applied a structured report template. The studies were classified into categories carried out at different stages as follows: A: baseline; B: between 1 and 4 y of follow-up; C: between 5 and 9 y; and D: after 10 years of follow-up. Demographics, genetics, biomarkers, clinical data, and cumulative years of therapy were included in the model. At the baseline study, the mean age was 37.3 years (1-80), and the median Spanish MRI score (S-MRI) was 8.40 (male patients: 9.10 vs. female patients: 7.71) (p < 0.001). BM clearance was faster and deeper in women during follow-up. Genotypes that do not include the c.1226A>G variant have a higher degree of infiltration and complications (p = 0.017). A random forest machine-learning model identified that BM infiltration degree, age at the start of therapy, and femur infiltration were the most important factors to predict the risk and severity of the bone disease. In conclusion, a structured bone marrow MRI reporting in GD is useful to standardize the collected data and facilitate clinical management and academic collaboration. Artificial intelligence methods applied to these studies can help to predict bone disease complications.

Long-term effects of eliglustat on skeletal manifestations in clinical trials of patients with Gaucher disease type 1

PURPOSE

Most patients with Gaucher disease have progressive and often disabling skeletal manifestations. We examined the long-term effect of eliglustat treatment on bone outcomes in clinical trials in adults with Gaucher disease type 1.

METHODS

Data from 4 completed phase 2 and 3 trials were evaluated in treatment-naïve patients or patients switching to eliglustat from enzyme replacement therapy (ERT).

RESULTS

Overall, 319 of 393 (81%) eliglustat-treated patients remained in their trials until completion or commercial eliglustat became available. Mean eliglustat treatment duration ranged from 3.3 to 6.5 years. In treatment-naïve patients and ERT-switch patients, frequency and severity of bone pain decreased during eliglustat treatment. Mean lumbar spine T-scores shifted from abnormal to normal in treatment-naïve patients and remained in the healthy reference range or improved modestly in ERT-switch patients. Mean total bone marrow burden score shifted from marked-to-severe to moderate in treatment-naïve patients and remained moderate in ERT-switch patients. MIP-1β (marker of active bone disease) was elevated at baseline and decreased to the healthy reference range in treatment-naïve patients and remained in the healthy reference range among ERT-switch patients.

CONCLUSION

These findings confirm the long-term efficacy of eliglustat on skeletal complications of Gaucher disease in treatment-naïve and ERT-switch patients.

Gaucher Disease: An Unusual Cause of Knee Pain

INTRODUCTION

Gaucher disease (GD) is a genetic lysosomal disorder leading to storage of the glycolipid molecule glucocerebroside in macrophages, causing multiorgan dysfunction. Bone marrow involvement may result in painful bone crisis and hematologic disturbance.

CASE REPORT

We present a case of a 13-year-old adolescent boy with right knee pain. Radiograph and magnetic resonance imaging of the distal femur indicated possible osteomyelitis or bone tumor. However, histologic examination of bone biopsy material suggested the diagnosis of GD, which was confirmed by detection of decreased β-glucocerebrosidase activity and identification of the exact gene mutation.

DISCUSSION

Many visceral and bone abnormalities of GD have been described. The diagnosis of GD is based on clinical and laboratory findings and is established by the measurement of β-glucocerebrosidase dysfunction and the study of GBA gene mutations. Treatment is currently based on enzyme replacement and substrate reduction.

CONCLUSION

This is a rare case of GD presenting initially with knee pain. Because early diagnosis is important for the treatment of this condition, orthopaedic surgeons should consider this uncommon cause in the differential diagnosis of joint pain.

The diagnosis and management of Gaucher disease in pediatric patients: Where do we go from here?

Gaucher disease (GD) is an autosomal recessive inherited lysosomal storage disease that often presents in early childhood and is associated with damage to multiple organ systems. Many challenges associated with GD diagnosis and management arise from the considerable heterogeneity of disease presentations and natural history. Phenotypic classification has traditionally been based on the absence (in type 1 GD) or presence (in types 2 and 3 GD) of neurological involvement of varying severity. However, patient management and prediction of prognosis may be best served by a dynamic, evolving definition of individual phenotype rather than by a rigid system of classification. Patients may experience considerable delays in diagnosis, which can potentially be reduced by effective screening programs; however, program implementation can involve ethical and practical challenges. Variation in the clinical course of GD and an uncertain prognosis also complicate decisions concerning treatment initiation, with differing stakeholder perspectives around efficacy and acceptable cost/benefit ratio. We review the challenges faced by physicians in the diagnosis and management of GD in pediatric patients. We also consider future directions and goals, including acceleration of accurate diagnosis, improvements in the understanding of disease heterogeneity (natural history, response to treatment, and prognosis), the need for new treatments to address unmet needs for all forms of GD, and refinement of the tools for monitoring disease progression and treatment efficacy, such as specific biomarkers.

Gaucher disease - bone involvement

Gaucher disease (GD) is a rare genetic disease caused by the enzymatic deficiency of beta-glucocerebrosidase. This will lead to the accumulation of sphingolipids in various organs, such as liver, spleen, bone marrow. Bone involvement is frequent in Gaucher patients, leading to bone pain, necrosis and even fractures or growth deficiency in children, with painful surgeries and progressively decreasing quality of life. The early treatment initiation in symptomatic patients is very important in lowering bone complications frequency and improve general status. We present the case of a young patient whose first manifestation of GD was a bone cystic lesion and the clinical evolution until treatment.

Correction of pathology in mice displaying Gaucher disease type 1 by a clinically-applicable lentiviral vector

Gaucher disease type 1 (GD1) is an inherited lysosomal disorder with multisystemic effects in patients. Hallmark symptoms include hepatosplenomegaly, cytopenias, and bone disease with varying degrees of severity. Mutations in a single gene, glucosidase beta acid 1 (GBA1), are the underlying cause for the disorder, resulting in insufficient activity of the enzyme glucocerebrosidase, which in turn leads to a progressive accumulation of the lipid component glucocerebroside. In this study, we treat mice with signs consistent with GD1, with hematopoietic stem/progenitor cells transduced with a lentiviral vector containing an RNA transcript that, after reverse transcription, results in codon-optimized cDNA that, upon its integration into the genome encodes for functional human glucocerebrosidase. Five months after gene transfer, a highly significant reduction in glucocerebroside accumulation with subsequent reversal of hepatosplenomegaly, restoration of blood parameters, and a tendency of increased bone mass and density was evident in vector-treated mice compared to non-treated controls. Furthermore, histopathology revealed a prominent reduction of Gaucher cell infiltration after gene therapy. The vector displayed an oligoclonal distribution pattern but with no sign of vector-induced clonal dominance and a typical lentiviral vector integration profile. Cumulatively, our findings support the initiation of the first clinical trial for GD1 using the lentiviral vector described here.

The International Collaborative Gaucher Group GRAF (Gaucher Risk Assessment for Fracture) score: a composite risk score for assessing adult fracture risk in imiglucerase-treated Gaucher disease type 1 patients

Background

Fractures in Gaucher disease type 1 (GD1) patients cause significant morbidity. Fracture risk may be decreased by enzyme replacement therapy (ERT) but not eliminated. When considering initiation of treatment, it is useful to know to what extent fixed patient-specific factors determine risk for future fractures beyond standard risk factors that change with time and treatment, such as decreased bone mineral density. We developed a tool called the GRAF score (Gaucher Risk Assessment for Fracture) that applies 5 widely available characteristics (sex, age at treatment initiation [ATI], time interval between diagnosis and treatment initiation, splenectomy status, history of pre-treatment bone crisis) and provides a practical method to assess future fracture risk when imiglucerase ERT is initiated.

Methods

Inclusion criteria: GD1 patients in the International Collaborative Gaucher Group Gaucher Registry as of September 2019 initially treated with alglucerase/imiglucerase; known splenectomy status; at least one skeletal assessment on treatment (3216 of 6422 patients). Data were analyzed by ATI group (< 18, ≥ 18 to < 50, or ≥ 50 years of age) using Cox proportional hazards regression with all 5 risk factors included in the multivariable model. A composite risk score was calculated by summing the contribution of each parameter weighted by the strength of its association (regression coefficient) with fracture risk.

Results

Patients were followed from the date of treatment initiation (or age 18 years for patients if treatment started earlier) to the date of first adult fracture (n = 288 first fracture endpoints), death, or end of follow-up. The GRAF score for each ATI group was associated with a 2.7-fold increased risk of adult fracture for each one-point increase (p < 0.02 for < 18 ATI, p < 0.0001 for ≥ 18 to < 50 ATI and ≥ 50 ATI).

Conclusions

The GRAF score is a tool to be used with bone density and other modifiable, non-GD-specific risk factors (e.g. smoking, alcohol intake, frailty) to inform physicians and previously untreated GD1 patients about risk for a future fracture after starting imiglucerase regardless of whether there is an eventual switch to an alternative ERT or to substrate reduction therapy. GRAF can also help predict the extent that fracture risk increases if initiation of treatment is further delayed.

Gaucher disease type 1 patients from the ICGG Gaucher Registry sustain initial clinical improvements during twenty years of imiglucerase treatment

BACKGROUND

Alglucerase enzyme replacement therapy was approved for Gaucher disease (GD) in the United States in 1991; imiglucerase in 1994. We report hematologic, visceral, bone pain, bone crisis, height, weight, and Body Mass Index (BMI) outcomes in patients treated for 20 (±3) years with subset analyses based on pre-treatment severity, genotype, and age at treatment initiation.

METHODS

GD type 1 (GD1) patients in the ICGG Gaucher Registry with complete sets of baseline, 10-year, and 20-year data are included (N = 475). Ten-year and 20-year data are compared to pre-treatment baseline, stratified by splenectomy status.

RESULTS

Non-splenectomized patients: Improvements observed at 10 years were maintained at 20 years for most outcomes. Mean changes from baseline at 10 and 20 years, respectively, were: spleen volume: 18.2 multiples of normal (MN) to 5.1 MN and 4.2 MN; liver volume: 1.8 MN to 1.0 MN and 1.0 MN; hemoglobin: 11.4 g/dL to 13.7 g/dL and 13.8 g/dL; platelet count: 91.6 × 10⁹/L to 168.0 × 10⁹/L and 169.1 × 10⁹/L; without bone crisis: 85.0% to 98.2% and 96.5%; without bone pain: 52.5% to 72.0% at 10 years, no significant change at 20 years (58.5%). Splenectomized patients: significant changes were observed in liver volume: 2.3 MN to 1.1 MN and 1.0 MN; hemoglobin: 11.7 g/dL to 13.3 g/dL and 13.4 g/dL; platelet count: 229.1 × 10⁹/L to 288.1 × 10⁹/L and 257.0 × 10⁹/L; without bone crisis: 52.2% to 91.3% and 100%; without bone pain: 16.3% to 30.6% (not significant) and 46.9%. Similar results were found in each of the subset analyses. Patients who start treatment during childhood have normal weight and height in young adulthood. Many treated adult patients are overweight or obese; however, this is consistent with BMI trends observed in the general population. After 1-2 years, the average biweekly imiglucerase dose is ~40 units/kg body weight.

CONCLUSION

Imiglucerase is an effective, long-term treatment for GD1. In a long-term observational setting, improvements seen during early treatment years are sustained by continuing treatment for 20 years, except for bone pain in non-splenectomized patients. These results are consistent when analyzed by different patient subsets, including by disease severity.

Bone fragility in patients affected by congenital diseases non skeletal in origin

BACKGROUND

Bone tissue represents a large systemic compartment of the human body, with an active metabolism, that controls mineral deposition and removal, and where several factors may play a role. For these reasons, several non-skeletal diseases may influence bone metabolism. It is of a crucial importance to classify these disorders in order to facilitate diagnosis and clinical management. This article reports a taxonomic classification of non-skeletal rare congenital disorders, which have an impact on bone metabolism METHODS: The International Osteoporosis Foundation (IOF) Skeletal Rare Diseases Working Group (SRD-WG), comprised of basic and clinical scientists, has decided to review the taxonomy of non-skeletal rare disorders that may alter bone physiology.

RESULTS

The taxonomy of non-skeletal rare congenital disorders which impact bone comprises a total of 6 groups of disorders that may influence the activity of bone cells or the characteristics of bone matrix.

CONCLUSIONS

This paper provides the first comprehensive taxonomy of non-skeletal rare congenital disorders with impact on bone physiology.

Identification of risk features for complication in Gaucher's disease patients: a machine learning analysis of the Spanish registry of Gaucher disease

BACKGROUND

Since enzyme replacement therapy for Gaucher disease (MIM#230800) has become available, both awareness of and the natural history of the disease have changed. However, there remain unmet needs such as the identification of patients at risk of developing bone crisis during therapy and late complications such as cancer or parkinsonism. The Spanish Gaucher Disease Registry has worked since 1993 to compile demographic, clinical, genetic, analytical, imaging and follow-up data from more than 400 patients. The aims of this study were to discover correlations between patients' characteristics at diagnosis and to identify risk features for the development of late complications; for this a machine learning approach involving correlation networks and decision trees analyses was applied.

RESULTS

A total of 358 patients, 340 type 1 Gaucher disease and 18 type 3 cases were selected. 18% were splenectomyzed and 39% had advanced bone disease. 81% of cases carried heterozygous genotype. 47% of them were diagnosed before the year 2000. Mean age at diagnosis and therapy were 28 and 31.5 years old (y.o.) respectively. 4% developed monoclonal gammopathy undetermined significance or Parkinson Disease, 6% cancer, and 10% died before this study. Previous splenectomy correlates with the development of skeletal complications and severe bone disease (p = 0.005); serum levels of IgA, delayed age at start therapy (> 9.5 y.o. since diagnosis) also correlates with severe bone disease at diagnosis and with the incidence of bone crisis during therapy. High IgG (> 1750 mg/dL) levels and age over 60 y.o. at diagnosis were found to be related with the development of cancer. When modelling the decision tree, patients with a delayed diagnosis and therapy were the most severe and with higher risk of complications.

CONCLUSIONS

Our work confirms previous observations, highlights the importance of early diagnosis and therapy and identifies new risk features such as high IgA and IgG levels for long-term complications.

Symmetric, bilateral upper and lower extremity lucent lesions in a patient with Gaucher's disease on enzyme replacement therapy

We report a case of a 6-year old girl with known type 3 Gaucher's Disease on enzyme replacement therapy who developed bilateral, symmetric osteolytic lesions in her humeri and femurs. While this manifestation of Gaucher's disease has been previously documented, it is an exceedingly rare variation. We observe that this patient shares 2 commonalities with 3 other patients reported in the literature to present with this phenotype. First, the patient's L444P/L444P genotype, present in approximately 11% of all Gaucher's patients, was also seen in these other patients. Second, like the other patients, this patient was treated with enzyme replacement therapy. It is unknown whether there is a correlation between these 2 independent variables and this rare phenotype, and further investigation may be warranted.

A Comprehensive Study of Bone Manifestations in Adult Gaucher Disease Type 1 Patients in Argentina

Gaucher disease (GD) is the most prevalent lysosomal storage disease, and bone involvement is the most disabling condition. The aim of the present study was to evaluate bone involvement in adult patients with GD, using an observational cross-sectional study. Patients were evaluated using X-rays, bone densitometry (BMD), trabecular bone score (TBS), magnetic resonance imaging (MRI), and biochemical bone markers. Thirty-two type 1GD patients were included (mean age: 40 ± 16 years). Patients had received velaglucerase for 2.7 ± 1.4 years; 19/32 had been treated previously with imiglucerase. Ninety-four percent of subjects met therapeutic goals for hematological parameters, and eight were splenectomized (SPX). Nineteen patients had irreversible bone lesions (IL), i.e., avascular necrosis, bone infarction, and/or vertebral fractures. MRI showed marrow infiltration in 71% of patients. Patients with IL had higher bone marrow burden than those without (p = 0.001). All SPX patients had IL, a higher prevalence of bone marrow edema (p = 0.02), and lower TBS (p = 0.03) than non-SPX patients. Only 18.7% of patients had abnormal BMD, with no correlation with fractures (FX). TBS values were < 1350 in 53% of patients and tended to be lower in those with FX (p = 0.06). Patients with P1NP in the lower quartile had lower TBS (p = 0.03) than those with P1NP in the higher quartiles. TBS correlated moderately but not significantly with P1NP (r = 0.32) and BMB (r = - 0.44). A high prevalence of IL was documented. Bone quality was more affected than BMD in fracture patients. Low bone formation, active bone marrow infiltration, and splenectomy might be implicated in IL.

Gaucher Disease in Bone: From Pathophysiology to Practice

Gaucher disease (GD) is a rare, genetic lysosomal disorder leading to lipid accumulation and dysfunction in multiple organs. Involvement of the skeleton is one of the most prevalent aspects of GD and a major cause of pain, disability, and reduced quality of life. Uniform recommendations for contemporary evaluation and management are needed. To develop practical clinical recommendations, an international group of experienced physicians conducted a comprehensive review of 20 years' of the literature, defining terms according to pathophysiological understanding and pointing out best practice and unmet needs related to the skeletal features of this disorder. Abnormalities of bone modeling, reduced bone density, bone infarction, and plasma cell dyscrasias accompany the displacement of healthy adipocytes in adult marrow. Exposure to excess bioactive glycosphingolipids appears to affect hematopoiesis and the balance of osteoblast and osteoclast numbers and activity. Imbalance between bone formation and breakdown induces disordered trabecular and cortical bone modeling, cortical bone thinning, fragility fractures, and osteolytic lesions. Regular assessment of bone mineral density, marrow infiltration, the axial skeleton and searching for potential malignancy are recommended. MRI is valuable for monitoring skeletal involvement: It provides semiquantitative assessment of marrow infiltration and the degree of bone infarction. When MRI is not available, monitoring of painful acute bone crises and osteonecrosis by plain X-ray has limited value. In adult patients, we recommend DXA of the lumbar spine and left and right hips, with careful protocols designed to exclude focal disease; serial follow-up should be done using the same standardized instrument. Skeletal health may be improved by common measures, including adequate calcium and vitamin D and management of pain and orthopedic complications. Prompt initiation of specific therapy for GD is crucial to optimizing outcomes and preventing irreversible skeletal complications. Investing in safe, clinically useful, and better predictive methods for determining bone integrity and fracture risk remains a need. © 2019 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

Ophthalmic manifestations of Gaucher disease: the most common lysosomal storage disorder

Gaucher disease (GD) results from a deficiency of glucocerebrosidase activity and the subsequent accumulation of the enzyme's metabolites, principally glucosylsphingosine and glucosylceramide. There are three principal forms: Type I, which is the most common, is usually considered non-neuronopathic. Type II, III and IIIc manifest earlier and have neurological sequelae due to markedly reduced enzyme activity. Gaucher's can be associated with ophthalmological sequelae but these have not been systematically reviewed. We therefore performed a comprehensive literature review of all such ophthalmic abnormalities associated with the different types of Gaucher disease. We systematically searched the literature (1950 - present) for functional and structural ocular abnormalities arising in patients with Gaucher disease and found that all subtypes can be associated with ophthalmic abnormalities; these range from recently described intraocular lesions to disease involving the adnexae, peripheral nerves and brain. In summary, Gaucher can affect most parts of the eye. Rarely is it sight-threatening; some but not all manifestations are amenable to treatment, including with enzyme replacement and substrate reduction therapy. Retinal involvement is rare but patients with ocular manifestations should be monitored and treated early to reduce the risk of progression and further complications. As Gaucher disease is also associated with Parkinsons disease and may also confer an increased risk of malignancy (particularly haematological forms and melanoma), any ocular abnormalities should be fully investigated to exclude these potential underlying conditions.

Association of Vitamin D Receptor Gene TaqI, BsmI, FokI, and ApaI Polymorphisms and Susceptibility to Hallux Valgus in the Chinese Population

Previous studies have indicated that vitamin D receptor (VDR) TaqI, BsmI, FokI and ApaI gene polymorphisms are associated with the risk of skeletal malformations with inflammation. However, the potential association of VDR gene polymorphisms with the susceptibility to hallux valgus remains unclear. To clarify this association, we compared the genotypes of 228 patients with hallux valgus with those of 200 controls using the Multiplex SNaPshot system. The χ² test was used to compare the allele and genotype frequencies between groups, and p ≤ .05 was considered statistically significant. The frequencies of the mutant allele C in TaqI (p= .036; odds ratio [OR] 1.57; 95% confidence interval [CI] 1.03-2.39) and mutant allele A in BsmI (p= .036; OR 1.33; 95% CI 1.02-1.74) were significantly greater in the patients than in the controls. In addition, after adjusting for sex and age, TaqI (p= .047; OR 1.61; 95% CI 1.00-2.58) and BsmI (p= .025; OR 1.67; 95% CI 1.06-2.61) were associated with the risk of hallux valgus through a dominant genetic model. A homozygous genetic model of BsmI was also significantly associated with the risk of hallux valgus (p= .033; OR 1.81; 95% CI 1.05-2.57). However, neither ApaI nor FokI were associated with increased susceptibility. To the best of our knowledge, we have reported for the first time that VDR gene TaqI and BsmI polymorphisms might contribute to the increased risk of hallux valgus in Chinese population.

Actual reason for bone fractures in the case of a patient followed-up with the osteogenesis imperfecta: Gaucher's Disease

Gaucher's disease (GD) is a rare disease characterized by a β-glucocerebroside accumulation in the reticulo-endothelial system. Patients may refer to the clinic with complaints of bone pain, hepatosplenomegaly, anemia, thrombocytopenia, growth retardation, interstitial pulmonary disease, pulmonary hypertension, and skeletal disorders. Skeletal system involvement is observed commonly in Gaucher patients and a significant cause of morbidity. Our patient was followed for several years as a glass child - osteogenesis imperfecta and he had joint deformities due to skeletal fractures. We wanted to present this case to raise awareness of GD's skeletal involvement and effects of late diagnosis.

Signs and symptoms in Gaucher Disease: priority nursing diagnoses

OBJECTIVE

Identify the signs and symptoms of patients with Gaucher Disease, inferring possible priority nursing diagnoses.

METHOD

Cross-sectional study, developed in a specialized laboratory, between 2013 and 2015. The sample (n = 91) comprised the records of patients with genetic diagnosis for Gaucher Disease. The study respected research norms.

RESULTS

Prevalence of female sex (57.1%), age at diagnosis between 0 and 10 years, and origin from the Southeast Region of Brazil were prevalent. Hematologic changes, bone pain, hepatomegaly, splenomegaly, and fatigue were the most recurrent signs and symptoms. The inferred diagnoses for the studied population were: Risk for bleeding; Fatigue; Chronic pain and Acute pain; Impaired physical mobility; Imbalanced nutrition: less than body requirements; and Risk for Developmental Delay.

CONCLUSION

The establishment of Priority Nursing Diagnoses based on signs and symptoms makes it possible to achieve expected outcomes for each individual in the care context.

In vitro osteoclastogenesis from Gaucher patients' cells correlates with bone mineral density but not with Chitotriosidase

Gaucher disease (GD) is caused by mutations on the gene encoding for the lysosomal enzyme glucocerebrosidase. Type I GD (GD1) patients present anemia, hepatosplenomegaly and bone alterations. In spite of treatment, bone alterations in GD patients persist, including poor bone mineral density (BMD). Mechanisms leading to bone damage are not completely understood, but previous reports suggest that osteoclasts are involved. Chitotriosidase (CHIT) is the most reliable biomarker used in the follow up of patients, although its correlation with bone status is unknown. The aim of this work was to study the pro-osteoclastogenic potential in patients and to evaluate its correlation with CHIT activity levels and clinical parameters. PBMCs from treated patients and healthy controls were cultured in the presence of M-CSF, and mature osteoclasts were counted. BMD, blood CHIT activity and serum levels of CTX, BAP, and cytokines were evaluated in patients. We found that blood CHIT activity and osteoclast differentiation were significantly increased in patients, but no correlation between them was observed. Interestingly, osteoclast numbers but not CHIT, presented a negative correlation with BMD expressed as Z-score. CTX, BAP and serum cytokines involved in bone remodeling were found altered in GD1 patients. These results show for the first time a correlation between osteoclast differentiation and BMD in GD1 patients, supporting the involvement of osteoclasts in the bone pathology of GD1. Our results also suggest that an altered immune response may play an important role in bone damage.

Skeletal involvement in type 1 Gaucher disease: Not just bone mineral density

Gaucher disease is characterized by multi-organ infiltration of phospholipid-laden macrophages. Bone involvement is characterized by typical deformities, osteopenia/osteoporosis, pathological fractures, and bone marrow infiltration (avascular osteonecrosis, infarction). Estimation of skeletal disease includes bone quality that contributes substantially to bone strength. We studied 23 type 1 Gaucher patients (median age 22years, range 3-73) on Enzyme Replacement Therapy from 2months to 26years (median 7years); 4 patients had pathological fractures, 10 bone infarctions, 6 avascular osteonecrosis. We noninvasively assessed bone quality by trabecular microarchitecture and macroscopic geometry, using two innovative dual-energy X-ray absorptiometry tools: Trabecular Bone Score (TBS) and Hip Structural Analysis (HSA). Bone quality parameters distinguished the patients with skeletal complications. TBS was significantly lower in patients with avascular osteonecrosis (p=0.049) and pathological fractures (p=0.024), while it could not identify those with bone infarctions. Among HSA parameters, the Cross Sectional Area of the intertrochanteric region and the Buckling Ratio of the narrow neck allowed the distinction of patients with avascular osteonecrosis. BMD was low in 11 patients (50%); neither BMD nor HSA were associated with pathological fractures. The combined evaluation of bone quality and bone quantity is useful to identify GD patients with more severe skeletal involvement.

Benign Bone Conditions That May Be FDG-avid and Mimic Malignancy

Positron emission tomography with the radiotracer ¹⁸F-fluoro-2-deoxy-d-glucose (FDG) plays an important role in the evaluation of bone pathology. However, FDG is not a cancer-specific agent, and knowledge of the differential diagnosis of benign FDG-avid bone alterations that may resemble malignancy is important for correct patient management, including the avoidance of unnecessary additional invasive tests such as bone biopsy. This review summarizes and illustrates the spectrum of benign bone conditions that may be FDG-avid and mimic malignancy, including osteomyelitis, bone lesions due to benign systemic diseases (Brown tumor, Erdheim-Chester disease, Gaucher disease, gout and other types of arthritis, Langerhans cell histiocytosis, and sarcoidosis), benign primary bone lesions (bone cysts, chondroblastoma, chondromyxoid fibroma, desmoplastic fibroma, enchondroma, giant cell tumor and granuloma, hemangioma, nonossifying fibroma, and osteoid osteoma and osteoblastoma), and a group of miscellaneous benign bone conditions (post bone marrow biopsy or harvest status, bone marrow hyperplasia, fibrous dysplasia, fractures, osteonecrosis, Paget disease of bone, particle disease, and Schmorl nodes). Several ancillary clinical and imaging findings may be helpful in discriminating benign from malignant FDG-avid bone lesions. However, this distinction is sometimes difficult or even impossible, and tissue acquisition will be required to establish the final diagnosis.

A Review of Gaucher Disease Pathophysiology, Clinical Presentation and Treatments

Gaucher disease (GD, ORPHA355) is a rare, autosomal recessive genetic disorder. It is caused by a deficiency of the lysosomal enzyme, glucocerebrosidase, which leads to an accumulation of its substrate, glucosylceramide, in macrophages. In the general population, its incidence is approximately 1/40,000 to 1/60,000 births, rising to 1/800 in Ashkenazi Jews. The main cause of the cytopenia, splenomegaly, hepatomegaly, and bone lesions associated with the disease is considered to be the infiltration of the bone marrow, spleen, and liver by Gaucher cells. Type-1 Gaucher disease, which affects the majority of patients (90% in Europe and USA, but less in other regions), is characterized by effects on the viscera, whereas types 2 and 3 are also associated with neurological impairment, either severe in type 2 or variable in type 3. A diagnosis of GD can be confirmed by demonstrating the deficiency of acid glucocerebrosidase activity in leukocytes. Mutations in the GBA1 gene should be identified as they may be of prognostic value in some cases. Patients with type-1 GD-but also carriers of GBA1 mutation-have been found to be predisposed to developing Parkinson's disease, and the risk of neoplasia associated with the disease is still subject to discussion. Disease-specific treatment consists of intravenous enzyme replacement therapy (ERT) using one of the currently available molecules (imiglucerase, velaglucerase, or taliglucerase). Orally administered inhibitors of glucosylceramide biosynthesis can also be used (miglustat or eliglustat).

DOENÇA DE GAUCHER TIPO 1 NO ESQUELETO: REVISÃO DA AMÉRICA LATINA

RESUMO A doença de Gaucher (DG) é a doença de depósito lisossômico mais prevalente, que se caracteriza pelo acúmulo de glicosilceramida e glucosilesfingosina em todos os tecidos do corpo. Com o advento da terapia de reposição de enzimas, o prognóstico dos pacientes com DG melhorou acentuadamente. Ainda assim, as manifestações esqueléticas associadas à DG respondem lentamente à terapia de reposição de enzimas e são as que contribuem de forma mais significativa para a morbidade do paciente. Esta revisão das manifestações ósseas da DG apresenta as mais recentes teorias sobre a sua fisiopatologia e uma revisão sistemática de estudos com pacientes latino-americanos que relataram a frequência das manifestações ósseas e os efeitos da terapia de reposição de enzimas sobre seu tratamento. Concluímos, destacando a importância da identificação precoce e do manejo adequado das doses apropriadas da terapia de reposição de enzimas para reduzir a morbidade causada pela DG.

Evaluation of Bone Mineral Density in Patients with Type 1 Gaucher Disease in Argentina

The purpose of this study was to evaluate the frequency of osteoporosis (OP) in patients with Gaucher disease (GD) in Argentina. GD patients from 28 centers were consecutively included from April 2012 to 2014. Bone mineral density (BMD) was determined by dual X-ray absorptiometry in the lumbar spine and the femoral neck or the total proximal femur for patients ≥20 yr of age, and by whole-body scan in the lumbar spine in patients <20 yr of age. In children, mineral density was calculated using the chronological age and Z height. OP diagnosis was determined following adult and pediatric official position of the International Society for Clinical Densitometry. A total of 116 patients were included, of which 62 (53.5%) were women. The median age was 25.8 yr. All patients received enzyme replacement therapy, with a median time of 9.4 yr. Normal BMD was found in 89 patients (76.7%), whereas low bone mass (LBM) or osteopenia was found in 15 patients (13%) and OP in 12 patients (10.3%). The analysis of the pediatric population revealed that 4 patients (9.3%) had LBM and 3 (7%) had OP (Z-score ≤ -2 + fractures height-adjusted by Z), whereas in the adult population (n = 73), 11 patients (15%) had LBM or osteopenia and 9 (12.3%) had OP. Bone marrow infiltration and the presence of fractures were significantly correlated with the presence of OP (p = 0.04 and <0.001, respectively). This is the first study in Argentina and in the region describing the frequency of OP or LBM in GD patients treated with imiglucerase using the official position of the International Society for Clinical Densitometry.

Skeletal involvement in Gaucher disease: An observational multicenter study of prognostic factors in the Argentine Gaucher disease patients

Patients with Gaucher type 1 (GD1) throughout Argentina were enrolled in the Argentine bone project to evaluate bone disease and its determinants. We focused on presence and predictors of bone lesions (BL) and their relationship to therapeutic goals (TG) with timing and dose of enzyme replacement therapy (ERT). A total of 124 patients on ERT were enrolled in a multi-center study. All six TG were achieved by 82% of patients: 70.1% for bone pain and 91.1% for bone crisis. However, despite the fact that bone TGs were achieved, residual bone disease was present in 108 patients on ERT (87%) at time 0. 16% of patients showed new irreversible BL (bone infarcts and avascular osteonecrosis) despite ERT, suggesting that they appeared during ERT or were not detected at the moment of diagnosis. We observed 5 prognostic factors that predicted a higher probability of being free of bone disease: optimal ERT compliance; early diagnosis; timely initiation of therapy; ERT initiation dose ≥45 UI/kg/EOW; and the absence of history of splenectomy. Skeletal involvement was classified into 4 major phenotypic groups according to BL: group 1 (12.9%) without BL; group 2 (28.2%) with reversible BL; group 3 (41.9%) with reversible BL and irreversible chronic BL; and group 4 (16.9%) with acute irreversible BL. Our study identifies prognostic factors for achieving best therapeutic outcomes, introduces new risk stratification for patients and suggests the need for a redefinition of bone TG. Am. J. Hematol. 91:E448-E453, 2016. © 2016 Wiley Periodicals, Inc.

Spontaneous rupture of the spleen in a patient with type I Gaucher's disease

Gaucher's disease (GD) is a relatively rare metabolic disease caused by inherited deficiency of the lysosomal enzyme glucocerebrosidase. Here we describe a very rare case of spontaneous rupture of the spleen in a 37-year-old male with GD. In this case, spontaneous rupture of the spleen was the only symptom of the disease. Such unusual presentation of GD prompted a differential diagnosis with more common forms of splenic rupture. We also discuss the disease process and future management options.

A review of glucosamine for knee osteoarthritis: why patented crystalline glucosamine sulfate should be differentiated from other glucosamines to maximize clinical outcomes

The European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) treatment algorithm for knee osteoarthritis (OA) recommends symptomatic slow-acting drugs for osteoarthritis (SYSADOAs) first line for the medium to long term management of OA, due to their ability to control pain, improve function, and delay joint structural changes. Among SYSADOAs, glucosamine is probably the most widely used intervention. In the present review of glucosamine for knee OA, we have investigated whether the evidence is greater for the patented crystalline glucosamine sulfate (pCGS) preparation (Rottapharm/Meda) than for other glucosamine formulations. Glucosamine is actually widely available in many forms, as the prescription-grade pCGS preparation, generic and over-the-counter formulations of glucosamine sulfate (GS) and food supplements containing glucosamine hydrochloride (GH), which vary substantially in molecular form, pharmaceutical formulation and dose regimens. Only pCGS is given as a highly bioavailable once daily dose (1500 mg) with a proven pharmacological effect. pCGS consistently reaches the plasma levels of around 10 μM required to inhibit interleukin-1 induced expression of genes involved in the pathophysiology of joint inflammation and tissue destruction, compared with sub-therapeutic levels achieved with GH. It is evident, from careful consideration of the evidence base, that only the pCGS formulation of glucosamine reliably provides an effect size on pain that is higher than that of paracetamol and equivalent to that provided by non-steroidal anti-inflammatory drugs. In comparison, the effect size on pain of non-crystalline GS preparations and GH from randomized controlled trials is repeatedly demonstrated to be zero. In addition, there is evidence that chronic administration of pCGS has disease-modifying effects, with a reduction in the need for total joint replacement surgery lasting for at least 5 years after treatment cessation. Consequently, the pCGS preparation (Rottapharm/Meda) is the logical choice, with demonstrated medium-term control of pain and lasting impact on disease progression.

Bone infarcts: Unsuspected gray areas?

There is agreement to label as bone infarcts avascular necrosis (AVN) occurring in the metaphyses or diaphyses of long bones, the terms AVN or osteonecrosis being used at the epiphyses. One might expect bone infarction to hold no mysteries. Oddly enough, however, scientific evidence about bone infarcts is extraordinarily scant. The prevalence of bone infarcts is unknown. The main sites of involvement are the distal femur, proximal tibia, and distal tibia. In patients without sickle cell disease or Gaucher's disease, involvement of the upper limbs and lesions confined to the diaphysis are so rare as to warrant a reappraisal of the diagnosis. Although widely viewed as a generally silent event, bone infarcts causes symptoms in half the cases. Standard radiographs are normal initially then show typical high-density lesions in the center of the marrow cavity. A periosteal reaction is common and may be the first and only radiographic change. Magnetic resonance imaging consistently shows typical features and therefore, in principle, obviates the need for other investigations. Bone infarcts are multifocal in over half the cases and, when multifocal, are usually accompanied with multiple foci of epiphyseal avascular necrosis. Thus, bone infarcts, whose prognosis is good per se (with the exception of the very low risk of malignant transformation), are usually a marker for systemic avascular necrosis. Consequently, patients with bone infarcts must be investigated both for known risk factors and for other foci of avascular necrosis, which may, in contrast, have function-threatening effects.

Standardization of MRI and Scintigraphic Scores for Assessing the Severity of Bone Marrow Involvement in Adult Patients With Type 1 Gaucher Disease

OBJECTIVE

MRI and (99m)Tc-sestamibi scintigraphy are used to estimate bone marrow infiltration in patients with Gaucher disease (GD), but comparison of data obtained at different institutions is difficult because different scores are employed for semiquantitative assessment. We developed normalized scores for comparing data both within a single method (MRI) and between different methods (MRI versus scintigraphy).

MATERIALS AND METHODS

We evaluated 51 patients with type 1 GD (26 women, 25 men; mean age ± SD, 36.3 ± 10.9 years old). T1- and T2-weighted turbo spin-echo sequences at 1.5 T served to derive the bone marrow burden score (0-16), the vertebra-disk ratio (VDR), the Terk score (0-3), and the Spanish-MRI score (S-MRI, 0-24). Scintigraphy was scored between 0 and 8. Each score was normalized into four categories: 0 = normal, 1 = mild, 2 = intermediate, 3 = severe involvement. Interobserver and intraobserver agreements were evaluated by kappa statistics; nonparametric statistics with Bonferroni correction assessed correlations among the various original and normalized scores.

RESULTS

Interobserver agreement was excellent for the original scores (κ = 0.730-0.843) and even more so for the normalized scores (κ = 0.775-0.940). Intraobserver agreement kappa values ranged from 0.753 to 0.937 for the original scores and 0.851 to 1.000 for the normalized scores. Highly significant correlations were found among the various original scores (r = 0.42-0.86, p values between 0.0296 and < 0.0001), except for VDR versus S-MRI and Terk. Normalization generally induced marginal reductions in statistical significance, whereas S-MRI versus VDR reached statistical significance with the normalized scores.

CONCLUSION

Our data indicate no significant loss of statistical information is caused by the normalization we employed. Our approach therefore facilitates comparison of different scores obtained in different institutions with different imaging modalities.

Bilateral Femoral Osteolytic Lesions in a Patient with Type 3 Gaucher Disease

Type 3 Gaucher disease (GD) manifests with hematologic, neurological and skeletal involvement including Erlenmeyer flask bone deformities, osteopenia, painful bone crises and fractures. We describe bilateral symmetric osteolytic lesions in a 23 year old with type 3 GD, chronically treated with enzyme replacement therapy. These atypical bone findings, previously reported in two similar patients with type 3 GD, expand our understanding of the evolving natural history of GD in the post-treatment era.

Clinical manifestations and management of Gaucher disease

Gaucher disease is a rare multi-systemic metabolic disorder caused by the inherited deficiency of the lysosomal enzyme β-glucocerebrosidase, which leads to the accumulation of its normal substrate, glucocerebroside, in tissue macrophages with damage to haematological, visceral and bone systems. Anaemia, thrombocytopenia, enlargement of liver and/or spleen, skeletal abnormalities (osteopenia, lytic lesions, pathological fractures, chronic bone pain, bone crisis, bone infarcts, osteonecrosis and skeletal deformities) are typical manifestations of the most prevalent form of the disease, the so-called non-neuronopathic type 1. However, severity and coexistence of different symptoms are highly variable. The determination of deficient β-glucocerebrosidase activity in leukocytes or fibroblasts by enzymatic assay is the gold standard for the diagnosis of Gaucher disease. Comprehensive and reproducible evaluation and monitoring of all clinically relevant aspects are fundamental for the effective management of Gaucher disease patients. Enzyme replacement therapy has been shown to be effective in reducing glucocerebroside storage burden and diminishing the deleterious effects caused by its accumulation. Tailored treatment plan for each patient should be directed to symptom relief, general improvement of quality of life, and prevention of irreversible damage.