Skeletal involvement in Gaucher's disease

Gaucher: A Systematic Review on Oral and Radiological Aspects

Background and Objectives: Gaucher disease (GD) is a lysosomal storage disorder with the genetic autosomal recessive transmission. Bone involvement is a prevalent finding in Gaucher disease. It causes deformity and limits daily activities and the quality of life. In 75% of patients, there is bone involvement. This review aims to evaluate the principal findings in the jaw by a Cone-beam computed tomography (CBTC) and X-ray orthopantomography; Materials and Methods: PubMed, Web of Science, Lilacs and Scopus were systematically searched until 31 December 2022. In addition, a manual search was performed using the bibliography of selected articles and a Google Scholar search. Clinical studies were selected that considered principal radiographic findings in radiography in a group of patients affected by GD. Results: Out of 5079 papers, four studies were included. The main findings are generalized rarefaction and enlarged narrow space, anodontia. Conclusions: The exact mechanism of bone manifestation is probably due to the infiltration of Gaucher cells in the bone marrow and, consequently, the destruction of bone architecture. All long bones are a potential means of skeletal manifestation. The jaw is more affected than the maxilla, and the principal features are cortical thinning, osteosclerosis, pseudocystic lesions, mental demineralization, flattening in the head of the condyle, effacement of anatomical structures, thickening of maxillary sinus mucosa. The dentist plays a crucial role in diagnosing and treating these patients. Sometimes the diagnosis can be made by a simple panoramic radiograph. All long bones are affected, and the mandible is particularly involved.

Cysteine cathepsins: A long and winding road towards clinics

Biomedical research often focuses on properties that differentiate between diseased and healthy tissue; one of the current focuses is elevated expression and altered localisation of proteases. Among these proteases, dysregulation of cysteine cathepsins can frequently be observed in inflammation-associated diseases, which tips the functional balance from normal physiological to pathological manifestations. Their overexpression and secretion regularly exhibit a strong correlation with the development and progression of such diseases, making them attractive pharmacological targets. But beyond their mostly detrimental role in inflammation-associated diseases, cysteine cathepsins are physiologically highly important enzymes involved in various biological processes crucial for maintaining homeostasis and responding to different stimuli. Consequently, several challenges have emerged during the efforts made to translate basic research data into clinical applications. In this review, we present both physiological and pathological roles of cysteine cathepsins and discuss the clinical potential of cysteine cathepsin-targeting strategies for disease management and diagnosis.

Diagnosing neuronopathic Gaucher disease: New considerations and challenges in assigning Gaucher phenotypes

Gaucher disease (GD), resulting from biallelic mutations in the gene GBA1, is a monogenic recessively inherited Mendelian disorder with a wide range of phenotypic presentations. The more severe forms of the disease, acute neuronopathic GD (GD2) and chronic neuronopathic GD (GD3), also have a continuum of disease severity with an overlap in manifestations and limited genotype-phenotype correlation. In very young patients, assigning a definitive diagnosis can sometimes be challenging. Several recent studies highlight specific features of neuronopathic GD that may provide diagnostic clues. Distinguishing between the different GD types has important therapeutic implications. Currently there are limited treatment options specifically for neuronopathic GD due to the difficulty in delivering therapies across the blood-brain barrier. In this work, we present both classic and newly appreciated aspects of the Gaucher phenotype that can aid in discriminating between acute and chronic neuronopathic GD, and highlight the continuing therapeutic challenges.

Henry J. Mankin: A Trailblazer in Skeletal Pathology Research

: Dr. Henry Mankin has made a profound impact in the fields of skeletal surgery and orthopedics. In a career spanning over 50 years, Dr. Mankin conducted extensive research on and provided treatment for numerous patients with Gaucher disease and spinal tumors such as sacral chordomas. Dr. Mankin's prolific career includes many leadership positions in the field of skeletal surgery, including Chief of Orthopaedics at the Hospital for Joint Diseases and at Massachusetts General Hospital. He has touched the lives of over 19,000 patients with bone and soft tissue tumors and undoubtedly shaped the future of skeletal surgery.

Gaucher disease iPSC-derived osteoblasts have developmental and lysosomal defects that impair bone matrix deposition

Gaucher disease (GD) is caused by bi-allelic mutations in GBA1, the gene that encodes acid β-glucocerebrosidase (GCase). Individuals affected by GD have hematologic, visceral and bone abnormalities, and in severe cases there is also neurodegeneration. To shed light on the mechanisms by which mutant GBA1 causes bone disease, we examined the ability of human induced pluripotent stem cells (iPSC) derived from patients with Types 1, 2 and 3 GD, to differentiate to osteoblasts and carry out bone deposition. Differentiation of GD iPSC to osteoblasts revealed that these cells had developmental defects and lysosomal abnormalities that interfered with bone matrix deposition. Compared with controls, GD iPSC-derived osteoblasts exhibited reduced expression of osteoblast differentiation markers, and bone matrix protein and mineral deposition were defective. Concomitantly, canonical Wnt/β catenin signaling in the mutant osteoblasts was downregulated, whereas pharmacological Wnt activation with the GSK3β inhibitor CHIR99021 rescued GD osteoblast differentiation and bone matrix deposition. Importantly, incubation with recombinant GCase (rGCase) rescued the differentiation and bone-forming ability of GD osteoblasts, demonstrating that the abnormal GD phenotype was caused by GCase deficiency. GD osteoblasts were also defective in their ability to carry out Ca2+-dependent exocytosis, a lysosomal function that is necessary for bone matrix deposition. We conclude that normal GCase enzymatic activity is required for the differentiation and bone-forming activity of osteoblasts. Furthermore, the rescue of bone matrix deposition by pharmacological activation of Wnt/β catenin in GD osteoblasts uncovers a new therapeutic target for the treatment of bone abnormalities in GD.

Gaucher disease: the role of the specialist on metabolic bone diseases

According to European legislation, a disease can be considered rare or "orphan" when it affects less than 1 subject of 2000 (1). Often these diseases affecting the pediatric age, are complex diseases and chronically debilitating and for this motive need the intervention of multidisciplinary skills specific. Among the rare disease as affecting the skeleton more than 400 are characterized by dysplastic changes of the skeleton (2). Alongside the disorders affecting the skeleton primitively, many systemic diseases can have a bone involvement. Among these, the Gaucher disease (GD), an heterogeneous lysosomal storage determined by hereditary enzyme deficiency of β-glucosidase. Patients with this disease have skeletal disorders of varying severity (Erlenmeyer flask deformity, lytic lesions and osteonecrosis, pathological fractures) that affects both the bone marrow, both mineralized bone with progressive damage of the tissue. The bone disease is the most debilitating of GD and can have a significant impact on the quality of life of patients. Thorough evaluations by monitoring biochemical markers of bone turnover and instrumental, with a quantitative and qualitative evaluation of the bone, are of fundamental importance to intervene early so they can prevent complications irreversible.

Histologic findings of femoral heads from patients with Gaucher disease treated with enzyme replacement

OBJECTIVES

To assess correlations of patient demographics, including enzyme replacement therapy (ERT) with bone histology, to facilitate decisions of whether and when to perform hip replacement surgery in patients with Gaucher disease.

METHODS

We examined the histology of surgically removed femoral heads and categorized findings by the presence or extent of osteonecrosis, Gaucher cell (GC) infiltration, and bone regeneration qualifiers using a tripartite histology-based scoring system.

RESULTS

Twenty-two patients with 26 bone specimens were evaluated. Seventeen patients (77%) were splenectomized, 16 (73%) received ERT, and 12 (55%) had the putatively milder genotype (N370S/N370S), with the rest putatively at increased risk for skeletal disease (N370S/other). The 3 histology subscores were applicable to all specimens. Osteonecrotic bone was seen in 19 of 26 (73%); osteoarthritis was seen in all cartilage specimens. Gaucher cell infiltration was not correlated with demographics or disease severity. A trend was noted between reduced GC infiltration and ERT (ρ = 0.407), but regeneration qualifiers were not correlated with ERT or other features.

CONCLUSIONS

Histologic findings of GC infiltration and bone regeneration qualifiers did not correlate with demographics or with exposure to ERT. Most specimens unexpectedly showed good regenerative responses to osteonecrosis despite heavy GC infiltration.

Jaws features in Type 1 Gaucher disease

PURPOSE

Our aims were to present 2 new cases of Gaucher disease involving the jaws and to review the literature.

MATERIALS AND METHODS

Two new cases and the literature from 1982-2011 were reviewed.

RESULTS

Ten articles describing 35 cases (for a total of 37 with 2 new cases presented) were analyzed. The mandible and maxilla were affected in 97.3% and 24.3% of the reported cases, respectively. Generalized rarefaction of bone (osteopenia) was present in 83.8%, and well-defined radiolucent lesions in 40.5%. The effects on the surrounding structures included loss of cortication of the mandibular canal (56.7%), cortical bone thinning (27%), expansion, root resorption (24.3%), mandibular canal displacement (18.9%), cortical perforation, maxillary sinus obliteration, and tooth displacement (10.8%).

CONCLUSIONS

Two distinct bone abnormalities with separate pathophysiologies, radiographic presentation, and effects on the surrounding structures are suggested: 1) generalized mandibular/maxillary osteopenia and 2) a well-defined radiolucent lesion, which appears only in the mandible. This review refutes 2 accepted assumptions; according to the results, 1) the most common manifestation is generalized osteopenia (and the resulting mandibular canal changes), whereas the well-defined radiolucent lesion is the next most common, and 2) cortical bone thinning/perforations and lamina dura thinning are not uncommon in these patients.

Mandibular and dental manifestations of Gaucher disease

Gaucher disease is a systemic lysosomal storage disorder with a high prevalence among Ashkenazi Jews. It is caused by an inherited deficiency of the lysosomal enzyme glucocerebrosidase. Common signs and symptoms include hepatosplenomegaly, anemia, thrombocytopenia, and skeletal involvement. Oral and dental manifestations are less commonly seen. These manifestations are often asymptomatic, although they may be detected by routine dental x-rays. There are several case reports and a few larger series published describing patients with Gaucher disease who have mandibulo-maxillofacial involvement. This review aims to examine the oral manifestations observed in Gaucher disease and to suggest practical guidelines for dealing with these often worrisome signs. Among the critical issues are the benign nature of Gaucher cell infiltration of the mandible and the critical importance of being prepared for postprocedure bleeding and/or infections. Therefore, it is essential that dental practitioners be aware of the possible oral and dental complications of Gaucher disease, as well as the available treatment modalities.

Gaucher disease: outcome following total hip replacements and effect of enzyme replacement therapy in a cohort of UK patients

Only a limited number of reports of total hip replacements (THRs) in patients with Gaucher disease (GD) have been published, with the majority showing high rates of early aseptic loosening as well as an increased number of peri-operative complications. We present a series of twelve THRs in nine affected patients, with a mean age of 39 years at the time of surgery (median 37 years; range 27-60 years). We examine the medium- to long-term results and present the outcome scores, survival, and assess the effect of enzyme replacement therapy (ERT). Four hips (33.3%) required revision for aseptic loosening at a mean time of 11.5 years. There was no significant difference in survival between the group on ERT at the time of surgery and group not on ERT. Those on ERT did, however, have fewer peri-operative complications and there was a trend to better outcome scores. Five of the 12 THRs were performed when the diagnosis of GD was unknown and all of these had early complications.?Our results show better survival of THRs in patients with GD than previously thought. The use of ERT pre-operatively did not have an effect on survival, nor outcome scores, but did reduce the peri-operative complication rate. Those not on ERT at the time of surgery were commenced on it at some point in their treatment (at an average of 8.6 years following THR) and we believe the use of ERT, at any time in the treatment, could have contributed to the improved survival seen in our series compared to historical results in the literature.

Therapeutic approaches to bone pathology in Gaucher disease: past, present and future

Enzyme replacement therapy (ERT) is effective for the treatment of the systemic manifestations of Gaucher disease (GD) and can have a significant impact on skeletal manifestations. Bone involvement is broad and can occur in otherwise clinically asymptomatic individuals. The heterogeneity in GD-related bone disease may implicate multiple pathological processes such as disruption of coordinated bone cell activity, in addition to the physical impact of Gaucher cells causing vascular occlusion. Accumulated data suggests that earlier treatment initiation decreases skeletal complications and that bone disease may require a longer duration of treatment and higher dose than is necessary for organ involvement and hematopoietic manifestations. However, in some patients, bone manifestations persist and even worsen despite ERT, regardless of dose or duration of treatment. Treating skeletal disease should be considered of equal importance as treating visceral and hematologic manifestations. When treatment decisions involve multiple enzyme preparations and other therapeutic modalities such small molecules, the choice should be tailored on an individual basis with continuing evaluation.

Osseous manifestations of adult Gaucher disease in the era of enzyme replacement therapy

Enzyme replacement therapy (ERT) for Gaucher disease with mannose-terminated glucocerebrosidase has proved its therapeutic position with salutary effects on hematologic abnormalities, visceral infiltration, and quality of life. The frequency of new bone complications is reduced but not eliminated. Established osteonecrosis is beyond salvage. A systematic description of the burden of bone manifestations, persisting despite ERT, should inform future remedial strategies. Thus, we conducted this study to quantify the burden of residual skeletal disease and to explore putative relationships between clinical, radiologic, and biochemical factors and bone sequelae associated with disability.Consecutive adult patients attending 3 referral centers in the United Kingdom were invited to participate. A representative group of 100 patients agreed to a structured interview, clinical examination, radiologic review, and completion of questionnaires. Osteonecrosis was evident in 43%, Erlenmeyer flask deformity in 59%, fragility fracture in 28%, osteomyelitis in 6%, and lytic lesions in 4%. Mobility was impaired in 32% of patients, while 15% experienced significant pain. The EuroQol 5D (EQ5D) quality of life summary measure was reduced and was associated with osteonecrosis and fragility fracture. Eight patients experienced new osteonecrosis after the start of ERT, though the presentation and evolution were often atypical. Nine patients had been treated from childhood and had an excellent outcome. Osteonecrosis was associated with age of presentation and with splenectomy-indeed, we observed a strong temporal association between splenectomy and incidence of osteonecrosis.The biomarkers PARC/CCL18 and chitotriosidase were associated with prevalent osteonecrosis, and, in particular, with osteonecrosis occurring despite treatment. This study documents significant residual skeletal pathology and disability in patients in the mature phase of their treatment in a developed region. The temporal association between splenectomy and osteonecrosis implies causation. The relationship between clinical and biochemical markers and existing bone complications sets the scene for future prospective studies that will focus on management strategies informed by credible assessment of risk.

Glucocerebrosidase gene-deficient mouse recapitulates Gaucher disease displaying cellular and molecular dysregulation beyond the macrophage

In nonneuronopathic type 1 Gaucher disease (GD1), mutations in the glucocerebrosidase gene (GBA1) gene result in glucocerebrosidase deficiency and the accumulation of its substrate, glucocerebroside (GL-1), in the lysosomes of mononuclear phagocytes. This prevailing macrophage-centric view, however, does not explain emerging aspects of the disease, including malignancy, autoimmune disease, Parkinson disease, and osteoporosis. We conditionally deleted the GBA1 gene in hematopoietic and mesenchymal cell lineages using an Mx1 promoter. Although this mouse fully recapitulated human GD1, cytokine measurements, microarray analysis, and cellular immunophenotyping together revealed widespread dysfunction not only of macrophages, but also of thymic T cells, dendritic cells, and osteoblasts. The severe osteoporosis was caused by a defect in osteoblastic bone formation arising from an inhibitory effect of the accumulated lipids LysoGL-1 and GL-1 on protein kinase C. This study provides direct evidence for the involvement in GD1 of multiple cell lineages, suggesting that cells other than macrophages may be worthwhile therapeutic targets.

Timing of initiation of enzyme replacement therapy after diagnosis of type 1 Gaucher disease: effect on incidence of avascular necrosis

Data from the International Collaborative Gaucher Group Gaucher Registry were analysed to assess the relationship between enzyme replacement therapy with imiglucerase (ERT) and incidence of avascular necrosis (AVN) in type 1 Gaucher disease (GD1), and to determine whether the time interval between diagnosis and initiation of ERT influences the incidence rate of AVN. All patients with GD1 enrolled in the Gaucher Registry who received ERT and did not report AVN prior to starting therapy (n = 2700) were included. The incidence rate of AVN following initiation of ERT was determined. An incidence rate of AVN of 13·8 per 1000 person-years was observed in patients receiving ERT. Patients who initiated ERT within 2 years of diagnosis had an incidence rate of 8·1 per 1000 person-years; patients who started ERT ≥2 years after diagnosis had an incidence rate of 16·6 per 1000 person-years. The adjusted incidence rate ratio was 0·59 [95% confidence interval (CI) 0·36–0·96, P = 0·0343]. Splenectomy was an independent risk factor for AVN (adjusted incidence rate ratio 2·23, 95% CI 1·61–3·08, P < 0·0001). In conclusion, the risk of AVN was reduced among patients who initiated ERT within 2 years of diagnosis, compared to initiating treatment ≥2 years after diagnosis. A higher risk of AVN was observed among patients who had previously undergone splenectomy.

Poor results of drilling in early stages of juxta-articular osteonecrosis in 12 joints affected by Gaucher disease

BACKGROUND AND PURPOSE

Gaucher disease is heterogeneous. One of the most devastating complications is bone involvement, ranging from mild osteopenia to osteonecrosis, but no markers have been discovered to predict onset and/or progression. We describe our experience in a large referral center using drilling for juxta-articular osteonecrosis in young patients with Gaucher disease.

PATIENTS AND METHODS

We retrospectively reviewed medical data from all patients who were recommended to undergo drilling for osteonecrosis of juxta-articular bone of the femoral head, the humeral head, or upper tibia for acute osteonecrosis at a pre-collapse stage.

RESULTS

11 patients (mean age 34 years) underwent drilling of 12 joints with juxta-articular osteonecrosis; 3 (mean age 51 years) refused intervention. 9 joints that were drilled showed advancing joint degeneration within 0.5 to 4 years. 3 joints have undergone replacement. Of the 3 joints that did not undergo drilling, 2 have undergone replacement and 1 has collapsed with osteoarthritis.

INTERPRETATION

We found equally poor outcome with and without drilling. Effective intervention can only be achieved by improving our understanding of bone physiology and pathophysiology in Gaucher disease.

Results of total hip arthroplasty in Gaucher's disease patients

There is controversy regarding the success of total hip arthroplasty (THA) in patients with Gaucher's disease. We present a retrospective study of nine total hip replacements in six patients (four primary THAs and five revisions). Four were female and two were male. All patients were of white ethnic origin. Five hips have required revision surgery for loosened implants (four once only and one twice). The average age at the time of primary THA was 35.3 years (13-54). The average duration between primary THA and first revision was 11.4 years (6-19). The duration between first and second revision in one hip was six years. The follow-up ranged between 2.5 years to 19 years. One patient developed superficial infection postoperatively which settled with wound debridement and antibiotics. Excessive peri-operative blood loss was noted in three patients.

Evidence-based recommendations for monitoring bone disease and the response to enzyme replacement therapy in Gaucher patients

BACKGROUND

Bone disease is a serious complication of Gaucher disease. Untreated, it can result in pain, permanent bone damage and disability. Enzyme replacement therapy reverses many of the clinical signs of Gaucher bone disease but early assessment and treatment, and regular monitoring, are essential in optimising outcomes.

SCOPE

In September 2005, a group of European experts met to review current knowledge and identify best practice and unmet needs in the monitoring of Gaucher bone disease and the response to enzyme replacement therapy.

METHODS

Medline searches of peer-reviewed literature (no date restrictions) were conducted and supplemented by additional information considered relevant by panellists to furthering discussions.

FINDINGS AND CONCLUSIONS

The group's recommendations included: currently used biochemical bone markers are not clinically practical or reliable; plain X-rays should not be the sole method of assessing bone disease; MRI is the most sensitive method for monitoring bone marrow infiltration by Gaucher cells; semi-quantitative methods for assessing bone marrow infiltration in routine clinical practice should use readily available technology, include an assessment of Gaucher cell infiltration in the lumbar spine and femur, and be validated for inter-rater reliability and in comparison to other methods; a multidisciplinary approach is required for the treatment of Gaucher patients; all Gaucher patients should receive a comprehensive initial radiologic evaluation for bone disease and ongoing radiological monitoring at least once every 2 years.

Serum levels of osteoprotegerin and osteoprotegerin polymorphisms in Gaucher disease

Bone involvement in Gaucher disease causes disability and reduced quality of life; loss of function and pain are important indications for enzyme replacement therapy. The purpose of this study was to ascertain whether osteoprotegerin (OPG), which decreases osteoclast activity, is indicative of incipient bone involvement by comparing OPG serum levels to Gaucher disease severity (SSI) and bone mineral density (BMD), and to correlate bone and disease markers to OPG polymorphisms: OPG1-2(A163G), OPG3-4(T129C) and OPG5-6(C1217T). Of 554 patients, 173 Ashkenazi Jewish patients with non-neuronopathic Gaucher disease were enrolled and 32 healthy Ashkenazi Jews served as controls. Serum OPG levels were detected by enzyme-linked immunosorbent assay and BMD was obtained by dual X-ray absorptiometry. OPG polymorphisms were determined in 63 randomly chosen patients. Serum OPG values for patients were not greater than in controls, but showed a statistically significant trend to increase with age (P = 0.057). No correlation existed between OPG levels and BMD or with genotype or other disease markers. A significant correlation was noted between OPG5-6 genotype and SSI. A significant difference was found between the allele distributions of each OPG polymorphism when compared with Caucasians and Ashkenazi Jews. OPG levels probably do not predict BMD in Gaucher disease and hence are not indicative of osteoporosis in Gaucher disease.

Recombinant glucocerebrosidase uptake by Gaucher disease human osteoblast culture model

Bone lesions are a major cause of morbidity in Gaucher disease (GD) type I. Enzyme replacement therapy (ERT) has been successful in treating many symptoms of type I GD but skeletal response lags behind. Local exogenous glucocerebrosidase supplementation in bone lesions via a drug delivery system may overcome this limitation. Although local enzyme supplementation aims to target lipid-engorged macrophages (Gaucher Cells) in bone compartment, enzyme uptake by osteoblasts is not excluded. To investigate the ability of human osteoblasts to internalize recombinant glucocerebrosidase (rGCR), we have used an artificial GD human osteoblasts cell culture system. MG63 human osteoblasts were treated with conduritol B epoxide (CBE) to induce complete and prolonged inhibition of endogenous glucocerebrosidase activity of cells. rGCR uptake by glucocerebrosidase-inactivated osteoblasts was examined using (125)I-radiolabelling, Western blot analysis and measurement of glucocerebrosidase activity. Analysis of radiolabeled enzyme uptake by CBE treated osteoblasts showed 67.9% of internalized protein in cell extract. Enzyme internalization was also observed by Western blot analysis where the amount of mature form of glucocerebrosidase protein recognized by the glucocerebrosidase antibody was increased following the administrations of rGCR. Moreover, enzymatic activity measurement showed 23.9% of glucocerebrosidase activity of control cells. The rGCR internalization by MG63 osteoblast seems to be partially mediated by mannose receptors. These data provide evidence that MG63 human osteoblasts are able to internalize rGCR.

Clinical evaluation of chemokine and enzymatic biomarkers of Gaucher disease

PURPOSE

Gaucher disease is an exemplary orphan disorder. Enzyme replacement therapy with imiglucerase is effective, but very expensive. To improve the assessment of severity of disease and responses to this costly treatment, we have evaluated several enzymatic biomarkers and a newly-described chemokine.

SUBJECTS AND METHODS

We studied 48 untreated adults with Type I Gaucher disease: 20 patients were studied after the introduction of enzyme replacement. Disease activity was monitored by serial measurement of platelet count, visceral volumes (spleen and liver) by magnetic resonance imaging, serum activities of total acid phosphatase, angiotensin-converting enzyme (ACE) and the lysosomal chitinase, chitotriosidase. Pulmonary and activation-regulated chemokine (PARC/CCL 18) was also determined in serum by ELISA.

RESULTS

Serum PARC concentrations were elevated 10-40-fold in patients with Gaucher disease compared with 67 healthy controls, without overlap (P<0.0001). Unlike chitotriosidase, PARC was detectable in all individuals. Serum PARC was a reliable indicator of splenic (R=0.53, P<0.01) and liver (R=0.65, P<0.01) volume and platelet count (R=0.50, P<0.01). In splenectomized patients and in patients with null alleles of the chitotriosidase gene, serum PARC concentration correlates with visceral volume and other biomarkers of disease activity. Unlike chitotriosidase, serum PARC concentrations showed unbiased covariation with splenic and platelet responsiveness to enzyme replacement.

CONCLUSION

Serum PARC concentrations are correlated with visceral Gaucher disease and with key clinical responses to enzyme complementation. Determination of this chemokine is a facile and universally applicable method that permits objective monitoring of enzyme replacement therapy for patients with Gaucher disease.

Anesthesia for obstetric patients with Gaucher disease: survey and review

Pregnancy and delivery in patients with non-neuronopathic Gaucher disease, whether treated with enzyme replacement or untreated, are usually uncomplicated. Various factors may influence mode of delivery, vaginal or cesarean section, as well as type of anesthesia, general or regional, used during delivery. This retrospective review was intended to highlight some of the practical issues relating to obstetric anesthetic management, based on a review of the literature and experiences from a large referral clinic for Gaucher disease. In the past decade, there were 16 deliveries in 11 women in our institution. There were five normal vaginal deliveries, two vacuum extractions, one placental extraction, and eight cesarean sections. Platelet counts were 27-215 x 10(9)/L. Two spontaneous deliveries and one vacuum extraction were performed under epidural anesthesia; two other women having vaginal deliveries and one vacuum extraction were given i.v. analgesia; the fifth was given i.v. patient-controlled analgesia. The placental extraction was performed under general anesthesia. Seven of the women having cesarean deliveries received spinal anesthesia; the breech presentation required general anesthesia. There were no anesthesia-related side effects or complications, although there were some instances of post-partum bleeding irrespective of enzyme therapy. Gaucher disease affects multiple organs and can be a challenge to the anesthesiologist. Based on this survey we suggest that anesthetic management requires particular attention to hematological parameters before delivery. A multidisciplinary approach and extensive communication among obstetrician, hematologist and anesthesiologist is required to anticipate the possibility of post-partum hemorrhage, and preclude skeletal damage.

Gaucher disease and bone: laboratory and skeletal mineral density variations during a long period of enzyme replacement therapy

The usefulness of bone turnover markers in Gaucher disease is still unclear and their utility in monitoring the effects of enzyme replacement therapy (ERT) on bone metabolism has not yet been investigated exhaustively. Skeletal involvement seems to improve slowly during ERT, but only a few studies evaluating bone mineral density (BMD) changes during a long follow-up period have been reported. The aim of this study was to assess the efficacy of ERT on bone involvement in a group of 12 type I Gaucher disease (GD I) patients by monitoring biochemical indices of bone resorption/formation and BMD measured by dual energy x-ray absorptiometry (DEXA). Serum (calcium, phosphorus, bone alkaline phosphatase isoenzyme, carboxyterminal propeptide of type I procollagen (PICP), carboxyterminal telopeptide of type I collagen (ICTP), osteocalcin, intact parathyroid hormone) and urinary (calcium, phosphorus, hydroxyproline and free deoxypyridinoline) markers of bone metabolism and lumbar BMD were measured at baseline, after 6 and 12 months, and then every year for a mean ERT follow-up period of 4.5 years (range 4.4-6 years). Twelve healthy adult subjects matched for age and sex were tested as negative controls. A significant decrease of PICP was detected in the patient group at baseline (mean value 100.52 ng/ml vs 142.45 ng/ml, p = 0.017), while ICTP was remarkably higher: mean value 3.93 ng/ml vs 2.72 ng/ml, p = 0.004 (two-sided Student's t-test). No changes in bone formation indices were observed during the follow-up period, while urinary calcium excretion increased significantly from 0.065 to 0.191 mg/mg creatinine (p = 0.0014) (repeated measures ANOVA). A significant BMD improvement was also detected after an average ERT period of 4.5 years: Z-score increased from -0.81 to -0.56 (p = 0.005) (two-sided Student's t-test). These data evidenced the ineffectiveness of the biochemical markers used in monitoring ERT efficacy in GD I skeletal involvement, whereas DEXA was demonstrated to be a reliable method with which to follow up BMD improvement.

Biological evaluation of calcium alginate microspheres as a vehicle for the localized delivery of a therapeutic enzyme

Gaucher disease (GD) is caused by the decreased activity and/or stability of the lysosomal enzyme glucocerebrosidase (GCR). The available treatment consists in the intravenous administration of exogenous GCR, and is effective in reverting most of the symptoms. However, in terms of bone pathology, which is among the most disabling manifestations, a slow and incomplete response is observed, indicating that adjuvant therapies are necessary to consistently restore GCR activity in bone and accelerate regeneration. In this study, calcium alginate microspheres were analyzed as a vehicle for localized GCR delivery to bone. Results demonstrated that the entrapped enzyme retained full activity and exhibited a broader pH-dependent activity profile, compared to that of free-GCR, with improved stability at physiological pH. GCR release profile was established, and it was demonstrated that GCR could be released in a sustained manner. The biological behavior of the system was evaluated by analyzing the uptake of released GCR by GCR-deficient cells from GD patients, using different techniques: GCR activity measurements, radiolabeling, and cellulose acetate electrophoresis. Results demonstrated that GCR was internalized by cells significantly enhancing the residual enzymatic activity. To achieve an activity reconstitution level comparable to that obtained using free-GCR, only half of the dose was required with entrapped-GCR.

Gaucher disease type 1: Revised recommendations on evaluations and monitoring for adult patients

For patients with type 1 Gaucher disease, challenges to patient care posed by clinical heterogeneity, variable progression rates, and potential permanent disability that can result from untreated or suboptimally treated hematologic, skeletal, and visceral organ involvement dictate a need for comprehensive, serial monitoring. An updated consensus on minimum recommendations for effective monitoring of all adult patients with type 1 Gaucher disease has been developed by the International Collaborative Gaucher Group (ICGG) Registry coordinators. These recommendations provide a schedule for comprehensive and reproducible evaluation and monitoring of all clinically relevant aspects of this disease. The initial assessment should include confirmation of deficiency of beta-glucocerebrosidase, genotyping, and a complete family medical history. Other assessments to be performed initially and at regular intervals include a complete physical examination, patient-reported quality of life using the SF-36 survey, and assessment of hematologic (hemoglobin and platelet count), visceral, and skeletal involvement, and biomarkers. Specific radiologic imaging techniques are recommended for evaluating visceral and skeletal pathology. All patients should undergo comprehensive regular assessment, the frequency of which depends on treatment status and whether therapeutic goals have been achieved. Additionally, reassessment should be performed whenever enzyme therapy dose is altered, or in case of significant clinical complication.

Dental profile of patients with Gaucher disease

BACKGROUND: This study was conducted to determine whether patients with Gaucher disease had significant dental pathology because of abnormal bone structure, pancytopenia, and coagulation abnormalities. METHODS: Each patient received a complete oral and periodontal examination in addition to a routine hematological evaluation. RESULTS: Gaucher patients had significantly fewer carious lesions than otherwise healthy carriers. Despite prevalence of anemia, there was no increase in gingival disease; despite the high incidence of thrombocytopenia, gingival bleeding was not noted; and despite radiological evidence of bone involvement, there was no greater incidence loss of teeth or clinical tooth mobility. CONCLUSIONS: These data represent the first survey of the oral health of a large cohort of patients with Gaucher disease. It is a pilot study of a unique population and the results of the investigation are indications for further research. Based on our findings, we recommend regular oral examinations with appropriate dental treatment for patients with Gaucher disease as for other individuals. Consultation between the dentist and physician, preferably one with experience with Gaucher disease, should be considered when surgical procedures are planned.

Subarachnoid anesthesia in a patient with type I Gaucher disease

Gaucher's disease is a rare genetic disorder characterized by lack or functional insufficiency of glucocerebrosidase, an enzyme accountable for intracellular hydrolysis of glucosyl ceramide and other glycosphingolipids, which results in macrophage storage in the mononuclear-macrophage system. The severity of Gaucher's disease is correlated with the extent to which the central nervous system is involved. It is associated with the so-called Gaucher's cells in the bone marrow, but is specifically diagnosed by showing enzyme acid beta-glucosidase activity in a sample of blood leukocyte or cultured macrophages from skin biopsy. In the last 10 years, an enzyme replacement therapy (alglucerase) for the disease has been available, which has significantly changed approaches to its treatment. Here we report the case of a 56-year-old female patient with type I Gaucher's disease who underwent surgery for subcapital hip fracture with subarachnoid anesthesia. Type I Gaucher's disease clinical and pathophysiologic aspects relevant to anesthetic management are discussed. As very few similar cases have been reported in the anesthesiology literature, it is our belief that the present case may help to elucidate some controversial issues relating to the perioperative anesthetic management of patients with type I Gaucher's disease.

Decreased bone density in splenectomized Gaucher patients receiving enzyme replacement therapy

Little is known about the effect of enzyme replacement therapy (ERT) on the bone abnormalities in Gaucher disease. Splenectomized Gaucher patients tend to suffer the most severe skeletal complications. We hypothesized that vitamin D supplementation would act synergistically with glucocerebrosidase infusions to increase bone density in splenectomized Gaucher patients. In a 24-month study, 29 splenectomized Gaucher patients were randomized to three groups: Group 1, calcitriol (1,25-dihydroxyvitamin D3; 0.25-3.0 microg/day) alone for the first 6 months with the addition of ceredase/cerezyme at 60 IU/kg every 2 weeks during months 7-12; Group 2, calcitriol together with ceredase/cerezyme at 60 IU/kg every 2 weeks during months 1-6; and Group 3, enzyme only at 60 IU/kg body wt every 2 weeks. In all three groups, enzyme dose was halved after the first 6 months of therapy. The primary outcome measure was bone mineral density of the lumbar spine measured by single-energy quantitative CT. Bone density by single-energy CT (P = 0.001) and by dual-energy CT (P = 0.06) declined overall, but there was no significant difference between the groups. Calcitriol had no significant effect on bone density. Fat fraction in lumbar spine increased (P = 0.000) and skeletal MRI scores improved. Bone-specific alkaline phosphatase (P = 0.002) and serum osteocalcin increased (P = 0.008), while blood cyclic AMP and urinary deoxypyridinoline did not change appreciably. Hemoglobin, platelet counts, and liver volume significantly improved. We conclude that ERT alone, or in combination with calcitriol, cannot repair the bone composition in splenectomized adult Gaucher patients. Alternatively, measuring trabecular bone density may be an inadequate marker of clinical efficacy for treating skeletal involvement in Gaucher disease.

Accelerated turnover of metaphyseal trabecular bone in mice overexpressing cathepsin K

This study is based on a hypothesis that overexpression of an osteoclast enzyme, cathepsin K, causes an imbalance in bone remodeling toward bone loss. The hypothesis was tested in transgenic (TG) mice harboring additional copies of the murine cathepsin K gene (Ctsk) identifiable by a silent mutation engineered into the construct. For this study, three TG mouse lines harboring 3-25 copies of the transgene were selected. Tissue specificity of transgene expression was determined by Northern analysis, which revealed up to 6-fold increases in the levels of cathepsin K messenger RNA (mRNA) in calvarial and long bone samples of the three TG lines. No changes were seen in the mRNA levels of other osteoclast enzymes, indicating that the increase in cathepsin K mRNA was not a reflection of activation of all osteoclast enzymes. Immunohistochemistry confirmed that cathepsin K expression in the TG mice was confined to osteoclasts and chondroclasts. Histomorphometry revealed a significantly decreased trabecular bone volume (BV), but, surprisingly, also a marked increase in the number of osteoblasts, the rate of bone turnover, and the amount of mineralizing surface (MS). However, monitoring of bone density in the proximal tibias of the TG mice with peripheral quantitative computed tomography (pQCT) failed to reveal statistically significant changes in bone density. Similarly, no statistically significant alterations were observed in biomechanical testing at the age of 7 months. The increases in parameters of bone formation triggered by increased cathepsin K expression is an example of the tight coupling of bone resorption and formation during the bone-remodeling cycle.

High-grade lymphoma mimicking bone crisis in Gaucher's disease

A 33-year-old woman with type 1 Gaucher's disease developed painful swelling of her right tibia. Initial diagnostics suggested a typical bone crisis. However, clinical course and subsequent imaging pointed to malignant disease, which was specified as high-grade lymphoma. Chemotherapy was applied together with enzyme replacement and resulted in complete remission of the lymphoma. We conclude that osseous lesions, although suggestive of common manifestations of Gaucher's disease, should be discriminated very carefully from neoplastic infiltration to maintain curative treatment options.

Extraordinary bone involvement in a gaucher disease type I patient

We report on a 63-year-old patient with Gaucher disease type I who developed severe bone involvement with destructive lesions and huge soft tissue extension in both humeri that appeared to evolve slowly. The clinical course and histopathological findings in our patient suggested a progressive extraosseous extension of the storage cells into the soft tissue, accompanied by a striking increase of fibrotic tissue and resulting in an impressive deformity. The extraordinary bone involvement in this patient expands our knowledge on the most severe skeletal complications of untreated Gaucher disease.