Enhancing access to treatment for Gaucher disease in India: The need for indigenous manufacturing.

Gaucher disease (GD) is a prevalent lysosomal storage disorder (LSD) that significantly impacts individuals' lives. However, the exorbitant prices of GD medications pose a major hurdle in ensuring widespread availability and affordability of treatment in India. The country heavily relies on imported medications, leading to high costs and limited access for many patients. This article aims to address this issue by advocating for the establishment of indigenous manufacturing capabilities for GD medicines in India. Through an examination of the current landscape of GD treatment, including the availability, affordability, and challenges associated with imported medications, this article highlights the urgent need for localized production. By focusing on the potential benefits of indigenous manufacturing, such as reduced costs, increased accessibility, and enhanced availability, this research aims to provide insights and recommendations to policymakers, healthcare professionals, and relevant stakeholders. The findings underscore the importance of developing domestic manufacturing capabilities to address the affordability and accessibility challenges faced by GD patients in India. The research also emphasizes the potential positive impact on the healthcare system, the pharmaceutical industry, and the overall well-being of individuals with GD. Ultimately, this article seeks to stimulate discussions and actions towards creating a sustainable framework for indigenous manufacturing of GD medicines, thereby improving the lives of those affected by this rare and debilitating condition.

A rare disease in adult women: Gaucher disease.

Gaucher disease is a rare, autosomal recessive disorder caused by inborn errors of metabolism. Globally, more than 27 million people are born each year, and approximately 19,000 neonates are born with lysosomal storage disease. We report a rare case of Gaucher disease in an adult female patient of non-consanguineous parents in a subtropical area of Jiangxi Province, China. This area has a high prevalence of schistosomiasis. The diagnosis of this case posed a great challenge because of the possible differential diagnoses of pancytopenia with hepatomegaly and giant splenomegaly. The key component of the patient's diagnosis was her medical history in which it was documented that her brother had died of hepatocellular carcinoma of unknown origin. We diagnosed the patient through a combination of a pathological biopsy and imaging plus the patient's medical history.

Development of a rare disease algorithm to identify persons at risk of Gaucher disease using electronic health records in the United States.

BACKGROUND: Early diagnosis of Gaucher disease (GD) allows for disease-specific treatment before significant symptoms arise, preventing/delaying onset of complications. Yet, many endure years-long diagnostic odysseys. We report the development of a machine learning algorithm to identify patients with GD from electronic health records. METHODS: We utilized Optum's de-identified Integrated Claims-Clinical dataset (2007-2019) for feature engineering and algorithm training/testing, based on clinical characteristics of GD. Two algorithms were selected: one based on age of feature occurrence (age-based), and one based on occurrence of features (prevalence-based). Performance was compared with an adaptation of the available clinical diagnostic algorithm for identifying patients with diagnosed GD. Undiagnosed patients highly-ranked by the algorithms were compared with diagnosed GD patients. RESULTS: Splenomegaly was the most important predictor for diagnosed GD with both algorithms, followed by geographical location (northeast USA), thrombocytopenia, osteonecrosis, bone density disorders, and bone pain. Overall, 1204 and 2862 patients, respectively, would need to be assessed with the age- and prevalence-based algorithms, compared with 20,743 with the clinical diagnostic algorithm, to identify 28 patients with diagnosed GD in the integrated dataset. Undiagnosed patients highly-ranked by the algorithms had similar clinical manifestations as diagnosed GD patients. CONCLUSIONS: The age-based algorithm identified younger patients, while the prevalence-based identified patients with advanced clinical manifestations. Their combined use better captures GD heterogeneity. The two algorithms were about 10-20-fold more efficient at identifying GD patients than the clinical diagnostic algorithm. Application of these algorithms could shorten diagnostic delay by identifying undiagnosed GD patients.

Gaucher disease prevalence in 600 patients affected by monoclonal gammopathy of undetermined significance.

BACKGROUND: Gaucher disease (GD) is a rare autosomal recessive inherited disorder caused by the lysosomal enzyme acid ß-glucosidase deficiency. Many patients experience a critical delay in the diagnosis of up to 8-10 years due to its rarity and variability in signs and symptoms, with the consultation of several specialists. PATIENTS AND METHODS: This prospective observational study analyzed the prevalence of GD in 600 patients with monoclonal gammopathy of uncertain significance (MGUS) from January 2018 until February 2022. RESULTS: The mean age of participants was 66 years, with a mean monoclonal component of 0.58 g/dL. In 433 MGUS patients with available data, anemia (hemoglobin level < 10 g/dL) was present in 31 patients (7%), and thrombocytopenia (platelet count <100.000/mm3 ) in 24 (5.5%). Of 600 MGUS patients tested for acid ß-glucosidase enzyme activity, 7 patients (1.2%) had activity below 2.5 nmol/h/mL. In comparison, GBA gene analysis was executed in 110 patients. It revealed 4 patients (0.7%) affected by GD (3 patients with compound heterozygous mutation and 1 with homozygous mutation), with a prevalence of 1 every 150 MGUS patients. Furthermore, 12 out of the remaining 106 evaluated patients (11%) were carriers of a single heterozygous mutation while having regular enzyme activity. CONCLUSIONS: The clinical heterogeneity of GD and frequent lack of awareness among physicians often lead to diagnostic delays and severe clinical manifestations. The role of MGUS in the presence of at least one clinical sign, such as low platelet count, organomegaly, bone pain, or bleeding tendency, could aid in initiating GD screening with DBS, thus reducing the period between symptom onset and the diagnosis of this rare disease.

Incidence of Pulmonary and Respiratory Conditions in Gaucher Disease from 2000 to 2020: A Multi-institutional Cohort Study.

BACKGROUND/AIM: Gaucher disease (GD) is a rare lysosomal storage disorder that can involve the lungs and pulmonary vasculature. The long-term effects of GD on respiratory health remain unclear due to limited data on the natural history of this disease. We analyzed electronic health records for 11,004 patients with GD over 10-20 years to determine the incidence of pulmonary hypertension (PH), lung disease, and other respiratory comorbidities and better understand disease course to guide management. PATIENTS AND METHODS: We conducted a retrospective cohort study using the TriNetX research database of 130 million international patients. The incidence of primary/secondary PH, pulmonary heart disease, interstitial/obstructive/restrictive lung disease, pulmonary hemorrhage, and pulmonary embolism was assessed in patients with GD from 2000-2020. RESULTS: Incidence rates of all conditions assessed increased from 10 to 20 years of follow-up. Excess risk of PH, lung disease, and pulmonary hemorrhage was significantly higher in GD patients after 20 versus 10 years. CONCLUSION: Extended follow-up in GD is associated with substantially higher risks of PH, lung disease and other respiratory comorbidities, highlighting the need for close monitoring and early intervention to mitigate long-term pulmonary decline. Improved understanding of mechanisms driving respiratory deterioration can support the development of novel treatments to optimize outcomes in this population at high risk of pulmonary morbidity and mortality.

[Misdiagnosis of Gaucher disease in real life: Retrospective study of the French Gaucher's disease registry]. / Les erreurs diagnostiques de la maladie de Gaucher dans la vraie vie : étude rétrospective du Registre français de la Maladie de Gaucher.

INTRODUCTION: Gaucher disease is an autosomal recessive genetic disorder. It is caused by a deficiency of the lysosomal enzyme, glucocerebrosidase which leads to an accumulation of glucosylceramide in the macrophages. Splenomegaly, hepatomegaly, cytopenias (anemia, thrombocytopenia) and bone disorders are the main symptoms. The diagnosis is often delayed, leading to unnecessary investigations and treatments, and delaying the specific treatment. The primary objective of our study was to establish, in patients who had a diagnostic delay of more than one year, the reported misdiagnoses before the final diagnosis. The secondary objectives were to investigate the risk factors associated with error and delayed diagnosis. METHODS: Retrospective study including patients with Gaucher disease from the French Gaucher Disease Registry. Collection of data by a single investigator from a standardized form. RESULTS: Among 83 patients with a known diagnostic delay, 13 patients (15 %) had one or two misdiagnoses. These included osteo-articular diagnoses (osteomyelitis, osteoarthritis, arthritis, osteochondritis, rheumatic fever, n=8), haematological diagnoses (gestational thrombocytopenia, immunological thrombocytopenia, n=4), infectious diagnoses (visceral leishmaniasis, mononucleosis, n=2) and hemochromatosis. The osteo-articular and infectious diagnoses concerned the child and the adolescent while the haematological diagnoses and the hemochromatosis concerned the adult. No factors were found associated with misdiagnoses. Patients with a diagnostic delay greater than one year were less likely to have hepatosplenomegaly as the first symptom. CONCLUSION: There is a risk of diagnostic error related to phenotypic heterogeneity and lack of specificity of Gaucher disease symptoms. This study helps to better identify the misdiagnoses associated with Gaucher disease.

Global Epidemiology of Gaucher Disease: an Updated Systematic Review and Meta-analysis.

BACKGROUND: Gaucher disease [GD], an autosomal recessive lysosomal storage disorder, is characterized by progressive lysosomal storage of glucocerebroside in macrophages predominantly in bone, bone marrow, liver, and spleen. Meta-analysis of global GD epidemiology was not available before this study. METHODS: To provide a systematic review and meta-analysis of birth prevalence and prevalence of GD in multiple countries. MEDLINE and EMBASE databases were searched for original research articles on the epidemiology of GD from inception until July 21, 2021. Meta-analysis, adopting a random-effects logistic model, was performed to estimate the birth prevalence and prevalence of GD. RESULTS: Eighteen studies that were screened of 1874 records were included for data extraction. The studies that fulfilled the criteria for inclusion involved 15 areas/countries. The global birth prevalence of GD was 1.5 cases [95% confidence interval: 1.0 to 2.0] per 100,000 live births. The global prevalence of GD was 0.9 cases [95% confidence interval: 0.7 to 1.1] per 100,000 inhabitants. CONCLUSIONS: This is the first comprehensive systematic review that presented quantitative data of GD global epidemiology. Quantitative data on global epidemiology of GD could be the fundamental to evaluate the global efforts on building a better world for GD patients.

Etiology of avascular necrosis of the hip and shoulder. Screening for Gaucher disease.

INTRODUCTION: Avascular necrosis (AON) of the hip and shoulder is a little studied disease and the predisposing risk factors for its development are not well known. A high percentage of patients are diagnosed with idiopathic osteonecrosis. This study aims to investigate the prevalence of potential etiological factors for AON and to screen for Gaucher disease among patients with idiopathic AON. MATERIAL AND METHODS: This retrospective, single-center, observational study was conducted on patients who had at least one episode of AON of the hip or shoulder at the Hospital de Poniente (Almería, Spain) from January 2010 to December 2019. Clinical and analytical data were collected. Patients whose medical record described no etiological factors for this disease were screened for Gaucher disease. RESULTS: The study sample consisted of 81 patients, of whom 58 were male. The mean age at presentation of AON was 45.9 years. They presented with unilateral hip necrosis (n=43), bilateral hip necrosis (n=34), bilateral hip and unilateral shoulder necrosis (n=3), and unilateral shoulder necrosis (n=1). The most frequent potential etiological factors were smoking (46.9%) and obesity (17.3%). Screening for Gaucher disease was performed in ten patients, all of whom tested negative. CONCLUSIONS: In our study population, the main potential etiological factors the onset of AON of the shoulder or hip were smoking and obesity. A high percentage of patients were diagnosed with idiopathic AON. We believe that a more exhaustive study of less frequent risk factors should be carried out in these cases.

Long-term bone outcomes in Italian patients with Gaucher disease type 1 or type 3 treated with imiglucerase: A sub-study from the International Collaborative Gaucher Group (ICGG) Gaucher Registry.

BACKGROUND: Gaucher disease (GD) is a lysosomal storage disorder. We evaluated the "real-world" effectiveness of first-line imiglucerase on long-term bone outcomes in Italian patients in the International Collaborative Gaucher Group (ICGG) Gaucher Registry. METHODS: Patients treated with imiglucerase for ≥2 years and with bone assessments at baseline and during follow-up were selected. Data on bone pain, bone crises, marrow infiltration, avascular necrosis, infarction, lytic lesions, Erlenmeyer flask deformity, bone fractures, mineral density, and imiglucerase dosage were evaluated. RESULTS: Data on bone manifestations were available for 73 of 229 patients (31.9 %). Bone crises frequency decreased significantly from baseline to the most recent follow-up (p < 0.001), with some improvement observed in bone pain prevalence. Bone pain and bone crises prevalence decreased significantly from baseline at 2 to <4 and 4 to <6 years (all p < 0.05). A low median (25th, 75th percentile) baseline imiglucerase dosage was identified in patients reporting bone pain or bone crises (15.0 [13.7, 30.0] and 22.8 [17.5, 36.0] U/kg once every 2 weeks, respectively). CONCLUSION: Our study suggests that the management of GD in Italy, with regards to imiglucerase dosage, is suboptimal and confirms the need for clinicians to monitor and correctly treat bone disease according to best practice guidelines.

Cancer risk and gammopathies in 2123 adults with Gaucher disease type 1 in the International Gaucher Group Gaucher Registry.

There are numerous reports of cancers in Gaucher disease (GD) from mostly small single-center studies; however, precise risk estimates and cancer types involved have not been delineated. We conducted a study involving 2123 patients with GD type 1 (GD1) to assess the incidence of hematological malignancies, gammopathies, and solid tumors in an international observational study, the International Cooperative Gaucher Group Gaucher Registry (Clinicaltrials.gov: NCT00358943). Risk for cancer overall and for each type of malignancy was compared to the United States (US) population using the Surveillance, Epidemiology, and End Results database. Natural history of gammopathy was determined through assessing the progression from a diagnosis of monoclonal gammopathy of unknown significance (MGUS) to multiple myeloma (MM). Risk for hematological malignancies was more than four times higher than expected compared to the general population: non-Hodgkin lymphoma was approximately three times higher; MM was approximately nine times higher. Age-specific incidence rates of MGUS were unexpectedly high among younger patients. The 10-year cumulative incidence of MM after diagnosis of MGUS was 7.9%, comparable to the general population. Compared to the general US population, GD1 patients were at higher risk for solid malignancies of liver (2.9 times), kidney (2.8 times), melanoma (2.5 times), and breast (1.4 times). Colorectal, prostate, and lung cancer risks were lower than expected. These findings help advance care of patients with GD1 by supporting recommendations for individualized monitoring for malignancies and antecedents such as MGUS for MM and provoke important questions of the role of glucosylceramide and related sphingolipids in cancer biology.

Evaluation of the Nutritional Status of Gaucher Disease Type I Patients under Enzyme Replacement Treatment.

(1) Background: Gaucher disease (GD) is a rare lysosomal storage disease. The few studies analyzing Resting Energy Expenditure (REE) in GD involved mainly untreated patients and supported a hypermetabolic condition possibly due to the associated inflammatory state. Definitive conclusions could not be drawn also because of the heterogeneity and the small size of the samples investigated. In order to expand current knowledge concerning, in particular the condition of patients under Enzyme Replacement Therapy (ERT), we evaluated the nutritional status of a relatively large sample of GD patients followed at Federico II University Hospital in Naples, Italy. (2) Methods: The study, having a cross-sectional design and involving 26 patients on ERT, included routine biochemical analyses, bioelectrical impedance analysis, indirect calorimetry, and administration of food frequency and physical activity questionnaires. The results in GD patients were compared with those from an appropriate control group. (3) Results: GD patients had normal biochemical parameters in 80% of cases, except for HDL-cholesterol, consumed a hyper-lipidic diet, and had a 60% prevalence of overweight/obesity. Body composition did not differ between patients and controls; however, measured REE was significantly lower than predicted and was reduced in comparison with the healthy controls. (4) Conclusions: This study provided novel elements to the present knowledge about REE and the nutritional status of GD patients under ERT. Its results warrant confirmation in even larger GD population samples and a more in-depth investigation of the long-term effects of treatment superimposed on the basic pathophysiological disease condition.

No association of Gaucher disease with COVID-19-related outcomes: a nationwide cohort study.

BACKGROUND: It is well documented that patients with chronic metabolic diseases, such as diabetes and obesity, are adversely affected by the COVID-19 pandemic. However, when the subject is rare metabolic diseases, there are not enough data in the literature. AIM: To investigate the course of COVID-19 among patients with Gaucher disease (GD), the most common lysosomal storage disease. METHODS: Based on the National Health System data, a retrospective cohort of patients with confirmed (polymerase chain reactionpositive) COVID-19 infection (n = 149 618) was investigated. The adverse outcomes between patients with GD (n = 39) and those without GD (n = 149 579) were compared with crude and propensity score-matched (PSM) groups. The outcomes were hospitalisation, the composite of intensive care unit (ICU) admission and/or mechanical ventilation and mortality. RESULTS: The patients with GD were significantly older and had a higher frequency of hypertension (HT), Type 2 diabetes mellitus (T2DM), dyslipidaemia, asthma or chronic obstructive pulmonary disease, chronic kidney disease, coronary artery disease, heart failure and cancer. Although hospitalisation rates in Gaucher patients were found to be higher in crude analyses, the PSM models (model 1, age and gender matched; model 2, matched for age, gender, HT, T2DM and cancer) revealed no difference for the outcomes between patients with GD and the general population. According to multivariate regression analyses, having a diagnosis of GD was not a significant predictor for hospitalisation (P = 0.241), ICU admission/mechanical ventilation (P = 0.403) or mortality (P = 0.231). CONCLUSION: According to our national data, SARS-CoV-2 infection in patients with GD does not have a more severe course than the normal population.

Abdominal lymphadenopathy in children with Gaucher disease: Relation to disease severity and glucosylsphingosine.

Few case reports and series reported abdominal lymphadenopathy (ALN) in people with Gaucher disease (GD). However, it's prevalence among Gaucher population, clinical implications and potential biomarkers are unknown. Hence this study aims to assess the prevalence of ALN among children with GD & to correlate it to neutrophil-lymphocytic-ratio (NLR), platelet-lymphocytic-ratio (PLR) and glucosylsphingosine (Lyso-GL1). Fifty children with GD (14 type-1 and 36 type-3) on enzyme-replacement therapy (ERT) were compared to 50 matched healthy controls, focusing on history of pressure manifestations by ALN (diarrhea, constipation, abdominal pain, intestinal obstruction), and history of splenectomy, with calculation of severity scoring index (SSI). NLR, PLR and Lyso-GL1 were measured. Abdominal-ultrasound was done with assessment of liver and spleen volumes and ALN. CT-scan was done for those having significant lymphadenopathy. Twenty-six children with GD had ALN (52%). The most common presentations were abdominal-pain (22%) & constipation (18%), with intestinal-obstruction in 3 children (6%). Children with GD had significantly higher NLR (p < .001) and decreased PLR (p = .024) compared to controls. Interestingly, children with GD having ALN had significantly higher SSI (.012), Lyso-GL1 (p = .002) and NLR (p = .001) than those without ALN. Multivariate-logistic regression showed that ALN was independently related to Lyso-GL1 (p = .027), NLR (p = .023) and SSI (p = .032). Thus, ALN is a prevalent GD morbidity with wide clinical-spectrum ranging from asymptomatic cases to intestinal obstruction. ALN is related to SSI, NLR and Lyso-GL1 in children with GD.HighlightsChildren with GD had significantly higher NLR and lower PLR compared to controls.Children with GD having ALN had significantly higher SSI, Lyso-GL1 and NLR than those without ALN.ALN was independently related to Lyso-GL1, NLR and SSI in children with GD.

Clinical-genetic characteristics and treatment outcomes of Turkish children with Gaucher disease type 1 and type 3: A sixteen year single-center experience.

Data from 38 children were retrospectively analyzed to determine the patient characteristics of Turkish children with Gaucher disease (GD) and evaluate the impact of enzyme replacement therapy (ERT) in a pediatric cohort consisting of two different sub-types of the disease, Gaucher disease type 1 (GD1) and type 3 (GD3). Both types were represented equally (GD1/GD3 = 20/18). L444P (35.5%) was the most common mutant allele while L444P/L444P (34.2%) was the most common genotype overall. Compound heterozygosity of N370S and L444P homozygosity were the dominant genotypes in Turkish children with GD1 and GD3, respectively. None of the patients had moderate to severe thrombocytopenia at last follow-up while the percent of patients with anemia decreased from 60% to 5.7% (p < 0.001). Significant improvements in mean liver (from 2.2 to 1.6 MN, p < 0.001) and spleen (from 15.5 to 7.6 MN, p < 0.001) volumes were observed in the first year of ERT. Linear growth was ameliorated as shown by the decrease in the percent of patients having short stature from 34.3% to 13.3% (p < 0.01) at year 5. Erlenmeyer flask deformity, osteopenia and scoliosis were common skeletal findings. Although none of the patients had lung disease at diagnosis, 20% developed radiological findings suggestive of pulmonary involvement. This single center experience is the first comprehensive study from Turkey not only reporting clinical and genetic characteristics of GD patients but also providing information on the outcomes of ERT in two different sub-types of GD. Genotypic background of Turkish children with GD is similar to western populations. Although visceral and hematological therapeutic goals are reached as early as one year of ERT in both sub-types, achieving normal growth takes several more years than suggested in significant number of children with GD.

Family caregivers of rare disease: A survey on health-related quality of life in family caregivers for Gaucher disease patients in China.

BACKGROUND: Rare diseases affect the health-related quality of life (HRQoL) of patients and their family caregivers (FCs). However, limited evidence is available on the HRQoL of FCs of patients with Gaucher disease (GD). This study aimed to assess HRQoL and related factors among FCs of patients with GD in China. METHODS: A cross-sectional online survey was conducted with 49 FCs recruited by convenience sampling. Participants completed the Medical Outcome Study Short Form-36 (SF-36), Zung's Self-Rating Anxiety Scale, Zung's Self-Rating Depression Scale, the Multi-dimensional Scale of Perceived Social Support, the Herth Hope Index, and a questionnaire about FCs' and patients' sociodemographic characteristics. Single-sample t tests, one-way analysis of variance, and multivariate linear regression analysis were used to analyze the data analysis. RESULTS: Participating FCs had significantly lower scores in all eight SF-36 domains compared with the general population in China (p < 0.01). FCs' gender, education, daily care time, anxiety, and the perceived disease severity of patients were significant predictors of SF-36 physical component summary scores. Caregiving help from others, anxiety, perceived disease severity, and medical insurance type were significant predictors of SF-36 mental component summary scores. CONCLUSION: The findings showed FCs of patients with GD had lower HRQoL. There is an urgent need to address the health concerns of FCs of people with rare diseases including their HRQoL.

Screening for Gaucher Disease Using Dried Blood Spot Tests: A Japanese Multicenter, Cross-sectional Survey.

Objective For patients with Gaucher disease (GD), a rare, inherited lysosomal storage disease, obtaining a definitive diagnosis is currently time-consuming and costly. A simplified screening method to measure the glucocerebrosidase (GBA) activity using dried blood spots (DBS) on filter paper has recently been developed. Using this newly developed screening method, we evaluated real-world GD screening in patients suspected of having GD. Methods This multicenter, cross-sectional, observational study with a diagnostic intervention component evaluated real-world screening in patients suspected of having GD based on their clinical symptoms and a platelet count <120,000/µL. The endpoint was the number of patients with low GBA activity determined using DBS. Results In 994 patients who underwent initial DBS screening, 77 had low GBA activity. The assay was not repeated in 1 patient who was diagnosed as having a high possibility of GD due to clinical symptoms, and a further 21 patients completed the study without undergoing the second assay. Of the remaining 55 patients who had 2 DBS assays performed, 11 had a low GBA activity in both assays. Overall, DBS screening identified 12 (1.2%) patients with a low GBA activity, a proportion consistent with prior screening studies. Conclusion These results suggest that the simplified DBS method was less burdensome to patients, was easily utilized by many physicians, and could be a useful first-tier screening assay for GD prior to initiating burdensome genetic testing.

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.