Spectrum of abdominal sonographic findings in 103 pediatric patients with Gaucher disease

Multiparametric magnetic resonance imaging of the liver and spleen in Gaucher disease

PURPOSE

To assess liver and spleen characteristics of a population with Gaucher disease (GD) using multiparametric MRI and MR elastography (MRE) for evaluation of diffuse liver and spleen disease, which includes liver fat fraction, liver and spleen volume and iron deposition, and liver and spleen stiffness correlated with DS3 Severity Scoring System for Gaucher disease (GD-DS3).

METHODS

We prospectively evaluated 41 patients with type 1 Gaucher disease using a 3.0 T MRI and MRE between January 2019 and February 2020. Clinical, laboratory, and imaging data was collected. Mann-Whitney, Kruskal-Wallis, and Spearman's correlation were applied to evaluate liver and spleen MRI and MRE, clinical and laboratory variables, and GD-DS3. ERT and SRT treatment groups were compared.

RESULTS

Hepatomegaly was seen in 15% and splenomegaly in 42% of the population. Moderate and strong and correlations were found between liver and spleen iron overload (rho = 0.537; p = 0.002); between liver and spleen volume (rho = 0.692, p < 0.001) and between liver and spleen stiffness (rho = 0.453, p = 0.006). Moderate correlations were found between liver stiffness and GD-DS3 (rho = 0.559; p < 0.001) and between splenic volume and GD-DS3 (rho = 0.524; p = 0.001).

CONCLUSION

The prevalence of hepatosplenomegaly, liver fibrosis, and liver iron overload in treated patients with GD is low, which may be related to the beneficial effect of treatment. Liver MRE and splenic volume correlate with severity score and may be biomarkers of disease severity.

Natural history and management of liver dysfunction in lysosomal storage disorders

Lysosomal storage disorders (LSD) are a rare group of genetic disorders. The major LSDs that cause liver dysfunction are disorders of sphingolipid lipid storage [Gaucher disease (GD) and Niemann-Pick disease] and lysosomal acid lipase deficiency [cholesteryl ester storage disease and Wolman disease (WD)]. These diseases can cause significant liver problems ranging from asymptomatic hepatomegaly to cirrhosis and portal hypertension. Abnormal storage cells initiate hepatic fibrosis in sphingolipid disorders. Dyslipidemia causes micronodular cirrhosis in lipid storage disorders. These disorders must be keenly differentiated from other chronic liver diseases and non-alcoholic steatohepatitis that affect children and young adults. GD, Niemann-Pick type C, and WD also cause neonatal cholestasis and infantile liver failure. Genotype and liver phenotype correlation is variable in these conditions. Patients with LSD may survive up to 4-5 decades except for those with neonatal onset disease. The diagnosis of all LSD is based on enzymatic activity, tissue histology, and genetic testing. Enzyme replacement is possible in GD and Niemann-Pick types A and B though there are major limitations in the outcome. Those that progress invariably require liver transplantation with variable outcomes. The prognosis of Niemann-Pick type C and WD is universally poor. Enzyme replacement therapy has a promising role in cholesteryl ester storage disease. This review attempts to outline the natural history of these disorders from a hepatologist’s perspective to increase awareness and facilitate better management of these rare disorders.

Massive Mesenteric Lymphadenopathy Causing Protein-losing Enteropathy in Gaucher Disease

Protein-losing enteropathy due to massive mesenteric lymphadenopathy is a rare complication of Gaucher disease which is generally refractory to treatment with enzyme replacement and substrate reduction therapies. It is postulated that lymph nodes may act as a "sanctuary site" into which these treatments cannot penetrate. We present the case of a male child with Gaucher disease who developed massive mesenteric lymph nodes despite otherwise successful treatment with enzyme replacement therapy, and subsequently developed protein-losing enteropathy. The sonographic and magnetic resonance appearances of this complication are shown. Large volume lymphadenopathy inevitably provokes concern about the possibility of malignancy, but in a patient with Gaucher disease-particularly with significant ascites and clinical features of protein-losing enteropathy-this rare complication should be considered.

Spleen nodules: a potential hallmark of Visceral Leishmaniasis in young children

BACKGROUND

Visceral leishmaniasis (VL) is a severe disease caused by Leishmania infantum in the Mediterranean basin, and is associated with considerable morbidity and mortality. Infantile VL may begin suddenly, with high fever and vomiting, or insidiously, with irregular daily fever, anorexia, and marked splenomegaly. Delays in diagnosis of VL are common, highlighting the need for increased awareness of clinicians for VL in endemic European countries.

CASE PRESENTATION

We report 4 cases of young children in northern Italy presenting with persistent fever of unknown origin and diagnosed with VL by serological and molecular methods. At the time of diagnosis, these patients showed an unusual echographic pattern characterized by multiple iso-hypoechoic nodules associated with splenomegaly.

CONCLUSION

We suggest that detection of spleen nodules represents a signature of VL in infants, thus helping to diagnose systemic Leishmania infantum infection in children.

Imaging of Gaucher disease

Gaucher disease is the prototypical lysosomal storage disease. It results from the accumulation of undegraded glucosylceramide in the reticuloendothelial system of the bone marrow, spleen and liver due to deficiency of the enzyme glucocerebrosidase. This leads to hematologic, visceral and skeletal maifestions. Build up of glucosylceramide in the liver and spleen results in hepatosplenomegaly. The normal bone marrow is replaced by the accumulating substrate leading to many of the hematologic signs including anemia. The visceral and skeletal manifestations can be visualized with various imaging modalities including radiography, computed tomography, magnetic resonance imaging (MRI) and radionuclide scanning. Prior to the development of enzyme replacement therapy, treatment was only supportive. However, once intravenous enzyme replacement therapy became available in the 1990s it quickly became the standard of care. Enzyme replacement therapy leads to improvement in all manifestations. The visceral and hematologic manifestations respond more quickly usually within a few months or years. The skeletal manifestations take much longer, usually several years, to show improvement. In recent years newer treatment strategies, such as substrate reduction therapy, have been under investigation. Imaging plays a key role in both initial diagnosis and routine monitoring of patient on treatment particularly volumetric MRI of the liver and spleen and MRI of the femora for evaluating bone marrow disease burden.

Gaucher disease

Gaucher disease is the commonest lysosomal storage disease seen in India and worldwide. It should be considered in any child or adult with an unexplained splenohepatomegaly and cytopenia which are seen in the three types of Gaucher disease. Type 1 is the non-neuronopathic form and type 2 and 3 are the neuronopathic forms. Type 2 is a more severe neuronopathic form leading to mortality by 2 years of age. Definitive diagnosis is made by a blood test-the glucocerebrosidase assay. There is no role for histological examination of the bone marrow, liver or spleen for diagnosis of the disease. Molecular studies for mutations are useful for confirming diagnosis, screening family members and prognosticating the disease. A splenectomy should not be performed except for palliation or when there is no response to enzyme replacement treatment or no possibility of getting any definitive treatment. Splenectomy may worsen skeletal and lung manifestations in Gaucher disease. Enzyme replacement therapy (ERT) has completely revolutionized the prognosis and is now the standard of care for patients with this disease. Best results are seen in type 1 disease with good resolution of splenohepatomegaly, cytopenia and bone symptoms. Neurological symptoms in type 3 disease need supportive care. ERT is of no benefit in type 2 disease. Monitoring of patients on ERT involves evaluation of growth, blood counts, liver and spleen size and biomarkers such as chitotriosidase which reflect the disease burden. Therapy with ERT is very expensive and though patients in India have so far got the drug through a charitable access programme, there is a need for the government to facilitate access to treatment for this potentially curable disease. Bone marrow transplantation is an inferior option but may be considered when access to expensive ERT is not possible.

Radiological aspects of Gaucher disease

Advances in imaging and the development of commercially available enzyme therapy have significantly altered the traditional radiology of Gaucher disease. The cost of treatment and need for monitoring response to therapy have magnified the importance of imaging. There are no recent comprehensive reviews of the radiology of this relatively common lysosomal storage disease. This article describes the modern imaging, techniques and radiological manifestations of Gaucher disease.

Focal splenic lesions in type I Gaucher disease are associated with poor platelet and splenic response to macrophage-targeted enzyme replacement therapy

Focal splenic lesions (FSL) occur in Gaucher disease type I (GD1), but their clinical significance is not known. Previous studies estimated the prevalence of FSL at 4% (pediatric) to 33% (adult) of GD1 patients and reported an association with splenomegaly. We tested the hypothesis that the presence of FSL is associated with suboptimal response to macrophage-directed enzyme replacement therapy (ERT). Additionally we investigated whether FSL were associated with other phenotypic features of GD1. The splenic parenchyma was assessed by MRI performed for routine evaluation of GD1 in 239 consecutive GD1 patients with intact spleens. The prevalence of FSL was 18.4% (44/239). Following a mean of 3.5 years of ERT, platelet response was inferior among patients with FSL (80,700 ± 9,600 to 90,100 ± 7,200/mm(3) , P = 0.2) compared to patients without FSL in whom there was a robust platelet response: 108,600 ± 5,670 to 150,200 ± 6,710/mm(3), P < 0.001. Compared to patients without FSL, patients harboring FSL had worse thrombocytopenia (platelet count: 83,700 ± 8,800 vs. 112,100 ± 4,200/mm(3), P = 0.004), greater frequency of pre-ERT splenomegaly, and greater post-ERT splenomegaly (8.5 ± 0.77 vs. 4.8 ± 0.25× normal, P < 0.001). Additionally, the prevalence of osteonecrosis was higher among patients with FSL compared to patients without FSL (38 vs. 20.7%, P = 0.026). FSL appear to be a determinant of response to ERT, suggesting studies comparing relative efficacy of newly emerging therapies for GD1 should adjust for this factor. Moreover, occurrences of FSL coincide with more severe manifestations of GD1 such as avascular osteonecrosis.

Gaucher disease: spectrum of sonographic findings in the liver

OBJECTIVE

Our large tertiary clinic for patients with Gaucher disease has used sonography as the preferred modality to monitor hepatosplenomegaly in hundreds of patients for more than 18 years. With the advent of specific enzyme replacement therapy (ERT), sonographic monitoring of changes in both hepatomegaly and the echogenicity of the hepatic tissue may highlight features that are amenable to ERT.

METHODS

All patients (500) seen at presentation and at annual or semiannual routine visits have undergone sonographic examinations by a single senior radiologist (I.H.-H.).

RESULTS

Thirty-nine patients (7.8%) had sonographic evidence of hepatic disease (21 male and 18 female; age range, 18-90 years); 26 (66.7%) of these received ERT, and 10 (25.6%) were splenectomized.

CONCLUSIONS

Liver findings are relatively rare. Among 500 patients, there was no instance of computed tomographic findings that had not been previously shown by sonography. Radiologists should be acquainted with the variable sonographic spectrum of the Gaucher liver. If hepatic lesions are small, hyperechoic, and slowly evolving, one may surmise that they are due to Gaucher cell accumulation. However, special attention should be paid to progressive deterioration and irregularities in liver texture because other metabolic processes and cancers must be ruled out.

Review of the safety and efficacy of imiglucerase treatment of Gaucher disease

Most patients who suffer from symptomatic Gaucher disease will benefit from enzyme replacement therapy (ERT) with imiglucerase. The safety profile is excellent, only a small percentage of those exposed developing antibodies; similarly, very few patients require pre-medication for allergic reactions. Within 3 to 5 years of imiglucerase therapy, best documented at doses of 30 to 60 units/kg/infusion, hepatosplenomegaly can be expected to be reduced so that the liver volume will be maintained at 1 to 1.5 times normal (30% to 40% reduction from advent of ERT) and spleen volume to </= 2 to 8 times normal (50% to 60% reduction from advent of ERT). For anemic and thrombocytopenic patients, with 2 to 5 years of imiglucerase, hemoglobin levels are expected to be >/= 11 g/dL for women and children and >/= 12 g/dL for men; and platelet counts in patients with an intact spleen, depending on the baseline value, should approximately be doubled. Bone crises and bone pain but not irreversible skeletal damage will improve in most patients. Nonetheless, some features and some symptomatic patients apparently do not respond equally well and/or perhaps inadequately. The benefit for patients with the neuronopathic forms is primarily in improved visceral and hematological signs and symptoms. There are still several unresolved issues, the high per-unit cost being an important one, which have spurred the development of biosimilar enzymes as well as chaperone therapies currently in clinical trials.

Review of the safety and efficacy of imiglucerase treatment of Gaucher disease

Most patients who suffer from symptomatic Gaucher disease will benefit from enzyme replacement therapy (ERT) with imiglucerase. The safety profile is excellent, only a small percentage of those exposed developing antibodies; similarly, very few patients require pre-medication for allergic reactions. Within 3 to 5 years of imiglucerase therapy, best documented at doses of 30 to 60 units/kg/infusion, hepatosplenomegaly can be expected to be reduced so that the liver volume will be maintained at 1 to 1.5 times normal (30% to 40% reduction from advent of ERT) and spleen volume to </= 2 to 8 times normal (50% to 60% reduction from advent of ERT). For anemic and thrombocytopenic patients, with 2 to 5 years of imiglucerase, hemoglobin levels are expected to be >/= 11 g/dL for women and children and >/= 12 g/dL for men; and platelet counts in patients with an intact spleen, depending on the baseline value, should approximately be doubled. Bone crises and bone pain but not irreversible skeletal damage will improve in most patients. Nonetheless, some features and some symptomatic patients apparently do not respond equally well and/or perhaps inadequately. The benefit for patients with the neuronopathic forms is primarily in improved visceral and hematological signs and symptoms. There are still several unresolved issues, the high per-unit cost being an important one, which have spurred the development of biosimilar enzymes as well as chaperone therapies currently in clinical trials.

Splenic nodules in paediatric Gaucher disease treated by enzyme replacement therapy

BACKGROUND

The natural history of focal splenic lesions in paediatric Gaucher disease (GD) is unknown and these lesions are thought to persist despite enzyme replacement therapy (ERT).

OBJECTIVE

To assess the prevalence, evolution and resolution of splenic nodules in a cohort of paediatric Gaucher patients treated with ERT.

MATERIALS AND METHODS

The US findings in 37 children with GD were retrospectively reviewed. A total of 28 children underwent serial abdominal US examinations as part of their initial assessment and during routine follow-up. All patients received ERT.

RESULTS

Six children (21%) had splenic nodules on US examination, either at presentation or on follow-up examination. In all six patients, the nodules had resolved on follow-up imaging, with resolution taking 17 months to 4 years 8 months. Two sets of siblings developed nodules that resolved over a similar time period.

CONCLUSION

Disappearance of focal splenic lesions in children with GD during follow-up has not been previously reported. The development of new focal splenic lesions in children with GD whilst on ERT has not been previously documented.

The pediatric spleen

Many pathological processes affect the spleen in children. As a basis for recognizing pathology, knowledge of the normal imaging appearance of the pediatric spleen is needed. In addition to congenital anomalies and trauma, pathology of the pediatric spleen includes enlargement (splenomegaly), cysts, neoplasms, infection and infarction. Specific diseases processes, including sickle cell anemia and Gaucher disease, may have specific affects on the spleen.

Recommendations for the management of the haematological and onco-haematological aspects of Gaucher disease

Current knowledge of the haematological and onco-haematological complications of type 1 Gaucher disease has been reviewed with the aim of identifying best clinical practice for treatment and disease management. It was concluded that: (i) Awareness of typical patterns of cytopenia can help clinicians distinguish haematological co-morbidities. (ii) Red blood cell studies and complete iron metabolism evaluation at baseline are recommended. (iii) Haemoglobin levels defining anaemia should be raised and used in Gaucher disease treatment and monitoring. (iv) Surgeons should be aware of potential bleeding complications during surgery in Gaucher patients. The higher incidence of multiple myeloma in Gaucher disease suggests that Gaucher patients should have their immunoglobulin profile determined at diagnosis and monitored every 2 years (patients <50 years) or every year (patients >50 years). If monoclonal gammopathy of undetermined significance (MGUS) is found, general MGUS guidelines should be followed. Future studies should focus on the utility of early treatment to prevent immunoglobulin abnormalities and multiple myeloma.

Gaucher disease in children: radiology of non-central nervous system manifestations

The radiological findings in paediatric Gaucher disease (GD) are reviewed and future challenges for radiology are discussed. This overview is based on a literature review and our experience of children with GD in one of two national institutions for paediatric GD in the UK. GD is known to progress more rapidly in childhood. Current imaging is mainly suitable for ascertaining the complications of GD. The UK recommendations for routine radiological surveillance are discussed. With enzyme replacement therapy (ERT), which dramatically modifies the course of the disorder, the challenge for radiology in the future is likely to be assessing treatment efficacy rather than the detection of disease complications. Disease manifestations are likely to change in those on ERT and the most notable recent alteration in the disease profile in childhood is the virtual disappearance of the acute bone crisis in this population.

Multiple hypoechoic hepatic lesions in a patient with Gaucher disease

The most common symptoms of Gaucher disease include hepatosplenomegaly and anemia and thrombocytopenia due to hypersplenism. We describe the case of a patient with Gaucher disease who had cachexia, massive hepatomegaly, and multiple focal hepatic lesions. The clinical and radiologic findings suggested malignancy. A biopsy specimen was taken from a hepatic lesion and revealed infiltration by Gaucher cells. We discuss our findings in light of the putative increased incidence of hematologic malignancies in patients with Gaucher disease.