Search

Gaucher disease (GD) is the most common lysosomal storage disease resulting from mutations in the lysosomal enzyme glucocerebrosidase (GCase). The hematopoietic abnormalities in GD include the presence of characteristic Gaucher macrophages that infiltrate patient tissues and cytopenias. At present, it is not clear whether these cytopenias are secondary to the pathological activity of Gaucher cells or a direct effect of GCase deficiency on hematopoietic development. To address this question, we differentiated induced pluripotent stem cells (iPSCs) derived from patients with types 1, 2, and 3 GD to CD34(+)/CD45(+)/CD43(+)/CD143(+) hematopoietic progenitor cells (HPCs) and examined their developmental potential. The formation of GD-HPCs was unaffected. However, these progenitors demonstrated a skewed lineage commitment, with increased myeloid differentiation and decreased erythroid differentiation and maturation. Interestingly, myeloid colony-formation assays revealed that GD-HPCs, but not control-HPCs, gave rise to adherent, macrophage-like cells, another indication of abnormal myelopoiesis. The extent of these hematologic abnormalities correlated with the severity of the GCase mutations. All the phenotypic abnormalities of GD-HPCs observed were reversed by incubation with recombinant GCase, indicating that these developmental defects were caused by the mutated GCase. Our results show that GCase deficiency directly impairs hematopoietic development. Additionally, our results suggest that aberrant myelopoiesis might contribute to the pathological properties of Gaucher macrophages, which are central to GD manifestations. The hematopoietic developmental defects we observed reflect hematologic abnormalities in patients with GD, demonstrating the utility of GD-iPSCs for modeling this disease., (©AlphaMed Press.)

Gaucher disease (GD) is an autosomal recessive disorder caused by mutations in the acid β-glucocerebrosidase (GCase; GBA) gene. The hallmark of GD is the presence of lipid-laden Gaucher macrophages, which infiltrate bone marrow and other organs. These pathological macrophages are believed to be the sources of elevated levels of inflammatory mediators present in the serum of GD patients. The alteration in the immune environment caused by GD is believed to play a role in the increased risk of developing multiple myeloma and other malignancies in GD patients. To determine directly whether Gaucher macrophages are abnormally activated and whether their functional defects can be reversed by pharmacological intervention, we generated GD macrophages by directed differentiation of human induced pluripotent stem cells (hiPSC) derived from patients with types 1, 2, and 3 GD. GD hiPSC-derived macrophages expressed higher levels of tumor necrosis factor α, IL-6, and IL-1β than control cells, and this phenotype was exacerbated by treatment with lipopolysaccharide. In addition, GD hiPSC macrophages exhibited a striking delay in clearance of phagocytosed red blood cells, recapitulating the presence of red blood cell remnants in Gaucher macrophages from bone marrow aspirates. Incubation of GD hiPSC macrophages with recombinant GCase, or with the chaperones isofagomine and ambroxol, corrected the abnormal phenotypes of GD macrophages to an extent that reflected their known clinical efficacies. We conclude that Gaucher macrophages are the likely source of the elevated levels of inflammatory mediators in the serum of GD patients and that GD hiPSC are valuable new tools for studying disease mechanisms and drug discovery., (© 2014 AlphaMed Press.)

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.

Mutations in the glucocerebrosidase gene (GBA) are associated with Gaucher's disease, the most common lysosomal storage disorder. Parkinsonism is an established feature of Gaucher's disease and an increased frequency of mutations in GBA has been reported in several different ethnic series with sporadic Parkinson's disease. In this study, we evaluated the frequency of GBA mutations in British patients affected by Parkinson's disease. We utilized the DNA of 790 patients and 257 controls, matched for age and ethnicity, to screen for mutations within the GBA gene. Clinical data on all identified GBA mutation carriers was reviewed and analysed. Additionally, in all cases where brain material was available, a neuropathological evaluation was performed and compared to sporadic Parkinson's disease without GBA mutations. The frequency of GBA mutations among the British patients (33/790 = 4.18%) was significantly higher (P = 0.01; odds ratio = 3.7; 95% confidence interval = 1.12-12.14) when compared to the control group (3/257 = 1.17%). Fourteen different GBA mutations were identified, including three previously undescribed mutations, K7E, D443N and G193E. Pathological examination revealed widespread and abundant alpha-synuclein pathology in all 17 GBA mutation carriers, which were graded as Braak stage of 5-6, and had McKeith's limbic or diffuse neocortical Lewy body-type pathology. Diffuse neocortical Lewy body-type pathology tended to occur more frequently in the group with GBA mutations compared to matched Parkinson's disease controls. Clinical features comprised an early onset of the disease, the presence of hallucinations in 45% (14/31) and symptoms of cognitive decline or dementia in 48% (15/31) of patients. This study demonstrates that GBA mutations are found in British subjects at a higher frequency than any other known Parkinson's disease gene. This is the largest study to date on a non-Jewish patient sample with a detailed genotype/phenotype/pathological analyses which strengthens the hypothesis that GBA mutations represent a significant risk factor for the development of Parkinson's disease and suggest that to date, this is the most common genetic factor identified for the disease.

Hematopoietic stem cell-based gene therapy offers the possibility of permanent correction for genetic disorders of the hematopoietic system. However, optimization of present protocols is required before gene therapy can be safely applied as general treatment of genetic diseases. In this study we have used a mouse model of type 1 Gaucher disease (GD) to demonstrate the feasibility of a low-risk conditioning regimen instead of standard radiation, which is associated with severe adverse effects. We first wanted to establish what level of engraftment and glucosylceramidase (GCase) activity is required to correct the pathology of the type 1 GD mouse. Our results demonstrate that a median wild-type (WT) cell engraftment of 7%, corresponding to GCase activity levels above 10 nmoles/hour and mg protein, was sufficient to reverse pathology in bone marrow and spleen in the GD mouse. Moreover, we applied nonmyeloablative doses of busulfan as a pretransplant conditioning regimen and show that even WT cell engraftment in the range of 1%-10% can confer a beneficial therapeutical outcome in this disease model. Taken together, our data provide encouraging evidence for the possibility of developing safe and efficient conditioning protocols for diseases that require only a low level of normal or gene-corrected cells for a permanent and beneficial therapeutic outcome.

The demonstration of tartrate-resistant acid phosphatase (TRAP) activity has long been a cornerstone in the diagnosis of hairy cell leukemia (HCL). Recently a monoclonal antibody to this enzyme has been developed that can be used in an immunoperoxidase method on paraffin-embedded tissues. By using a peroxidase-labeled streptavidin biotin method, paraffin sections of B5 and formalin-fixed tissue from 86 cases of HCL (41 bone marrow, 36 spleen, 9 liver) were stained with the antibody to TRAP and compared against staining for CD20 (L26) and DBA.44 (DAKO, Carpinteria, Calif). In addition, 193 specimens (127 bone marrow, 42 lymph node, 19 spleen, 5 other) from a variety of neoplastic and nonneoplastic hematologic conditions were stained using the monoclonal antibody to TRAP. For comparison, these cases were also stained with DBA.44. In the cases of HCL, 80 of 86 specimens were immunoreactive for TRAP. While the antibody to TRAP generally stained less than 50% of the hairy cells, CD20 and DBA.44 stained 90% and 50% to 60% of hairy cells, respectively. Two of three cases of marginal zone lymphoma showed weak immunoreactivity to the TRAP antibody. Two specimens from a patient with Gaucher's disease and 8 of 13 cases of mastocytosis also showed positivity to the TRAP antibody in the macrophages and mast cells, respectively. In contrast, staining for DBA.44 was positive in 3 of 9 cases of B-cell large cell lymphoma, 1 of 4 cases of mantle cell lymphoma, and in the paraimmunoblasts of 1 of 7 cases of small lymphocytic lymphoma. Only HCL was TRAP and DBA.44 positive. This antibody to TRAP is a useful addition to the diagnosis of HCL but should be used in conjunction with CD20 and DBA.44. The use of this antibody to determine minimal residual disease after chemotherapy was not addressed.

Partial splenectomy is currently the favoured surgical approach for Gaucher's disease. Preservation of splenic tissue is indicated to prevent susceptibility to overwhelming postsplenectomy sepsis, to delay the massive deposition of glucocerebroside in the liver and bones, and to relieve symptoms of hypersplenism. Controversial issues and technical problems related to partial splenectomy for Gaucher's disease are discussed and a definition of critical splenic mass considered.

Two patients with Type 1 (adult) Gaucher's disease and major skeletal involvement with multiple fractures have been treated with the second generation bisphosphonate pamidronate for extensive periods. There was evidence of an immediate reduction in bone resorption, with increased calcium absorption (delayed in Patient 1), improved calcium balance and maintained or improved bone density indices in the axial and peripheral skeleton. There was no evidence of immediate relapse on treatment cessation. No toxic effects of pamidronate treatment were identified and subjective skeletal pain diminished in both patients. Histomorphometry of transiliac bone biopsies obtained before the start of treatment, after double in vivo tetracycline labelling, represents one of the earliest reports of the quantitative findings in iliac bone invaded by Gaucher cells.

The clinical and pathologic features of two brothers with the adult form of Gaucher's disease, both of whom developed cerebral glioblastoma multiforme, are presented. Neither patient had a long-standing neurologic disorder, and morphologic evidence of nervous system glucocerebroside storage was not seen. Despite the known increased incidence of malignancy in Gaucher's disease, a review of the literature and of sixty-two Mayo Clinic cases of adult onset Gaucher's disease revealed only one other instance of the association with glioma. The significance of the relationship is unknown.

Patients with acute infantile or type II neuropathic Gaucher's disease demonstrate neurologic deficits that are seemingly greater than the extent of the central nervous system involvement found at autopsy. Examination of the brain of an affected child shows widespread deposition of lipid in a pattern not recognized heretofore. Based on these observations, the authors hypothesize that widespread deposition of the Gaucher glucocerebroside elicits a mild tissue response, which functionally becomes highly significant.

A 49-year-old white woman who presented with multiple lytic bone lesions was found to have Gaucher-like storage cells in multiple bone marrow aspirates and a percutaneous bone marrow biopsy several months before the development of overt disseminated lymphoma. Open bone biopsies of three different sites at initial presentation revealed only necrotic debris and a nondiagnostic polymorphic infiltrate. Elevated leukocyte beta-glucocerebrosidase levels ruled out the diagnosis of classic Gaucher's disease. The ultrastructural characteristics of these storage cells were found to be identical to those of pseudo-Gaucher cells found in patients with chronic myelogenous leukemia and distinctly different from those previously reported in other non-Hodgkin's lymphoma or plasma cell dyscrasias. A possible pathogenetic mechanism is suggested.

A patient with chronic Gaucher's disease is described who developed glomerulopathy 24 years after splenectomy terminating in renal failure. The pathological changes of this very rare complication of Gaucher's disease are described. The few similar cases reported in the literature are reviewed and the possible pathogenetic pathways discussed.

This report describes a 28-year-old woman with the acquired immune deficiency syndrome (AIDS) with culture-proven disseminated Mycobacterium avium intracellulare infection. The histopathologic and cytologic features in this case were unique in that these organisms that stained positively with the Ziehl-Neelsen and periodic acid-Schiff (PAS) stains were numerous, present intracellularly within histiocytes, transforming them into pseudogaucher cells. Differential diagnostic criteria for pseudogaucher cells and abnormal macrophage handling of the intracellular organisms in AIDS are discussed.

A case of Hodgkin's disease associated with long-standing Gaucher's disease is presented and compared with the only previously reported case. The two diseases coexisted in lymph nodes both above and below the diaphragm, liver, bone marrow, and pancreas. The question of a possible relationship of the two diseases is discussed.

The authors studied an 18-year-old woman with stage IIIB nodular sclerosis Hodgkin's disease whose bone marrow contained abnormal storage cells that resembled Gaucher cells by light microscopic examination ("pseudo-Gaucher" cells). Electron microscopic examination revealed that these cells differed from true Gaucher cells and resembled storage cells previously described in chronic myelogenous leukemia. The patient's peripheral blood leukocyte beta-glucosidase and serum acid phosphatase levels were elevated, ruling out the diagnosis of inherited Gaucher's disease. After treatment with six monthly cycles of systemic chemotherapy (nitrogen mustard, vincristine, procarbazine, bleomycin, doxorubicin, and prednisone), all signs of Hodgkin's disease and pseudo-Gaucher cells disappeared. Repeat leukocyte beta-glucosidase and serum acid phosphatase levels were unchanged. The present case is unique with its documentation of classical enzyme patterns for beta-glucosidase and acid phosphatase and electron microscopic features. The authors postulate that pseudo-Gaucher cells result from excessive cell breakdown with an overload of available beta-glucosidase.

The Gaucher cells of seven patients with Gaucher's disease were examined by both transmission and scanning electron microscopy. The ultrastructure of the cells, as seen by transmission electron microscopy, did not differ from that reported in the literature. The surface structure varied not only in the different patients but also in the same individual. The cells were oval or round, most of them with a rough surface due to presence of microvilli, ruffles, ridges, and blebs of various numbers and shapes. In two patients the Gaucher cells showed phagocytosis. The appearance of the surface ultrastructure of the Gaucher cells supports the accepted view that they are related to the cells of the reticuloendothelial system.

Serum angiotensin-converting enzyme in a patient with type 2 acute neuronopathic Gaucher's disease (242 nmol/min/ml) was 10.8 times higher than values for eight patients with other hereditary neurologic abnormalities (22.5 +/- 2.0) and 9.4 times higher than those for 12 patients with other diseases (25.7 +/- 2.6) (P less than 0.001). Serum lysozyme was not elevated in the patient with type 2 Gaucher's disease. These results indicate that elevated serum angiotensin-converting enzyme in an infant with neurologic involvement and hepatosplenomegaly is suggestive of the possibility of type 2 Gaucher's disease. Typical Gaucher's cells and fibrosis were observed by light and electron microscopy of the liver. An aspect hitherto unreported in Gaucher's disease or in the liver was that approximately 20% of the collagen fibrils were of the long-spacing type, with periodicity of 1,000 to 1,100 A and diameters of 900 to 1,500 A.