Xylosyltransferase 2 deficiency and organ homeostasis.

In this paper we characterize the function of Xylosyltransferase 2 (XylT2) in different tissues to investigate the role XylT2 has in the proteoglycan (PG) biochemistry of multiple organs. The results show that in all organs examined there is a widespread and significant decrease in total XylT activity in Xylt2 knock out mice (Xylt2-/-). This decrease results in increased organ weight differences in lung, heart, and spleen. These findings, in addition to our previous findings of increased liver and kidney weight with loss of serum XylT activity, suggest systemic changes in organ function due to loss of XylT2 activity. The Xylt2-/- mice have splenomegaly due to enlargement of the red pulp area and enhanced pulmonary response to bacterial liposaccharide. Tissue glycosaminoglycan composition changes are also found. These results demonstrate a role of XylT2 activity in multiple organs and their PG content. Because the residual XylT activity in the Xylt2-/- is due to xylosyltransferase 1 (XylT1), these studies indicate that both XylT1 and XylT2 have important roles in PG biosynthesis and organ homeostasis.

The role of AGK in thrombocytopoiesis and possible therapeutic strategies.

Abnormal megakaryocyte development and platelet production lead to thrombocytopenia or thrombocythemia and increase the risk of hemorrhage or thrombosis. Acylglycerol kinase (AGK) is a mitochondrial membrane kinase that catalyzes the formation of phosphatidic acid and lysophosphatidic acid. Mutation of AGK has been described as the major cause of Sengers syndrome, and the patients with Sengers syndrome have been reported to exhibit thrombocytopenia. In this study, we found that megakaryocyte/platelet-specific AGK-deficient mice developed thrombocytopenia and splenomegaly, mainly caused by inefficient bone marrow thrombocytopoiesis and excessive extramedullary hematopoiesis, but not by apoptosis of circulating platelets. It has been reported that the G126E mutation arrests the kinase activity of AGK. The AGK G126E mutation did not affect peripheral platelet counts or megakaryocyte differentiation, suggesting that the involvement of AGK in megakaryocyte development and platelet biogenesis was not dependent on its kinase activity. The Mpl/Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (Stat3) pathway is the major signaling pathway regulating megakaryocyte development. Our study confirmed that AGK can bind to JAK2 in megakaryocytes/platelets. More interestingly, we found that the JAK2 V617F mutation dramatically enhanced the binding of AGK to JAK2 and greatly facilitated JAK2/Stat3 signaling in megakaryocytes/platelets in response to thrombopoietin. We also found that the JAK2 JAK homology 2 domain peptide YGVCF617CGDENI enhanced the binding of AGK to JAK2 and that cell-permeable peptides containing YGVCF617CGDENI sequences accelerated proplatelet formation. Therefore, our study reveals critical roles of AGK in megakaryocyte differentiation and platelet biogenesis and suggests that targeting the interaction between AGK and JAK2 may be a novel strategy for the treatment of thrombocytopenia or thrombocythemia.

Spleen thickness can predict significant liver pathology in patients with chronic hepatitis B with persistently normal alanine aminotransferase or minimally raised alanine aminotransferase: a retrospective study.

OBJECTIVE: Liver biopsy is the gold standard test for assessment of liver pathology. This study was performed to assess the predictive value of spleen thickness for liver pathology and the role of routine follow-up procedures in significant liver pathology for patients with chronic hepatitis B (CHB) with persistently normal alanine aminotransferase (PNALT) or minimally raised alanine aminotransferase (ALT). METHODS: Patients with CHB who underwent percutaneous liver biopsy were retrospectively reviewed. The relationship of liver pathology with age, ALT, hepatitis B e-antigen, and spleen thickness was statistically analyzed, and the predictive accuracy of spleen thickness was evaluated. RESULTS: In total, 80.65% of patients had significant necroinflammation and/or fibrosis. Nearly 60% of patients had splenomegaly, of which 89.12% had a histopathological grade of ≥G2 and/or S2. Spleen thickness was predictive of liver pathology, and significant histological findings increased as the hepatitis B virus (HBV) DNA level increased. CONCLUSIONS: Spleen thickness is an effective predictor of liver pathology in patients with PNALT or minimally raised ALT. Additionally, the prevalence of significant histological findings tended to increase as the HBV DNA level increased. Patients with CHB and splenomegaly and a high HBV DNA level should be treated early with antivirals to improve liver pathology.

Biochemical and molecular characterization of adult patients with type I Gaucher disease and carrier frequency analysis of Leu444Pro - a common Gaucher disease mutation in India.

BACKGROUND: Gaucher disease is a rare pan-ethnic disorder which occurs due to an increased accumulation of undegraded glycolipid glucocerebroside inside the cells' lysosomes. A beta-Glucosidase (GBA) gene defect results in glucocerebrosidase enzyme deficiency. Though the disease is mainly diagnosed in childhood, the adult manifestation is often missed or identified late due to the failure to recognize the heterogeneous clinical presentation. The present study includes seven unrelated Indian adult patients (age range: 20-40 years) having splenomegaly, with or without hepatomegaly, cytopenia and bone abnormality. METHODS: The biochemical investigation implicated measuring plasma chitotriosidase enzyme activity followed by confirmatory test of ß-Glucosidase enzyme activity from the leukocytes. The molecular characterization involved patients' initial screening for the common Gaucher mutation (Leu444Pro). Later, all patients were subjected to whole GBA gene coding region study using bidirectional Sanger sequencing. The population screening for common Gaucher disease mutation (Leu444Pro) was executed in 1200 unrelated and healthy Indian subjects by Restriction Fragment Length Polymorphism-Polymerase Chain Reaction technique. The allele frequency was calculated using Hardy-Weinberg formula. RESULTS: The biochemical analysis revealed a significant reduction in the ß-Glucosidase activity in all the patients. Also, an elevated level of plasma Chitotriosidase activity in five patients supported their diagnosis of Gaucher disease. Sanger sequencing established four patients with homozygous variation and three patients with compound heterozygous variation in GBA gene. This study uncovers two missense variants (Ala448Thr and Val17Gly) not previously reported in Gaucher disease patients. Also the known mutations like Leu444Pro, Arg329Cys, Asp315Asn, Ser125Arg, and Arg395Cys were identified in these patients. The homology modeling suggested the destabilization of the protein structure due to novel variants. The Leu444Pro mutation screening in the Indian population spotted two people as a carrier. This emerged the carrier frequency of 1:600 along with wild-type allele frequency 0.97113 and mutant allele frequency 0.02887. CONCLUSIONS: The study reports novel and known variants identified in the GBA gene in seven adult patients. The given study is the first report on the carrier frequency of the Leu444Pro mutant allele in an Indian population which will help understanding the burden and susceptibility of Gaucher disease to affect next generation in India.

Safety and Efficacy of Fedratinib in Patients With Primary or Secondary Myelofibrosis: A Randomized Clinical Trial.

IMPORTANCE: Myelofibrosis (MF) is a BCR-ABL-negative myeloproliferative neoplasm characterized by anemia, splenomegaly, debilitating constitutional symptoms, and shortened survival. Fedratinib, a JAK2-selective inhibitor, previously demonstrated clinically beneficial activity in patients with MF in early-phase trials. OBJECTIVE: To evaluate the efficacy and safety of fedratinib therapy in patients with primary or secondary (post-polycythemia vera or post-essential thrombocythemia) MF. DESIGN, SETTING, AND PARTICIPANTS: Double-blind, randomized, placebo-controlled phase 3 study in 94 sites in 24 countries in which 289 adult patients (≥18 years of age) with intermediate-2 or high-risk primary MF, post-polycythemia vera MF, or post-essential thrombocythemia MF were randomly assigned between December 2011 and September 2012 to once-daily oral fedratinib, at a dose of 400 mg or 500 mg, or placebo, for at least 6 consecutive 4-week cycles. MAIN OUTCOMES AND MEASURES: The primary end point was spleen response (≥35% reduction in spleen volume from baseline as determined by magnetic resonance imaging or computed tomography) at week 24 and confirmed 4 weeks later. The main secondary end point was symptom response (≥50% reduction in total symptom score, assessed using the modified Myelofibrosis Symptom Assessment Form). RESULTS: The primary end point was achieved by 35 of 96 (36% [95% CI, 27%-46%]) and 39 of 97 (40% [95% CI, 30%-50%]) patients in the fedratinib 400-mg and 500-mg groups, vs 1 of 96 (1% [95% CI, 0%-3%]) in the placebo group (P < .001). Symptom response rates at week 24 were 33 of 91 (36% [95% CI, 26%-46%]), 31 of 91 (34% [95% CI, 24%-44%]), and 6 of 85 (7% [95% CI, 2%-13%]) in the fedratinib 400-mg, 500-mg, and placebo groups, respectively (P < .001). Common adverse events with fedratinib treatment were anemia, gastrointestinal symptoms, and increased levels of liver transaminases, serum creatinine, and pancreatic enzymes. Encephalopathy was reported in 4 women who received fedratinib 500 mg/d. A diagnosis of Wernicke encephalopathy was supported by magnetic resonance imaging in 3 cases and suspected clinically in 1 case. CONCLUSIONS AND RELEVANCE: Fedratinib therapy significantly reduced splenomegaly and symptom burden in patients with MF. These benefits were accompanied by toxic effects in some patients, the most important being encephalopathy of unknown mechanism. Clinical development of fedratinib was subsequently discontinued. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT01437787.

An ACE diagnosis.

Gaucher's disease is not commonly considered in the differential diagnosis of adult patients with hepatosplenomegaly and increased serum ACE. A 19-year-old girl presented with recurrent epigastric and left hypochondrial pain over a period of 9 years, associated with episodes of nausea and diarrhoea. She was extensively investigated and found to have splenomegaly and raised serum ACE. A screen for haematological disorders was negative. She reported an insect bite during an overseas holiday preceding her symptoms. She was therefore also screened for infectious causes of hepatosplenomegaly but without success. Later on in life, she reported joint pain and discomfort. Sarcoidosis was thought to be the putative cause on more than one occasion. However, the presence of splenomegaly and her relatively young age, led the rheumatologist to the correct diagnosis.

Splenomegaly in myelofibrosis--new options for therapy and the therapeutic potential of Janus kinase 2 inhibitors.

Splenomegaly is a common sign of primary myelofibrosis (PMF), post-polycythemia vera myelofibrosis (post-PV MF), and post-essential thrombocythemia myelofibrosis (post-ET MF) that is associated with bothersome symptoms, which have a significant negative impact on patients' quality of life. It may also be present in patients with advanced polycythemia vera (PV) or essential thrombocythemia (ET). Until recently, none of the therapies used to treat MF were particularly effective in reducing splenomegaly. The discovery of an activating Janus kinase 2 (JAK2) activating mutation (JAK2V617F) that is present in almost all patients with PV and in about 50-60 % of patients with ET and PMF led to the initiation of several trials investigating the clinical effectiveness of various JAK2 (or JAK1/JAK2) inhibitors for the treatment of patients with ET, PV, and MF. Some of these trials have documented significant clinical benefit of JAK inhibitors, particularly in terms of regression of splenomegaly. In November 2011, the US Food and Drug Administration approved the use of the JAK1- and JAK2-selective inhibitor ruxolitinib for the treatment of patients with intermediate or high-risk myelofibrosis, including PMF, post-PV MF, and post-ET MF. This review discusses current therapeutic options for splenomegaly associated with primary or secondary MF and the treatment potential of the JAK inhibitors in this setting.

Role of BI-1 (TEGT)-mediated ERK1/2 activation in mitochondria-mediated apoptosis and splenomegaly in BI-1 transgenic mice.

Bax Inhibitor-1 (BI-1) is an evolutionally conserved apoptotic suppressor and belongs to the BI-1 family of proteins, which contain BI-1-like transmembrane domains. As their cellular functions and regulatory mechanisms remain incompletely understood, we compared their anti-apoptotic properties. Forced expression of BI-1 resulted in the most effective suppression of stress-induced apoptosis, compared with other family members, together with significant extracellular signal-regulated kinase (ERK)1/2 activation. BI-1-mediated ERK1/2 activation led to the suppression of mitochondria-mediated reactive oxygen species (ROS) production. Involvement of the ERK signaling pathway in BI-1-induced anti-apoptotic effects was confirmed by knockdown studies with ERK- or BI-1-specific siRNA. Moreover, we produced transgenic (TG) mice overexpressing BI-1, and the relationship between ERK1/2 activation and the suppression of ROS production or apoptosis was confirmed in mouse embryonic fibroblast (MEF) cells derived from these mice. Interestingly, we found that BI-1 TG mice showed splenomegaly and abnormal megakaryopoiesis. Taken together, our results suggest that BI-1-induced ERK1/2 activation plays an important role in the modulation of intracellular ROS generation and apoptotic cell death and may also affect autoimmune response.

Splenomegaly in FOLFOX-naïve stage IV or recurrent colorectal cancer patients due to chemotherapy-associated hepatotoxicity can be predicted by the aspartate aminotransferase to platelet ratio before chemotherapy.

BACKGROUND: Chemotherapy-associated hepatotoxicity is a common cause of postoperative complications after major hepatectomy. Splenomegaly may indicate portal hypertension due to chemotherapy. To identify chemotherapy-naïve patients with liver damage, the splenic volume (SV) and aspartate aminotransferase to platelet ratio (APR) were investigated. METHODS: Seventy-one patients receiving FOLFIRI, FOLFOX, or FOLFOX plus bevacizumab as first-line chemotherapy were included in this study. The SV measurement was performed by helical computed tomography volumetry, and the SV index (SVI) was calculated during 6 cycles of chemotherapy. The APR was used as an indicator of liver injury and the APR index (APRI) was calculated. RESULTS: The SVI and APRI were significantly higher in the FOLFOX group than in the FOLFIRI group. In the FOLFOX group, the maximum APR during FOLFOX administration was significantly higher in the subjects with SVI ≥ +30% than in those with SVI < +30% (p < 0.01). The incidences of grade 3 or 4 adverse events and grade 2 or greater histopathological sinusoidal injury were significantly higher in the SVI ≥ +30% than in the SVI < +30% group. Interestingly, the SVI was significantly higher in the group with APR ≥ 0.17 before FOLFOX than in the subjects with an APR < 0.17 before FOLFOX (p < 0.05). CONCLUSION: Splenomegaly due to FOLFOX-associated hepatotoxicity can be predicted if the APR before FOLFOX is 0.17 or higher.

The effect of the Gly139His, Gly143His, and Ser142His mouse heme oxygenase-1 mutants on the HO reaction in vivo and in vitro.

Heme oxygenase-1 (HO-1), which catalyzes the degradation of heme to iron, carbon monoxide, and biliverdin, performs a cytoprotective function. Previous studies on the crystal structure of the human and rat HO-1 in complex with heme showed that Gly139His (G139H) and Gly143His (G143H) mutants have no HO activity. In the present study, we reported the effect of the G139H, G143H, and Ser142His mutants of mouse HO-1 on the HO reaction in vivo and in vitro. In vitro, of the mutant transfectants, only Ser142His catalyzed degradation of heme, retaining 31.7% of the wild-type mouse HO-1 activity, whereas G139H and G143H mutants exhibited no activity. In vivo, only Tg HO-1 G143H females presented with anemia, enlarged spleen and tissue iron overload, which was similar to HO-1(-/-) mice. The results suggested the critical role of Gly139 and Gly143 in maintaining HO-1 activity in vitro and the critical role of Gly143 in maintaining HO-1 activity in vivo.

The AMPKγ1 subunit plays an essential role in erythrocyte membrane elasticity, and its genetic inactivation induces splenomegaly and anemia.

AMP-activated protein kinase (AMPK) is an αßγ heterotrimer conserved throughout evolution and important for energy sensing in all eukaryote cells. AMPK controls metabolism and various cellular events in response to both hormones and changes in cellular energy status. The γ subunit senses intracellular energy status through the competitive binding of AMP and ATP. We show here that targeted disruption of the mouse AMPKγ1 gene (Prkag1) causes regenerative hemolytic anemia by increasing the sequestration of abnormal erythrocytes. Prkag1(-/-) mice displayed splenomegaly and iron accumulation due to compensatory splenic erythropoiesis and erythrophagocytosis. Moreover, AMPKγ1-deficient erythrocytes were highly resistant to osmotic hemolysis and poorly deformable in response to increasing shear stress, consistent with greater membrane rigidity. No change in cytoskeletal protein composition was observed; however, the phosphorylation level of adducin, a protein promoting the binding of spectrin to actin, was higher in AMPKγ1-deficient erythrocytes. Together, these results demonstrate that AMPKγ1 subunit is required for the maintenance of erythrocyte membrane elasticity.

Maintenance of red blood cell integrity by AMP-activated protein kinase alpha1 catalytic subunit.

AMP-activated protein kinase (AMPK) plays a pivotal role in regulating cellular energy metabolism. We previously showed that AMPKalpha1-/- mice develop moderate anemia associated with splenomegaly and high reticulocytosis. Here, we report that splenectomy of AMPKalpha1-/- mice worsened anemia supporting evidence that AMPKalpha1-/- mice developed a compensatory response through extramedullary erythropoiesis in the spleen. Transplantation of bone marrow from AMPKalpha1-/- mice into wild-type recipients recapitulated the hematologic phenotype. Further, AMPKalpha1-/- red blood cells (RBC) showed less deformability in response to shear stress limiting their membrane flexibility. Thus, our results highlight the crucial role of AMPK to preserve RBC integrity.

AMPKalpha1 deletion shortens erythrocyte life span in mice: role of oxidative stress.

AMP-activated protein kinase (AMPK) is an energy sensor essential for maintaining cellular energy homeostasis. Here, we report that AMPKalpha1 is the predominant isoform of AMPK in murine erythrocytes and mice globally deficient in AMPKalpha1 (AMPKalpha1(-/-)), but not in those lacking AMPKalpha2, and the mice had markedly enlarged spleens with dramatically increased proportions of Ter119-positive erythroid cells. Blood tests revealed significantly decreased erythrocyte and hemoglobin levels with increased reticulocyte counts and elevated plasma erythropoietin concentrations in AMPKalpha1(-/-) mice. The life span of erythrocytes from AMPKalpha1(-/-) mice was less than that in wild-type littermates, and the levels of reactive oxygen species and oxidized proteins were significantly increased in AMPKalpha1(-/-) erythrocytes. In keeping with the elevated oxidative stress, treatment of AMPKalpha1(-/-) mice with the antioxidant, tempol, resulted in decreased reticulocyte counts and improved erythrocyte survival. Furthermore, the expression of Foxo3 and reactive oxygen species scavenging enzymes was significantly decreased in erythroblasts from AMPKalpha1(-/-) mice. Collectively, these results establish an essential role for AMPKalpha1 in regulating oxidative stress and life span in erythrocytes.

Deficiency in activation-induced cytidine deaminase promotes systemic autoimmunity in lpr mice on a C57BL/6 background.

Activation-induced deaminase (AID) is a prerequisite for immunoglobulin (Ig) class-switch recombination and somatic hypermutation, which is critical for antibody affinity maturation. IgM and IgG autoantibodies are characteristic of the systemic autoimmune disorders such as lupus. However, the relative contributions of hypermutated high-affinity IgG antibodies and germline-encoded IgM antibodies to systemic autoimmunity are not defined fully. The role of AID in autoimmunity is unclear. The current study used AID-deficient mice to investigate the role of AID in the development and pathogenesis of murine lupus. C57BL/6 mice deficient in both Fas and AID were generated. Compared to their AID-competent littermates, AID(-/-) lymphoproliferative (lpr) mice produced significantly elevated levels of IgM autoreactive antibodies with enhanced germinal centre (GC) response, developed more advanced splenomegaly and exhibited more severe glomerulonephritis. Thus, AID may play an important role in the negative regulation of systemic autoimmune manifestations in murine lupus. The results also indicate that hypermutated high-affinity IgG antibodies are not necessary for the development of autoimmune syndrome in lpr mice on a C57BL/6 background.

[Gaucher disease: importance of early diagnosis and therapy]. / Gaucher-kór: a korai diagnózis és terápia jelentôsége.

Gaucher disease is the most common lysosomal storage disorder caused by deficiency of the lysosomal enzyme glucocerebrosidase. By the end of 2006, the total enrollment in the international Gaucher Disease Registry included 4584 patients, 34 of them were Hungarian. The disease has three main types: non neuropathic (Type 1), acute neuropathic (Type 2), and chronic neuropathic (Type 3). The non-neuropathic type has the highest prevalence and also the greatest variability. The first symptoms occur before 10 years of age in more than 50% of the patients. Early onset of the clinical symptoms and signs predispose patients to severe phenotype and irreversible complications. Safe and efficient enzyme substitution therapy has been available from 1991 and applied since 1992 in Hungary. Optimal dose and early therapy are effective in stopping disease progression, leading to the regression of visceral and haematological abnormalities, preventing irreversible bone deformities, and providing a better quality of life. The authors present here three patients with Gaucher disease diagnosed in early childhood. They highlight the importance of early diagnosis and treatment before the development of severe co-morbidities or irreversible complications. They also analyse the challenges for pediatricians in establishing correct diagnosis of Gaucher disease in time.

Anemia and splenomegaly in cGKI-deficient mice.

To explore the functional significance of cGMP-dependent protein kinase type I (cGKI) in the regulation of erythrocyte survival, gene-targeted mice lacking cGKI were compared with their control littermates. By the age of 10 weeks, cGKI-deficient mice exhibited pronounced anemia and splenomegaly. Compared with control mice, the cGKI mutants had significantly lower red blood cell count, packed cell volume, and hemoglobin concentration. Anemia was associated with a higher reticulocyte number and an increase of plasma erythropoietin concentration. The spleens of cGKI mutant mice were massively enlarged and contained a higher fraction of Ter119(+) erythroid cells, whereas the relative proportion of leukocyte subpopulations was not changed. The Ter119(+) cGKI-deficient splenocytes showed a marked increase in annexin V binding, pointing to phosphatidylserine (PS) exposure at the outer membrane leaflet, a hallmark of suicidal erythrocyte death or eryptosis. Compared with control erythrocytes, cGKI-deficient erythrocytes exhibited in vitro a higher cytosolic Ca(2+) concentration, a known trigger of eryptosis, and showed increased PS exposure, which was paralleled by a faster clearance in vivo. Together, these results identify a role of cGKI as mediator of erythrocyte survival and extend the emerging concept that cGMP/cGKI signaling has an antiapoptotic/prosurvival function in a number of cell types in vivo.

A host lipase detoxifies bacterial lipopolysaccharides in the liver and spleen.

Much of the inflammatory response of the body to bloodborne Gram-negative bacteria occurs in the liver and spleen, the major organs that remove these bacteria and their lipopolysaccharide (LPS, endotoxin) from the bloodstream. We show here that LPS undergoes deacylation in the liver and spleen by acyloxyacyl hydrolase (AOAH), an endogenous lipase that selectively removes the secondary fatty acyl chains that are required for LPS recognition by its mammalian signaling receptor, MD-2-TLR4. We further show that Kupffer cells produce AOAH and are required for hepatic LPS deacylation in vivo. AOAH-deficient mice did not deacylate LPS and, whereas their inflammatory responses to low doses of LPS were similar to those of wild type mice for approximately 3 days after LPS challenge, they subsequently developed pronounced hepatosplenomegaly. Providing recombinant AOAH restored LPS deacylating ability to Aoah(-/-) mice and prevented LPS-induced hepatomegaly. AOAH-mediated deacylation is a previously unappreciated mechanism that prevents prolonged inflammatory reactions to Gram-negative bacteria and LPS in the liver and spleen.

Effective cell and gene therapy in a murine model of Gaucher disease.

Gaucher disease (GD) is a lysosomal storage disorder due to an inherited deficiency in the enzyme glucosylceramidase (GCase) that causes hepatosplenomegaly, cytopenias, and bone disease as key clinical symptoms. Previous mouse models with GCase deficiency have been lethal in the perinatal period or viable without displaying the clinical features of GD. We have generated viable mice with characteristic clinical symptoms of type 1 GD by conditionally deleting GCase exons 9-11 upon postnatal induction. Both transplantation of WT bone marrow (BM) and gene therapy through retroviral transduction of BM from GD mice prevented development of disease and corrected an already established GD phenotype. The gene therapy approach generated considerably higher GCase activity than transplantation of WT BM. Strikingly, both therapeutic modalities normalized glucosylceramide levels and practically no infiltration of Gaucher cells could be observed in BM, spleen, and liver, demonstrating correction at 5-6 months after treatment. The findings demonstrate the feasibility of gene therapy for type 1 GD in vivo. Our type 1 GD mice will serve as an excellent tool in the continued efforts toward development of safe and efficient cell and gene therapy for type 1 GD.

[A retrospective study on enzyme replacement therapy in patients with Gaucher disease].

OBJECTIVE: Gaucher disease is the most common lysosomal storage disorder. A deficiency of beta-glucocerebrosidase causes accumulation of the glucocerebroside in macrophages throughout the body. This study summarizes the effects of enzyme replacement therapy (ERT) with Imiglucerase in children with Gaucher disease. METHODS: Data from 72 patients (46 were male and 26 female, age ranged from 16 months to 22 years, median 8 years and 8 months) who were treated in the hospital between May 1999 and October 2005 were collected and analyzed, 57 of the patients had type 1 Gaucher disease, 2 patients with type 2, and 13 patients with type 3. Twenty-two patients had undergone total splenectomy. Imiglucerase was given at an initial dose 60 U/kg body weight by intravenous infusion every 2 weeks. The dose was reduced to 45 U/kg when they had achieved the specified therapeutic goals after 2 years. Clinical outcome data of Imiglucerase treatment were collected using routine Gaucher clinical measures, including growth, hematology, liver and spleen 3-dimensional measurements, and skeletal assessments every 3 - 6 months. RESULTS: Three patients were lost to follow-up, 4 patients died, and 65 patients continued to receive the therapy. Hemoglobin and platelet levels of the patients with intact spleen increased most rapidly from the first 12 months of ERT (P < 0.01). Hemoglobin level of the patients who had undergone splenectomy determined at 30 months of treatment was higher than that of baseline (P < 0.01), but platelet levels were not significantly different (P > 0.05). The volumes of the liver decreased after the 6 months of ERT, decreased in average by (39 +/- 17)% at 24 months (P < 0.01). The volumes of spleen decreased after the 12 months of ERT by (59 +/- 21)% at 24 months (P < 0.01). During the first 12 month, the height and weight of the patients who were 2 - 12 years old increased (8.6 +/- 4.3) cm and (2.6 +/- 1.7) kg, respectively, and those of the patients who were 12 - 18 years old increased (5.2 +/- 3.9) cm and (4.5 +/- 3.3) kg, separately. Bone pain reported by 16 patients relieved after 3 months of treatment. But radiological evidence of bone disease did not change. The signs and symptoms of CNS involvement in patients with type 2 and type 3 disease were not improved. No serious adverse events were reported. CONCLUSIONS: ERT with Imiglucerase could improve the quality of life of the patients with Gaucher disease by ameliorating the Gaucher disease-associated anemia, thrombocytopenia, organomegaly, growth retardation and bone pain.

Overexpression of protein kinase C-{epsilon} in the mouse epidermis leads to a spontaneous myeloproliferative-like disease.

Protein kinase C (PKC)-epsilon, a Ca(2+)-independent, phospholipid-dependent serine/threonine kinase, is among the PKC isoforms expressed in mouse epidermis. We reported that FVB/N transgenic mouse lines that overexpress (8- or 18-fold) PKC-epsilon protein in basal epidermal cells and cells of the hair follicle develop papilloma-independent squamous cell carcinoma (SCC) elicited by 7,12-dimethylbenz(a)anthracene initiation and 12-O-tetradecanoylphorbol-13-acetate-promotion or by repeated ultraviolet radiation exposures. The susceptibility to the development of SCC was proportional to the level of expression of the PKC-epsilon transgene. We now report that PKC-epsilon FVB/N transgenic mice (line 215) that overexpress in epidermis approximately 18-fold PKC-epsilon protein more than their wild-type littermates spontaneously develop a myeloproliferative-like disease (MPD) in 100% of PKC-epsilon transgenic mice. The MPD was characterized by an excess of neutrophils and eosinophils, resulting in invasion of almost all vital organs of the mouse by 6 months of age. On gross examination these mice present with splenomegaly, hepatomegaly, and severe lymphadenopathy. Examination of the bone marrow revealed almost complete effacement by neutrophils, eosinophils, and their precursors. Furthermore, the spleen and lymph nodes were enlarged and exhibited marked extramedullary hematopoiesis. Complete pathological analysis of the second PKC-epsilon transgenic mouse (line 224) that expresses approximately eightfold PKC-epsilon protein more than their wild-type littermates revealed no remarkable findings in any of the affected organs as seen in line 215. However, peripheral blood analyses of PKC-epsilon transgenic mice indicated significant increases of neutrophils in the circulating blood in both PKC-epsilon transgenic lines. To determine whether there was an imbalance of cytokines in PKC-epsilon transgenic mice (line 215), resulting in aberrant myelopoiesis, we analyzed 17 cytokines in the peripheral blood. This analysis indicated that interleukin-5, interleukin-6, and granulocyte-colony stimulating factor were up-regulated as a function of age. The transgene PKC-epsilon was not detected in any of the affected organs (bone marrow, liver, spleen, lung) We suggest that overexpression of PKC-epsilon in the epidermis may lead to the induction of specific cytokines that may, in a paracrine mechanism, perturb normal hematopoiesis in bone marrow resulting in a granulocytic skew toward that of neutrophils and eosinophils. The susceptibility of PKC-epsilon transgenic mice to the induction of SCC and the spontaneous development of MPD are unrelated.