Novel vectors and approaches for gene therapy in liver diseases

Gene therapy is becoming an increasingly valuable tool to treat many genetic diseases with no or limited treatment options. This is the case for hundreds of monogenic metabolic disorders of hepatic origin, for which liver transplantation remains the only cure. Furthermore, the liver contains 10-15% of the body's total blood volume, making it ideal for use as a factory to secrete proteins into the circulation. In recent decades, an expanding toolbox has become available for liver-directed gene delivery. Although viral vectors have long been the preferred approach to target hepatocytes, an increasing number of non-viral vectors are emerging as highly efficient vehicles for the delivery of genetic material. Herein, we review advances in gene delivery vectors targeting the liver and more specifically hepatocytes, covering strategies based on gene addition and gene editing, as well as the exciting results obtained with the use of RNA as a therapeutic molecule. Moreover, we will briefly summarise some of the limitations of current liver-directed gene therapy approaches and potential ways of overcoming them.

Patients with Gaucher disease display systemic oxidative stress dependent on therapy status

Gaucher disease is an autosomal recessive metabolic disorder caused by mutations in GBA1, which encodes for the lysosomal hydrolase enzyme, β-glucocerebrosidase. The resulting misfolded protein can trigger endoplasmic reticulum stress and an unfolded protein response within the affected cells. The enzyme deficiency leads to accumulation of its substrates, glucosylceramide and glucosylsphingosine, within macrophage lysosomes and with prominent disease manifestations in macrophage rich tissues. Resultant lysosomal pathology and impaired autophagy leads to redox imbalance, mitochondrial dysfunction and intracellular oxidative stress. Here we have systematically examined a role for oxidative stress in individuals affected by Gaucher disease. We compared multiple oxidative stress biomarkers in plasma and red blood cell samples from patients who are currently untreated, with those who are stable on standard-of-care therapy, and with healthy controls. We found significant differences in key oxidative stress biomarkers in untreated patients compared to healthy control. In treated patients, results generally fell between the controls and the untreated patients. Interestingly, even asymptomatic and minimally symptomatic untreated patients had evidence of significant systemic oxidative stress. We conclude that underlying oxidative stress may contribute to Gaucher disease pathophysiology including long-term adverse outcomes such as Parkinsonism and malignancies. Therapies targeting oxidative stress may prove useful as adjuvant treatments for Gaucher disease and other lysosomal storage disorders.

Very rare condition of multiple Gaucheroma: A case report and review of the literature

Background

This study presented a 3 years old boy with Gaucher disease (GD) who was treated with enzyme replacement therapy(ERT) for 19 months and developed multiple Gaucheroma. The literature was reviewed.

Methods

The medical chart and literature were reviewed. A boy presented at the age of 15 months with anemia, thrombocytopenia, and hepatosplenomegaly. Enzyme assay and gene mutations confirmed GD. ERT was administered. When the boy was 3 years old, multiple masses were discovered from abdominal MRI and biopsy revealed Gaucheroma. We reviewed 20 GD patients with Gaucheroma and Gaucher cell infiltrated lymphadenopathies.

Conclusion

Gaucheroma is a rare condition in regularly treated GD patients. This patient showed poor response to doubled ERT doses. The imaging studies are necessary for Gaucher patients to detect Gaucheroma and determine their malignancy. Regular checkups are recommended in all GD patients even with ERT treatment, due to the possibility of having a deteriorating change, like Gaucheroma.

Very rare condition of multiple Gaucheroma: A case report and review of the literature

Background

This study presented a 3 years old boy with Gaucher disease (GD) who was treated with enzyme replacement therapy (ERT) for 19 months and then developed multiple Gaucheroma. Review of literature was performed simultaneously.

Methods

The medical chart and literature were reviewed. A boy presented at the age of 15 months with anemia, thrombocytopenia, and hepatosplenomegaly. GD was confirmed by enzyme assay and gene mutations. ERT was administered right after the diagnosis. When the boy was 3 years old, multiple masses were discovered during a regular checkup abdominal MRI and biopsy revealed Gaucheroma. We also reviewed 20 GD patients with Gaucheroma and Gaucher cell infiltrated lymphadenopathies.

Conclusion

Gaucheroma is a rare condition of regularly treated GD patients. This patient even showed poor response to doubled ERT doses. The imaging studies are necessary for Gaucher patients to detect Gaucheroma and determine their malignancy. Regular checkups are recommended in all GD patients even with regular treatment, due to the possibility of having deteriorating change, like Gaucheroma.

Characteristics of 26 patients with type 3 Gaucher disease: A descriptive analysis from the Gaucher Outcome Survey

The Gaucher Outcome Survey (GOS) is an international disease-specific registry established in 2010 for patients with a confirmed diagnosis of Gaucher disease (GD), regardless of GD type or treatment status. Historically, there has been a limited understanding of type 3 GD (GD3) and its natural history in patients irrespective of their treatment status. Here, we describe the disease characteristics of patients with GD3 enrolled in GOS. As of October 2015, 1002 patients had been enrolled, 26 of whom were reported as GD3. The majority of patients with GD3 were from the US (13; 50.0%), seven (26.9%) were from the UK, three (11.5%) from Israel, and three (11.5%) from Brazil. No patients were of Ashkenazi Jewish origin. Median age of symptom onset was 1.4 (interquartile range: 0.5–2.0) years. The most common GBA1 mutation genotype was L444P/L444P, occurring in 16 (69.6%) of 23 patients who had genotyping information available. Nine patients reported a family history of GD (any type). Of 21 patients with treatment status information, 20 (95.2%) had received GD-specific treatment at any time, primarily imiglucerase (14 patients) and/or velaglucerase alfa (13 patients). Hemoglobin concentrations and platelet counts at GOS entry were within normal ranges for most patients, and there were no reports of severe hepatomegaly or of splenomegaly in non-splenectomized patients, most likely indicative of the effects of treatment received prior to GOS entry. This analysis provides information on the characteristics of patients with GD3 that could be used as the baseline for longitudinal follow-up of these patients.