Immunoglobulin Heavy Chain Gene Rearrangements in Patients with Gaucher Disease

Hematological manifestations and complications of Gaucher disease

Introduction: Gaucher disease (GD), although pan-ethnic and rare (common in Ashkenazi Jews), is of great importance to hematologists both for diagnosis and management. The need for increased awareness of GD is that delayed diagnosis may lead to preventable irreversible complications (mainly skeletal) or unnecessary invasive procedures (e.g. bone marrow biopsy), and the birth of another affected sibling due to lack of genetic consulting.Areas covered: The review outlines the common hematological manifestations of GD, including splenomegaly, thrombocytopenia, and anemia. Other hematological manifestations such as coagulation abnormalities, platelet dysfunction, gammopathy, and other hematological malignancies associated with GD are also discussed. Current and future treatment modalities are delineated, including enzyme replacement and substrate reduction therapy, pharmacological chaperon, and gene therapy. A literature search was conducted to identify original research articles relevant to hematology manifestations and GD published before November 2020.Expert opinion: Patients with GD should be ideally followed and treated in a center of excellence where the GD expert benefits from experienced consultants in relevant disciplines. Due to the availability of several very expensive treatment options, it is important to have an unbiased expert who can select the most suitable management for the individual patients (including withholding prescription in asymptomatic patients).

Serum protein profile analysis in lysosomal storage disorders patients

INTRODUCTION

Serum protein electrophoresis (SPE) is a well-established technique to identify alterations in plasma protein profiles, caused by diseases as multiple myeloma (MM). In addition, it could be a cost-effective technique to discover new plasma biomarkers. Relation between MM and lysosomal storage diseases (LSDs) as Gaucher disease has been set out but, it has not been evaluated on other LSDs nor the utility of the SPE as first step on LSDs biomarkers discovery projects.

MATERIALS AND METHODS

Stored plasma samples at diagnosis from several LSDs patients underwent analysis. Quality control was checked prior to the SPE was analyzed by capillary electrophoresis. The analysis for monoclonal spikes and the differences between each fraction on patients' samples vs the control data previously published, were evaluated. Furthermore, immunoprotein quantification and free light chains ratio were done by nephelometry and turbidimetry.

RESULTS

Seventy-five samples of LSD patients at diagnosis, were assessed. The frequency of the MGUS on LSDs patients was not higher than in general population whereas one lysosomal acid lipase deficiency infant showed increased IgA and kappa deviation. Regarding to the usefulness of SPE in biomarkers discovery, statistically significant differences were observed on SPE fractions between LSDs and healthy population.

DISCUSSION

The evaluation of SPE fractions can be a useful tool to understand pathophysiologic aspects in LDSs and, to simplify new marker discovery projects. In some of them, the MGUS appearance is a risk factor for the MM development despite its frequency is not increased on the studied LSDs at diagnosis.

Peripheral neural response and sex hormones in type 1 Gaucher disease

Background

In a rare Gaucher disease, reduced activity of lysosomal b-glucocerebrosidase incompletely blocks glucosphingolipid catabolism. Accumulation of the unhydrolyzed substrate glucosylceramide within lysosomes results in progressive, multisystem Gaucher disease, classified into three types. Both parkinsonism and peripheral neuropathy are observed in cases of putative non-neuronopathic type 1 disease. In the current study we investigated whether the peripheral neural response in type 1 Gaucher disease patients, with no neural manifestations is conditioned by the influence of sex hormones.

Methods

The catalytic activity of b-glucocerebrosidase in peripheral blood leukocytes was determined spectrofluorometrically. Direct sequencing of the GBA1 gene was performed. Somatosensory evoked potentials were recorded after electrical stimulation of the median nerve of both arms. Stimuli of 0.2 ms duration at a frequency of 5 Hz were used. Sex hormones were determined by radioimmunoassay using a gamma scintillation counter.

Results

Analysis of the somatosensory evoked potentials revealed significant differences in peak latencies on periphery between men and women in both control and type 1 Gaucher disease groups. Analysis by gender showed significant associations between latencies and sex hormones only in female patients: negative correlation between oestradiol concentration and N9 peak latency, and a strong negative correlation of testosterone levels with all peak latencies on the periphery (N9-N13).

Conclusions

A relationship between testosterone concentrations and the latencies of potentials evoked on peripheral nerves exists only in females with type 1 Gaucher disease. We point out sexual dimorphism in the development of this entity.