Giorgia Puorro

A Combined Nucleic Acid and Protein Analysis in Friedreich Ataxia: Implications for Diagnosis, Pathogenesis and Clinical Trial Design

Background Friedreichs ataxia (FRDA) is the most common hereditary ataxia among caucasians. The molecular defect in FRDA is the trinucleotide GAA expansion in the first intron of the FXN gene, which encodes frataxin. No studies have yet reported frataxin protein and mRNA levels in a large cohort of FRDA patients, carriers and controls. Methodology/Principal Findings We enrolled 24 patients with classic FRDA phenotype (cFA), 6 late onset FRDA (LOFA), all homozygous for GAA expansion, 5 pFA cases who harbored the GAA expansion in compound heterozygosis with FXN point mutations (namely, p.I154F, c.482+3delA, p.R165P), 33 healthy expansion carriers, and 29 healthy controls. DNA was genotyped for GAA expansion, mRNA/FXN was quantified in real-time, and frataxin protein was measured using lateral-flow immunoassay in peripheral blood mononuclear cells (PBMCs). Mean residual levels of frataxin, compared to controls, were 35.8%, 65.6%, 33%, and 68.7% in cFA, LOFA, pFA and healthy carriers, respectively. Comparison of both cFA and pFA with controls resulted in 100% sensitivity and specificity, but there was overlap between LOFA, carriers and controls. Frataxin levels correlated inversely with GAA1 and GAA2 expansions, and directly with age at onset. Messenger RNA expression was reduced to 19.4% in cFA, 50.4% in LOFA, 52.7% in pFA, 53.0% in carriers, as compared to controls (p<0.0001). mRNA levels proved to be diagnostic when comparing cFA with controls resulting in 100% sensitivity and specificity. In cFA and LOFA patients mRNA levels correlated directly with protein levels and age at onset, and inversely with GAA1 and GAA2. Conclusion/Significance We report the first explorative study on combined frataxin and mRNA levels in PBMCs from a cohort of FRDA patients, carriers and healthy individuals. Lateral-flow immunoassay differentiated cFA and pFA patients from controls, whereas determination of mRNA in q-PCR was sensitive and specific only in cFA.

Epoetin alfa increases frataxin production in Friedreich's ataxia without affecting hematocrit

Objective of the study was to test the efficacy, safety, and tolerability of two single doses of Epoetin alfa in patients with Friedreichs ataxia. Ten patients were treated subcutaneously with 600 IU/kg for the first dose, and 3 months later with 1200 IU/kg. Epoetin alfa had no acute effect on frataxin, whereas a delayed and sustained increase in frataxin was evident at 3 months after the first dose (+35%; P < 0.05), and up to 6 months after the second dose (+54%; P < 0.001). The treatment was well tolerated and did not affect hematocrit, cardiac function, and neurological scale. Single high dose of Epoetin alfa can produce a considerably larger and sustained effect when compared with low doses and repeated administration schemes previously adopted. In addition, no hemoglobin increase was observed, and none of our patients required phlebotomy, indicating lack of erythropoietic effect of single high dose of erythropoietin.

Long-term effect of epoetin alfa on clinical and biochemical markers in friedreich ataxia

Friedreich ataxia is an autosomal recessive disease with no available therapy. Clinical trials with erythropoietin in Friedreich ataxia patients have yielded conflicting results, and the long‐term effect of the drug remains unknown.

Dimethyl fumarate mediates Nrf2-dependent mitochondrial biogenesis in mice and humans

The induction of mitochondrial biogenesis could potentially alleviate mitochondrial and muscle disease. We show here that dimethyl fumarate (DMF) dose-dependently induces mitochondrial biogenesis and function dosed to cells in vitro, and also dosed in vivo to mice and humans. The induction of mitochondrial gene expression is more dependent on DMFs target Nrf2 than hydroxycarboxylic acid receptor 2 (HCAR2). Thus, DMF induces mitochondrial biogenesis primarily through its action on Nrf2, and is the first drug demonstrated to increase mitochondrial biogenesis with in vivo human dosing. This is the first demonstration that mitochondrial biogenesis is deficient in Multiple Sclerosis patients, which could have implications for MS pathophysiology and therapy. The observation that DMF stimulates mitochondrial biogenesis, gene expression and function suggests that it could be considered for mitochondrial disease therapy and/or therapy in muscle disease in which mitochondrial function is important.

Stability of erythropoietin repackaging in polypropylene syringes for clinical use

Introduction: Epoetin alfa (Eprex®) is a subcutaneous, injectable formulation of short half-life recombinant human erythropoietin (rHuEPO). To current knowledge there are no published studies regarding the stability of rHuEPO once repackaging occurs (r-EPO) for clinical trial purposes. Materials and methods: We assessed EPO concentration in Eprex® and r-EPO syringes at 0, 60, 90, and 120 days after repackaging in polypropylene syringes. R-EPO was administered to 56 patients taking part in a clinical trial in Friedreich Ataxia. Serum EPO levels were measured at baseline and 48 h after r-EPO administration. Results: No differences were found between r-EPO and Eprex® syringes, but both globally decreased in total EPO content during storage at 4 °C. Patients receiving r-EPO had similar levels in EPO content as expected from previous trials in Friedreich Ataxia and from pharmacokinetics studies in healthy volunteers. Discussion: We demonstrate that repackaging of EPO does not alter its concentration if compared to the original product (Eprex®). This is true both for repackaging procedures and for the stability in polypropylene tubes. The expiration date of r-EPO can be extended from 1 to 4 months after repackaging, in accordance with pharmacopeia rules.

Growth hormone/IGF-1 axis longitudinal evaluation in clinically isolated syndrome patients on interferon β-1b therapy: Stimulation tests and correlations with clinical and radiological conversion to multiple sclerosis

Growth hormone (GH)/insulin‐like growth factor 1 (IGF‐1) axis abnormalities in multiple sclerosis (MS) suggest their role in its pathogenesis. Interferon β (IFN‐β) efficacy could be mediated also by an increase of IGF‐1 levels. A 2‐year longitudinal study was performed to estimate the prevalence of GH and/or IGF‐1 deficiency in clinically isolated syndrome (CIS) patients and their correlation with conversion to MS in IFN treated patients.

Mobitz type I and II atrioventricular blocks during fingolimod therapy

We investigated patients who showed a second-degree atrioventricular block (S-AVB) after the first fingolimod administration. We observed six patients with S-AVB, three Mobitz type I, and three type II. Monitoring continued on the second day for all patients. Three patients showed persistence of the S-AVB, with resolution on the second or third day. One patient had a persistent S-AVB up to the fourth day when fingolimod was discontinued. We conclude that Mobitz type II S-AVB is possible during fingolimod therapy. Patients with S-AVB could be monitored until resolution of the S-AVBs, as these may persist several days after the first fingolimod administration.

Correction to: Peripheral markers of autophagy in polyglutamine diseases

Dr. Peluso’s given name and family name were initially interchanged inadvertently. The correct names have been corrected above. The original article was corrected.