Study of miRNA Expression Pattern as Diagnostic and Prognostic Biomarker in Amyotrophic Lateral Sclerosis

Etude de l'Expression Des Micro-RNA Comme Biomarqueur Diagnostic et Pronostic Dans la Sclérose Latérale Amyotrophique

The principal goal is to demonstrate that a specific pattern of microRNA (miRNA) expression can be correlated with the definite diagnostic of Amyotrophic Lateral Sclerosis (ALS). The investigators will use biological sample (from muscle biopsy, Cerebrospinal Fluid (CSF) and blood sample) collected in three control populations: definite ALS patients according to El Escorial diagnostic criterion, control patients without any neurological disease having an orthopedic surgery for shoulder disease, and control patient explored for peripheral neuropathy and myopathy. A second goal will correlate the miRNA pattern to the severity and/or progression rate of the motor neurons define as the progression rate of the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS) score/year.

Amyotrophic Lateral Sclerosis is an adult-onset neuro degenerative disease leading to muscle wasting, palsy and death due to respiratory failure within 3 to 5 years. The only effective drug (Riluzole) increases the life expectancy for about three months, knowing that on average, the diagnostic is given after a delay of one year in France. The identification of new biomarkers for early diagnostic is therefore of fundamental importance. This could improve the treatment efficacy but also give important clues about the prognostic, the rate of evolution and overall help identify new targets for future therapeutics. The investigators' goals are to find specific miRNA patterns expression associated to ALS in humans and use those patterns as diagnostic and prognostic tools.

miRNA are non-coding small fragments of RNA that binds mRNA and can down regulate their expression. In humans, around 700 miRNA have been so far identified. The role of miRNA in human pathology is well established in various types of cancer, but recent works have emphasize their role in neuro degenerative diseases and their expression profile can considered specific for Alzheimer, Parkinson and Huntington diseases. Very few data are currently available about their expression pattern in ALS. Previous studies have however shown that down regulating of some miRNA in spinal cord Moto neurons can trigger an ALS-like clinical phenotype. A more recent work on transgenic murine model SOD1 G93A has demonstrated the role of the specific miRNA206 in regulating the re-innervation processes at the neuro-muscular junction. Mi206 have the ability to promote the re-innervation process and therefore to slow the disease progression.

This research aimed to study the expression of more than 700 miRNA in four different groups (20 patients per group): ALS patients, normal control having a shoulder surgery during which they will have a muscle (deltoid) biopsy, patients explored for peripheral neuropathy with a blood sample, a lumbar puncture for CSF examination and neuro-muscular biopsy and patient explored for myopathy with a blood sample, a lumbar puncture for CSF examination and a muscular biopsy. The ALS group will be followed up every 4 months with ALSFRS scoring and blood sample and a second CSF sample only at M12. miRNA pattern expression will be compared and considered significant for a 2-fold change.

Inclusion Criteria:

For ALS patients:

• Age between 45 and 70 years old
• Patients with definite criteria of ALS according to revised El Escorial criterion (1998).
• ALS Patients with a clinical motor impairment of the limbs +/- impairment of the bulbar muscles.
• Patients with a clinical motor impairment on the deltoid muscle (MRC score<5)

For control patients:

• Age between 45 and 70 years old
• Patients having an orthopedic surgery of the shoulder with a normal neurological examination
• Patients having a peripheral neuropathy with a motor component needing a biological blood sample, a lumbar puncture for CSF examination and a neuro-muscular biopsy for complete diagnostic
• Patients having a muscular myopathy needing a biological blood sample and a deltoid muscle biopsy for complete diagnostic.
• Patients affiliated to a governmental health plan
• Clear and loyal consent form written and signed by the patient and the investigator ( before any exam and at least the day of inclusion)

Exclusion Criteria:

• Patients not eligible for a muscle biopsy (anti-coagulation, anti aggregation or blood coagulation pathologies)
• Patients not eligible for lumbar puncture (anti-coagulation, anti aggregation or blood coagulation pathologies, recent spine surgery, acquired or congenital spine malformation, clinical signs of intracranial hypertension, cutaneous infection at the punction site).
• ALS patient with isolated bulbar symptoms
• Patients with a clinical syndrome of ALS-plus associating extra-pyramidal symptoms, cerebellar or spino-cerebellar syndromes autonomic disorders or ocular palsy.
• Patients with marked cognitive impairments (MMS<24/30 or BREF<14/18)
• Pregnant or breastfeeding women
• Patients with any neurological or non-neurological disorders interfering with the ALSFRS score
• Patients who could not express their consent
• Patients in emergency situation
• Patients under guardianship or judicial protection
• Pace maker, cochlear implant
• Spinal cord compression or trauma
• Spine surgery
• Spinal deformity
• Claustrophobia
• Metallic foreign body
• Pregnancy
• Vital capacity < 50 %