Molecular Profile of the Evolution of Inclusion Body Myositis

Inclusion Criteria (early-stage sIBM patients):

• Patient suffering from sIMB according to the ENMC 2011 criteria: "sIMB defined on histological and clinical features" with, on the inclusion visit day:

  • duration of the disease > 12 months;
  • onset of the disease > 45 years;
  • quadriceps weakness ≥ hip flexors and/or fingers flexors weakness > shoulder abductors;
  • CPK ≤ 15 x ULN.
• Patient with available biopsy showing alterations compatible with an inflammatory myopathy (endomysial inflammatory infiltrate, overexpression of HLA class I), but not specific to sIMB, in particular with no associated degenerative and/or mitochondrial pathologies (protein aggregates: amyloid, p62, SMI-31, TDP-43; 15-18nm filaments; ragged red fibers; COX negative fibers).
• Patient whose sIMB diagnosis has been histologically confirmed with a second muscle biopsy showing the typical histological hallmarks (endomysial inflammatory infiltrate, overexpression of HLA class I and an associated degenerative and/or mitochondrial pathology).
• Patient who gave his consent for the use of the biological material from the muscle biopsy at the time of the diagnosis.
• Patient affiliated to a social security regimen.
• Signed and written informed consent.

Exclusion Criteria (early-stage sIBM patients):

• Patient with a known medical record that could significantly influence the results of the study: auto-immune disease with conjunctive tissue inflammation (overlap myositis, rheumatoid arthritis, lupus, vasculitis, spondylarthritis, scleroderma, psoriatic arthritis), disease causing nerve-damage (Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis), auto-immune neuropathy (chronic polyradiculoneuritis and variants (multifocal motor neuropathy with conduction blocks, anti-MAG neuropathy)).
• Presence of the following histological characteristics in the muscle biopsy pointing to degenerative and/or mitochondrial pathologies: protein aggregates (amyloid, p62, SM-31, TDP-43), 15-18nm filaments, ragged red fibers or fibers with decreased COX activity.

• Patient who received one of the following treatments, prior to the first muscle biopsy:

  • anti-inflammatory drugs in the past week;
  • corticotherapy in the past month;
  • immunosuppressive agents in the past 3 months;
  • other treatments: chloridin, amiodarone, colchicine, vincristine in the past 6 months.
• Patient under curators or guardianship.
• Pregnant woman.

Inclusion Criteria (late-stage sIMB patients):

• Patient suffering from sIMB according to the ENMC 2011 criteria: "sIMB defined on histological and clinical features" with, on the inclusion visit day:

  • duration of the disease > 12 months;
  • onset of the disease > 45 years;
  • quadriceps weakness ≥ hip flexors and/or fingers flexors weakness > shoulder abductors;
  • CPK ≤ 15 x ULN.
• Patient whose sIMB diagnosis has been histologically confirmed with a muscle biopsy featuring the following characteristics: endomysial inflammatory infiltrate, rimmed vacuoles and protein aggregates (amyloid, p62, SM-31, TDP-43) or presence of 15-18nm filaments.
• Patient who gave his consent for the use of the biological material from the muscle biopsy at the time of the diagnosis.
• Patient affiliated to a social security regimen.
• Signed and written informed consent.

Non-inclusion criteria (late-stage sIMB patients):

• Patient with a known medical record that could significantly influence the results of the study: auto-immune disease with conjunctive tissue inflammation (overlap myositis, rheumatoid arthritis, lupus, vasculitis, spondylarthritis, scleroderma, psoriatic arthritis), disease causing nerve-damage (Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis), auto-immune neuropathy (chronic polyradiculoneuritis and variants (multifocal motor neuropathy with conduction blocks, anti-MAG neuropathy)).

• Patient who received one of the following treatments, prior to the muscle biopsy that confirmed the diagnosis:

  • anti-inflammatory drugs in the past week;
  • corticotherapy in the past month;
  • immunosuppressive agents in the past 3 months;
  • other treatments: chloridin, amiodarone, colchicine, vincristine in the past 6 months.
• Patient under curators or guardianship.
• Pregnant woman.

Inclusion Criteria (control subjects):

• Signed and written informed consent for the use of muscle tissue used collected for the diagnosis of a CPK elevation and/or myopathy and/or myalgias.
• No signs of muscular weakness at the time of the muscle biopsy.
• Age > 45, correlated to the age of sIMB patients, allowing for the constitution of a homogeneous group compared to sIMB patients.
• Patient affiliated to a social security regimen.
• Signed and written informed consent.

Non-inclusion criteria (control subjects):

• Subject with a muscle biopsy showing signs of inflammation and/or vacuoles and/or dystrophy.
• Subject with a known medical record that could significantly influence the results of the study: auto-immune disease with conjunctive tissue inflammation (overlap myositis, rheumatoid arthritis, lupus, vasculitis, spondylarthritis, scleroderma, psoriatic arthritis), disease causing nerve-damage (Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis), auto-immune neuropathy (chronic polyradiculoneuritis and variants (multifocal motor neuropathy with conduction blocks, anti-MAG neuropathy)).
• Subject with a confirmed sIMB diagnosis.

• Patient who received one of the following treatments, prior to the muscle biopsy that confirmed the diagnosis:

  • anti-inflammatory drugs in the past week;
  • corticotherapy in the past month;
  • immunosuppressive agents in the past 3 months;
  • other treatments: chloridin, amiodarone, colchicine, vincristine in the past 6 months.
• Patient under curators or guardianship.
• Pregnant woman.