Anti-cytosolic 5'-nucleotidase 1A (cN1A) autoantibodies in motor neuron diseases

Inclusion body myositis (IBM) is the most common acquired muscle disease in patients older than 50 years. Asymmetric weakness and early involvement of quadriceps and forearm flexors are key clinical features. Muscle biopsy remains the gold standard diagnostic test, which has high specificity, but low sensitivity.1 In addition to the canonical pathologic features of IBM, upregulation of major histocompatibility complex class I and accumulation of various proteins (p62, SMI-31, and TDP-43) have been adopted to the 2011 European Neuromuscular Center diagnostic criteria for IBM.1 The recent identification of anti-cytosolic 5'-nucleotidase 1A (cN1A) autoantibodies by immunoblotting in patients with IBM has raised the question whether we should incorporate these particular antibodies into the diagnostic criteria for IBM.2,3 Anti-cN1A antibodies may be positive several years predating the IBM diagnosis.3 The clinical features of patients with motor neuron disease (MND) with lower motor neuron findings could resemble those of patients with IBM, given their common age group and asymmetry in muscle weakness and atrophy. Here I present 2 patients with MND who had positive anti-cN1A antibodies.
Source: Neurology - Category: Neurology Authors: Tags: Anterior nerve cell disease, Amyotrophic lateral sclerosis, Muscle disease CLINICAL/SCIENTIFIC NOTES Source Type: research