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

Abstract

Dr. Liewluck recently described 2 patients with motor neuron disease who tested positive for anti-cN1A antibodies by ELISA, an autoantibody reported to be highly specific for inclusion body myositis (IBM). Commenting on this report, Dr. Budhram notes that the anti-cN1A antibody isotype identified in both patients was lacking. He explains that some ELISA tests may identify the presence of immunoglobulin (Ig) G, IgA, or IgM anti-cN1A antibodies, and are potentially somewhat less specific for IBM. He suggests that anti-cN1A antibody isotype data should routinely be included in publications reporting its presence in different patient populations, since this information may provide insight into isotype specificity (or lack thereof) for the diagnosis of IBM. In response, Dr. Liewluck explains that the antibody isotype was not included due to the limited word count and clarifies that the test was done at the commercial laboratory, which detected only the IgG subtype. Dr. Liewluck recently described 2 patients with motor neuron disease who tested positive for anti-cN1A antibodies by ELISA, an autoantibody reported to be highly specific for inclusion body myositis (IBM). Commenting on this report, Dr. Budhram notes that the anti-cN1A antibody isotype identified in both patients was lacking.