Background The association between idiopathic inflammatory myopathies and neoplasms (paraneoplastic syndrome) has been widely studied in the literature, particularly in patients with dermatomyositis (DM).
Objectives The objective of this study was to determine the profile of myositis-specific (MSA) and myositis associated autoantibodies (MAA) in patients with paraneoplastic myopathy.
Methods We identified all patients with paraneoplastic myopathy addressed by the Internal Medicine Department to the Immunology Department of the “La Rabta” Hospital between January 2006 and February 2014 for immunological tests. The MSA (anti-Mi-2, anti-Jo-1, anti-PL-7, anti-PL-12, anti-EJ, anti-OJ, anti-SRP) and MAA (anti-Ku, ani-PM-Scl75, anti-PM-Scl100, anti-Ro-52) were detected by immunodot (Euroimmun®).
Results We identified 8 patients with paraneoplastic myopathy (4 women and 4 men) with a mean age of 50.7 years. All had DM. The associated neoplasms affected various sites: nasopharynx, lung, colon, cervix, breast, etc. Two patients had an associated Sjogren's syndrome. Half of the patients (4/8) had at least one autoantibody: Three patients had 2 autoantibodies and one patient had one autoantibody.
Among MSA, anti-Mi-2 and anti-SRP were positive in 1/8 cases each. No patient had anti-synthetase antibodies (anti-Jo-1, PL-7, PL-12, EJ and OJ). Among MAA, anti-PM-Scl75 and Ro-52 were positive in 1/8 and 4/8 cases, respectively. No patient had anti-Ku nor anti-PM-Scl100.
Conclusions Initially, the presence of MSA or MAA was an argument against the paraneoplastic nature of myopathy. Later, other authors reported that nearly 5% of paraneoplastic myopathy had these autoantibodies. These data need to be confirmed on a larger cohort with searching for anti-TIF1-γ antibodies (Transcriptional intermediary factor 1-gamma), which seems most specific of paraneoplastic myopathies.
Disclosure of Interest None declared