Objective.: To compare the clinical characteristics and identify the longterm outcomes of Chinese patients with different antisynthetase antibodies.Methods.: We investigated retrospectively 124 consecutive patients with antisynthetase syndrome. Medical records, laboratory results, and computed tomography images were obtained.Results.: The antisynthetase antibodies we investigated were anti-Jo1 (n = 62), anti-PL7 (n = 31), anti-PL12 (n = 12), and anti-EJ (n = 19). The overall prevalence of interstitial lung disease (ILD) reached 94.4% among study patients. Eleven patients (8.9%) developed rapidly progressive ILD (RP-ILD). Eight patients (6.5%) experienced malignancy. RP-ILD was statistically more prevalent in patients with antisynthetase syndrome with anti-PL7 than those without anti-PL7 (p = 0.028). Anti-Ro52–positive patients with antisynthetase syndrome experienced higher frequency of RP-ILD than those without anti-Ro52 (p = 0.001). Further, anti-PL7–positive patients coexisting with anti-Ro52 exhibited more RP-ILD than those without anti-Ro52 (p = 0.001). Patients with antisynthetase syndrome with RP-ILD had a higher proportion of neutrophils in bronchoalveolar lavage fluid and serum ferritin than those without RP-ILD (p = 0.006 and p = 0.013, respectively). Although no differences were observed between the Kaplan-Meier curves of the 4 antisynthetase antibodies subgroups (p = 0.349), the survival rate of patients with anti-PL7 decreased more rapidly in the early stage of longterm followup compared with those with other antisynthetase antibodies. The presence of RP-ILD, malignancy, and elevated serum ferritin was identified to be associated with poor prognosis in patients with antisynthetase syndrome.Conclusion.: Our study investigates the clinical phenotypes and outcomes of patients with antisynthetase syndrome with distinct antisynthetase antibodies and highlights the link between the anti-PL7 antibody and RP-ILD.

Cancer is a significant complication contributing to increased mortality in idiopathic inflammatory myopathies (IIMs), and the association between IIMs and cancer has been extensively reported. Myositis-specific autoantibodies (MSAs) can help to stratify patients into more homogeneous groups and may be used as a biomarker for cancer-associated myositis. In this study, we aimed to systematically define the cancer-associated MSAs in IIMs. Serum from 627 patients with IIMs was tested for MSAs. The cancer risk with different MSAs was estimated by standardized incidence ratio (SIR). Paraneoplastic manifestation, such as the close temporal relationship between myositis onset and cancer diagnoses in patients with different MSAs, was also evaluated. Compared with the general Chinese population, patients with IIMs and anti-transcriptional intermediary factor (TIF1)-γ antibodies (SIR = 17.28, 95% CI 11.94 to 24.14), anti-nuclear matrix protein (NXP2) antibodies (SIR = 8.14, 95% CI 1.63 to 23.86), or anti-SAE1 antibodies (SIR = 12.92, 95% CI 3.23 to 32.94), or who were MSAs-negative (SIR = 3.99, 95% CI 1.96 to 7.14) faced increased risk of cancer. There was no association between specific MSAs subtypes and certain types of cancer. Paraneoplastic manifestations were observed in the patients carrying anti-TIF1-γ, as well as other MSAs. There were no prognostic differences among the patients with cancer-associated myositis (CAM) from different MSAs subgroups. However, in comparison to those with cancer unrelated to myositis, CAM had a worse prognosis, with an age-adjusted and sex-adjusted Cox hazard ratio (HR) of 10.8 (95% CI 1.38-84.5, p = 0.02) for all-cause mortality. Our study demonstrates in what is, to our knowledge, the largest population examined to date, that anti-SAE1, and previously reported anti-TIF1-γ and anti-NXP2 antibodies, are all associated with an increased risk of cancer in patients with IIMs. Moreover, our data suggest that in some cases, anti-HMGCR, anti-Jo-1 and anti-PL-12 antibody production might also be driven by malignancy. This can aid in the etiologic research of paraneoplastic myositis and clinical management.

To define potential factors that could predict concomitant neoplastic diseases in patients diagnosed with PM/DM, which could inform screening decisions. Two researchers independently reviewed articles from Pubmed (MEDLINE), EMBASE, Cochrane Plus Library and ISI Web of Knowledge with no restrictions on study design or language. Given that some of the studies combined PM and DM patients as research subjects while others included only DM patients, data were subjected to meta-analyses for all combined PM/DM studies and studies that included only DM patients to obtain informative results. For PM/DM patients, the following factors are all associated with an increased risk of malignancy: older age, age greater than 45, male sex, dysphagia, cutaneous necrosis, cutaneous vasculitis, rapid onset of myostis (35 mm/hr), higher CRP levels, or anti-p155 antibody. In addition, the presence of anti-ENA antibodies seem to be related to reduced risk of malignancy. Awareness and implementation of early-stage cancer screening in PM/DM patients who have these identified factors – such as being older than 45, male sex, cutaneous necrosis, cutaneous vasculitis – are of crucial importance from public health and clinical perspectives and provide insight into the etiopathogenesis of CAM.