Usefulness of anti-p155 autoantibody for diagnosing cancer-associated dermatomyositis: A systematic review and meta-analysis

Objective Anti-p155 autoantibody, which was recently described in adult patients with dermatomyositis (DM), seems to be associated with cancer in this population. We performed a systematic review and meta-analysis to ascertain the accuracy of anti-p155 testing for the diagnosis of cancer-associated myositis. Methods We searched relevant databases, with no restrictions on study design or language, for original studies that included adult patients with probable/definite DM or amyopathic DM who were evaluated for neoplasm and anti-p155 status. Pooled sensitivity and specificity were calculated using a bivariate model. We computed the diagnostic odds ratio (OR), likelihood ratios (LRs) for positive and negative test results, positive and negative predictive values, and the summary receiver operating characteristic (SROC) curve. Statistical heterogeneity between studies was assessed using the I2 statistic, and 95% confidence intervals (95% CIs) were computed for the parameters studied. Results Six studies including a total of 312 adult patients with DM were selected. The pooled sensitivity of anti-p155 for diagnosing cancer-associated DM was 78% (95% CI 45-94%), and specificity was 89% (95% CI 82-93%). The diagnostic OR was 27.26 (95% CI 6.59-112.82), and LRs for positive and negative test results were 6.79 (95% CI 4.11-11.23) and 0.25 (95% CI 0.08-0.76), respectively. Heterogeneity was substantial except with regard to the LR for a positive test result. The area under the SROC curve was 0.91 (95% CI 0.88-0.93). Taking the pooled prevalence of 17% as pretest probability, anti-p155 had a positive predictive value of 58% and a negative predictive value of 95%. Conclusion Our findings indicate that anti-p155 autoantibody determination is useful for diagnosing cancer-associated myositis and guiding disease management. © 2012 American College of Rheumatology.