FRI0252 HIGH EARLY MORTALITY IN IDIOPATHIC INFLAMMATORY MYOPATHIES: RESULTS FROM INCEPTION COHORT AT A TERTIARY CARE CENTER IN NORTHERN INDIA
Authors: P. Mehta, L. Gupta
Journal: Annals of the Rheumatic Diseases (2020)

Background: The idiopathic inflammatory myopathies (IIM) lead to significant morbidity and mortality. Understanding short term outcomes is the 1st step towards addressing risk factors for poor prognosis. Objectives: To assess the response to therapy, disease and treatment related morbidity and mortality in an inception cohort of IIM and determine the predictors of early mortality. Methods: Sixty-nine patients with a physician diagnosis of IIM as per 2017 ACR/EULAR classification criteria were recruited into an inception cohort from Dec 2017 to Nov 2019. Their follow-up data was recorded from June 2019 to December 2019. Clinical, laboratory and outcome variables were recorded as delineated in Figure 1A. Baseline characteristics were compared between deaths versus survivors, responders versus non-responders and those with and without major infections. Results are expressed as median (IQR). SPSS, v23, IBM 2010 was used for statistical analysis. Results: Of the 69 (54 female and 15 male) patients of median age 40 (23-51) and disease duration 3 (IQR 1-6) months, Dermatomyositis (DM) was the most common subset 26 (37.6%) (Fig, 1B). Myositis Specific and Myositis Associated Antibody (MSA and MAA) were positive in 30 (43.4%) and 11 (17%) respectively (Fig. 1 C). Forty-eight patients followed-up over 10 (IQR 4.5-13) months accounting for 473 patient years, of which 8 (16.6%) suffered mortality and three PM were reclassified (Fig, 1B). Four (10%) had minimal, 3 (7.5%) had moderate and 33 (82.5%) had a major clinical response (Fig. 2A) with treatment. Eight (20%) of the 40 who survived had a relapse and 13 (32.5%) had steroid related complications. Eleven (27.5%) had at least 1 infection and it correlated with duration of steroid use (p-0.009, RR 0.78, 0.6-0.9) but not the cumulative dose of steroid (p-0.147) Duration of symptoms prior to treatment, subtype of myositis, MSA or presence of ILD did not predict the short-term response. 6-month survival was 83.3% (Figure 2B). Rapidly progressive ILD was the most common cause of death followed closely by malignancy and infection (n=3, 37.5%)(Table 1). Diagnosis of Cancer associated myositis (OR 6.1), positive anti-MDA5 (OR 5.8) and a negative ANA (OR 5.8) were predictors of early mortality. Table 1. Clinical details of the 8 patients who died on follow up. Case No. Diagn-osis Gen-der Age at disease onset (y) Duration of disease in months MSA MAA Cause of death Place of death 1 DM M 57 4 Anti-MDA 5 Anti- Ro 52 RP ILD Hospital 2 DM M 53 12 Negative Negative Disseminated Tuberculosis Hospital 3 DM F 68 6 Anti-TIF 1 y Negative Malignancy Home 4 JDM F 14 1 Negative Negative RP ILD Hospital 5 OM F 43 1 Negative Anti-PM/Scl Unclear Home 6 OM F 45 6 Anti-Jo 1 Anti- Ro 52 LRTI Home 7 DM M 80 1 Negative Anti- Ro 52 Malignancy Home 8 DM F 31 3 Anti-MDA 5 Negative RP ILD Hospital DM- Dermatomyositis, JM- Juvenile Dermatomyositis, OM- Overlap Myositis, M- Male, F- Female, MSA- Myositis Specific Autoantibodies, MAA- Myositis Associated Autoantibodies, RP ILD- Rapidly Progressive Interstitial Lung Disease, LRTI- Lower Respiratory Tract Infection Conclusion: Indian patients with IIM suffer high early mortality attributable to RP ILD, cancer and infections. Positive anti-MDA 5 and a negative ANA predict poor survival. Acknowledgments: Muscle Autoantibody testing was funded by APLAR. Disclosure of Interests: None declared