Background: Haemorrhagic myositis is an uncommon but feared complication of inflammatory myopathy1. This study aims to characterise patients affected by this complication in a local cohort of inflammatory myositis.
Methods:A retrospective review of patients diagnosed with inflammatory myopathy from year 2013 to 2017 at St George Hospital was conducted. Cases complicated by haemorrhage were identified. The myositis panel performed includes anti-Mi2, anti-PL-7, anti-PL-12, anti-Ku, anti-EJ, anti-OJ and anti-SRP antibodies. Extended line immunoassay was performed on patients presenting in 2017, encompassing anti-MDA5, anti-NXP2, anti-SAE1, anti-TIF antibodies and HMG-CoA reductase antibodies.
Results:2 of the 17 cases of myositis cases identified by retrospective review were complicated by haemorrhage confirmed on magnetic resonance imaging. A literature review identified 8 reports of haemorrhagic myositis in the context of a diagnosis of an inflammatory myopathy. 25% were positive for anti-Ro52 antibodies2, 25% were ANA negative, and 50% had positive ANA with no myositis antibody. 75% of cases had retroperitoneal bleeding, of which only 1 survived2. 60% of cases resulted in death.
Conclusions:This review highlights the importance of recognising haemorrhagic myositis as a complication of inflammatory myopathies and caution with the use of heparin in dermatomyositis. It also is the first description of haemorrhagic myositis occurring in a patient with anti-Mi2 antibodies, in addition to the newer anti-SAE1 antibodies, with histo-pathological evidence of complement damage to capillaries on muscle biopsy. Prophylactic heparin was ceased on discovery of haemorrhagic complications, with good survival outcomes for both patients.