Relationship between osteonecrosis and antiphospholipid antibodies in patients with systemic lupus erythematosus: a systematic review protocol.

Introduction Osteonecrosis (ON) is characterised by the destruction of the normal blood supply to the bone tissue. ON is the main cause of disability in patients with systemic lupus erythematosus (SLE). Studies have reported the existence of many risk factors for SLE complicated by ON, including the use of high-dose glucocorticoids and high disease activity. The correlation between antiphospholipid antibodies (aPLs) and ON in SLE has been controversial. We aim to conduct a systematic review of the literature related to SLE, aseptic ON and aPLs, to provide a reference for the clinical screening of high-risk patients and for early prevention. Methods and analysis The following six databases will be searched: MEDLINE/PubMed, Embase, Web of Science, Chinese Biomedical Literature Database, Wan-Fang Database and China National Knowledge Infrastructure. The database searches will not be restricted by date. Case–control studies, cohort studies or observational studies that compare aPLs between SLE patients with and without ON will be considered eligible. Articles published in English and Chinese will be included. Two researchers will independently perform the processes of study selection, data extraction and study quality assessment. The Newcastle–Ottawa Quality Assessment Scale will be used to assess the quality of the retrieved studies. A meta-analysis will be performed after screening the studies. Data will be analysed using ORs for dichotomous data. Ethics and dissemination Ethical approval is not required because this systematic review will use published data. The systematic review will be electronically disseminated through a peer-reviewed publication or conference presentations. PROSPERO registration number CRD42020209637.