Incidence and Clinical Outcomes of Newonset Autoimmune Connective Tissue Diseases after Covid-19 Infection- a Systematic Literature Review

ABSTRACT

Background/Aims Cases of new autoimmune and autoinflammatory conditions have been reported among COVID-19 survivors. A literature review on newonset autoimmune connective tissue diseases (ACTDs) following infection with COVID-19 is lacking.This systematic literature review aimed to evaluate the potential association between COVID-19 infection and the development of new-onset ACTDs in adults. Methods Articles published until September 2022, investigating the association between COVID-19 infection and new-onset ACTDs were included. The ''population'' searched was patients with disease terms for autoimmune connective tissue diseases, including (but not limited to) systemic lupus erythematosus (SLE), Sjogren's syndrome, systemic sclerosis (SSc), any idiopathic inflammatory myositis (IIM), antisynthetase syndrome, mixed CTD and undifferentiated CTD (and related MeSH terms), with ''intervention'' as COVID-19 and related terms. For terms for COVID-19, a dedicated search strategy developed by the National Institute for Clinical Excellence was used.Medline, Embase, and Cochrane databases were searched, restricted to English-language articles only. Eligible articles were case reports and series (of any sample size), observational studies, qualitative studies and randomised controlled trials. Patients developing ACTDs without prior COVID-19 or reporting flares of existing ACTDs were excluded. Information was extracted on patient demographics, new ACTDs' onset time, clinical characteristics, COVID-19 and ACTD treatment, and COVID-19 and ACTDs outcomes. The protocol was registered in PROSPERO (CRD42022358750). Results After deduplication, 2239 articles were identified. After screening title and , 2196 papers were excluded, with 43 proceeding to fulltext screening. Ultimately, 28 articles (all single case reports) were included. Of the 28 included patients, 64.3% were female. The mean age was 51.1 years (range 20-89 years). The USA reported the most cases (9/28). ACTD diagnoses comprised 11 (39.3%) IIM (including 4 cases of dermatomyositis);7 (25%) SLE;4 (14.3%) anti-synthetase syndrome;4 (14.3%) SSc;2 (7.1%) other ACTD (one diagnosed with lupus/MCTD overlap). Of eight, four (14.3%) patients (including that with lupus/MCTD) were diagnosed with lupus nephritis. The average onset time from COVID-19 infection to ACTD diagnosis was 23.7days. A third of the patients were admitted to critical care, one for ACTD treatment for SLE with haemophagocytic lymphohistiocytosis (14 sessions of plasmapheresis, rituximab and intravenous corticosteroids) and nine due to COVID-19. The majority (80%) of patients went into remission of ACTD following treatment, while two (10%) patients died- one due to macrophage activation syndrome associated with anti-synthetase syndrome and two from unreported causes. Conclusion Our results suggest a potential association between COVID-19 infection and new-onset ACTDs, predominantly in young females, reflective of wider CTD epidemiology. The aetiology and mechanisms by which ACTDs arise following COVID-19 infection remain unknown and require more robust epidemiological data.