A Scoping Literature Review of Lung HRCT in Connective Tissue Disease: Descriptions and Prediction of Mortality

Background and Objectives: This scoping literature review is intended to describe the characteristic HRCT lung findings related to interstitial lung disease (ILD) which occur in: dermatomyositis/polymyositis (DM/PM), rheumatoid arthritis (RA), Sjogren’s Syndrome (SjS), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc). In addition, we examined whether HRCT features in these diseases could predict mortality. Methods: We reviewed the medical literature from PubMed, EMBASE and Cochran reviews from 1993 to 2021, in DM/PM, RA, SJS, SLE and SSc. The articles were extracted according to defined inclusion/exclusion criteria using standardized forms with double extraction of 20% of the articles Analysis included descriptive statistics plus tabulations for comparisons of frequency, prevalence, and prediction of mortality Results: Of 478 publications, 110 studies were included. HRCT features consistent with ILD reported with variable prevalence (often depending on study design) in RA (15-43%), SjS (~50%), DM/PM (~60%), SSc (~53%) and SLE (53%) patients. Usual interstitial pneumonia (UIP) frequently predicted mortality as did, less commonly, honeycombing and increasing fibrosis. Other non-HRCT factors such as decreased FVC, DLCO, increased age, smoking and male gender were predictors of mortality in RA and SSc. Additionally, predictors of mortality were: UIP in RA; increased skin involvement in SSC, diffuse alveolar hemorrhage in SLE (although rare) and MDA5 in DM, when available. Conclusion: ILD and increased fibrosis, by HRCT, is relatively common in these connective tissue diseases and plays a significant role in mortality. Specific occurrences such as UIP (RA), increased skin involvement (SSC), diffuse alveolar hemorrhage (SLE) and MDA 5 (DM) also affected mortality.