Previous studies have described an increased risk of developing an additional connective tissue disease (CTD) when one such ailment is present. We examine here the likelihood that individuals with systemic lupus erythematosus (SLE) screen positive for one or more of the following five autoimmune CTDs: Sjögren's syndrome, scleroderma, rheumatoid arthritis, dermatomyositis/polymyositis, and mixed connective tissue disorder. Five hundred SLE-diagnosed subjects were asked to complete a CTD screening questionnaire (CSQ). The results were analyzed according to the set of diagnostic criteria given by the American College of Rheumatology to identify probable cases of each CTD. Significant standardized prevalence ratios and comorbidities indicate an increased risk for the other autoimmune CTDs. In all, 96% of the subjects screened positive for at least one additional CTD, and 13% screened positive for at least two additional CTDs. We see that the SLE-diagnosed population may benefit from further attention regarding the presence of additional CTDs, which may further inform treatment strategies. We also see the application of the CSQ as a potentially important tool for clinical practice, and we describe the present study's limitations along with possible ways that these can be addressed.
Keywords: autoimmune connective tissue disease; community health; disease management; screening questionnaire; systemic lupus erythematosus.