Choosing wisely? Multiple Sclerosis and Laboratory Screening for Autoimmune Differential Diagnoses

Abstract Background A variety of diseases can mimic the presentation of multiple sclerosis (MS). Diagnosing MS requires the exclusion of conditions considered in the differential diagnosis of MS. The guidelines of the German Society of Neurology (DGN) recommend analyzing 13 mandatory and 9 optional laboratory parameters. The mandatory recommendations include antinuclear antibodies (ANA) as well as antibodies against double-stranded DNA (anti-dsDNA Abs)). Methods In a cohort of MS outpatients, those patient records were analyzed in which test results for all or at least some of the recommended laboratory parameters were available. In addition to these laboratory parameters, MRI data, family history, clinical presentation, evoked potentials, and CSF findings were analyzed. Furthermore, a questionnaire was used to prospectively collect information about rheumatological symptoms relevant to the differential diagnosis of MS. Results In 197 of the included 554 patients, at least some of the recommended differential diagnostic laboratory parameters were available. In 59.4% of these patients, ANA titers ≥ 1:80 were detected. Neither ANA nor ANCA nor anti-dsDNA abs were able to distinguish