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 between MS and non-MS. In 124 MS patients, 54.8% had positive ANA titers ≥1:80. MS patients with these titers suffered more frequently from autoimmune diseases and were more likely to have a family history of MS. Of the remaining 73 patients without MS, 67.1% were ANA positive. In this patient population, the ANA-positive patients were more frequently diagnosed with psychiatric diseases. In the prospectively surveyed MS patients with an ANA titer >1:160, no rheumatologic disease was diagnosed during the average follow-up period of 1.9 years.
Conclusion In line with the "Choosing Wisely" recommendations of the American College of Rheumatology, mandatory laboratory screening appears to offer no benefit to the initial diagnosis of multiple sclerosis, unless a specific differential diagnosis is to be excluded.
Key words
multiple sclerosis - differential diagnosis - ANA
