A third of their multiple sclerosis patients without rheumatic conditions tested positive for autoantibodies. These neurologists say their routine use in MS diagnosis is unwarranted.
Solomon AJ, Hills W, Chen Z et al. Autoantibodies and Sjogren’s Syndrome in Multiple Sclerosis, a Reappraisal. PLoS ONE (2013) 8:6:e65385
The routine practice of testing for autoantibodies associated with rheumatic disease as part of the workup for multiple sclerosis (MS) is probably unjustified, according to new evidence from a team of neurologists and others at the University of Vermont and Oregon Health & Science University (OHSU). In a patient who has strong clinical evidence of MS but lack signs of a rheumatic disease, positive values for ANA, SSA, rheumatoid factor, and lupus anticoagulant are probably no more than misleading and confusing, they conclude.
Most prior studies of this issue are probably also misleading, they write, having taken place before the recognition of neuromyelitis optica (NMO) and NMO spectrum disorders as distinct from MS. Their study examined a convenience sample of women with MS being seen at the OHSU Multiple Sclerosis Center, after excluding those diagnosed with NMO/NMO spectrum disorder, a comorbid rheumatologic disorder (lupus, APL antibody syndrome, or rheumatoid arthritis), or a history of infection with HIV, HTLV Type I, or hepatitis C.
They tested the remaining 91 women for antinuclear antibody (ANA), the Sjogren syndrome biomarkers SSA and SSB, rheumatoid factor, anticardiolipin antibodies, and lupus anticoagulant. Overall, 35 of the 91 women with uncomplicated MS, or 38%, tested positive for autoantibodies. The ANA score was positive for 23 (31%). Smaller numbers of women were positive for other autoantibodies. None of these showed any relationship with clinical history, symptoms, or drug treatments.
Four patients tested positive for the SSA antibody associated with Sjogren syndrome. Although some of them reported dry eyes or dry mouth, none met diagnostic criteria for Sjogrens syndrome. All 4 were also negative for the biomarker associated with NMO. The researchers suspect that in these cases the symptoms arose as side effects of the drugs used to treat MS.
Although rheumatologic syndromes may have nervous system manifestations, they say, without a clinical "red flag" for a rheumatic condition, testing for these autoantibodies in the differential diagnosis of MS merely increases costs without any benefit, and may lead to unnecessary further tests and consultations.