New MS criteria may create more false positives

The revised McDonald criteria for multiple sclerosis (MS) has led to more diagnoses in patients with clinically isolated syndrome (CIS), but a new study of the criteria has suggested that they may lead to a number of false positive MS diagnoses among patients with a less severe disease state.

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“In our data, specificity of the 2017 criteria was significantly lower than for the 2010 criteria,” Roos M. van der Vuurst de Vries, MD, from the department of neurology at Erasmus Medical Center in Rotterdam, the Netherlands, and her colleagues wrote in JAMA Neurology. “Earlier data showed that the previous McDonald criteria lead to a higher number of MS diagnoses in patients who will not have a second attack.”

Dr. van der Vuurst de Vries and her colleagues analyzed data from 229 patients with a CIS who underwent an MRI of the spinal cord to assess for dissemination in space (DIS); of these, 180 patients were scored for both DIS and dissemination in time (DIT) and had a “baseline MRI scan that included T1 images after gadolinium administration or scans that did not show any T2 hyperintense lesions.” Some patients also underwent a baseline lumbar puncture if clinically required.

Patients were assessed using both the 2010 and 2017 McDonald criteria for MS, and results were measured using sensitivity, specificity, positive predictive and negative predictive values, and accuracy at 1-year, 3-year, and 5-year follow-up. “The most important addition is that the new criteria allow MS diagnosis when the MRI scan meets criteria for DIS and unique oligoclonal bands (OCB) are present in [cerebrospinal fluid], even in absence of DIT on the MRI scan,” the researchers wrote. “The other major difference is that not only asymptomatic but also symptomatic lesions can be used to demonstrate DIS and DIT on MRI. Furthermore, cortical lesions can be used to demonstrate dissemination in space.”

The researchers found that 124 patients met 2010 DIS criteria (54%) and that 74 patients (60%) went on to develop clinically definite MS, while 149 patients (65%) met 2017 DIS criteria, and 89 patients (60%) went on to clinically definite MS. There were 46 patients (26%) who met 2010 DIT criteria, and 33 of those patients (72%) were diagnosed with clinically definite MS; 126 patients (70%) met 2017 DIT criteria, and 76 of those patients (60%) had clinically definite MS. The sensitivity for the 2010 criteria was 36% (95% confidence interval, 27%-47%)versus 68% for the 2017 criteria (95% CI, 57%-77%; P less than .001). However, specificity for the 2017 criteria was lower (61%; 95% CI, 50%-71%) when compared with the 2010 criteria (85%; 95% CI, 76%-92%; P less than .001). Researchers found more baseline MS diagnoses with the 2017 criteria than with the 2010 criteria, but they noted that 14 of 22 patients (64%) under the 2010 criteria and 26 of 48 patients (54%) under the 2017 criteria with MS had a second attack within 5 years.

The study was supported by the Dutch Multiple Sclerosis Research Foundation. One or more authors received compensation from Teva, Merck, Roche, Sanofi Genzyme, Biogen, and Novartis in the form of honoraria, for advisory board membership, as travel grants, or for participation in trials.

SOURCE: van der Vuurst de Vries RM, et al. JAMA Neurol. 2018 Aug 6. doi: 10.1001/jamaneurol.2018.2160.