PARIS—Oligoclonal bands, together with symptomatic lesions disseminated in space, increase the risk of multiple sclerosis (MS), according to data presented at the Seventh Joint ECTRIMS–ACTRIMS Meeting. MRI dissemination in space (DIS) at any time plus positive oligoclonal bands should be considered as an additional criterion for MS diagnosis, according to the researchers.
Previous research has suggested that the presence of oligoclonal bands in typical clinically isolated syndromes (CIS) increases the risk of a second attack independently of MRI findings. Georgina Arrambide, MD, PhD, a neurologist at Vall d’Hebron University Hospital in Barcelona, and colleagues studied an ongoing CIS cohort to explore whether oligoclonal bands would be a valuable criterion for MS diagnosis in the context of the 2010 McDonald criteria.
An Examination of MRIs
The investigators obtained MRIs at three to five months after CIS diagnosis, at one year, and at every five years. Oligoclonal bands were determined by isoelectric focusing combined with immunoblotting. Dr. Arrambide and colleagues selected 565 patients with oligoclonal band determination and sufficient data on baseline brain MRI to assess 2010 DIS and dissemination in time (DIT) considering the symptomatic lesions. They excluded 167 participants (29.6%) who already fulfilled DIS and DIT criteria and divided the remaining 398 participants into groups with no DIS and no DIT (n = 218), DIS only (n = 164), and DIT only (n = 16).
Next, the researchers performed Cox proportional hazards regression models with 2010 McDonald as the outcome, using no DIS no DIT with no lesions (n = 107) as the reference for no DIS no DIT with one or more lesion, DIS only, and DIT only. To assess performance, Dr. Arrambide’s group selected cases with a follow-up of three or more years or a second attack within three years of the CIS (n = 305). These participants were divided into groups with no DIS and no DIT (n = 165), DIS only (n = 129), and DIT only (n = 11). The investigators classified participants with no DIS and no DIT with one or more lesion (n = 93) and DIS only according to their oligoclonal band status. They assessed sensitivity, specificity, accuracy, positive predictive value, and negative predictive value with 2010 McDonald at three years as the outcome.
Oligoclonal Bands Increased Risk of Conversion to MS
The adjusted hazard ratios of second attack were 2.8 for no DIS and no DIT with one or more lesion and negative oligoclonal bands, 6.4 for no DIS and no DIT with one or more lesion and positive oligoclonal bands, 9.7 for DIS only with negative oligoclonal bands, 14.8 for DIS only with positive oligoclonal bands, and 7.9 for DIT only. Regarding performance, specificity was 77.6 for no DIS no DIT with one or more lesion and negative oligoclonal bands, 89.1 for no DIS no DIT with one or more lesion and positive oligoclonal bands, 92.5 for DIS only and negative oligoclonal bands, 88.1 for DIS only and positive oligoclonal bands, and 97.8 for DIT only. DIS only with positive oligoclonal bands had the highest sensitivity (46.2), accuracy (64.6), and positive predictive value (83.2).