Among patients with multiple sclerosis, oligoclonal bands were more common and levels of CSF protein and immunoglobulin G were higher with primary progressive disease than with relapsing-onset disease.
MONTREAL—Retrospective data indicate that primary progressive multiple sclerosis (MS) and relapsing-onset MS have different immunologic etiologies, researchers reported at the 25th Annual Meeting of the Consortium of Multiple Sclerosis Centers.
Pedro Lourenco, from the Department of Neurology at the University of British Columbia in Vancouver, and colleagues investigated whether oligoclonal band (OCB)/CSF findings are associated with disease course and progression in patients with MS. They also investigated whether ethnicity and testing bias affected such associations. The researchers performed retrospective analyses in a sample of 6,935 patients with MS who registered at the British Columbia MS Clinics between 1982 and 2010.
Among this cohort, 1,120 patients had OCB/CSF testing, and a comparison of these patients with untested patients indicated a testing bias. Male gender was more common in tested than in untested patients, at 32.2% and 27.7%, respectively. In addition, the mean age at symptom onset was 35.0 for the tested patients, versus 31.5 for the untested patients.
OCBs were detected in 694 (72.5%) of the 957 patients tested for the bands. They were detected in 107 (79.8%) of 134 patients with primary progressive MS, compared with 587 (71.3%) of the 823 patients with relapsing-onset MS. The difference between disease courses was greater among Caucasian patients—OCBs were detected in 70 (87.5%) of the 80 Caucasian patients with primary progressive disease and 360 (71.9%) of the 499 Caucasian patients with relapsing-onset disease. There were no associations between disease progression outcomes and OCB status, however.
On average, patients with primary progressive disease had total CSF immunoglobulin G levels of 64.1 mg/L, compared with 52.0 mg/L in patients with relapsing-onset disease. Average total protein levels also were higher in patients with primary progressive MS than in patients with relapsing-onset MS, at 502 mg/L and 174 mg/L, respectively.
These results suggest that there are “different immunologic etiologies for relapsing-onset and primary progressive MS,” the researchers concluded.
—Jack Baney