The prominence of Oligoclonal Bands for clinical conversion in Radiologically isolated syndrome: 10-year follow-up study in Isfahan, Iran

Background

Since data is limited on radiologically isolated syndrome (RIS) subjects in certain regions like the Middle East, we aimed to further explore the replicability and generalizability of previously suggested predictors among a cohort of Iranian RIS subjects and report the long-term clinically definite MS (CDMS) conversion rate in this cohort.

Methods

We conducted a prospective 10-year cohort on our RIS participants, during which we collected the MRI, paraclinical, and demographic data of the subjects, and identified those who converted to CDMS.

Results

Out of 35 participants, 10 (28.5 %) developed CDMS during an average of 5.58 ± 3.08 years (range: 4 months to 10.33 years). OCB positivity was the only definitive predictor for conversion to CDMS in this cohort (P-value = 0.006), but other previously reported risk factors such as spinal cord lesions or age lacked statistical significance (P-values > 0.05). We also reported the median survival time as 114 months, the proportion surviving after 14 months as 96.9 % ± 3.1 %, and the overall conversion rate as 0.05 cases per year.

Conclusion

Our results highlight OCB as an important predictive factor of clinical conversion in RIS. The prominence of OCB suggests a need for routine CSF analysis in RIS subjects and could guide clinicians in deciding which RIS subjects benefit from DMTs.