Tear analysis as a tool to detect oligoclonal bands in radiologically isolated syndrome.

BACKGROUND: Although radiologically isolated syndrome (RIS) is a newly defined entity, incidental findings of T2 hypersignals on brain MRI can lead to misdiagnosis or useless investigations. The detection of oligoclonal bands (OCBs) in cerebrospinal fluid (CSF) is a major indicator that helps in diagnosis of subclinical inflammatory disease of the central nervous system, but lumbar puncture still remains an invasive option. METHODS: We have prospectively included patients with RIS, have compared the results of CSF and tear OCB detection by isoelectric focusing (IEF) and assessed concordance between OCB detection in tears and in CSF. Tears were collected using a Schirmer strip. RESULTS: In 45 recruited RIS patients, OCBs were detected in CSF for 55% (25/45) and in tears for 50% (21/42) of samples. CONCLUSIONS: We suggest that tear OCB detection may replace CSF OCB detection as a diagnostic tool in patients with RIS and be useful in follow-up.