Silver stained isoelectrophoresis of tears and cerebrospinal fluid in multiple sclerosis

Cerebrospinal fluid (CSF) analysis aids in the diagnosis of multiple sclerosis. However, this examination is invasive. The aim of this study was to assess the potentials of a new method of tears isoelectrophoresis (IEF). Silver staining of IEF was used to examined tears and CSF from 123 patients including 60 patients with multiple sclerosis (MS), 50 other neurological patients and 13 patients with inflammatory neurological diseases. Tears were collected on a Shirmer strip placed in one eye, avoiding reflex secretion. This method of IEF with silver staining allowed the detection of oligoclonal bands in tears that were truly immunoglobulin G on immunofixation. The concordance rate between tears and CSF was 83%, meaning that CSF provided no more information than tears analysis in 83% of cases. Sensitivity in tears (72%) and CSF (75%) was very close as was specificity (respectively 84 % and 86 %). High concordance between tears and CSF is the first step in developing a non invasive test which could replace lumbar puncture, particularly when this procedure is not fearalele or is refused by the patient.