Abstract
Background: To demonstrate an inflammatory process in the central nervous system, the presence of at least two immunoglobulin (Ig) bands in the cerebrospinal fluid (CSF) is required. So far, the presence of a single abnormal Ig band is considered as negative. Objective: The objective was to assess retrospectively the significance of a single CSF Ig band in clinical practice. Methods and results: Out of 10,286 CSF analyses, we retained 214 results with single Ig. An inflammatory neurological disorder was diagnosed in 41% of patients. Conclusion: Despite a modest sensitivity, the presence of a single CSF Ig band may be a biomarker of an inflammatory mechanism and, as such, may prompt the clinician to repeat the analysis when the clinical context remains suggestive.