Background: Intrathecal IgG synthesis (ITGS), in conjunction with magnetic resonance imaging, can help in the early diagnosis of multiple sclerosis (MS). Recently, we developed a new oligoclonal IgG band (OCGB) test for ITGS detection that is more sensitive and easier to interpret than previously described methods.
Objective: To assess the accuracy of a new OCGB detection test in the diagnosis of MS.
Design: Prospective observational study.
Setting: A hospital neurology department. Patients A total of 385 patients with various neurologic disorders.
Main outcome measures: The sensitivity and specificity of the OCGB detection test for MS diagnosis.
Results: Intrathecal IgG synthesis was found in 127 patients with MS (96.2%), 18 (35.3%) with central nervous system infections, and 1 with motor neuron disease. Two patterns reflected ITGS. One pattern, showing OCGBs restricted to cerebrospinal fluid, was predominantly found in MS. The other pattern, with OCGBs in serum and additional bands in cerebrospinal fluid, was mostly found in central nervous system infections. No patients with other inflammatory neurologic diseases showed ITGS. These patients frequently displayed a mirror pattern, with identical bands in serum and cerebrospinal fluid. Considering all patients, the sensitivity for the diagnosis of MS was 96.2%, and the specificity was 92.5%. Excluding infections, which usually do not present a differential diagnosis problem with MS, the sensitivity was still 96.2%, and the specificity increased to 99.5%.
Conclusion: The accuracy of this OCGB method reinforces the value of cerebrospinal fluid studies in the early differential diagnosis of MS.