Detection of oligoclonal bands in patients with neurologic diseases: comparison between agarose gel-, immunofixation- and isoelectric-focusing electrophoresis.

BACKGROUND

The presence of oligoclonal bands (OCBs) in cerebrospinal fluid (CSF) often implies the involvement of the humoral immune response in the disease process. We compared three methods of electrophoresis to determine the frequency and pattern of OCBs in Chinese patients with various neurologic diseases.

METHODS

CSF samples and matched serum samples were collected from 122 patients. OCBs were examined in all the CSF samples after agarose gel electrophoresis (AGE) or isoelectric-focusing electrophoresis (IEF); some samples were selected and concentrated for immunofixation electrophoresis (IFE).

RESULTS

While 46.7% of the CSF samples showed elevated immunoglobulins using AGE, OCBs were unequivocally identified in 16.4% of samples. In contrast, the detection rate of OCBs using IEF was 54.1%, while that of monoclonal bands was 4.9%. Some OCBs could be detected by IFE, which demonstrated that most of them were IgG-kappa. Using IEF, the sensitivity was 66.7% in multiple sclerosis, 47.8% in myelopathy, 88.9% in chronic inflammatory demyelinating polyradiculoneuropathy, 62.5% in acute inflammatory demyelinating polyradiculoneuropathy, 80.0% in meningoencephalitis and 23.0% in other neurologic diseases.

CONCLUSIONS

IEF was the most sensitive method for detecting OCBs. Most patients with type 2 or type 3 patterns of OCBs had multiple sclerosis or meningoencephalitis, although some of these patients may present with a type 4 pattern. Most patients with other diseases had identical patterns of OCBs in both serum and CSF.