OLIGOCLONAL BANDING

CLINICAL UTILITY:

The test for oligoclonal banding in cerebrospinal fluid (CSF) is of importance in the diagnosis of multiple sclerosis (MS), but is not specific for that disease. While the diagnosis of MS must be made on the basis of clinical evidence, the appearance of oligoclonal bands in a patient’s CSF offers laboratory confirmation of the disease. In MS, the CSF immunoglobulins migrate in a characteristic pattern during agarose electrophoresis, displaying 2 or more distinct prominent bands in the gamma region. Since these oligoclonal bands do not appear in electrophoresis of the patient’s serum, their appearance seems to indicate local CSF production of immunoglobulins (IgG). The pattern of banding tends to be unique for each patient and to remain relatively constant during the course of the disease. CSF banding patterns also occur in some other neurological diseases, but the banding pattern is usually less prominent.

METHOD DESCRIPTION:

To test for oligoclonal bands in CSF, which are absent in serum, high resolution agarose electrophoresis is performed in parallel on the patient’s CSF and serum. If 2 or more bands are found in the CSF gamma region, and the serum gamma region is homogeneous, the result is reported as “oligoclonal banding present.” If the bands are prominent and distinctive, characteristic of MS, they are reported as “prominent oligoclonal banding present”.

If bands appear in both CSF and serum, their presence is noted, with the comment: “CSF oligoclonal banding reflects pattern of serum. Impression is negative for oligoclonal banding.” If CSF only has been sent, and bands are present, the report will read: “Possible oligoclonal banding pattern present in CSF; recommend serum be sent for comparison.”

REFERENCE RANGE:

No oligoclonal bands present.

SPECIMEN REQUIREMENTS:

5.0 ml or more CSF, with 0.5 ml serum drawn the same day.



FIGURE 1: CSF OLIGOCLONAL BANDING
Agarose electrophoresis gel demonstrating several discrete bands migrating in the gamma region of the cerebrospinal fluid, and not visible in serum. This oligoclonal banding pattern is characteristic of multiple sclerosis, and suggests ongoing synthesis of a limited spectrum of immunoglobulins in the central nervous system.