I spent a few more minutes looking into this. From
Establishing CSF markers that permit evaluation of the various biological processes in multiple sclerosis remains a challenge. Of all the biological processes, inflammatory markers are probably the best identified. Detection of oligoclonal immunoglobulin bands in the CSF is now established as the single most useful laboratory marker in the CSF to aid in the diagnosis of multiple sclerosis. Markers of demyelination, remyelination, neuro-axonal loss, neural repair and regeneration, and astrogliosis are only now being recognized. A good surrogate for any of these pathophysiological processes has not been defined to date.
...Presence of OCBs in the CSF is indicative of abnormally increased synthesis of intrathecal IgG. Often, but not always, this finding is associated with an elevation of IgG index and 24-hour IgG synthesis. While the latter two measures are quantitative, definition of IgG bands is a qualitative measure of the IgG produced, namely, an evaluation of the charge heterogeneity of the intrathecal immunoglobulins. Although quantitation of IgG bands can be quite readily accomplished, there is little value in this exercise as the number of bands seldom correlates with the degree of disability. Instead, it may be an indirect measure of the duration of the disease. Bands that appear seldom disappear; new bands appear over time and as the disease endures, the number of bands also increases. Although there is evidence that the number of bands seldom correlates with disability, there is some evidence to suggest that the disease is milder in band-negative patients, who comprise < 3% of all MS patients.[14–16]
From me: Note that this article does not reference any data indicating that the higher the number of o-bands unique to the cerebrospinal fluid, the more likely it is that MS is present, nor does this value correlate to degree of disability.
The following is from Quix, who unfortunately no longer posts here. Quix is an MD, a former pediatrician, whose MS forced her to cease practice. However, her invaluable contributions to this forum over 5 years or so are what drew me and many others in.They formed the basis for our wonderful Health Pages, now defunct by MedHelp edict, as are all MH Health Pages. Nevertheless, Quix's understandably-worded explanations can absolutely be relied on. Use the spyglass icon at the top to find her contributions on all MS questions.
Quix too emphasizes o-bands unique to the spinal fluid, no emphasis on greater numbers.