Thanks for the explanation, hc! Very helpful for me as well. Going to go have a gander at that link.
They do not test for the same thing. Cytokines signal cells of the immune system. O bands are the immunoglobulins produced by the cells.
"Multiple sclerosis (MS) is caused by immune cells that activate a cascade of chemicals in the brain, attacking and degrading the insulation that keeps neuronal signals moving. These chemicals, called cytokines, drive the inflammation in the brain, attracting more immune cells, and causing the debilitating disease marked by loss of neurological function. Researchers have now discovered the role of a major cytokine in multiple sclerosis that could be a target for new therapy against the disease."
Excerpt from Thomas Jefferson University. "Cytokine may play major role in multiple sclerosis." ScienceDaily. ScienceDaily, 29 April 2015. .
I've never heard of anyone being tested for cytokine levels as part of the MS diagnostic process. This leads me to believe that they are separate, distinct tests.