Are CSF neopterin levels a marker of disease activity in multiple sclerosis?

The study aimed to evaluate neopterin levels in cerebro-spinal fluid (CSF) as a marker of disease activation and progression of multiple sclerosis (MS). Neopterin, a substance known to be released from macrophages and monocytes at increased rates in cellular immune reactions, was investigated by radioimmunoassay, in the CSF of 19 patients with MS during exacerbations of the disease, in 34 patients with other neurological diseases (OND) and in 20 normal subjects used as controls. Poser's criteria were used for the diagnosis of MS. Although elevated neopterin levels in the CSF of patients with MS during exacerbations have been reported by other investigators, we found such elevation in only 4 out of 19 patients with MS (21%), in 5 out of 34 patients with OND (14.7%), and in none of the control group. Student's t-test was used for statistical analysis. There was no significant difference in the CSF values of the MS patients, the patients with OND (p > 0.05) or the controls. These results indicate that neopterin levels in CSF may not be considered a marker of disease activity in MS.