[Findings of cerebrospinal fluid in the diagnosis of multiple sclerosis].

In order to define the cerebrospinal fluid (CSF) profile indicative of multiple sclerosis (MS), it is essential that each laboratory specifies the percentage of clinically definite MS patients with as well as the ranges of obtained values for each CSF parameter in these patients. CSF of 92 patients with clinically defined MS were analysed for cell count, concentrations of total protein, albumin and IgG, blood-CSF barrier function as assessed by CSF/serum albumin quotient, quantitative measurements of intrathecal IgG production (IgG index and IgG daily synthesis rate) and the presence of CSF oligoclonal IgG. For the detection of CSF oligoclonal IgG the isoelectric focusing (IEF) of unconcentrated CSF on agarose with transfer of proteins to cellulose nitrate and immunoperoxidase staining, was performed. CSF oligoclonal IgG bands not matched in parallel sera were detected in 96% of MS patients. Quantitative measurements of intrathecal IgG synthesis were significantly less sensitive than IEF. The concentration of total proteins in CSF was normal in 48% of patients, slightly elevated in 7% of patients and moderately elevated in 4% of patients with clinically definite MS. CSF cell count was normal in 71% of patients and slightly increased in the remaining 29%. The differential cell count was normal in all patients. CSF albumin and CSF/serum albumin quotient were elevated in 58 identical MS patients of 92 tested, indicating slight or, rarely moderate dysfunction of CSF-brain barrier in these patients. In 99% of MS patients, the total protein was <980 mg/L, the albumin <740 mg/L and the total cell count <20 cells per mm3. According to our data, the CSF findings that support the diagnosis of clinically definite MS are: 1) the presence of intrathecally produced CSF oligoclonal IgG by IEF; 2) normal or slightly to moderately elevated level of CSF proteins and albumin; 3) normal CSF-brain barrier function or slight to, rarely, moderate CSF-brain barrier dysfunction as assesed by CSF/serum albumin quotient, and 4) normal cell count or slight pleocytosis. If this profile is not found in a patient suspected of MS, the diagnosis should be questioned or a complication should be expected.