Impairment of blood-cerebrospinal fluid barrier in multiple sclerosis

The blood-CSF barrier (BCB) function in active multiple sclerosis (MS) was studied by means of CSF proteins analysis using disc electrophoresis and immunofixation. Forty-five CSF samples were obtained by repeat lumbar punctures at various intervals, from four autopsy-proven cases and three male and nine female patients with clinically definite MS. When total protein content was increased, the percentages of prealbumin and tau fraction were decreased significantly in association with the presence of haptoglobin (Hp) polymers in nearly all the samples, as a result of increased permeability of the BCB. Even when the total protein content was normal, Hp polymers were detected in 56% of the samples, and the tau fraction tended to be decreased. Monoclonal immunoglobulin and Hp polymers were both recognized in some cases. The results suggested a more frequent occurrence of BCB impairment in MS than had formerly been revealed by CSF albumin analysis, and accorded with the recent reports of contrast-enhancing lesions of MS brain in computerized tomography.