Abstract

There are several claims that B₁₂ concentrations in serum and cerebrospinal fluid are grossly abnormal in multiple sclerosis, but results are conflicting. This paper reports measurements of these concentrations in 40 serum samples and 23 samples of lumbar cerebrospinal fluid from cases of multiple sclerosis, and in appropriate controls, using Euglena gracilis, z strain. The serum concentrations were found to be normal; the mean concentration in cerebrospinal fluid was slightly reduced, but all values were within the control range.

In both control samples and samples from cases of multiple sclerosis, the B₁₂ concentration in lumbar cerebrospinal fluid was correlated with the concentration in serum. There was no correlation between B₁₂ concentration and total protein in cerebrospinal fluid.

A number of estimations of serum B₁₂ were also made with Lactobacillus leichmannii, after extraction in the presence and absence of cyanide. These showed a difference between cases of multiple sclerosis and controls, one interpretation of which might be that the serum in multiple sclerosis contains an abnormally low concentration of hydroxocobalamin.