Interpretation of Cerebrospinal Fluid Protein Assays in Various Neurologic Diseases

Albumin and immunoglobulin G (IgG) were determined in cerebrospinal fluid (CSF) and serum, and the CSF/serum albumin Index (CSF x 103/serum albumin concentration ratio) and IgG Index [(CSF/serum igG)/(CSF/serum albu-min)] were calculated. Data for these indices and oligoclonal banding are described in 23 cases of multiple sclerosis (MS), 19 of systemic lupus erythematosus (SLE), eight of sarcoid-osis, 48 cases of miscellaneous disease, and 25 control patients with nonspecific complaints. Of the MS, SLE, and sarcoidosis patient groups, 8.5%, 26%, and 12.5 % showed an abnormally high CSF/serum albumin Index; 87%, 16%, and 0 % an increased IgG Index; and 87.5%, 42 % and 0% showed positive oligoclonal banding. lgG Index and oligo-clonal banding results for MS patients differed significantly from the sarcoidosis (p <.001) and SLE (p <.05) groups