To compare the proportions of immune cells in CSF among patients with neurosarcoidosis (NS) and multiple sclerosis (MS).

MS and NS have different pathogenesis but overlap in their clinical presentations and cerebrospinal fluid (CSF) findings. We hypothesized that immune cell profiles and CD4/CD8 ratios in CSF may help differentiate the two disorders.

19 patients with NS had available CSF flow cytometry (age: 55.9±10.8 years; 68% female; 63% African American; 68% on immunomodulatory medication at the time of CSF collection). Compared to matched MS patients, the patients with NS had significantly higher leukocyte count in CSF (60.8±116.3 v. 2.1±2.6 cells/mm³, p=0.034), higher protein (124.5±129.0 v. 35.7±19.6 mg/dL, p= 0.0053), and lower number of CSF-restricted oligoclonal bands (1.7±2.4 v. 7.7±5.2, p=0.0001), while glucose and IgG index were similar. On CSF flow cytometry, NS patients had 77%±17% small T-lymphocytes, v. 80%±11% in MS (p=0.52); 3%±4% small mature B lymphocytes, v. 2%±2% for MS (p=0.34); 4%±3% NK cells, v. 3%±5% in MS (p=0.46); 9%±12% monocytes, v. 9%±8% for MS (p=1.0). CD4/CD8 ratio in NS - 4.2:1±1.6:1 - was non-significantly higher than in MS - 3.3:1±1.4:1 (p=0.09). Kappa/lambda ratios in NS and MS were very similar: 1.6:1±0.5:1 v. 1.5:1±0.6 in MS (p=0.51).

CSF of NS patients differed from MS in total leukocyte count, protein and OCB, but not in the proportion of immune cells. Neither the CD4/CD8 ratio nor the proportion of mature B lymphocytes helped discriminate between the two diseases.