In patients with pneumococcal meningitis, CSF levels of MASP-2 were positively correlated to C5a (ρ = 0.481, P < 0.0001), C5b-9 (ρ = 0.560, P < 0.0001) and the CSF protein concentration (ρ = 0.488, P < 0.0001), but not to CSF leukocyte count (ρ = 0.088, P = 0.130). This evidence concerns the gene C5 and pneumococcal meningitis.