In a group of 3 486 patients with neurological diseases, CSF and serum concentrations of haptoglobin were measured simultaneously with other protein fractions: albumin, immunoglobulins (IgA, IgM, IgG), alfa 1-micro- globulin, complement (C3, C4) antithrombin III, the other apolipoproteins (Apo A-I, Apo A-II, Apo B), acute phase reactants (prealbumin, alfa 1-antitrypsin, CRP, orosomukoid, fibrinogen, transferrin) (Turbox-Orion analyzer). Haptoglobin concentrations were compared with concentrations of the other CSF protein fractions using linear regression analysis both in the group of patients with normal biochemical and cytological CSF findings and after division of the group according to the presence of specific cytological and biochemical CSF syndromes. Specific biological function of haptoglobin was observed. It behaves as a substantial inflammatory marker, and its concentration is increased in inflammatory diseases of the CNS. In patients with malignancies of the CNS a marked increase of haptoglobin serum concentrations was also observed.

        Key words: haptoglobin, CSF cytology, acute phase proteins.