The aim of the study was to investigate the frequency of oligoclonal IgG bands (OB) in cerebrospinal fluid and serum in autoimmune paraneoplastic neurological syndromes. From the clinical point of view the main aim was the characterization of neurological paraneoplastic syndromes regarding to the stage of the neurological deficiency and the cause of death in cohorts of OB positive and negative patients. Methods: The detection of antineuronal paraneoplastic antibodies anti-Hu, anti-Ri and anti-Yo was done by indirect immunofluorescence with Western blot confirmation of positive samples. Oligoclonal IgG bands were investigated by isoelectric focusing, immunoblot and immunoenzymatic staining. Detection of more than 2 OB was considered as a positive finding. Results: In the group of 4 patients with anti-Yo antibodies, 3 of them had positive OB in CSF and serum. 1 patient was OB negative. They had severe neurological deficiency and 3 patients died because of neurological complica- tions. In the group of 6 patients (anti-Hu, anti-Ri), 2 patients were OB positive with severe neurological deficiency and died because of the progression of oncological disease. Four patients without OB had clinical patterns of encephalomyelitis/sensory neuropathy with different stages of motor disturbances. Two of them died because of oncological disease (slight and severe neurological deficiency) and 2 patients survive (slight and moderate deficiency resp.). Conclusion: In the cohort of 10 patients (n=10) with paraneoplastic neurological syndromes we found oligoclo- nal IgG bands in 50%. The presence of OB was connected with more severe neurological deficiency and more often with death because of neurological complications compared with the group of OB negative patients.

        Key words: paraneoplastic neurological syndromes, oligoclonal IgG bands, anti-Hu, anti-Ri, anti-Yo.